Merge pull request #8 from TeachBooks/main

pull main towards update general design guide
2026-11-12 22:25:52 +00:00 · 2024-04-02 22:19:04 +02:00 · 2024-04-02 22:19:04 +02:00 · 5ed53f5cc0
commit 5ed53f5cc0
parent 8ab80ce67d e2847515fd
139 changed files with 2225 additions and 665 deletions
--- a/book/_toc.yml
+++ b/book/_toc.yml
@ -66,51 +66,58 @@ parts:
      - file: basics/steel/products_2_cold_rolled_sections
      - file: basics/steel/products_3_welded_sections
      - file: basics/steel/explanation_cross_sectional_quantities
-      - file: basics/steel/dimension_tables
+      - file: basics/steel/section_tables
      - file: basics/steel/castellated_beams
      - file: basics/steel/integrated_beams
-      - file: basics/steel/steel_tube_profiles
-      - file: basics/steel/tube_profiles_trusses
-    - file: basics/wood/wood
+      - file: basics/steel/hollow_sections
+      - file: basics/steel/hollow_sections_trusses
+    - file: basics/timber/timber
      sections:
-      - file: basics/wood/information
-      - file: basics/wood/material_characteristics
-      - file: basics/wood/dimension_tables
+      - file: basics/timber/information
+      - file: basics/timber/material_characteristics
+      - file: basics/timber/products
+      - file: basics/timber/dimension_tables

  - caption: Design guidelines
    numbered: 2
    chapters:
-    - file: design/Beton/Beton
+    - file: design/concrete/concrete
      sections:
-      - file: design/Beton/stabiliteit
-      - file: design/Beton/vloeren
-      - file: design/Beton/balken
-      - file: design/Beton/wanden
-      - file: design/Beton/kolommen
-      - file: design/Beton/verbindingen
-    - file: design/Staal/Staal
+      - file: design/concrete/spans_in_concrete
+      - file: design/concrete/reinforcement_tables
+      - file: design/concrete/bubbledeck_floors
+      - file: design/concrete/composite_floors
+      - file: design/concrete/hollow_core_slabs
+      - file: design/concrete/precast_concrete_planks
+      - file: design/concrete/prefab_prestressed_beams
+      - file: design/concrete/bridge_beams
+    - file: design/steel/steel
      sections:
-      - file: design/Staal/stabiliteit
-      - file: design/Staal/vloeren
-      - file: design/Staal/balken
-      - file: design/Staal/wanden
-      - file: design/Staal/kolommen
-      - file: design/Staal/verbindingen
-    - file: design/Hout/Hout
+      - file: design/steel/spans_in_steel
+      - file: design/steel/steel_structures
+      - file: design/steel/connections_matrix
+      - file: design/steel/connections
+      - file: design/steel/buckling
+    - file: design/timber/timber
      sections:
-      - file: design/Hout/stabiliteit
-      - file: design/Hout/vloeren
-      - file: design/Hout/balken
-      - file: design/Hout/wanden
-      - file: design/Hout/kolommen
-      - file: design/Hout/verbindingen
+      - file: design/timber/spans_in_timber
+      - file: design/timber/timber_structures_and_details
+      - file: design/timber/connection_elements
+      - file: design/timber/trusses_and_joints
+    - file: design/foundations/foundations
+      sections:
+      - file: design/foundations/information
+      - file: design/foundations/design_guide
+      - file: design/foundations/foundation_methods_1
+      - file: design/foundations/foundation_methods_2
+      - file: design/foundations/tables

  - caption: Examples
    numbered: 2
    chapters:
-    - file: examples/wood/wood
+    - file: examples/timber/timber
      sections:
-      - file: examples/wood/voorontwerp_houten_hal
+      - file: examples/timber/voorontwerp_houten_hal
    - file: examples/steel/steel
      sections:
      - file: examples/steel/3d
--- a/book/basics/Images/construction_types_spans.png
+++ b/book/basics/Images/construction_types_spans.png
--- a/book/basics/concrete/Images/2nd_Sticht_bridge.png
+++ b/book/basics/concrete/Images/2nd_Sticht_bridge.png
--- a/book/basics/concrete/Images/Oosterscheldekering.png
+++ b/book/basics/concrete/Images/Oosterscheldekering.png
--- a/book/basics/concrete/Images/prefab_hsc_beams.png
+++ b/book/basics/concrete/Images/prefab_hsc_beams.png
--- a/book/basics/concrete/Images/product1_floors_combination_floors.png
+++ b/book/basics/concrete/Images/product1_floors_combination_floors.png
--- a/book/basics/concrete/Images/product1_floors_composite_plank_floor.png
+++ b/book/basics/concrete/Images/product1_floors_composite_plank_floor.png
--- a/book/basics/concrete/Images/product1_floors_composite_steelconcrete_floors.png
+++ b/book/basics/concrete/Images/product1_floors_composite_steelconcrete_floors.png
--- a/book/basics/concrete/Images/product1_floors_double_Tslabs.png
+++ b/book/basics/concrete/Images/product1_floors_double_Tslabs.png
--- a/book/basics/concrete/Images/product1_floors_hollow_core_slabs.png
+++ b/book/basics/concrete/Images/product1_floors_hollow_core_slabs.png
--- a/book/basics/concrete/Images/product1_floors_inverted_u_slabs.png
+++ b/book/basics/concrete/Images/product1_floors_inverted_u_slabs.png
--- a/book/basics/concrete/Images/product2_beams_cast_in_situ_reinforced_beams.png
+++ b/book/basics/concrete/Images/product2_beams_cast_in_situ_reinforced_beams.png
--- a/book/basics/concrete/Images/product2_beams_prefab_prestressed_beams_infra.png
+++ b/book/basics/concrete/Images/product2_beams_prefab_prestressed_beams_infra.png
--- a/book/basics/concrete/Images/product2_beams_prefab_prestressed_beams_nonresidential.png
+++ b/book/basics/concrete/Images/product2_beams_prefab_prestressed_beams_nonresidential.png
--- a/book/basics/concrete/Images/product3_columns_cast_in_situ_columns.png
+++ b/book/basics/concrete/Images/product3_columns_cast_in_situ_columns.png
--- a/book/basics/concrete/Images/product3_columns_prefab_columns.png
+++ b/book/basics/concrete/Images/product3_columns_prefab_columns.png
--- a/book/basics/concrete/Images/reinforcement_cover.png
+++ b/book/basics/concrete/Images/reinforcement_cover.png
--- a/book/basics/concrete/Images/reinforcement_lap_splice_length.png
+++ b/book/basics/concrete/Images/reinforcement_lap_splice_length.png
--- a/book/basics/concrete/Images/reinforcement_minimal_bar_distances.png
+++ b/book/basics/concrete/Images/reinforcement_minimal_bar_distances.png
--- a/book/basics/concrete/Images/sheet_piling.png
+++ b/book/basics/concrete/Images/sheet_piling.png
--- a/book/basics/concrete/concrete_construction_applications.ipynb
+++ b/book/basics/concrete/concrete_construction_applications.ipynb
@ -4,7 +4,49 @@
   "cell_type": "markdown",
   "metadata": {},
   "source": [
-    "# Concrete construction applications"
+    "# Concrete construction applications\n",
+    "\n",
+    "`````{admonition} Translated from the article:\n",
+    ":class: tip\n",
+    "Beton als conventioneel bouwmateriaal (Concrete as conventional building material). In Cement 2002 no. 4 by Prof. dr. Ir. Joost Walraven\n",
+    "`````\n",
+    "The first applications of plain unreinforced concrete were constructed by the Romans as massive structures. The concrete was only loaded in compression. The material had a strong heterogeneous character and had very low strength. Measurements from a city wall near Cologne which was built around 50 A.D. indicate a stenght of about 10 N/mm2. Methods to increase the strength of the concrete have always been a lower water-cement ratio and more closely packed aggregates. In practice the minimum for the water cement ratio lies at 0.4 as lower values decrease the workability of the concrete\n",
+    "\n",
+    "```{figure} Images/Oosterscheldekering.png\n",
+    "---\n",
+    "---\n",
+    "Oosterscheldekering\n",
+    "```\n",
+    "For the pylons in the Oosterschelde storm surge barrier (1979-1981) and the accompanying treshold beams, upper beams and hammerheads a concrete strength of B25 (now C20/25 \n",
+    "red.) was used to obtain sufficient workability. Until about 10 year ago the realiztation of B45 (now C35/45 red.) on site was a great achievement. Meanwhile the understanding of concrete technology has improved significantly which has led to revolutionary developments. In 1990 it was discovered that the addition of silicafume to concrete resulted in a significant strength increase. This a important effect on the internal force distribution in the concrete \n",
+    "```{figure} Images/2nd_Sticht_bridge.png\n",
+    "---\n",
+    "---\n",
+    "2nd Sticht bridge\n",
+    "```\n",
+    "The Second Stichtse Bridge is the first large prestressed bridge in Europe using high strength concrete. The cost of the high strength concrete are twice the costs of normal strength concrete but this is compensated by substantial other advantages. About 30% less concrete is needed, and due to the reduction of the concrete cross section about 25% less prestressing steel is needed. Because of the reduced dead weight of the bridge the length of the segments could be increased from the traditional 3,5 m to 5m, which lead to a much shorter construction time.\n",
+    "\n",
+    "```{figure} Images/prefab_hsc_beams.png\n",
+    "---\n",
+    "---\n",
+    "Prefab HSC beams\n",
+    "```\n",
+    "```{Note}\n",
+    "Prefabricated beams made of B200 (now ‘C200’) contain only a few prestressing strands as other reinforcement is unnecessary.\n",
+    "```\n",
+    "A large drawback of traditional concrete was that it had to be compacted by hand with the aid of internal vibrators. By adding slightly more bonding agent than necessary \n",
+    "for the good functioning of the concrete, thin layers of lubricant occur in the hardened concrete around every aggregate, causing them to ‘float’. The application of this type of concrete is developing very fast in the prefab concrete industry. At the construction site this material is also very desirable because it causes less noise nuisance \n",
+    "to the environment. The material has properties which lie between traditional concrete and steel.\n",
+    "```{figure} Images/sheet_piling.png\n",
+    "---\n",
+    "---\n",
+    "Sheet piling\n",
+    "```\n",
+    "As an alternative for the steel crest gates of the storm surge barrier in the Oosterschelde students have studied an application of high strength concrete for the gates. They are much heavier than the steel gates but require far less maintenance due to the expected durability of the material. This leads to an overall lower cost if the concrete gates would have been used. \n",
+    "\n",
+    "In the area between B100 and B200 (now C90/105 and a fictitious ‘C200’) self compacting fiber concrete can be an interesting alternative for very high strength concrete (>B200). Delft University of Technology has developed a mixture which reached a strength of 75 N/mm2 after 12 hours. This early high strength makes this mixture very interesting for the prefabrication industry.\n",
+    "\n",
+    "In cooporation with a prefabricator sheet piles were constructed out of this material in B120 (now a fictitious ‘C120’). The price of this self compacting concrete is about four times the price of the regular B65 (now C55/67) but the cross section can be reduced by 75%. Further cost reduction arises from easier transport and handling on site."
   ]
  },
  {
--- a/book/basics/concrete/information.ipynb
+++ b/book/basics/concrete/information.ipynb
@ -4,7 +4,19 @@
   "cell_type": "markdown",
   "metadata": {},
   "source": [
-    "# Information"
+    "# Information\n",
+    "\n",
+    "## Different sources\n",
+    "\n",
+    "  - **Internet**\n",
+    "    - [VBI.nl](https://www.vbi.nl/): Hollow core slabs and system floors (only in Dutch)\n",
+    "    - [Spanbeton.nl](https://www.spanbeton.nl/): Large prefab elements used in road- and railway construction, hydraulic engineering, industrial buildings, and concrete sheet piling (only in Dutch)\n",
+    "    - [Dycore.nl](https://www.dycore.nl/): Different floor systems. CAD drawings and details can be downloaded. Design graphs are available (only in Dutch)\n",
+    "    - [Bubbledeck.nl](https://www.bubbledeck.nl/): The new bubble-deck system to construct lighter floors (only in Dutch)\n",
+    "    - [Haitsma.nl](https://www.haitsma.nl/): Bridges, foundations, offices, parking lots. CAD details and design graphs (only in Dutch)\n",
+    "    - [Koraton.be](https://www.koraton.be/): Different system floors (in Dutch or French)\n",
+    "    - [Heidelbergcement.com](https://www.heidelbergcement.com/): General information on cement and concrete (most languages available)\n",
+    "  - **Magazines**: Cement projects, elements, and materials\n"
   ]
  },
  {
--- a/book/basics/concrete/material_characteristics_concrete.ipynb
+++ b/book/basics/concrete/material_characteristics_concrete.ipynb
--- a/book/basics/concrete/material_characteristics_concrete_steel.ipynb
+++ b/book/basics/concrete/material_characteristics_concrete_steel.ipynb
@ -4,7 +4,25 @@
   "cell_type": "markdown",
   "metadata": {},
   "source": [
-    "# Material characteristics concrete steel"
+    "# Material characteristics concrete steel\n",
+    "\n",
+    "This paragraph contains information on the material properties of reinforcement steel.\n",
+    "\n",
+    "## Strength and stiffness\n",
+    "\n",
+    "### Material properties (bars)\n",
+    "\n",
+    "| Steel Grade         | Tensile Strength $( f_{t;k} )$ (N/mm²) | Yield Stress $( f_{y;k} )$ (N/mm²) | Strain at Maximum Load $\\varepsilon_{su}$ ‰ |\n",
+    "|---------------------|-----------------------------------------|-------------------------------------|----------------------------------------------------|\n",
+    "| FeB 400 HWL, HK     | 400                                     | 350                                 | 4.00                                               |\n",
+    "| FeB 500 HWL, HK     | 500                                     | 435                                 | 3.25                                               |\n",
+    "| FeB 500 HKN         | 500                                     | 435                                 | 2.75                                               |\n",
+    "\n",
+    "### Material properties (nets)\n",
+    "\n",
+    "| Steel Grade         | Tensile Strength $( f_{t;k} )$ (N/mm²) | Design value tensile strength $( f_{y;k} )$ (N/mm²) | Strain at Maximum Load $\\varepsilon_{su}$ ‰ |\n",
+    "|----------------------------|-------------------------|--------------------------------------|------------------------------------------------|\n",
+    "| FeB 500 HKN, HWN           | 500                     | 435                                  | 2.175                                          |\n"
   ]
  },
  {
--- a/book/basics/concrete/products_1_floors.ipynb
+++ b/book/basics/concrete/products_1_floors.ipynb
@ -4,7 +4,82 @@
   "cell_type": "markdown",
   "metadata": {},
   "source": [
-    "# Products 1: floors"
+    "# Products 1: floors\n",
+    "\n",
+    "## Hollow core slabs\n",
+    "```{figure} Images/product1_floors_hollow_core_slabs.png\n",
+    "---\n",
+    "align: right\n",
+    "---\n",
+    "Hollow core slabs\n",
+    "```\n",
+    "\n",
+    "Sections of hollow core slabs, prefabricated and prestressed\n",
+    "\n",
+    "Applications: In all buildings hollow core slabs can be used as floors and roofs. Room for ducts and slots can be foreseen and provided during fabrication. Hollow core slabs are easily combined with \n",
+    "hat-beams.\n",
+    "\n",
+    "## Inverted U-slabs\n",
+    "```{figure} Images/product1_floors_inverted_u_slabs.png\n",
+    "---\n",
+    "align: right\n",
+    "---\n",
+    "Inverted U-slabs\n",
+    "```\n",
+    "\n",
+    "Inverted U-slabs with integrated isolation. The slabs are placed next to each other and the joints are filled with mortar.\n",
+    "\n",
+    "Applications: Applicated as ground floor in residential and non residential buildings.\n",
+    "\n",
+    "## Combination floors\n",
+    "```{figure} Images/product1_floors_combination_floors.png\n",
+    "---\n",
+    "align: right\n",
+    "---\n",
+    "Combination floors\n",
+    "```\n",
+    "\n",
+    "Combination floors. Prefabricated inverted T-beams with EPS isolation and cast in situ concrete \n",
+    "\n",
+    "Application: The type of floors is used frequently as ground floor above crawl spaces in residential building because of the simple construction and good isolation properties.\n",
+    "\n",
+    "## Composite steel-concrete floors\n",
+    "```{figure} Images/product1_floors_composite_steelconcrete_floors.png\n",
+    "---\n",
+    "align: right\n",
+    "---\n",
+    "Composite steel-concrete floors\n",
+    "```\n",
+    "\n",
+    "A trapezoidal metal plate is used as working floor, formwork and reinforcement of the concrete \n",
+    "compression layer.\n",
+    "\n",
+    "Application: Used as floor system in (high rise) steel structures. Can be propped temporarily during casting which can lead to significant spans. The system offers relatively large flexibility for odd shaped floors.\n",
+    "\n",
+    "## Composite plank floor\n",
+    "```{figure} Images/product1_floors_composite_plank_floor.png\n",
+    "---\n",
+    "align: right\n",
+    "---\n",
+    "Composite plank floor\n",
+    "```\n",
+    "\n",
+    "A thin prefab concrete plate with protruding reinforcement is placed. In situ a compressive concrete layer is placed.\n",
+    "\n",
+    "Applications: Floors of concrete structures in residential and non residential buildings.\n",
+    "\n",
+    "## Double T-slabs\n",
+    "```{figure} Images/product1_floors_double_Tslabs.png\n",
+    "---\n",
+    "align: right\n",
+    "---\n",
+    "Double T-slabs\n",
+    "```\n",
+    "\n",
+    "Prefab, prestressed TT-beam.\n",
+    "\n",
+    "Applications: prestressed, prefabricated floor beam system for large spans and/or heavily \n",
+    "loaded beams. Is used mainly in non-residential buildings like parking garages and offices."
   ]
  },
  {
--- a/book/basics/concrete/products_2_beams.ipynb
+++ b/book/basics/concrete/products_2_beams.ipynb
@ -6,7 +6,41 @@
   "source": [
    "# Products 2: beams\n",
    "\n",
-    "\n"
+    "## Prefab prestressed beams (non-residential buildings)\n",
+    "```{figure} Images/product2_beams_prefab_prestressed_beams_nonresidential.png\n",
+    "---\n",
+    "align: right\n",
+    "---\n",
+    "Prefab prestressed beams (non-residential buildings)\n",
+    "```\n",
+    "\n",
+    "Rectangular, I- en T-profiles, prefab prestressed beams.\n",
+    "\n",
+    "Applications:the different types of beams are used as main beams in floor and roof structures but also as butresses in masonry structures. Prefab beams can also be used in foundations.\n",
+    "\n",
+    "## Prefab prestressed beams (infra)\n",
+    "```{figure} Images/product2_beams_prefab_prestressed_beams_infra.png\n",
+    "---\n",
+    "align: right\n",
+    "---\n",
+    "Prefab prestressed beams (infra)\n",
+    "```\n",
+    "\n",
+    "Prestressed inverted T-beams and box-beams\n",
+    "\n",
+    "Applications: this type of beam is mainly used in infrastructural constructions like bridges and viaducts. Very large spans and curved beams (in two directions) are possible.\n",
+    "\n",
+    "## Cast in situ reinforced beams\n",
+    "```{figure} Images/product2_beams_cast_in_situ_reinforced_beams.png\n",
+    "---\n",
+    "align: right\n",
+    "---\n",
+    "Cast in situ reinforced beams\n",
+    "```\n",
+    "\n",
+    "Cast in situ in formwork with reinforcement.\n",
+    "\n",
+    "Applications: used frequently as foundation beams and in simple structures with small spans."
   ]
  },
  {
--- a/book/basics/concrete/products_3_columns.ipynb
+++ b/book/basics/concrete/products_3_columns.ipynb
@ -4,7 +4,31 @@
   "cell_type": "markdown",
   "metadata": {},
   "source": [
-    "# Products 3: columns"
+    "# Products 3: columns\n",
+    "\n",
+    "## Prefab columns\n",
+    "```{figure} Images/product3_columns_prefab_columns.png\n",
+    "---\n",
+    "align: right\n",
+    "---\n",
+    "Prefab columns\n",
+    "```\n",
+    "\n",
+    "Prefab columns, beams are placed on corbels with neoprene bearing pads.\n",
+    "\n",
+    "Applications: Part of prefab structural systems. Possible for buildings from 0 to 2 storeys. The prefab columns are usually combined with (prestressed) beams and for example hollow core slabs or precast composite planks.\n",
+    "\n",
+    "## Cast in situ columns\n",
+    "```{figure} Images/product3_columns_cast_in_situ_columns.png\n",
+    "---\n",
+    "align: right\n",
+    "---\n",
+    "Cast in situ columns\n",
+    "```\n",
+    "\n",
+    "Round and square cast in situ concrete columns.\n",
+    "\n",
+    "Applications: Nowadays round cardboard formworks are less expensive because excessive carpentry is avoided. Reusable formworks (square or round) are also used."
   ]
  },
  {
--- a/book/basics/concrete/reinforcement.ipynb
+++ b/book/basics/concrete/reinforcement.ipynb
@ -6,6 +6,110 @@
   "source": [
    "# Reinforcement\n",
    "\n",
+    "## Reinforcement areas for beams and columns\n",
+    "\n",
+    "|Diameter $\\phi$ [mm] |$A_s$ [mm^2] ||||||||||\n",
+    "|---|------|------|------|------|------|------|------|------|------|------|\n",
+    "|  | 1 bar    | 2 bars   | 3 bars   | 4 bars   | 5 bars   | 6 bars | 7 bars | 8 bars  | 9 bars  | 10 bars   |\n",
+    "| 6 | 28   | 57   | 85   | 113  | 141  | 170  | 198  | 226  | 254  | 283  |\n",
+    "| 8 | 50   | 101  | 151  | 201  | 251  | 302  | 352  | 402  | 452  | 503  |\n",
+    "| 10| 79   | 157  | 236  | 314  | 393  | 471  | 550  | 628  | 707  | 785  |\n",
+    "| 12| 113  | 226  | 339  | 452  | 565  | 679  | 792  | 905  | 1018 | 1131 |\n",
+    "| 16| 201  | 402  | 603  | 804  | 1005 | 1206 | 1407 | 1608 | 1810 | 2011 |\n",
+    "| 20| 314  | 628  | 942  | 1257 | 1571 | 1885 | 2199 | 2513 | 2827 | 3142 |\n",
+    "| 25| 491  | 982  | 1473 | 1963 | 2454 | 2945 | 3436 | 3927 | 4418 | 4909 |\n",
+    "| 32| 804  | 1608 | 2413 | 3217 | 4021 | 4825 | 5630 | 6434 | 7238 | 8042 |\n",
+    "\n",
+    "\n",
+    "## Reinforcement in nets for slabs\n",
+    "| Spacing (c.t.c.) [m] | Bars/length [1/m]| Total area per meter width [mm²/m]|||||||\n",
+    "|-----------------------|------------|--------------------------------------|---|---|---|---|---|---|\n",
+    "| | | $\\phi = 6 [mm]$ | $\\phi = 8 [mm]$ | $\\phi = 10 [mm]$ | $\\phi = 12 [mm]$ | $\\phi = 16 [mm]$ | $\\phi = 20 [mm]$ | $\\phi = 25 [mm]$ |\n",
+    "| 70                    | 14.29      | 404                                  | 718 | 1122 | 1616 | 2873 | 4489 | 7015 |\n",
+    "| 75                    | 13.33      | 377                                  | 670 | 1047 | 1508 | 2680 | 4188 | 6543 |\n",
+    "| 80                    | 12.50      | 353                                  | 628 | 982  | 1414 | 2513 | 3927 | 6136 |\n",
+    "| 85                    | 11.76      | 333                                  | 591 | 924  | 1330 | 2365 | 3695 | 5773 |\n",
+    "| 90                    | 11.11      | 314                                  | 558 | 873  | 1257 | 2234 | 3490 | 5454 |\n",
+    "| 95                    | 10.53      | 298                                  | 529 | 827  | 1191 | 2117 | 3308 | 5169 |\n",
+    "| 100                   | 10.00      | 283                                  | 503 | 785  | 1131 | 2011 | 3142 | 4909 |\n",
+    "| 105                   | 9.52       | 269                                  | 479 | 748  | 1077 | 1914 | 2991 | 4673 |\n",
+    "| 110                   | 9.09       | 257                                  | 457 | 714  | 1028 | 1828 | 2856 | 4462 |\n",
+    "| 115                   | 8.70       | 246                                  | 437 | 683  | 984  | 1749 | 2733 | 4271 |\n",
+    "| 120                   | 8.33       | 236                                  | 419 | 654  | 942  | 1675 | 2617 | 4089 |\n",
+    "| 125                   | 8.00       | 226                                  | 402 | 628  | 905  | 1609 | 2513 | 3927 |\n",
+    "| 130                   | 7.69       | 217                                  | 387 | 604  | 870  | 1546 | 2416 | 3775 |\n",
+    "| 135                   | 7.41       | 210                                  | 373 | 582  | 838  | 1490 | 2328 | 3637 |\n",
+    "| 140                   | 7.14       | 202                                  | 359 | 561  | 808  | 1436 | 2243 | 3505 |\n",
+    "| 145                   | 6.90       | 195                                  | 347 | 542  | 780  | 1387 | 2168 | 3387 |\n",
+    "| 150                   | 6.67       | 189                                  | 335 | 524  | 754  | 1341 | 2095 | 3274 |\n",
+    "| 155                   | 6.45       | 182                                  | 324 | 507  | 730  | 1297 | 2026 | 3166 |\n",
+    "| 160                   | 6.25       | 177                                  | 314 | 491  | 707  | 1257 | 1964 | 3068 |\n",
+    "| 165                   | 6.06       | 171                                  | 305 | 476  | 685  | 1218 | 1904 | 2975 |\n",
+    "| 170                   | 5.88       | 166                                  | 296 | 462  | 665  | 1182 | 1847 | 2886 |\n",
+    "| 175                   | 5.71       | 161                                  | 287 | 449  | 646  | 1148 | 1794 | 2803 |\n",
+    "| 180                   | 5.56       | 157                                  | 280 | 437  | 629  | 1118 | 1747 | 2729 |\n",
+    "| 185                   | 5.41       | 153                                  | 272 | 425  | 612  | 1088 | 1700 | 2656 |\n",
+    "| 190                   | 5.26       | 149                                  | 264 | 413  | 595  | 1058 | 1653 | 2582 |\n",
+    "| 195                   | 5.13       | 145                                  | 258 | 403  | 580  | 1031 | 1612 | 2518 |\n",
+    "| 200                   | 5.00       | 141                                  | 251 | 393  | 566  | 1005 | 1571 | 2454 |\n",
+    "| 250                   | 4.00       | 113                                  | 201 | 314  | 452  | 804  | 1257 | 1964 |\n",
+    "\n",
+    "\n",
+    "`````{Note}\n",
+    "In concrete plates (floors and walls) the reinforcement is usually specified as the the type of bar and the spacing (Ø12-200) rather than the number of bars per meter (5 Ø12)\n",
+    "`````\n",
+    "\n",
+    "## Lab splice length\n",
+    "\n",
+    "```{figure} Images/reinforcement_lap_splice_length.png\n",
+    "---\n",
+    "align: right\n",
+    "---\n",
+    "```\n",
+    "\n",
+    "In some cases the reinforcement bars need to be coupled because of the limited lengths of the bars or to ease execution. This is done by placing two bars relatively close to each other for a certain lap length. The forces are transmitted by shear and compressive stresses in the concrete. For a first design the lap length can be estimated as: \n",
+    "\n",
+    "40 x Ø (diameter smallest bar)\n",
+    "\n",
+    "For exact calculations, see EC2\n",
+    "\n",
+    "## Cover\n",
+    "\n",
+    "| Structural Element | Cover c [mm] per environment | |  | Increase [mm] | |\n",
+    "|--------------------|--------------|---------------|-----------------------|---------------------------|-------------------|\n",
+    "||dry|wet|salt or aggresive|modified surface|uninspected table surface|\n",
+    "| Plaat en wand      | 15           | 25            | 30                    | +5                        | +5                |\n",
+    "| Balk, poer en console | 25         | 30            | 35                    | +5                        | +5                |\n",
+    "| Kolom              | 30           | 35            | 40                    | +5                        | +5                |\n",
+    "\n",
+    "```{figure} Images/reinforcement_cover.png\n",
+    "---\n",
+    "align: right\n",
+    "---\n",
+    "```\n",
+    "`````{Note}\n",
+    "Further demands:  \n",
+    "c ≥ Ø (for bars ≤ Ø 25 mm)  \n",
+    "c ≥ 1,5Ø (for bars > Ø 25 mm)  \n",
+    "prestressing steel: + 5 mm\n",
+    "`````\n",
+    "\n",
+    "Under certain conditions it is allowed to bundle 2 of three bars together without spacing. These bundles can be regarded as a single bar with the same cross section (mm2\n",
+    ") as the total bundle.\n",
+    "\n",
+    "## Minimal bar distances\n",
+    "```{figure} Images/reinforcement_minimal_bar_distances.png\n",
+    "---\n",
+    "align: right\n",
+    "---\n",
+    "```\n",
+    "\n",
+    "The spacing between (not c.t.c distance) the bars should be not less than the maximum of:\n",
+    "- the bar diameter\n",
+    "- the maximum aggregate size + 5 mm\n",
+    "- 20 mm\n",
+    "\n",
+    "When bars are placed in separate layers, care must be taken that good compaction of the concrete must be possible. In the case of walls there must be enough room to cast concrete in the lower regions of the wall. At laps the distances between the bars may be smaller.\n",
    "\n"
   ]
  },
--- a/book/basics/general_materials.ipynb
+++ b/book/basics/general_materials.ipynb
@ -4,13 +4,42 @@
   "cell_type": "markdown",
   "metadata": {},
   "source": [
-    "# General materials"
+    "# General materials\n",
+    "\n",
+    "This chapter offers infomation on the different structural materials. The materials are compared on a few characteristic aspects. More detailed information can be found in the chapters.\n",
+    "\n",
+    "## Material and construction types\n",
+    "\n",
+    "### Construction types and spans\n",
+    "\n",
+    "```{figure} Images/construction_types_spans.png\n",
+    "---\n",
+    "scale: 100%\n",
+    "align: right\n",
+    "---\n",
+    "Construction types and spans\n",
+    "```\n",
+    "\n",
+    "## Material properties\n",
+    "\n",
+    "| Property           | Timber                                            | Steel                                             | Concrete (in situ)                              | Concrete (prestressed and/or precast)           |\n",
+    "|--------------------|---------------------------------------------------|---------------------------------------------------|--------------------------------------------------|--------------------------------------------------|\n",
+    "| Self Weight        | Small (4 to 10 kN/m³, depending on the species)  | Large (78.5 kN/m³) but relatively low self weight, large spans are possible (optimized cross sections); steel use per m² roof area: 0.3 to 1 kN | Large (24 kN/m³), this has consequences for the foundation and maximum span; not economical with low variable load | Large (24 kN/m³), this has consequences for the foundation dimensions; fairly large, but favorable with respect to buckling and deformation limits |\n",
+    "| Fire Resistance    | Small dimensions have low fire resistance; Larger sections have good fire resistance | The structure has low fire resistance, but does not burn itself | Good resistance if the cover is sufficient | Less resistance than in situ concrete due to deterioration of the prestressing steel. Does not collapse easily, but is not reliable after a fire |\n",
+    "| Water Tightness    | Dependent on the application                      | Not applicable                                    | Good                                             | Good                                             |\n",
+    "| Thermal Properties | Not susceptible to thermal influences              | Sensitive to temperature changes; bad without insulation | Low thermal insulation, beware of thermal bridges | Low thermal insulation, beware of thermal bridges |\n",
+    "| Acoustic Properties| Acceptable to good; sound reflection is high with corrugated sheet metal in roofs and walls | Air sound insulation is good, contact sound insulation is bad | Air sound insulation is good, contact sound insulation is bad | Adaptability in relation to doors, windows, etc. is good, if the appropriate measures are taken in advance |\n",
+    "| Adaptability       | Good                                              | Good                                              | Good, if the appropriate measures are taken in advance | Standard product; tolerances must be incorporated in the design |\n",
+    "| Adaptability to ducts             | Trusses are especially suitable for carrying trough of ducts; connection can be done fairly easy | Information is needed upfront and must be processed very accurately. After casting, extra measures are difficult to incorporate | Limited possibilities upfront. After casting, adaption is very difficult | Low                                        |\n",
+    "| Suitability for later adjustments| Good                                                     | Good                                                     | Difficult                                                 | Low                                                      |\n",
+    "| Labour intensity                 | See steel. A lot of preparation in the factory, resulting in fast and simple assembly on site | The formwork and falsework are very labour intensive. If possible, use standard formwork. Avoid small amounts of concrete at great heights | Factory product with fast assembly on site. Extra stressing on site requires specialized tools and crew | N/A                                                      |\n",
+    "| Necessity of serial production   | Not necessary                                            | Not necessary                                            | Preferred, but less necessary than with prefab concrete  | Necessary, because of the high costs of moulds          |\n",
+    "| Residual value after demolition  | Low positive residual value, but demolition is easy      | Positive residual value; demolition is expensive         | Negative residual value                                  | N/A                                                      |\n",
+    "| Erection speed                   | Fairy quick                                              | Short construction time                                  | Low construction speed due to the time needed for hardening, reuse of formwork, and influences of the weather | Fast montage, but delivery and hardening times must be accounted for |\n",
+    "| Needed construction site          | Limited                                                  | Small                                                    | A lot of space needed for preparation of formwork and reinforcement | Small                                                    |\n",
+    "| Hygiene                           | When the correct sections are used, almost no dust collection on certain profiles | Dust is easily collected                                | Very suitable for dust-sensitive structures              | Good, partially dependent on cross-section               |\n",
+    "\n"
   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": []
  }
 ],
 "metadata": {
--- a/book/basics/steel/Images/L_and_Z_sections.png
+++ b/book/basics/steel/Images/L_and_Z_sections.png
--- a/book/basics/steel/Images/airport_stuttgart.png
+++ b/book/basics/steel/Images/airport_stuttgart.png
--- a/book/basics/steel/Images/airshiphall_germany.png
+++ b/book/basics/steel/Images/airshiphall_germany.png
--- a/book/basics/steel/Images/beam_column.png
+++ b/book/basics/steel/Images/beam_column.png
--- a/book/basics/steel/Images/castellated_beams.png
+++ b/book/basics/steel/Images/castellated_beams.png
--- a/book/basics/steel/Images/chs_rhs.png
+++ b/book/basics/steel/Images/chs_rhs.png
--- a/book/basics/steel/Images/chs_seamless.png
+++ b/book/basics/steel/Images/chs_seamless.png
--- a/book/basics/steel/Images/chs_support.png
+++ b/book/basics/steel/Images/chs_support.png
--- a/book/basics/steel/Images/chs_welded2.png
+++ b/book/basics/steel/Images/chs_welded2.png
--- a/book/basics/steel/Images/chs_welded_plates.png
+++ b/book/basics/steel/Images/chs_welded_plates.png
--- a/book/basics/steel/Images/connection_beamcolumn_elongated_endplate.png
+++ b/book/basics/steel/Images/connection_beamcolumn_elongated_endplate.png
--- a/book/basics/steel/Images/connection_beams_endplate.png
+++ b/book/basics/steel/Images/connection_beams_endplate.png
--- a/book/basics/steel/Images/connection_hebeam_ipebeam_hecolumn.png
+++ b/book/basics/steel/Images/connection_hebeam_ipebeam_hecolumn.png
--- a/book/basics/steel/Images/dintelhaven.png
+++ b/book/basics/steel/Images/dintelhaven.png
--- a/book/basics/steel/Images/hea_column_support.png
+++ b/book/basics/steel/Images/hea_column_support.png
--- a/book/basics/steel/Images/hea_heb_hem_sections.png
+++ b/book/basics/steel/Images/hea_heb_hem_sections.png
--- a/book/basics/steel/Images/ipe_inp_sections.png
+++ b/book/basics/steel/Images/ipe_inp_sections.png
--- a/book/basics/steel/Images/maeslantkering.png
+++ b/book/basics/steel/Images/maeslantkering.png
--- a/book/basics/steel/Images/millenium_dome_london.png
+++ b/book/basics/steel/Images/millenium_dome_london.png
--- a/book/basics/steel/Images/moment_of_inertia.png
+++ b/book/basics/steel/Images/moment_of_inertia.png
--- a/book/basics/steel/Images/node_rhs.png
+++ b/book/basics/steel/Images/node_rhs.png
--- a/book/basics/steel/Images/oosterscheldekering.png
+++ b/book/basics/steel/Images/oosterscheldekering.png
--- a/book/basics/steel/Images/other.png
+++ b/book/basics/steel/Images/other.png
--- a/book/basics/steel/Images/possible_shapes.png
+++ b/book/basics/steel/Images/possible_shapes.png
--- a/book/basics/steel/Images/project_norway.png
+++ b/book/basics/steel/Images/project_norway.png
--- a/book/basics/steel/Images/radius_of_gyration.png
+++ b/book/basics/steel/Images/radius_of_gyration.png
--- a/book/basics/steel/Images/rhs_support.png
+++ b/book/basics/steel/Images/rhs_support.png
--- a/book/basics/steel/Images/sheet_piles.png
+++ b/book/basics/steel/Images/sheet_piles.png
--- a/book/basics/steel/Images/space_frame_node.png
+++ b/book/basics/steel/Images/space_frame_node.png
--- a/book/basics/steel/Images/stress_strain_steel.png
+++ b/book/basics/steel/Images/stress_strain_steel.png
--- a/book/basics/steel/Images/truss_rectangular_hollow_sections.png
+++ b/book/basics/steel/Images/truss_rectangular_hollow_sections.png
--- a/book/basics/steel/Images/u_and_c_profiles.png
+++ b/book/basics/steel/Images/u_and_c_profiles.png
--- a/book/basics/steel/Images/uap_unp_sections.png
+++ b/book/basics/steel/Images/uap_unp_sections.png
--- a/book/basics/steel/Images/vierendeel.png
+++ b/book/basics/steel/Images/vierendeel.png
--- a/book/basics/steel/Images/warren_pratt_truss.png
+++ b/book/basics/steel/Images/warren_pratt_truss.png
--- a/book/basics/steel/Images/welded_integrated_beams.png
+++ b/book/basics/steel/Images/welded_integrated_beams.png
--- a/book/basics/steel/Images/welds_k_joint.png
+++ b/book/basics/steel/Images/welds_k_joint.png
--- a/book/basics/steel/explanation_cross_sectional_quantities.ipynb
+++ b/book/basics/steel/explanation_cross_sectional_quantities.ipynb
@ -5,7 +5,42 @@
   "metadata": {},
   "source": [
    "# Explanation cross sectional properties\n",
-    "\n"
+    "\n",
+    "## Castellated beams IPE/HEA/HEB\n",
+    "```{figure} Images/moment_of_inertia.png\n",
+    "---\n",
+    "align: left\n",
+    "---\n",
+    "```\n",
+    "\n",
+    "### The carthesian coordinate system\n",
+    "In this coordinate system the axes are defined as follows:  \n",
+    "x-axis: length axis of the element  \n",
+    "y-axis: cross product of x and z axis  \n",
+    "z-axis: downward axis\n",
+    "\n",
+    "| Name                                       | Structural Mechanics  | NEN-EN 1993                                      |\n",
+    "|--------------------------------------------|------------------------- | ----------------------------------------------|\n",
+    "| Moment of inertia around y-axis (Resistance against moments in x-z plane) | $I_{zz}$ | $I_{y}$ |\n",
+    "| Moment of inertia around z-axis (Resistance against moments in x-y plane ) | $I_{yy}$ | $I_{z}$ |\n",
+    "| Section modulus around y-axis (Resistance against moments in x-z plane) | $W_{zz}$ | $W_{y}$ |\n",
+    "| Section modulus around z-axis (Resistance against moments in x-y plane) | $W_{yy}$ | $W_{z}$ |\n",
+    "\n",
+    "\n",
+    "## Top hat beams\n",
+    "```{figure} Images/radius_of_gyration.png\n",
+    "---\n",
+    "align: left\n",
+    "---\n",
+    "```\n",
+    "\n",
+    "The radius of gyration is needed to determine the slenderness of a structure. When the radius of gyration and the buckling curve are known, the buckling force can be determined.\n",
+    "\n",
+    "Radius of gyration around strong axis (y-axis)  \n",
+    "$ i_y = \\sqrt{\\frac{I_y}{A}} $\n",
+    "\n",
+    "Radius of gyration around weak axis (z-axis)  \n",
+    "$ i_z = \\sqrt{\\frac{I_z}{A}} $"
   ]
  },
  {
--- a/book/basics/steel/hollow_sections.ipynb
+++ b/book/basics/steel/hollow_sections.ipynb
@ -0,0 +1,132 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Hollow sections\n",
+    "\n",
+    "Structural design is an iterative process where attention to function, material, force and form is essential. Available production techniques of steel profiles offer a wide range of possibities for a more free form.\n",
+    "\n",
+    "Hollow sections became possible because of the fast developments in the production of seamless and welded tubes. Plates, rolled sections and tubular sections can be rolled or folded in every possible form. These possibities bring the structural advantages of the tubular sections within reach for multiple forms of construction.\n",
+    "\n",
+    "In nature, various examples show the excellent properties of hollow sections when loaded in compression, torsion and bending in multiple directions. Especially torsion can be taken up easily in comparison with open profiles.\n",
+    "\n",
+    "Seamless rolled tubes are at the moment only applied in structures where very high structural demands are stated. The mechanical properties of these tubular sections can be \n",
+    "improved after production by heat treatment (annealing).\n",
+    "\n",
+    "For ordinary structure, mostly welded hollow sections are used. By means of automated welding processes, these tubular sections are provided with a longitudinal or spiral weld. The ends of the hollow sections can be provided with the necessary connection provisions. \n",
+    "\n",
+    "Using the current production techniques the structural engineer only needs to find the correct fabrication technique, structural shape, material quality, conservation and erection method to make a structural design.\n",
+    "\n",
+    "**Sources**\n",
+    " - Hollow sections in Structural Applications, J. Wardenier. \n",
+    " - ESDEP CD-ROM\n",
+    " - Bouwen met Staal CD-ROM\n",
+    "\n",
+    "```{note}\n",
+    "This section has been made with support of J. Wardenier, ESDEP and Bouwen met Staal.\n",
+    "```\n",
+    "\n",
+    "## Possible shapes\n",
+    "Preferably, use the following abbreviations for the different hollow sections:  \n",
+    "Square Hollow Sectios **SHS**  \n",
+    "Circular Hollow Section **CHS**  \n",
+    "Rectangular Hollow Section **RHS**\n",
+    "\n",
+    "```{figure} Images/possible_shapes.png\n",
+    "---\n",
+    "align: right\n",
+    "---\n",
+    "Possible shapes\n",
+    "```\n",
+    "\n",
+    "## Production method\n",
+    "RHS are made by distorting a hollow section by means of rolling. This distorting can take place both hot (920 ˚ C) and cold for seamless and welded tubular sections. For this process, mostly longitudinal welded sections are used.\n",
+    "\n",
+    "Hot rolled sections have sharp corners, while cold formed sections have rounder corners.\n",
+    "\n",
+    "```{figure} Images/chs_seamless.png\n",
+    "---\n",
+    "align: left\n",
+    "height: 200px\n",
+    "---\n",
+    "CHS, seamless\n",
+    "```\n",
+    "```{figure} Images/chs_welded_plates.png\n",
+    "---\n",
+    "align: right\n",
+    "height: 200px\n",
+    "---\n",
+    "CHS, welded plates\n",
+    "```\n",
+    "```{figure} Images/chs_welded2.png\n",
+    "---\n",
+    "---\n",
+    "CHS, welded plates schematic\n",
+    "```\n",
+    "\n",
+    "## Applications\n",
+    "\n",
+    "### Maeslantkering\n",
+    "```{figure} Images/maeslantkering.png\n",
+    "---\n",
+    "---\n",
+    "Maeslantkering, Nieuwe Waterweg\n",
+    "```\n",
+    "At the Maeslantkering in the Nieuwe Waterweg the 240 m long trusses are made of welded circular hollow sections with a diameter of 1,8 m and a thickness of 60 to 90 mm. These trusses support the closed hollow barrier. For more information see Bouwen met Staal magazine 101 (1991) p. 35-44; 121 (1994) p. 42-48 and 135 (1997) p. 8-24.\n",
+    "\n",
+    "### Dintelhaven railway bridge\n",
+    "```{figure} Images/dintelhaven.png\n",
+    "---\n",
+    "---\n",
+    "Dintelhaven railway bridge\n",
+    "```\n",
+    "At the Dintelhaven railway bridge the two leaning arches are made of hollow sections. This ensured a stable structure with a minimum amount of bracing. The stay cables support a continuous I-beam which supports the bridge deck. For more information see Bouwen met Staal magazine 142 (1998) p. 16-23.\n",
+    "\n",
+    "### Oosterscheldekering\n",
+    "```{figure} Images/oosterscheldekering.png\n",
+    "---\n",
+    "---\n",
+    "Oosterscheldekering\n",
+    "```\n",
+    "\n",
+    "The vertical lift doors in the Oosterschelde storm surge barrier are made of circular hollow sections in the 3D truss beam supporting the watertight door (segment-shape \n",
+    "shells, loaded only in tension). Function, construction and materials are widely discussed in Bouwen met Staal magazine 76 (1986)."
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": []
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.8.0"
+  },
+  "widgets": {
+   "application/vnd.jupyter.widget-state+json": {
+    "state": {},
+    "version_major": 2,
+    "version_minor": 0
+   }
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 4
+}
--- a/book/basics/steel/hollow_sections_trusses.ipynb
+++ b/book/basics/steel/hollow_sections_trusses.ipynb
@ -0,0 +1,151 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Hollow sections and trusses\n",
+    "\n",
+    "## Trusses\n",
+    "The most economical application of a truss using rectangular or circular hollow sections demands the number of nodes to be as small as possible. For this reason the Warren truss is prefered most of the time. If no diagonals can or may be applied, this can for example be a wish of the architect, vierendeel-beams need to be applied, where chords and verticals are connected with moment resisting joints.\n",
+    "\n",
+    "The truss bars are defined by their system length (ls) and the height (h) of the structure.  \n",
+    "In general h=1/15 · l is an economical structural height.\n",
+    "\n",
+    "Depending on the type of truss that is chosen the connections are of the X, T, Y, N or K-type. It is vital that the design of the connections is incorporated in the design as soon as possible. If the design of the bars is only based on the axial force, a lot of extra stiffeners may be needed in the connections. This does not mean that each connection needs to be designed in detail in the concept phase of a project, but the diagonals and chords need to be dimensioned such that a suitable node is possible which can be fabricated economically.\n",
+    "\n",
+    "Guidelines for an optimal design:  \n",
+    "- Truss design is based on hinged connections between the elements. Secondary bending moments are neglected in the ‘static’ design.\n",
+    "- In practice all nodes are designed centrically. This means the centerlines of all connecting elements intersect at one point. However, sometimes small eccentricities are unavoidable to aid simple fabrication.\n",
+    "- Preferably the diagonals are connected with a small gap. If the two diagonals overlap at the connection, difficult cuts have to be made, especially with circular hollow sections. Welding is also more complicated at overlap joints. However, overlap joints have higher design resistances.\n",
+    "- For trusses in general the following distribution is made: 50% of the weight for the compression chord; 30% of the weight for the tension chord; 20% for the diagonals.\n",
+    "\n",
+    "## Truss types\n",
+    "\n",
+    "```{figure} Images/warren_pratt_truss.png\n",
+    "---\n",
+    "align: left\n",
+    "scale: 94%\n",
+    "---\n",
+    "Warren Truss and Pratt truss\n",
+    "```\n",
+    "```{figure} Images/vierendeel.png\n",
+    "---\n",
+    "align: right\n",
+    "scale: 94%\n",
+    "---\n",
+    "Vierendeelbeam with and without bracings\n",
+    "```\n",
+    "\n",
+    "All trusses must be supported out of their plane to prevent them from ‘toppling over’. Also the chord under compression must be supported to prevent buckling out of plane.\n",
+    "\n",
+    "## Applications\n",
+    "```{figure} Images/node_rhs.png\n",
+    "---\n",
+    "align: left\n",
+    "height: 200px\n",
+    "---\n",
+    "Node RHS\n",
+    "```\n",
+    "```{figure} Images/airshiphall_germany.png\n",
+    "---\n",
+    "align: right\n",
+    "height: 200px\n",
+    "---\n",
+    "Airshiphall in Germany\n",
+    "```\n",
+    "```{figure} Images/project_norway.png\n",
+    "---\n",
+    "align: left\n",
+    "height: 200px\n",
+    "---\n",
+    "Project Norway\n",
+    "```\n",
+    "```{figure} Images/millenium_dome_london.png\n",
+    "---\n",
+    "align: right\n",
+    "height: 200px\n",
+    "---\n",
+    "Millenium Dome, London\n",
+    "```\n",
+    "```{figure} Images/airport_stuttgart.png\n",
+    "---\n",
+    "scale: 70%\n",
+    "---\n",
+    "Airport Stuttgart\n",
+    "```\n",
+    "\n",
+    "## Truss connections\n",
+    "\n",
+    "Circular hollow sections can be connected by:  \n",
+    "- Prefabricated nodes.  \n",
+    "- Parts that allow for a bolted joint.  \n",
+    "- Welded to a node plate.  \n",
+    "- Directly welded to the other member.\n",
+    "\n",
+    "For transportation or temporary connections during erection bolted joints are preferred. For space frames, a prefabricated node is preferred. The simplest solution is directly welding two member to each other. Today the required cutting for such a direct connection is no longer a problem.\n",
+    "\n",
+    "```{figure} Images/chs_support.png\n",
+    "---\n",
+    "---\n",
+    "CHS support\n",
+    "```\n",
+    "```{figure} Images/rhs_support.png\n",
+    "---\n",
+    "---\n",
+    "RHS support\n",
+    "```\n",
+    "```{figure} Images/beam_column.png\n",
+    "---\n",
+    "---\n",
+    "Beam-column\n",
+    "```\n",
+    "```{figure} Images/welds_k_joint.png\n",
+    "---\n",
+    "---\n",
+    "Welds (K-joint)\n",
+    "```\n",
+    "Connections, in this case a K-joint in a truss can be realized without overlap (a ‘gap’ joint) and with overlap. While designing such a joint, the possible effects of the geometry must be taken into account: eccentricity, peak stresses and possible fabrication problems.\n",
+    "\n",
+    "```{figure} Images/other.png\n",
+    "---\n",
+    "---\n",
+    "Other\n",
+    "```\n"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": []
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.8.0"
+  },
+  "widgets": {
+   "application/vnd.jupyter.widget-state+json": {
+    "state": {},
+    "version_major": 2,
+    "version_minor": 0
+   }
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 4
+}
--- a/book/basics/steel/information.ipynb
+++ b/book/basics/steel/information.ipynb
@ -4,7 +4,23 @@
   "cell_type": "markdown",
   "metadata": {},
   "source": [
-    "# Information"
+    "# Information\n",
+    "\n",
+    "## Different sources\n",
+    "\n",
+    "  - **Internet**\n",
+    "    - [Corusconstruction](https://www.corusconstruction.com/) hot rolled and cold formed sections (blue book), composite slab floors, sheet piling, bolts, details, case studies\n",
+    "    - [Voetstalpine](https://www.voestalpine.com/sadef/en/SEO/cold-formed-profiles) cold formed profiles\n",
+    "    - [Bouwen met Staal](https://www.bouwenmetstaal.nl/) (dutch) steel profiles, links, tools\n",
+    "\n",
+    "  - **Magazines**:\n",
+    "    - Bouwen met staal (dutch): projects, materials\n",
+    "\n",
+    "  - **Books**: \n",
+    "    - Overspannend staal, Basisboek, Construeren A, B (dutch): design methods, examples and material information. Note: these books are based on the old dutch code\n",
+    "\n",
+    "  - **Search terms**:\n",
+    "    - Steel, steelprofiles, steelconstruction."
   ]
  },
  {
--- a/book/basics/steel/material_characteristics.ipynb
+++ b/book/basics/steel/material_characteristics.ipynb
@ -6,7 +6,39 @@
   "source": [
    "# Material characteristics\n",
    "\n",
-    "\n"
+    "This section contains various tables depicting the material properties of the different steel grades.\n",
+    "\n",
+    "## Strength and stiffness\n",
+    "\n",
+    "| Property                                | S235  | S275  | S355  | S420  | S460  |\n",
+    "|-----------------------------------------|-------|-------|-------|-------|-------|\n",
+    "| Density $ρ_k$ [kg/m³]                     | 7850  | 7850  | 7850  | 7850  | 7850  |\n",
+    "| Young’s Modulus $E_k$ [N/mm²]             | 210 × 10³ | 210 × 10³ | 210 × 10³ | 210 × 10³ | 210 × 10³ |\n",
+    "| Design Yield Stress $f_{y;d}$ [N/mm²]       | 235   | 275   | 355   | 420   | 460   |\n",
+    "| Design Tensile Strength $f_{t;d}$ [N/mm²]   | 360   | 430   | 510   | --    | --    |\n",
+    "| Yield Strain $ε_{y;d}$ [‰]                  | 1.12  | 1.31  | 1.69  | --    | --    |\n",
+    "| Shear Modulus $G_k$ [N/mm²]               | 8.1 × 10⁴ | 8.1 × 10⁴ | 8.1 × 10⁴ | 8.1 × 10⁴ | 8.1 × 10⁴ |\n",
+    "| Coefficient of Thermal Expansion $α$ [K⁻¹] | 12 × 10⁻⁶ | 12 × 10⁻⁶ | 12 × 10⁻⁶ | 12 × 10⁻⁶ | 12 × 10⁻⁶ |\n",
+    "\n",
+    "\n",
+    "Higher steel grades are also available (up to S1100). The design rules stated in EC3 and this section only apply for the mentioned steel grades. The given values are only applicable to plates, flanges, etc with a maximum thickness of 40 mm acciording to NEN-EN 10025.\n",
+    "\n",
+    "## Stress-strain diagram\n",
+    "\n",
+    "```{figure} Images/stress_strain_steel.png\n",
+    "---\n",
+    "align: right\n",
+    "---\n",
+    "Stress-strain diagram steel\n",
+    "```\n",
+    "```{Note}\n",
+    "$ε_{y;d}$ : design yield strain  \n",
+    "$f_{t;d}$ : design tensile strength  \n",
+    "$f_{y;d}$ : design yield stress  \n",
+    "tan α : E_d  (Young’s modulus)\n",
+    "```\n",
+    "\n",
+    "In ordinary calculation the distrubution of forces and structural checks are executed using linear elasticity. In practice this means that as soons as the steel starts to yield, the structure is assumed to have failed. Only the linear part of the diagram shown above is used. The maximum strain is limited by the values given in the material properties table.\n"
   ]
  },
  {
--- a/book/basics/steel/products_1_hot_rolled_sections.ipynb
+++ b/book/basics/steel/products_1_hot_rolled_sections.ipynb
@ -4,7 +4,122 @@
   "cell_type": "markdown",
   "metadata": {},
   "source": [
-    "# Products 1: hot-rolled sections"
+    "# Products 1: hot-rolled sections\n",
+    "\n",
+    "## I-sections\n",
+    "```{figure} Images/ipe_inp_sections.png\n",
+    "---\n",
+    "align: left\n",
+    "---\n",
+    "IPE and INP sections\n",
+    "```\n",
+    "```{figure} Images/connection_beams_endplate.png\n",
+    "---\n",
+    "align: right\n",
+    "---\n",
+    "Connection between two beams by means of an endplate.\n",
+    "```\n",
+    "```{figure} Images/connection_beamcolumn_elongated_endplate.png\n",
+    "---\n",
+    "align: left\n",
+    "---\n",
+    "Connection between beam (I-section) and column (H-section) by means of an elongated endplate.\n",
+    "```\n",
+    "\n",
+    "| Type | Size | $h$ (mm) | $b$ (mm) | $M_{y;el;d}$ S235 (kNm) | $M_{y;el;d}$ S355 (kNm) |\n",
+    "|------|------|--------|--------|---------------------|---------------------|\n",
+    "| IPE  | 80 - 600 | 80 - 600 | 42 - 300 | 4,56 - 1076 | 6,89 - 1627 |\n",
+    "| INP  | 80 - 750 | 80 - 750 | 46 - 263 | 4,71 - 1467 | 7,71 - 2216 |\n",
+    "\n",
+    "Applications: Light structures in residential and non-residential buildings. Used a lot in industrial buildings. It is also possible to use the I sections to make castellated beams.\n",
+    "\n",
+    "## H-sections\n",
+    "```{figure} Images/hea_heb_hem_sections.png\n",
+    "---\n",
+    "align: left\n",
+    "---\n",
+    "HE-A, HE-B,HE-M sections, for each  \n",
+    "series the interior dimensions correspond.\n",
+    "```\n",
+    "```{figure} Images/connection_hebeam_ipebeam_hecolumn.png\n",
+    "---\n",
+    "align: right\n",
+    "---\n",
+    "Connection between HE-beam and IPE-beam  \n",
+    "on a HE-column.\n",
+    "```\n",
+    "```{figure} Images/hea_column_support.png\n",
+    "---\n",
+    "align: left\n",
+    "---\n",
+    "HE-A column support\n",
+    "```\n",
+    "\n",
+    "| Type | Size | $h$ (mm) | $b$ (mm) | $M_{z;el;d}$ S235 (kNm) | $M_{z;el;d}$ S355 (kNm) |\n",
+    "|------|------|--------|--------|--------------------|--------------------|\n",
+    "| HE A | 100 - 1000 | 96 - 990 | 100 - 300 | 17,1 - 2629 | 25,8 - 3972 |\n",
+    "| HE B | 100 - 1000 | 100 - 1000 | 100 - 300 | 21,1 - 3030 | 31,9 – 4578 |\n",
+    "| HE M | 100 - 1000 | 120 – 1008 | 106 - 302 | 44,8 - 3368 | 67,6 – 5088 |\n",
+    "\n",
+    "\n",
+    "Applications: H-sections are useful for compression elements (columns) or beams where the structural height has to be limited. The increase in section modulus is achieved by using thicker flanges. Due to their large width the H-sections retain their shape relatively well.\n",
+    "\n",
+    "## U-sections\n",
+    "```{figure} Images/uap_unp_sections.png\n",
+    "---\n",
+    "align: left\n",
+    "---\n",
+    "UAP and UNP sections\n",
+    "```\n",
+    "\n",
+    "| Type | Size | $h$ (mm) | $b$ (mm) | $M_{z;el;d}$ S235 (kNm) | $M_{z;el;d}$ S355 (kNm) |\n",
+    "|------|------|--------|--------|--------------------|--------------------|\n",
+    "| UAP  | 80 - 400 | 80 - 400 | 45 - 100 | 6,29 - 128 | 9,51 - 193 |\n",
+    "| UNP  | 80 - 400 | 80 - 400 | 45 - 100 | 6,22 - 239 | 9,4 - 361 |\n",
+    "\n",
+    "\n",
+    "Applications: Floor edges and landings. Connections between UNP-sections can be complicated due to the inclined edges.U-profiles are not symmetrical, causing the sections to bend along both axes when loaded vertically.\n",
+    "\n",
+    "## Hollow sections\n",
+    "```{figure} Images/chs_rhs.png\n",
+    "---\n",
+    "align: left\n",
+    "---\n",
+    "CHS (circular hollow section) and  \n",
+    "RHS (rectangular hollow section)\n",
+    "```\n",
+    "```{figure} Images/space_frame_node.png\n",
+    "---\n",
+    "align: right\n",
+    "---\n",
+    "Space frame node, made  \n",
+    "from hollow sections.\n",
+    "```\n",
+    "```{figure} Images/truss_rectangular_hollow_sections.png\n",
+    "---\n",
+    "align: left\n",
+    "---\n",
+    "Truss made of rectangular hollow sections. The bridge lies between the \n",
+    "trusses rather than on top of them.\n",
+    "```\n",
+    "\n",
+    "| Type | Size | $h$ (mm) | $t$ (mm) |\n",
+    "|------|------|--------|--------|\n",
+    "| CHS  | 42,4 - 610 | 42,4 - 610 | 2,6 - 30 |\n",
+    "| RHS  | 40 - 400 | 40 - 400 | 3 - 16 |\n",
+    "\n",
+    "\n",
+    "Application: (3D)trusses, columns.\n",
+    "\n",
+    "## Sheet piling\n",
+    "```{figure} Images/sheet_piles.png\n",
+    "---\n",
+    "align: left\n",
+    "---\n",
+    "Different sheet piling sections (U and Z sections)\n",
+    "```\n",
+    "\n",
+    "Applications: Basement walls, foundations, and hydraulic engineering. Sheet piles are available in different sizes and lengths. Sheet piles are used as walls in building pits and structres below ground level. Vertical loads can also be taken. "
   ]
  },
  {
--- a/book/basics/steel/products_2_cold_rolled_sections.ipynb
+++ b/book/basics/steel/products_2_cold_rolled_sections.ipynb
@ -4,7 +4,40 @@
   "cell_type": "markdown",
   "metadata": {},
   "source": [
-    "# Products 2: cold-rolled sections"
+    "# Products 2: cold-rolled sections\n",
+    "\n",
+    "## U and C profiles\n",
+    "```{figure} Images/u_and_c_profiles.png\n",
+    "---\n",
+    "align: left\n",
+    "---\n",
+    "Cold formed sections with and without stiffeners are available with equal (eq) or unequal (ue) height and width.\n",
+    "```\n",
+    "\n",
+    "| Type  | Size     | $h$ (mm)   | $b$ (mm)   |\n",
+    "|-------|----------|----------|----------|\n",
+    "| $CFU_{eq}$ | 10 - 100 | 10 - 100 | 10 - 100 |\n",
+    "| $CFU_{ue}$ | 10 - 160 | 10 - 160 | 10 - 70  |\n",
+    "| $CFC$   | 25 - 100 | 25 - 100 | 25 - 50  |\n",
+    "\n",
+    "Applications: Are used in residential buildings, carcase work, storage systems and finishings. Also used as purlins, or floorbeams. Due to plastic strains during fabrication the material properties differ from hot rolled sections.\n",
+    "\n",
+    "## L and Z profiles\n",
+    "```{figure} Images/L_and_Z_sections.png\n",
+    "---\n",
+    "align: left\n",
+    "---\n",
+    "Cold formed L or Z sections with and without stiffeners with equal (eq) or unequal (eu) height and width.\n",
+    "```\n",
+    "\n",
+    "| Type  | Size      | $h$ (mm)   | $b$ (mm)   |\n",
+    "|-------|-----------|----------|----------|\n",
+    "| $CF_{Leq}$ | 15 - 80   | 15 - 80  | 15 - 80  |\n",
+    "| $CFL_{ue}$ | 20 - 100  | 20 - 100 | 15 - 50  |\n",
+    "| $CFZ$  | 30 - 50   | 30 - 50  | 38 - 57  |\n",
+    "\n",
+    "\n",
+    "Applications: Are used in residential buildings, carcase work, storage systems and finishings. Also used as purlins, or floorbeams. Due to plastic strains during fabrication the material properties differ from hot rolled sections."
   ]
  },
  {
--- a/book/basics/steel/products_3_welded_sections.ipynb
+++ b/book/basics/steel/products_3_welded_sections.ipynb
@ -4,7 +4,34 @@
   "cell_type": "markdown",
   "metadata": {},
   "source": [
-    "# Products 3: welded sections"
+    "# Products 3: welded sections\n",
+    "\n",
+    "## Castellated beams IPE/HEA/HEB\n",
+    "```{figure} Images/castellated_beams.png\n",
+    "---\n",
+    "align: left\n",
+    "---\n",
+    "Non-residential buidlings. Castellated beams can be built by cutting a H or I section in one cut without loss of material. Round holes are also possible, but are less economical due to material losses and extra cutting.\n",
+    "```\n",
+    "\n",
+    "| Type | Size        | $h$ (mm)      | $b$ (mm)      |\n",
+    "|------|-------------|-------------|-------------|\n",
+    "| IPE  | 180 - 600   | 270 - 900   | 91 - 220    |\n",
+    "| HEA  | 180 - 1000  | 257 - 1485  | 180 - 300   |\n",
+    "| HEB  | 180 - 1000  | 270 - 1500  | 180 - 300   |\n",
+    "\n",
+    "Applications: Large, light spans with possibilities to incorporate building services in the structural height. Strength increases only slightly. Stiffness of the sections \n",
+    "increases despite the increased shear deformations. Castellated beams are very sensitive to lateral torsion buckling and have reduced shear capacity.\n",
+    "\n",
+    "## Top hat beams\n",
+    "```{figure} Images/welded_integrated_beams.png\n",
+    "---\n",
+    "align: left\n",
+    "---\n",
+    "Welded integrated beams (top hat beams)\n",
+    "```\n",
+    "\n",
+    "Applications: Top hat beams are very useful in combination with prefab concrete floors such as hollow core slabs or composite floors. (see cb 6 and cb 7). By integrating the beam in the floor, the total structural height is reduced and fire resistance increased."
   ]
  },
  {
--- a/book/basics/wood/dimension_tables.ipynb
+++ b/book/basics/wood/dimension_tables.ipynb
@ -4,7 +4,7 @@
   "cell_type": "markdown",
   "metadata": {},
   "source": [
-    "# Dimension tables\n",
+    "# Section tables\n",
    "\n",
    "\n"
   ]
--- a/book/basics/steel/steel_tube_profiles.ipynb
+++ b/book/basics/steel/steel_tube_profiles.ipynb
@ -1,46 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Steel tube profiles\n",
-    "\n",
-    "\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": []
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 3",
-   "language": "python",
-   "name": "python3"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 3
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython3",
-   "version": "3.8.0"
-  },
-  "widgets": {
-   "application/vnd.jupyter.widget-state+json": {
-    "state": {},
-    "version_major": 2,
-    "version_minor": 0
-   }
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 4
-}
--- a/book/basics/steel/tube_profiles_trusses.ipynb
+++ b/book/basics/steel/tube_profiles_trusses.ipynb
@ -1,46 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Tube profiles and trusses\n",
-    "\n",
-    "\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": []
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 3",
-   "language": "python",
-   "name": "python3"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 3
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython3",
-   "version": "3.8.0"
-  },
-  "widgets": {
-   "application/vnd.jupyter.widget-state+json": {
-    "state": {},
-    "version_major": 2,
-    "version_minor": 0
-   }
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 4
-}
--- a/book/basics/timber/Images/gluelaminated_timber.png
+++ b/book/basics/timber/Images/gluelaminated_timber.png
--- a/book/basics/timber/Images/pedestrian_bridge.png
+++ b/book/basics/timber/Images/pedestrian_bridge.png
--- a/book/basics/timber/Images/roof_beams.png
+++ b/book/basics/timber/Images/roof_beams.png
--- a/book/basics/timber/Images/roof_efteling.png
+++ b/book/basics/timber/Images/roof_efteling.png
--- a/book/basics/timber/Images/roundwood.png
+++ b/book/basics/timber/Images/roundwood.png
--- a/book/basics/timber/Images/solidwood.png
+++ b/book/basics/timber/Images/solidwood.png
--- a/book/basics/timber/Images/stems_efteling.png
+++ b/book/basics/timber/Images/stems_efteling.png
--- a/book/basics/timber/dimension_tables.ipynb
+++ b/book/basics/timber/dimension_tables.ipynb
--- a/book/basics/timber/information.ipynb
+++ b/book/basics/timber/information.ipynb
@ -0,0 +1,62 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Information\n",
+    "\n",
+    "## Different sources\n",
+    "\n",
+    "  - **Internet**\n",
+    "    - [Centrum Hout](https://www.centrumhout.nl/) buildings, bridges, other structures, photos, ideas\n",
+    "    - [houtdatabase.nl](https://www.houtdatabase.nl/) durability properties of timber species\n",
+    "\n",
+    "  - **Books**: \n",
+    "    - Holzbau Atlas, J. Natterer, T. Herzog, M. Volz: buildings, photos, drawings, connections.\n",
+    "    - STEP 1, 2 Timber Engineering, Centrum Hout: calculation methods for timber structures\n",
+    "    - Timber Construction Manual, Brikhäuser: examples of timber structres and connections\n",
+    "\n",
+    "  - **Magazines**:\n",
+    "    - Het Houtblad (ductch), Centrum Hout\n",
+    "    - Hout in de bouw (dutch), Schiedam Nijgh Periodieken\n",
+    "\n",
+    "  - **Search terms**:\n",
+    "    - Glulam, cross laminated timer"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": []
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.8.0"
+  },
+  "widgets": {
+   "application/vnd.jupyter.widget-state+json": {
+    "state": {},
+    "version_major": 2,
+    "version_minor": 0
+   }
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 4
+}
--- a/book/basics/timber/material_characteristics.ipynb
+++ b/book/basics/timber/material_characteristics.ipynb
@ -0,0 +1,219 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Material characteristics\n",
+    "\n",
+    "This section contains tables with the material properties of the different timber strength classes. With the aid of a modification factor the characteristic values are adapted to the local environment and use.\n",
+    "\n",
+    "## Durability class\n",
+    "\n",
+    "The upper table below can be used to judge whether wood species belonging to a particular durability class (D1-D5) is sufficiently durable or needs extra protection. The durability class of different wood species is depicted in the lower table below. The higher the durability class, the less durable a wood species.\n",
+    "\n",
+    "| Use class | D1 | D2 | D3       | D4 | D5 |\n",
+    "|----|----|----|----------|----|----|\n",
+    "| 1  | O  | O  | O        | O  | O  |\n",
+    "| 2  | O  | O  | O        |(O) |(O) |\n",
+    "| 3  | O  | O  | (O)      |(O)-(X)|(O)-(X) |\n",
+    "| 4  | O  |(O) | (X)      | X  | X  |\n",
+    "| 5  | O  | X  | (X)      | X  | X  |\n",
+    "\n",
+    "O: Natural durability is sufficient  \n",
+    "(O): Natural durability in principle sufficient but some circumstances require wood treatment  \n",
+    "(O)-(X): Natural durability can be sufficient  \n",
+    "(X): Chemical treatment is advisable but for some applications the natural durability can suffice  \n",
+    "X: Chemical treatment is necessary\n",
+    "\n",
+    "| Species           | Natural durability  |\n",
+    "|-------------------|---------------------|\n",
+    "| Spruce            | D4                  |\n",
+    "| Pine              | D3-D4               |\n",
+    "| Oak (European)    | D2                  |\n",
+    "| Oak (American)    | D4                  |\n",
+    "| Larch             | D3-D4               |\n",
+    "| Azobe             | D2                  |\n",
+    "| Robinia           | D1-D2               |\n",
+    "| Western Red Cedar | D2-D3               |\n",
+    "\n",
+    "## Use class\n",
+    "\n",
+    "| Class | Description                                                                                                  | Example           |\n",
+    "|-------|--------------------------------------------------------------------------------------------------------------|-------------------|\n",
+    "| 1     | Situations in which the wood or wood-based product is inside a construction, not exposed to the weather and wetting. | roof beam         |\n",
+    "| 2     | Situations in which the wood or wood-based product is under cover and not exposed to the weather (particularly rain and driven rain) but where occasional, but not persistent, wetting can occur. | beam of open canopy |\n",
+    "| 3     | Situations in which the wood or wood-based product is above ground and exposed to the weather (particularly rain) | external column  |\n",
+    "| 4     | A situation in which the wood or wood-based product is in direct contact with ground and/or fresh water      | foundation pile  |\n",
+    "| 5     | A situation in which the wood or wood-based product is permanently or regularly submerged in salt water (i.e. sea water and brackish water) | sea lock gate     |\n",
+    "\n",
+    "## Service classes\n",
+    "\n",
+    "| Service class | Environment | R.H. in construction*                   | Use class |\n",
+    "|---------------|-------------------------|----------------------------|-----------|\n",
+    "| 1             | Relative humidity exceeding 65% only a few weeks per year. Temperature 20°C,  | 12% R.H. | 1         |\n",
+    "| 2             | Relative humidity exceeding 85% only a few weeks per year. Temperature 20°C  | 20% R.H. | 1         |\n",
+    "| 2             | If the component is in a situation where it could be subjected to prolonged wetting by liquid water e.g. condensation | 20% R.H.| 2         |\n",
+    "| 3             | Climatic conditions leading to higher moisture contents than in service class 2 | > 20% R.H. | 3 or higher if used externally |\n",
+    "\n",
+    "\n",
+    "* The relative humidity of in the material given in this column holds for most softwoods\n",
+    "\n",
+    "## Load duration class\n",
+    "Load duration class | Order of load duration      | Example                \n",
+    "--------------------|------------------------------|------------------------\n",
+    "Permanent           | More than 10 years          | Self weight            \n",
+    "Long-term           | 6 months to 10 years        | Storage                \n",
+    "Medium-term         | 1 week to 6 months           | Imposed floor load, snow\n",
+    "Short-term          | Less than 1 week             | Snow, wind             \n",
+    "Instantaneous       | -                            | Wind, accidental load  \n",
+    "\n",
+    "## Modification factors $k_{mod}$\n",
+    "\n",
+    "| Material                   | Service class | Permanent | Long-term | Medium-term | Short-term | Instantaneous |\n",
+    "|----------------------------|---------------|-----------|-----------|-------------|------------|---------------|\n",
+    "| Solid Timber and Glued Laminated Timber | 1 | 0.60 | 0.70 | 0.80 | 0.90 | 1.10 |\n",
+    "| Solid Timber and Glued Laminated Timber | 2 | 0.60 | 0.70 | 0.80 | 0.90 | 1.10 |\n",
+    "| Solid Timber and Glued Laminated Timber | 3 | 0.50 | 0.55 | 0.65 | 0.70 | 0.90 |\n",
+    "\n",
+    "\n",
+    "Note that the modification factor needs to be chosen according to the load duration of the whole load combination.\n",
+    "\n",
+    "## Creep factors $k_{def}$\n",
+    "The creep factor is based on the service class.\n",
+    "\n",
+    "| Material                   | 1   | 2   | 3   |\n",
+    "|----------------------------|-----|-----|-----|\n",
+    "| Solid Timber and Glued Laminated Timber | 0.60 | 0.80 | 2.00 |\n",
+    "\n",
+    "## Material properties: solid timber\n",
+    "\n",
+    "| Material property         | C14   | C16   | C18   | C20   | C22   | C24   | C27   | C30   | C35   |\n",
+    "|--------------|------|------|------|------|------|------|------|------|------|\n",
+    "| Bending $f_{m;k}$ (N/mm²) | 14 | 16 | 18 | 20 | 22 | 24 | 27 | 30 | 35 |\n",
+    "| Tension $f_{t;0;k}$ // (N/mm²) | 8   | 10   | 11   | 12   | 13   | 14   | 16   | 18   | 21   |\n",
+    "| Tension $f_{t;90;k}$ ┴ (N/mm²) | 0.4 | 0.4 | 0.4 | 0.4 | 0.4 | 0.4 | 0.4 | 0.4 | 0.4 |\n",
+    "| Compression $f_{c;0;k}$ // (N/mm²) | 16  | 17  | 18  | 19  | 20  | 21  | 22  | 23  | 25  |\n",
+    "| Compression $f_{c;90;k}$ ┴ (N/mm²) | 2.0 | 2.2 | 2.2 | 2.3 | 2.4 | 2.5 | 2.6 | 2.7 | 2.8 |\n",
+    "| Shear $f_{v;k}$ (N/mm²)        | 3.0 | 3.2 | 3.4 | 3.6 | 3.8 | 4.0 | 4.0 | 4.0 | 4.0 |\n",
+    "| Mean MOE $E_{0;\\text{mean}}$ (N/mm²)  | 7000 | 8000 | 9000 | 9500 | 10000 | 11000 | 11500 | 12000 | 13000 |\n",
+    "| 5% MOE $E_{0,05}$ (N/mm²)     | 4700 | 5400 | 6000 | 6400 | 6.7   | 7400  | 7700  | 8000  | 8700  |\n",
+    "| Mean MOE $E_{90;\\text{mean}}$ (N/mm²) | 230  | 270  | 300  | 320  | 0.33  | 370   | 380   | 400   | 430   |\n",
+    "| Mean shear modulus $G_{\\text{mean}}$ (N/mm²) | 440  | 500  | 560  | 590  | 630   | 690   | 720   | 750   | 810   |\n",
+    "| Density $\\rho_k$ (kg/m³)           | 290  | 310  | 320  | 330  | 340   | 350   | 370   | 380   | 400   |\n",
+    "| Mean density $\\rho_{\\text{mean}}$ (kg/m³) | 350  | 370  | 380  | 390  | 410   | 420   | 450   | 460   | 480   |\n",
+    "\n",
+    "MOE = modulus of elasticity or Young’s modulus\n",
+    "\n",
+    "```{note}\n",
+    "Timber in strength classes C40 and C45 may not be readily available\n",
+    "```\n",
+    "\n",
+    "## Material properties: glued laminated timber\n",
+    "\n",
+    "| Material property                  | GL24h    | GL28h    | GL32h    |\n",
+    "|------------------------------------|----------|----------|----------|\n",
+    "| Bending $f_{m;k}$ (N/mm²)         | 24       | 28       | 32       |\n",
+    "| Tension $f_{t;0;k}$ // (N/mm²)   | 16.5     | 19.5     | 22.5     |\n",
+    "| Tension $f_{t;90;k}$ ┴ (N/mm²)   | 0.4      | 0.45     | 0.5      |\n",
+    "| Compression $f_{c;0;k}$ // (N/mm²) | 24       | 26.5     | 29       |\n",
+    "| Compression $f_{c;90;k}$ ┴ (N/mm²) | 2.7      | 3.0      | 3.3      |\n",
+    "| Shear $f_{v;k}$ (N/mm²)            | 2.7      | 3.2      | 3.8      |\n",
+    "| Mean MOE $E_{0;\\text{mean}}$ (N/mm²) | 11600    | 12600    | 13700    |\n",
+    "| 5% MOE $E_{0,05}$ (N/mm²)         | 9400     | 10200    | 11100    |\n",
+    "| Mean MOE $E_{90;\\text{mean}}$ (N/mm²) | 390      | 420      | 460      |\n",
+    "| Mean shear modulus $G_{\\text{mean}}$ (N/mm²) | 720     | 780      | 850      |\n",
+    "| Density $\\rho_k$ (kg/m³)             | 380      | 410      | 430      |\n",
+    "| Mean density $\\rho_{\\text{mean}}$ (kg/m³) | 420   | 450      | 470      |\n",
+    "\n",
+    "## Material properties continued: solid timber\n",
+    "\n",
+    "|    | C40 | C45 | C50 | D18 | D24 | D30 | D35 | D40 | D50 | D60 | D70 |\n",
+    "|-----|-----|-----|-----|-----|-----|-----|-----|-----|-----|-----|-----|\n",
+    "| $f_{m;k}$   | 40  | 45  | 50  | 18  | 24  | 30  | 35  | 40  | 50  | 60  | 70  |\n",
+    "| $f_{t;0;k}$ // | 24  | 27  | 30  | 11  | 14  | 18  | 21  | 24  | 30  | 36  | 42  |\n",
+    "| $f_{t;90;k}$ ┴ | 0.4 | 0.4 | 0.4 | 0.6 | 0.6 | 0.6 | 0.6 | 0.6 | 0.6 | 0.6 | 0.6 |\n",
+    "| $f_{c;0;k}$ // | 26  | 27  | 29  | 18  | 21  | 23  | 25  | 26  | 29  | 32  | 34  |\n",
+    "| $f_{c;90;k}$ ┴ | 2.9 | 3.1 | 3.2 | 7.5 | 7.8 | 8.0 | 8.1 | 8.3 | 9.3 | 10.5| 13.5|\n",
+    "| $f_{v;k}$   | 4.0 | 4.0 | 4.0 | 3.4 | 4.0 | 4.0 | 4.0 | 4.0 | 4.0 | 4.5 | 5.0 |\n",
+    "| $E_{0;\\text{mean}}$ | 14000 | 15000 | 16000 | 9500  | 10000 | 11000 | 12000 | 13000 | 14000 | 17000 | 20000 |\n",
+    "| $E_{0,05}$   | 9400  | 10000 | 10700 | 8000  | 8500  | 9200  | 10100 | 10900 | 11800 | 14300 | 16800 |\n",
+    "| $E_{90;\\text{mean}}$ | 470   | 500   | 530   | 630   | 670   | 730   | 800   | 860   | 930   | 1130  | 1330  |\n",
+    "| $G_{\\text{mean}}$ | 880   | 940   | 1000  | 590   | 620   | 690   | 750   | 810   | 880   | 1060  | 1250  |\n",
+    "| $\\rho_k$    | 420   | 440   | 460   | 475   | 485   | 530   | 540   | 550   | 620   | 700   | 900   |\n",
+    "| $\\rho_{\\text{mean}}$ | 500   | 520   | 550   | 570   | 580   | 640   | 650   | 660   | 750   | 840   | 1080  |\n",
+    "\n",
+    "\n",
+    "## Design values of material properties in ULS\n",
+    "\n",
+    "The material properties given in the tables above are characteristic values. Depending on the local environment, use and load duration these values have to be adjusted to design values. The design value of the Young’s modulus is used to determine the force distribution in a statically indeterminate structure.\n",
+    "\n",
+    "Strength properties:  \n",
+    "$X_d = k_{mod} \\cdot \\frac{X_k}{\\gamma_M}$\n",
+    "\n",
+    "Stiffness properties:  \n",
+    "$E_d = \\frac{E_{mean}}{\\gamma_M}$  \n",
+    "$G_d = \\frac{G_{mean}}{\\gamma_M}$\n",
+    "\n",
+    "Where:  \n",
+    "$X_d$ = Design value of strength property  \n",
+    "$X_k$ = Characteristic value of strength property  \n",
+    "$E_d$ = Design value of Young’s modulus  \n",
+    "$E_{mean}$ = Characteristic value of Young’s modulus  \n",
+    "$k_{mod}$ = modification factor  \n",
+    "$\\gamma_M$ = model factor; 1,25 for glued laminated timber, 1,3 for solid timber and connections\n",
+    "\n",
+    "## Final deflection\n",
+    "\n",
+    "The final deflection in SLS including creep effects is defined as:  \n",
+    "$u_{fin} = u_{fin;G} + u_{fin;Q;1} + \\Sigma u_{fin;Q;i}$  \n",
+    "$u_{fin;G} = u_{inst;G} \\cdot (1 + k_{def})$  \n",
+    "$u_{fin;Q;1} = u_{inst;Q;1} \\cdot (1 + \\psi_{2,1} \\cdot k_{def})$  \n",
+    "$u_{fin;Q;i} = u_{inst;Q;i} \\cdot (\\psi_0 + \\psi_{2,i} \\cdot k_{def})$  \n",
+    "\n",
+    "Where:  \n",
+    "$u_{fin}$ = final deflection  \n",
+    "$u_{inst}$ = instantaneous deflection  \n",
+    "$u_G$ = deflection under permanent load  \n",
+    "$u_{Q;1}$ = deflection under leading variable load  \n",
+    "$u_{Q;i}$ = deflection under other variable load  \n",
+    "$\\Psi_0$ = load combination factor (see also |general|loads|)  \n",
+    "$\\Psi_2$ = factor for quasi permanent value of variable load i  \n",
+    "$k_{def}$ = creep factor"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": []
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.8.0"
+  },
+  "widgets": {
+   "application/vnd.jupyter.widget-state+json": {
+    "state": {},
+    "version_major": 2,
+    "version_minor": 0
+   }
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 4
+}
--- a/book/basics/timber/products.ipynb
+++ b/book/basics/timber/products.ipynb
@ -0,0 +1,100 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Products\n",
+    "\n",
+    "## Roundwood (debarked stems or milled cylindrical)\n",
+    "\n",
+    "```{figure} Images/roundwood.png\n",
+    "---\n",
+    "---\n",
+    "Roundwood\n",
+    "```\n",
+    "\n",
+    "```{figure} Images/stems_efteling.png\n",
+    "---\n",
+    "align: left\n",
+    "---\n",
+    "Stems used in the construction of the  \n",
+    "entrance of theme park the ‘Efteling’ in Kaatsheuvel.\n",
+    "```\n",
+    "```{figure} Images/roof_efteling.png\n",
+    "---\n",
+    "align: right\n",
+    "---\n",
+    "The roof of the entrance of the  \n",
+    "‘Efteling’ consists almost entirely of roundwood.\n",
+    "```\n",
+    "Applications: Roundwood is used for a wide range of structures such as bridges, towers, buildings and foundation piles. In modern architecture roundwood can for example be found in the columns of the MVRDV expo building.\n",
+    "\n",
+    "## Solid wood (sawn sections)\n",
+    "```{figure} Images/solidwood.png\n",
+    "---\n",
+    "---\n",
+    "Solid wood\n",
+    "```\n",
+    "Applications: Solid wood can be used for small structures, roofs, purlins, floors (both beams and purlins), and trusses.\n",
+    "\n",
+    "## Glue laminated timber\n",
+    "\n",
+    "```{figure} Images/gluelaminated_timber.png\n",
+    "---\n",
+    "---\n",
+    "From left to right: horizontally laminated, vertically laminated, finger joint.\n",
+    "```\n",
+    "\n",
+    "```{figure} Images/pedestrian_bridge.png\n",
+    "---\n",
+    "align: left\n",
+    "---\n",
+    "Pedestrian bridge made from straight and curved glued  \n",
+    "laminated timber.\n",
+    "```\n",
+    "```{figure} Images/roof_beams.png\n",
+    "---\n",
+    "align: right\n",
+    "---\n",
+    "Roof beams made of glued  \n",
+    "laminated timber.\n",
+    "```\n",
+    "Applications: Glued laminated timber is used frequently because of the many possible shapes and lengths. However, the length of elements can be restricted by transport. Large spans, three hinged frames, trusses, arches and frames are also possible with glued laminated timber"
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": []
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.8.0"
+  },
+  "widgets": {
+   "application/vnd.jupyter.widget-state+json": {
+    "state": {},
+    "version_major": 2,
+    "version_minor": 0
+   }
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 4
+}
--- a/book/basics/timber/timber.md
+++ b/book/basics/timber/timber.md
@ -1,4 +1,4 @@
-# Wood
+# Timber

 ```{tableofcontents}
 ```
--- a/book/design/Beton/Beton.md
+++ b/book/design/Beton/Beton.md
@ -1,13 +0,0 @@
-# Concrete
-
-This chapter contains the following sections:
-
-```{tableofcontents}
-```
-
-```{Note}
-Nog toe te voegen:
- Vuistregels in vorm van grafieken (zie aparte excel)
- Verbindingen hout verdiepingsbouw en CLT
- 3D weergave van verbindingen
-```
--- a/book/design/Beton/wanden.ipynb
+++ b/book/design/Beton/wanden.ipynb
@ -1,44 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Wanden"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": []
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 3",
-   "language": "python",
-   "name": "python3"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 3
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython3",
-   "version": "3.8.0"
-  },
-  "widgets": {
-   "application/vnd.jupyter.widget-state+json": {
-    "state": {},
-    "version_major": 2,
-    "version_minor": 0
-   }
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 4
-}
--- a/book/design/Hout/stabiliteit.ipynb
+++ b/book/design/Hout/stabiliteit.ipynb
@ -1,44 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Stabiliteit\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": []
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 3",
-   "language": "python",
-   "name": "python3"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 3
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython3",
-   "version": "3.8.0"
-  },
-  "widgets": {
-   "application/vnd.jupyter.widget-state+json": {
-    "state": {},
-    "version_major": 2,
-    "version_minor": 0
-   }
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 4
-}
--- a/book/design/Hout/verbindingen.ipynb
+++ b/book/design/Hout/verbindingen.ipynb
@ -1,44 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Verbindingen"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": []
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 3",
-   "language": "python",
-   "name": "python3"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 3
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython3",
-   "version": "3.8.0"
-  },
-  "widgets": {
-   "application/vnd.jupyter.widget-state+json": {
-    "state": {},
-    "version_major": 2,
-    "version_minor": 0
-   }
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 4
-}
--- a/book/design/Hout/vloeren.ipynb
+++ b/book/design/Hout/vloeren.ipynb
@ -1,44 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Vloeren"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": []
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 3",
-   "language": "python",
-   "name": "python3"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 3
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython3",
-   "version": "3.8.0"
-  },
-  "widgets": {
-   "application/vnd.jupyter.widget-state+json": {
-    "state": {},
-    "version_major": 2,
-    "version_minor": 0
-   }
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 4
-}
--- a/book/design/Hout/wanden.ipynb
+++ b/book/design/Hout/wanden.ipynb
@ -1,44 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Wanden"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": []
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 3",
-   "language": "python",
-   "name": "python3"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 3
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython3",
-   "version": "3.8.0"
-  },
-  "widgets": {
-   "application/vnd.jupyter.widget-state+json": {
-    "state": {},
-    "version_major": 2,
-    "version_minor": 0
-   }
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 4
-}
--- a/book/design/Staal/Staal.md
+++ b/book/design/Staal/Staal.md
@ -1,13 +0,0 @@
-# Steel
-
-This chapter contains the following sections:
-
-```{tableofcontents}
-```
-
-```{Note}
-Nog toe te voegen:
- Vuistregels in vorm van grafieken (zie aparte excel)
- Verbindingen hout verdiepingsbouw en CLT
- 3D weergave van verbindingen
-```
--- a/book/design/Staal/balken.ipynb
+++ b/book/design/Staal/balken.ipynb
@ -1,44 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Balken"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": []
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 3",
-   "language": "python",
-   "name": "python3"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 3
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython3",
-   "version": "3.8.0"
-  },
-  "widgets": {
-   "application/vnd.jupyter.widget-state+json": {
-    "state": {},
-    "version_major": 2,
-    "version_minor": 0
-   }
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 4
-}
--- a/book/design/Staal/kolommen.ipynb
+++ b/book/design/Staal/kolommen.ipynb
@ -1,44 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Kolommen"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": []
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 3",
-   "language": "python",
-   "name": "python3"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 3
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython3",
-   "version": "3.8.0"
-  },
-  "widgets": {
-   "application/vnd.jupyter.widget-state+json": {
-    "state": {},
-    "version_major": 2,
-    "version_minor": 0
-   }
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 4
-}
--- a/book/design/Staal/stabiliteit.ipynb
+++ b/book/design/Staal/stabiliteit.ipynb
@ -1,44 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Stabiliteit\n"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": []
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 3",
-   "language": "python",
-   "name": "python3"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 3
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython3",
-   "version": "3.8.0"
-  },
-  "widgets": {
-   "application/vnd.jupyter.widget-state+json": {
-    "state": {},
-    "version_major": 2,
-    "version_minor": 0
-   }
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 4
-}
--- a/book/design/Staal/verbindingen.ipynb
+++ b/book/design/Staal/verbindingen.ipynb
@ -1,44 +0,0 @@
-{
- "cells": [
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": [
-    "# Verbindingen"
-   ]
-  },
-  {
-   "cell_type": "markdown",
-   "metadata": {},
-   "source": []
-  }
- ],
- "metadata": {
-  "kernelspec": {
-   "display_name": "Python 3",
-   "language": "python",
-   "name": "python3"
-  },
-  "language_info": {
-   "codemirror_mode": {
-    "name": "ipython",
-    "version": 3
-   },
-   "file_extension": ".py",
-   "mimetype": "text/x-python",
-   "name": "python",
-   "nbconvert_exporter": "python",
-   "pygments_lexer": "ipython3",
-   "version": "3.8.0"
-  },
-  "widgets": {
-   "application/vnd.jupyter.widget-state+json": {
-    "state": {},
-    "version_major": 2,
-    "version_minor": 0
-   }
-  }
- },
- "nbformat": 4,
- "nbformat_minor": 4
-}
--- a/Show more
+++ b/Show more