{ "metadata": { "name": "", "signature": "sha256:8adf459ea4014e5f8ac2990e8d05feaccf30880e758648b173bb1fd18b74b81a" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Appendix A: Review of Properties of Plane Area" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example A.1, Page No:486" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Variable Decleration\n", "A=2000 #Area of the plane in mm^2\n", "Ix=40*10**6 #Momnet of Inertia in mm^4\n", "d1=90 #Distance in mm\n", "d2=70 #Distance in mm\n", "\n", "#Calculations\n", "Ix_bar=Ix-(A*d1**2) #Moment of Inertia along x_bar axis in mm^4\n", "Iu=Ix_bar+A*d2**2 #Moment of Inertia along U-axis in mm^4\n", "\n", "#Result\n", "print Ix_bar\n", "print \"The moment of inertia along u-axis is\",round(Iu,1),\"mm^4\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "23800000\n", "The moment of inertia along u-axis is 33600000.0 mm^4\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example A.2, Page No:486" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Variable Decleration\n", "R=45 #Radius of the circle in mm\n", "r=20 #Radius of the smaller circle in mm\n", "h=100 #Depth of the straight section in mm\n", "\n", "#Calculations\n", "#Part 1\n", "\n", "#Triangle\n", "b=2*R #Breadth in mm\n", "A_t=b*h*0.5 #Area in mm^2\n", "Ix_bar_t=b*h**3*36**-1 #Moment of inertia in mm^4\n", "y_bar1=2*3**-1*h #centroidal axis in mm\n", "Ix_t=Ix_bar_t+A_t*y_bar1**2 #moment of inertia in mm^4\n", "\n", "#Semi-circle\n", "A_sc=pi*R**2*0.5 #Area of the semi-circle in mm^2\n", "Ix_bar_sc=0.1098*R**4 #Moment of inertia in mm^4\n", "y_bar2=h+(4*R*(3*pi)**-1) #Distance of centroid in mm\n", "Ix_sc=Ix_bar_sc+A_sc*y_bar2**2 #Moment of inertia in mm^4\n", "\n", "#Circle\n", "A_c=pi*r**2 #Area of the circle in mm^2\n", "Ix_bar_c=pi*r**4*4**-1 #Moment of inertia in mm^4\n", "y_bar3=h #Distance of centroid in mm\n", "Ix_c=Ix_bar_c+A_c*y_bar3**2 #Moment of inertia in mm^4\n", "\n", "#Composite Area\n", "A=A_t+A_sc-A_c #Total area in mm^2\n", "Ix=Ix_t+Ix_sc-Ix_c #Moment of inertia in mm^4\n", "\n", "#Part 2\n", "y_bar=(A_t*y_bar1+A_sc*y_bar2-A_c*y_bar3)/(A) #Location of centroid in mm\n", "Ix_bar=Ix-A*y_bar**2 #Moment of inertia in mm^4\n", "\n", "#Result\n", "print \"Moment of inertia about x-axis is\",round(Ix),\"mm^4\"\n", "print \"Moment of inertia about the centroidal axis is\",round(Ix_bar),\"mm^4\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Moment of inertia about x-axis is 55377079.0 mm^4\n", "Moment of inertia about the centroidal axis is 7744899.0 mm^4\n" ] } ], "prompt_number": 14 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example A.3, Page No:488" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Variable Decleration\n", "t=20 #Thickness in mm\n", "h=140 #Depth in mm\n", "w=180 #Width in mm\n", "\n", "#Calculations\n", "Ixy_1=0+(h*t*t*0.5*h*0.5) #product of inertia in mm^4\n", "Ixy_2=0+((w-t)*t*(w+t)*0.5*t*0.5) #Product of inertia in mm^4\n", "Ixy=Ixy_1+Ixy_2 #Product of inertia in mm^4\n", "\n", "#Result\n", "print \"The Product of inertia is\",round(Ixy),\"mm^4\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The Product of inertia is 5160000.0 mm^4\n" ] } ], "prompt_number": 16 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example A.4, Page No:495" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Variable Decleration\n", "t=30 #Thickness in mm\n", "h=200 #Depth of the section in mm\n", "w=160 #Width in mm\n", "the=50 #Angle in degrees\n", "\n", "\n", "#Calculations\n", "A1=t*h #Area of the web portion in mm^2\n", "A2=(w-t)*t #Area of the flange portion in mm^2\n", "x_bar=(A1*t*0.5+A2*(t+(w-t)*0.5))/(A1+A2) #Location of x_bar in mm\n", "y_bar=(A1*h*0.5+A2*t*0.5)/(A1+A2) #Location of y_bar in mm\n", "\n", "#Simplfying the computation\n", "a=t*h**3*12**-1\n", "b=A1*(200*0.5-y_bar)**2\n", "c=(w-t)*t**3*12**-1\n", "d=A2*(t*0.5-y_bar)**2\n", "Ix_bar=a+b+c+d #Moment of inertia about x-axis in mm^4\n", "\n", "#Simplifying the computation\n", "p=h*t**3*12**-1\n", "q=A1*(t*0.5-x_bar)**2\n", "r=t*(w-t)**3*12**-1\n", "s=A2*((w-t)*0.5+t-x_bar)**2\n", "Iy_bar=p+q+r+s #Moment of inertia about y-axis in mm^4\n", "\n", "#Simplfying the computation\n", "a1=(t*0.5-x_bar)*(h*0.5-y_bar)\n", "a2=(t*0.5-y_bar)*((w-t)*0.5+t-x_bar)\n", "Ixy_bar=A1*a1+A2*a2 #Moment of inertia in mm^4\n", "\n", "#Part 1\n", "#Simplfying the computation\n", "a3=(Ix_bar+Iy_bar)*0.5\n", "a4=(0.5*(Ix_bar-Iy_bar))**2\n", "a5=Ixy_bar**2\n", "I1=a3+np.sqrt(a4+a5) #Moment of inertia in mm^4\n", "I2=a3-np.sqrt(a4+a5) #Moment of inertia in mm^4\n", "\n", "ThetaRHS=-(2*Ixy_bar)/(Ix_bar-Iy_bar) #RHS of the tan term\n", "theta1=arctan(ThetaRHS)*0.5*180*pi**-1 #Angle in degrees\n", "theta2=theta1+90 #Angle in degrees\n", "\n", "#Part 2\n", "Iu=a3+np.sqrt(a4)*np.cos(2*the*pi*180**-1)-(Ixy_bar)\\\n", " *np.sin(2*the*pi*180**-1) #Moment of inertia in mm^4\n", "Iv=a3-np.sqrt(a4)*np.cos(2*the*pi*180**-1)+(Ixy_bar)\\\n", " *np.sin(2*the*pi*180**-1) #Moment of inertia in mm^4\n", "Iuv=np.sqrt(a4)*np.sin(2*the*pi*180**-1)+(Ixy_bar)\\\n", " *np.cos(2*the*pi*180**-1) #Moment of inertia in mm^4\n", " \n", " \n", "#Result\n", "print \"The Principal Moment of inertias are as follows\"\n", "print \"I1=\",round(I1),\"mm^4 and I2=\",round(I2),\"mm^4\"\n", "print \"Princial direction are theta1=\",round(theta1,1), \"degrees\"\\\n", " \" theta2=\",round(theta2,1),\"degrees\"\n", "print \"The moment of inertia along the uv-axis is\",round(Iuv),\"mm^4\" " ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The Principal Moment of inertias are as follows\n", "I1= 47240734.0 mm^4 and I2= 11198811.0 mm^4\n", "Princial direction are theta1= 31.6 degrees theta2= 121.6 degrees\n", "The moment of inertia along the uv-axis is 10817183.0 mm^4\n" ] } ], "prompt_number": 51 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example A.5, Page No:497" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Variable Decleration\n", "Ix_bar=37.37*10**6 #Moment of inertia in mm^4\n", "Iy_bar=21.07*10**6 #Moment of inertia in mm^4\n", "Ixy_bar=-16.073*10**6 #Moment of inertia in mm^4\n", "\n", "#Calculations\n", "b=(Ix_bar+Iy_bar)*0.5 #Parameter for the circle in mm^4\n", "R=sqrt(((Ix_bar-Iy_bar)*0.5)**2+Ixy_bar**2) #Radius of the Mohr's Circle in mm^4\n", "\n", "#Part 1\n", "I1=b+R #MI in mm^4\n", "I2=b-R #MI in mm^4\n", "theta1=arcsin(abs(Ixy_bar)/R)*180*pi**-1*0.5 #Angle in degrees\n", "theta2=theta1+90 #Angle in degrees\n", "\n", "#Part 2\n", "alpha=(100-theta1*2)*0.5 #Angle in degrees\n", "Iu=round(b,2)+round(R,3)*round(np.cos(alpha*pi*180**-1),2) #MI in mm^4\n", "Iv=round(b,2)-round(R,3)*round(np.cos(alpha*pi*180**-1),2) #MI in mm^4\n", "Iuv=R*np.sin(2*alpha*pi*180**-1) #MI in mm^4\n", "\n", "#Result\n", "print \"The Principal Moment of inertias are as follows\"\n", "print \"I1=\",round(I1),\"mm^4 and I2=\",round(I2),\"mm^4\"\n", "print \"Princial direction are theta1=\",round(theta1,1), \"degrees\"\\\n", " \" theta2=\",round(theta2,1),\"degrees\"\n", "print \"The moment of inertia along the uv-axis is\",round(Iuv),\"mm^4\" \n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The Principal Moment of inertias are as follows\n", "I1= 47241205.0 mm^4 and I2= 11198795.0 mm^4\n", "Princial direction are theta1= 31.6 degrees theta2= 121.6 degrees\n", "The moment of inertia along the uv-axis is 10817230.0 mm^4\n" ] } ], "prompt_number": 73 } ], "metadata": {} } ] }