{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Cross sectional quantitites" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Definition section parameters\n", "| Surface |Static moment of area| Moment of Inertia | Polar moment of inertia | Steiner's rule |\n", "|--------------|---------------------|------------------------------|-----------------------------------------|----------------|\n", "|$A=\\int_A\\,dA$|$S_y = \\int_A y\\, dA$|$I_{yy}=I_z=\\int_A y^2\\,dA$ |$I_p = \\int_A r^2\\, dA = I_{yy} + I_{zz}$|$I_{\\overline{yy}}=I_{yy(own)}+\\bar{y}_c^2 \\cdot A$| \n", "| |$S_z = \\int_A z\\, dA$|$I_{yz}=I_{zy}=\\int_A y*z\\,dA$| |$I_{\\overline{yz}}=I_{\\overline{zy}}=I_{yz(own)}+\\bar{y}_c \\cdot \\bar{z}_c \\ A$|\n", "| | |$I_{zz}=I_{y}=\\int_A z^2\\,dA$ | |$I_{\\overline{zz}}=I_{zz(own)}+\\bar{z}_c^2 \\cdot A$" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Section parameters\n", "\n", "```{figure} Images/Rectangle shape.jpg\n", "---\n", "scale: 100%\n", "---\n", "```\n", "\n", "### Square\n", "|Area, centre of gravity| Moments of intertia own | other |\n", "|-----------------------|-------------------------|-----------------------------|\n", "|$A=bh$ |$I_{yy}=\\frac{1}{12}*b^3*h$ |$I_{\\overline{yy}}=1/3b^3h$ | \n", "|$\\bar{y}_C=\\frac{1}{2}b$ |$I_{zz}=\\frac{1}{12}bh^3$ |$I_{\\overline{zz}}=\\frac{1}{3}bh^3$ |\n", "|$\\bar{z}_C=\\frac{1}{2}b$ |$I_{yz}=\\frac{1}{12}bh^3$ |$I_{\\overline{yz}}=\\frac{1}{4}b^2h^2$|\n", "\n", "```{figure} Images/Parallelogram shape.jpg\n", "---\n", "scale: 100%\n", "---\n", "```\n", "\n", "### Parallelogram\n", "|Area, centre of gravity | Moments of intertia own | other |\n", "|---------------------------|-------------------------------|-------------------------------|\n", "|$A=bh$ |$I_{yy}=\\frac{1}{12}(a^2+b^2)$|$I_{\\overline{yy}}=1/3bh^3$ | \n", "|$\\bar{y}_C=\\frac{1}{2}(a+b)$ |$I_{zz}=\\frac{1}{12}bh^3$ | |\n", "|$\\bar{z_C}=\\frac{1}{2}h$ |$I_{yz}=\\frac{1}{12}abh^2$ | |\n", "\n", "```{figure} Images/Triangle shape.jpg\n", "---\n", "scale: 100%\n", "---\n", "```\n", "\n", "### Triangle\n", "|Area, centre of gravity | Moments of intertia own | other |\n", "|------------------------------|----------------------------------|---------------------------------|\n", "|$A=\\frac{1}{2}bh$ |$I_{yy}=\\frac{1}{36}*(a^2-ab+b^2)$|$I_{\\overline{zz}}=\\frac{1}{3}bh^3$ | \n", "|$\\bar{y}_C=\\frac{1}{3}(2a-b)$ |$I_{zz}=\\frac{1}{36}bh^3$ |$I_{\\overline{yz}}=\\frac{1}{8}(2a-b)bh^2$|\n", "|$\\bar{z}_C=\\frac{2}{3}h$ |$I_{yz}=\\frac{1}{72}abh^2$ |$I_{\\overline{\\overline{zz}}}=\\frac{1}{12}bh^3$ |\n", "\n", "```{figure} Images/Trapezoid shape.jpg\n", "---\n", "scale: 100%\n", "---\n", "```\n", "\n", "### Trapezoid\n", "|Area, centre of gravity | Moments of intertia own | other | \n", "|-----------------------------------------|-----------------------------------------------|----------------------------------------------------|\n", "|$A=\\frac{1}{2}(a+b)h$ |$I_{zz}=\\frac{1}{36}\\frac{a^2+4ab+b^2}{a+b}h^3$|$I_{\\overline{zz}}=\\frac{1}{3}bh^3$ | \n", "|$\\bar{y}_C=\\frac{1}{3}\\frac{a+2b}{a+b}h$ | |$I_{\\overline{\\overline{zz}}}=\\frac{1}{12}(a+3b)h^3$|\n", "|$\\bar{z}_C=\\frac{2}{3}h$ | | |\n", "\n", "```{figure} Images/Circle shape.jpg\n", "---\n", "scale: 100%\n", "---\n", "```\n", "\n", "### Circle\n", "|Area, centre of gravity | Moments of intertia own | other | \n", "|------------------------|------------------------------|-----------------------------------------------------|\n", "|$A=πR^2$ |$I_{yy}=I_{zz}=\\frac{1}{4}R^4$|$I_{\\overline{yy}}=I_{\\overline{zz}}=\\frac{5}{4}πR^4$| \n", "| |$I_{yz}=0$ |$I_{\\overline{\\overline{yz}}}=πR^4$ |\n", "| |$I_p=\\frac{1}{2}πR^4$ | |\n", "\n", "```{figure} Image/Thick walled ring shape.jpg\n", "---\n", "scale: 100%\n", "---\n", "```\n", "\n", "### Thick-walled ring\n", "|Area, centre of gravity | Moments of intertia own | other | \n", "|------------------------|-----------------------------------------|-----------------|\n", "|$A=πR_0^2R_i^2$ |$I_{yy}=I_{zz}=\\frac{1}{4}π(R_0^4-R_i^4)$| | \n", "| |$I_{yz}=0$ | |\n", "| |$I_p=\\frac{1}{2}π(R_0^4-R_i^4)$ | |\n", "\n", "```{figure} Images/Thin walled ring shape.jpg\n", "---\n", "scale: 100%\n", "---\n", "```\n", "\n", "### Thin-walled ring\n", "|Area, centre of gravity | Moments of intertia own | other | \n", "|------------------------|------------------------------|--------------------------------------------|\n", "|$A=2πRt$ |$I_{yy}=I_{zz}=πR^3t$ |$I_{\\overline{yy}}=I_{\\overline{zz}}=3πR^3t$| \n", "| |$I_{yz}=0$ | |\n", "| |$I_p=\\frac{1}{2}πR^3t$ | |\n", "\n", "```{figure} Images/Half circle shape.jpg\n", "---\n", "scale: 100%\n", "---\n", "```\n", "\n", "### Half circle\n", "|Area, centre of gravity | Moments of intertia own | other | \n", "|--------------------------|--------------------------------------|-----------------------------------------------------|\n", "|$A=\\frac{1}{2}πR^2$ |$I_{yy}=\\frac{1}{8}πR^4$ |$I_{\\overline{yy}}=I_{\\overline{zz}}=\\frac{1}{8}πR^4$| \n", "|$\\bar{y}_C=0$ |$I_{zz}=(\\frac{π}{8}-\\frac{8}{9π})R^4$|$I_{\\overline{\\overline{yz}}}=0$ |\n", "|$\\bar{z}_C=\\frac{4}{3π}R$ |$I_{yz}=0$ | |\n", "\n", "```{figure} Images/Half thin walled ring shape.jpg\n", "---\n", "scale: 100%\n", "---\n", "```\n", "\n", "### Half thin-walled ring\n", "|Area, centre of gravity | Moments of intertia own | other | \n", "|------------------------|-------------------------------|------------------------------------------------------|\n", "|$A=πRt$ |$I_{yy}=I_{zz}=\\frac{1}{2}R^3t$|$I_{\\overline{yy}}=I_{\\overline{zz}}=\\frac{1}{2}πR^3t$| \n", "|$\\bar{y}_C=0$ |$I_{zz}=0$ |$I_{\\overline{yz}}=0$ |\n", "|$\\bar{z}_C=0$ |$I_{yz}=0$ | |" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Centre of gravity for moment diagrams\n", "\n", "```{figure} Images/Centre of gravity 1.jpg\n", "---\n", "scale: 100%\n", "---\n", "```\n", "\n", "```{figure} Images/Centre of gravity 2.jpg\n", "---\n", "scale: 100%\n", "---\n", "```\n", "\n", "```{figure} Images/Centre of gravity 3.jpg\n", "---\n", "scale: 100%\n", "---\n", "```\n", "\n", "```{figure} Images/Centre of gravity 4.jpg\n", "---\n", "scale: 100%\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 }