{ "metadata": { "name": "", "signature": "sha256:ced402d1abd8ee6656b1d5779752e65300ae4ab42f06bdc7c60dba927fb54a5a" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 12:Deflection of Beams" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem 12.1,page no.518" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Given\n", "#Variable declaration\n", "L=6*1000 #Length in mm\n", "W=50*1000 #Point load in N\n", "I=78e6 #Moment of Inertia in mm^4\n", "E=2.1e5 #Young's modulus in N/sq.mm\n", "\n", "#Calculation\n", "yc=round((W*L**3)/(48*E*I),3) #The deflection at the centre in mm\n", "thetaB=round(math.degrees((W*L**2)/(16*E*I)),4) #The slope at the supports\n", "\n", "#Result\n", "print \"Deflection at the centre =\",yc,\"mm\"\n", "print \"NOTE:The answer given for slope at the support is wrong.The correct answer is,\"\n", "print \"Slope at the support =\",thetaB,\"degree\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Deflection at the centre = 13.736 mm\n", "NOTE:The answer given for slope at the support is wrong.The correct answer is,\n", "Slope at the support = 0.3935 degree\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem 12.2,page no.518" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Given\n", "#Variable declaration\n", "L=4*1000 #Length in mm\n", "\n", "#Calculation\n", "thetaA=round(math.radians(1),5) #Slope at the ends in radians\n", "yc=float(str(thetaA*(L/3))[:5]) #Deflection at the centre in mm\n", "\n", "#Result\n", "print \"Deflection at the centre =\",yc,\"mm\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Deflection at the centre = 23.26 mm\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem 12.3,page no.519" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Given\n", "#Variable declaration\n", "L=3*1000 #Length in mm\n", "\n", "#Calculation\n", "thetaA=round(math.radians(1),5) #Slope at the ends in radians\n", "yc=float(str(thetaA*(L/3))[:5]) #Deflection at the centre in mm\n", "\n", "#Result\n", "print \"Deflection at the centre =\",yc,\"mm\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Deflection at the centre = 17.45 mm\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem 12.4,page no.526" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Given\n", "#Variable declaration\n", "L=5*1000 #Length in mm\n", "W=5*1000 #Point load in N\n", "a=3*1000 #Distance between point load and left end in mm\n", "E=2e5 #Young's modulus in N/sq.mm\n", "I=1e8 #Moment of Inertia in mm^4\n", "\n", "#Calculation\n", "b=L-a #Width in mm\n", "#case(i):The slope at the left support\n", "thetaA=-(W*a*b)/(6*E*I*L)*(a+2*b)\n", "#case(iii): The deflection under the load\n", "yc=(W*a**2*b**2)/(3*E*I*L)\n", "#case(iii):The maximum deflection\n", "y_max=round((W*b)/(9*math.sqrt(3)*E*I*L)*(((a**2)+(2*a*b))**(3/2)),4)\n", "\n", "#Result\n", "print\"slope at the left support =\",thetaA,\"radians\"\n", "print\"Deflection under the load =\",yc,\"mm\"\n", "print\"Maximum deflection =\",y_max,\"mm\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "slope at the left support = -0.00035 radians\n", "Deflection under the load = 0.6 mm\n", "Maximum deflection = 0.6173 mm\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem 12.5,page no,529" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from __future__ import division\n", "import math\n", "\n", "#Given\n", "#Variable declaration\n", "b=200 #Width in mm\n", "d=300 #Depth in mm\n", "L=5*1000 #Span in mm\n", "L_star=5 #Span in m\n", "w=9*1000 #Uniformly distributed load in N/m \n", "E=1e4 #Young's modulus in N/sq.mm\n", "\n", "#Calculation\n", "W=w*L_star #Total load in N\n", "I=b*d**3/12 #Moment of Inertia in mm^4\n", "\n", "#case(i):the slope at the support\n", "thetaA=round(-(W*(L**2))/(24*E*I),4)\n", "\n", "#case(ii):maximum deflection\n", "yc=str((W*L**3)/(E*I)*(5/384))[:5]\n", "\n", "#Result\n", "print\"Slope at the support =\",-thetaA,\"radians\"\n", "print\"Maximum deflection =\",yc,\"mm\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Slope at the support = 0.0104 radians\n", "Maximum deflection = 16.27 mm\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem 12.6,page no.529" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Given\n", "#Variable declaration\n", "L=5*1000 #Length in mm\n", "L_star=5 #Length in m\n", "w=9 #Uniformly distributed load in kN/m\n", "f=7 #Bending stress in N/sq.mm\n", "E=1e4 #Young's modulus in N/sq.mm\n", "yc=10 #Central deflection in mm\n", "\n", "#Calculation\n", "W=w*L_star*1e3 #Total load in N \n", "bd3=((W*(L**3)*12*5)/(E*yc*384)) #width X depth^3 in mm^4\n", "M=(W*L/8) #Maximum bending moment in Nmm \n", "bd2=round(M*12/(f*2),2) #width X depth^2 in mm^3\n", "d=round(bd3/bd2,2) #Depth of beam in mm\n", "b=str(M*12/(f*2)/d**2)[:6] #Width of beam in mm\n", "\n", "#Result\n", "print \"Depth of beam =\",d,\"mm\"\n", "print \"Width of beam =\",b,\"mm\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Depth of beam = 364.58 mm\n", "Width of beam = 181.36 mm\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem 12.7,page no.531" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Given \n", "#Variable declaration\n", "L=5*1000 #Length in mm\n", "f=8 #Bending stress in N/sq.mm\n", "yc=10 #Central deflection in mm\n", "E=1.2e4 #Young's modulus in N/sq.mm\n", "\n", "#Calculation\n", "d=round((5*L**2*(f*2*8))/(E*384*yc)*1e-1,2) #Depth of beam in cm\n", "\n", "#Result\n", "print \"Depth of beam =\",d,\"cm\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Depth of beam = 34.72 cm\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem 12.8,page no.534" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Given\n", "#Variable declaration\n", "L=6*1000 #Length in mm\n", "W=40*1000 #Point load in N\n", "a=4*1000 #Distance of point load from left support in mm\n", "I=7.33e7 #Moment of Inertia in mm^4\n", "E=2e5 #Young's modulus in sq.mm\n", "\n", "#Calculation\n", "b=L-a #Width of beam in mm\n", "yc=round(-(W*a**2*b**2)/(3*E*I*L),1) #Deflection under the load in mm\n", "\n", "#Result\n", "print \"Deflection under the load =\",yc,\"mm\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Deflection under the load = -9.7 mm\n" ] } ], "prompt_number": 4 }, { "cell_type": "code", "collapsed": false, "input": [], "language": "python", "metadata": {}, "outputs": [] } ], "metadata": {} } ] }