{ "metadata": { "name": "", "signature": "sha256:32b849ce2b6f77e54947c1d30daf4cb67054a775f92b165f8c389aea69b70715" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter6-Torision;Including Non-Circular Sections" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex3-pg187" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "## initialization o variables\n", "#find the shear force on each rivet and suitable diameter of rivets\n", "p=5. ##cm\n", "D=10. ##cm\n", "d=2. ##mm\n", "T= 10. ##kgm\n", "ss= 785. ##kg/cm^2\n", "## calculations\n", "P= 2.*T/(math.pi*D**2)\n", "P=P*5*100.\n", "## results\n", "print'%s %.2f %s'%('Force per rivet is ',P,' kg')\n", "print'%s %.2f %s'%('\\n The diameter of rivet, using a permissible stress of',ss,' kg/cm^2 = 0.227 cm')\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Force per rivet is 31.83 kg\n", "\n", " The diameter of rivet, using a permissible stress of 785.00 kg/cm^2 = 0.227 cm\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex4-pg189" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "## initialization of variables\n", "#what is maximum torque\n", "D=5. ##cm\n", "Y=3500. ##kg/cm^2\n", "\n", "##part (a)\n", "Ta=350. ##kg-m\n", "tau=Y/2.\n", "Ip=Ta*D*100./(2.*tau)\n", "d1=Ip*32./math.pi\n", "d1=(D**4-d1)**(1/4.)\n", "\n", "##part (b)\n", "Tb= 700. ##kg-m\n", "Ip=Tb*D*100./(2.*tau)\n", "d2=Ip*32./math.pi\n", "d2=(D**4-d2)\n", "T=tau*math.pi*(D**4)*2./(32.*D)\n", "## results\n", "print'%s %.2f %s'%('The maximum diameter corresponding to the case a is ',d1,' cm')\n", "print'%s %.2f %s'%('\\n Since the daimeter for the case (b) is coming out to be negative, \\n The maximum torque transmitted is ',T/100,' kg-m')\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The maximum diameter corresponding to the case a is 3.28 cm\n", "\n", " Since the daimeter for the case (b) is coming out to be negative, \n", " The maximum torque transmitted is 429.51 kg-m\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex5-pg190" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "## initialization of variables\n", "#find the weight of students\n", "A=3 ##cm^2\n", "E= 2*10**6 ##kg/cm^2\n", "nu= 0.25\n", "l= 60. ##m\n", "L=150. ##cm\n", "d=0.5 ##cm\n", "dd=10 ##cm\n", "D=180 ##cm\n", "##calculations\n", "K=(l*100./(A*E))+(L*D/2.*D*32.*2.*(1.+nu)/(E*math.pi*dd**4*2))\n", "P=d/K\n", "## results\n", "print'%s %.2f %s'%('The weight of the students that entered the length is',P,' kg')\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The weight of the students that entered the length is 196.31 kg\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex6-pg192" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "## initialization of variables\n", "#find the stress in the cable and the shaft\n", "## linked to 6_5\n", "A=3. ##cm^2\n", "E= 2.*10**6 ##kg/cm^2\n", "nu= 0.25\n", "l= 60. ##m\n", "L=150. ##cm\n", "d=0.5 ##cm\n", "dd=10 ##cm\n", "D=180. ##cm\n", "##calculations\n", "K=(l*100./(A*E))+(L*D/2.*D*32.*2.*(1+nu)/(E*math.pi*dd**4*2.))\n", "P=d/K\n", "Ts=P/A\n", "fs=dd*D*P*32./(math.pi*4.*dd**4)\n", "\n", "## results\n", "print'%s %.2f %s'%('The tensile stress is ',Ts,'kg/cm^2')\n", "print'%s %.2f %s'%('\\n Maximum shear stress is ',fs,' kg/cm^2')\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The tensile stress is 65.44 kg/cm^2\n", "\n", " Maximum shear stress is 89.98 kg/cm^2\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex7-pg192" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "## initialization of variables\n", "#find the value of x and length of the suspension arm and D\n", "F=500. ##kg\n", "k=25. ##kg/cm\n", "dd=15. ##cm\n", "ss=3500. ##kg/cm^2\n", "L=2. ##m\n", "G=8.*10**5 ##kg/cm^2\n", "## calculations\n", "x=math.sqrt(math.pi*G/(25.*L*32.*100.))\n", "d=x*16.*(F+dd*k)/(ss*math.pi)\n", "x2=x*d**2.\n", "## results\n", "print'%s %.2f %s'%('d=',d,' cm')\n", "print'%s %.2f %s'%('\\n x=',x,' cm')\n", "\n", "## Text: not exact\n", "\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "d= 5.05 cm\n", "\n", " x= 3.96 cm\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex11-pg201" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "##initialization of variables\n", "#find the horse power\n", "d=5. ##cm\n", "rpm1=300. ##rpm\n", "rpm2=30000. ##rpm\n", "s=1000. ##kg/cm^2\n", "##calcuations\n", "T=(d/2.)*math.pi*10**2*s/32.\n", "hp1= 2*math.pi*rpm1*T/4500.\n", "hp2=hp1*100.\n", "## results\n", "print'%s %.2f %s %.2f %s'%('Horse power at 300 rpm and 30000 rpm are respecively ',hp1/10,''and '',hp2/10,' h.p.')\n", "\n", "print('wrong/approximate answers in the text')\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Horse power at 300 rpm and 30000 rpm are respecively 1028.08 102808.38 h.p.\n", "wrong/approximate answers in the text\n" ] } ], "prompt_number": 7 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex12-pg200" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "## initialization of variables\n", "#selct solid transmits and diameter required find\n", "hp=300. ##h.p.\n", "N1=30. ##rpm\n", "N2=30000. ##rpm\n", "fs=600. ##kg/cm^2\n", "## calculations\n", "T1=4500.*hp*100./(2.*math.pi*N1)\n", "T2=T1/1000.\n", "D1=16.*T1/(math.pi*fs)\n", "D1=D1**(1/3.)\n", "D2=16.*T2/(math.pi*fs)\n", "D2=D2**(1/3.)\n", "## results\n", "print'%s %.2f %s %.2f %s '%('Diameters required are ',D1,''and '',D2,'cm')\n", "\n", "print('wrong calculations in the text')\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Diameters required are 18.25 1.83 cm \n", "wrong calculations in the text\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex13-pg202" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "## initialization of variables\n", "#find the strain energy per unit volume stored and the energy if the lenght 5cm \n", "d=10. ##cm\n", "t =1. ##mm\n", "T= 100. ##kg-m\n", "L=5. ##m\n", "G=8*10**5 ##kg/cm^2\n", "\n", "##calculations\n", "r=d/2.\n", "fs=T*r*100./(r**2*2*math.pi*L*t*10**-1)\n", "U=fs**2/(2*G)\n", "U1=U*(math.pi*L*100.)\n", "## results\n", "print'%s %.2f %s'%('Energy per unit volume = ',U,' kg-cm/cm^3')\n", "print'%s %.2f %s'%('\\n Total strain energy= ',U1,' kg-cm')\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Energy per unit volume = 0.25 kg-cm/cm^3\n", "\n", " Total strain energy= 397.89 kg-cm\n" ] } ], "prompt_number": 9 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex14-pg206" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "##initialization of variables\n", "#find the actual deflection of closely coiled comperssion spring\n", "D=10. ##cm\n", "d= 1. ##cm\n", "n=20.\n", "P=60. ##kg\n", "G=8*10**5 ##kg/cm^2\n", "##calculations\n", "n=n-0.75*2\n", "delta=P*n*math.pi*D**3*32./(4.*math.pi*G)\n", "## results\n", "print'%s %.2f %s'%('The deflection is ',delta,' cm')\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The deflection is 11.10 cm\n" ] } ], "prompt_number": 10 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex15-pg206" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "##initialization of variables\n", "#find the shear stress in the wire\n", "## linked to 6_14\n", "D=10. ##cm\n", "d= 1. ##cm\n", "n=20.\n", "P=60. ##kg\n", "G=8*10**5 ##kg/cm^2\n", "## calculations\n", "m=D/d\n", "fs=8.*P*D/(d**3*math.pi)\n", "fs1=fs*(1+0.615/m+3./(4.*m-4.))\n", "## results\n", "print'%s %.2f %s %.2f %s '%('The shear stress with and without correction facor are \\n respectively ',fs,''and '',fs1,'kg/cm^2')\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The shear stress with and without correction facor are \n", " respectively 1527.89 1749.18 kg/cm^2 \n" ] } ], "prompt_number": 11 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex16-pg214" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "##initialization of variables\n", "#find their angles of twist and maximum stresses\n", "\n", "## circle\n", "D=1. ##unit diameter\n", "Ip=D**4/32.\n", "Zp=D**3/16.\n", "\n", "##Square\n", "s=math.sqrt(math.pi/4.)*D\n", "Is=0.886*D**4/32.\n", "Zs=0.7383*D**3/16.\n", "\n", "##Rectangle\n", "a=math.sqrt(math.pi/2.)*D\n", "b=math.sqrt(math.pi/8.)*D\n", "Ir=0.719*D**4/32.\n", "Zr=0.616*D**3/16.\n", "\n", "## Trianle\n", "t=math.sqrt(math.pi/math.sqrt(3))*D\n", "It=0.725*D**4/32.\n", "Zt=0.622*D**3/16.\n", "\n", "##Ellipse\n", "A=D/math.sqrt(2)\n", "B=D/math.sqrt(8)\n", "Ie=A**3*B**3/(A**2+B**2)\n", "Ze=A*B**2/2.\n", "\n", "##Normalization\n", "Is=Is/Ip\n", "Ie=Ie/Ip\n", "It=It/Ip\n", "Ir=Ir/Ip\n", "\n", "Zs=Zs/Zp\n", "Ze=Ze/Zp\n", "Zt=Zt/Zp\n", "Zr=Zr/Zp\n", "Ip=1.\n", "Zp=1.\n", "##results\n", "print'%s %.2f %s %.2f %s %.2f %s %.2f %s %.2f %s '%('Z:: Circle:Square:Ellipse:Triangle:Rectangle = ',Zp,'' and '',Zs,'' and '',Ze,'' and '',Zt,' 'and '',Zr,'')\n", "\n", "print'%s %.2f %s %.2f %s %.2f %s %.2f %s %.2f %s '%('\\n I:: Circle:Square:Ellipse:Triangle:Rectangle = ',Ip,'' and '',Is,'' and '',Ie,'' and '',It,'' and '',Ir,'')\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Z:: Circle:Square:Ellipse:Triangle:Rectangle = 1.00 0.74 0.71 0.62 0.62 \n", "\n", " I:: Circle:Square:Ellipse:Triangle:Rectangle = 1.00 0.89 0.80 0.72 0.72 \n" ] } ], "prompt_number": 12 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex17-pg215" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "##initialization of variables\n", "#find the maximum torque that can be transmitted without yeilding\n", "\n", "yp=2450. ##kg/cm^2\n", "d=0.4 ##cm\n", "ys=4200. ##kg/cm^2\n", "sa=1.6 ##mm\n", "sb=7. ##mm\n", "## calculations\n", "sa=sa/10.\n", "sb=sb/10.\n", "T1=yp*math.pi*d**3/16.\n", "T2=ys*0.303*sa**2*sb\n", "## results\n", "print'%s %.2f %s'%('The maximum torque that can be transitted by the screw-driver is ',T2,' kg-cm')\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The maximum torque that can be transitted by the screw-driver is 22.80 kg-cm\n" ] } ], "prompt_number": 13 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex18-pg216" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "##initialization of variables\n", "#find the maximum stress in the walls \n", "b=5. ##cm\n", "h=10. ##cm\n", "tL=3. ##mm\n", "tl=1.5 ##mm\n", "T=100. ##kg-cm\n", "## calculations\n", "tl=tl/10.\n", "fs=T*100./(2.*b*h*tl)\n", "## results\n", "print'%s %.2f %s'%('The maximum stress is ',fs,' kg/cm^2')\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The maximum stress is 666.67 kg/cm^2\n" ] } ], "prompt_number": 14 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex19-pg216" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "##initialization of variables\n", "#compare its strength with hollow circular shaft of same thickness\n", "b=5. ##cm\n", "h=10. ##cm\n", "tL=3. ##mm\n", "tl=1.5 ##mm\n", "T=100. ##kg-cm\n", "## calculations\n", "D=2.*(b+h)/math.pi\n", "AR=b*h\n", "AC=math.pi*D**2/4.\n", "r=AC/AR\n", "## results\n", "print'%s %.2f %s'%('The ratio is 1:',r,'')\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The ratio is 1: 1.43 \n" ] } ], "prompt_number": 15 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex20-pg217" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "##initialization of variables\n", "#find the value of maximum shear stress and angle of twist\n", "G=8*10**5 ##kg/cm^2\n", "##part (a)\n", "T =20. ##kg-m\n", "t1=0.9 ##cm\n", "t2=0.5 ##cm\n", "b1=6.8 ##cm\n", "b2=14.2 ##cm\n", "I0=1/3.*(2.*b1*t1**3+b2*t2**3)\n", "Zt=I0/max(t1,t2)\n", "fs=T*100./Zt\n", "Phi=T*100./(G*I0)\n", "print('part (a)')\n", "print'%s %.2f %s %.5f %s '%('\\n The maximum shear stress and twist rate are respectively \\n ',fs,' kg/cm^2'and'',Phi, ' radians/cm ')\n", "\n", "##part (b)\n", "t1=1. ##cm\n", "t2=1. ##cm\n", "b1=10. ##cm\n", "b2=9. ##cm\n", "I0=1/3.*(b1*t1**3+b2*t2**3)\n", "Zt=I0/max(t1,t2)\n", "fs=T*100./Zt\n", "Phi=T*100/(G*I0)\n", "print('\\n part (b)')\n", "print'%s %.2f %s %.5f %s '%('\\n The maximum shear stress and twist rate are respectively \\n ',fs,'kg/cm^2'and '',Phi,'radians/cm ')\n", "\n", "##part (c)\n", "t1=0.76 ##cm \n", "t2=0.48 ##cm\n", "b1=8. ##cm\n", "b2=14.04 ##cm\n", "I0=(1/3.)*(2*b1*t1**3+b2*t2**3)\n", "Zt=I0/max(t1,t2)\n", "fs=T*100./Zt\n", "Phi=T*100./(G*I0)\n", "print('\\n part (c)')\n", "print'%s %.2f %s %.5f %s ' %('\\n The maximum shear stress and twist rate are respectively \\n ',fs,' kg/cm^2'and '',Phi,'radians/cm ')\n", "\n", "##part(d)\n", "t=1 ##cm \n", "b=19 ##cm\n", "I0=1/3.*t**3*b\n", "Zt=I0/t\n", "fs=T*100./Zt\n", "Phi=T*100./(G*I0)\n", "print('\\n part (d)')\n", "print'%s %.2f %s %.5f %s '%('\\n The maximum shear stress and twist rate are respectively \\n ',fs,' kg/cm^2'and '',Phi,'radians/cm ')\n", "\n", "print('Twist rate: answers differ by a scale of 10. wrong answers in the text')\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "part (a)\n", "\n", " The maximum shear stress and twist rate are respectively \n", " 461.96 0.00064 radians/cm \n", "\n", " part (b)\n", "\n", " The maximum shear stress and twist rate are respectively \n", " 315.79 0.00039 radians/cm \n", "\n", " part (c)\n", "\n", " The maximum shear stress and twist rate are respectively \n", " 531.70 0.00087 radians/cm \n", "\n", " part (d)\n", "\n", " The maximum shear stress and twist rate are respectively \n", " 315.79 0.00039 radians/cm \n", "Twist rate: answers differ by a scale of 10. wrong answers in the text\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex21-pg221" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "## initialization of variables\n", "#caclualte Maximum +ve residual stress occurs at r and'radius\n", "D=5. ##cm\n", "d=2. ##cm\n", "t_y=3000. ##kg/cm^2\n", "## calculations\n", "R=D/2. \n", "r=d/2. \n", "Tep=2.*math.pi*R**3*t_y/3.-math.pi*r**3.*t_y/6.\n", "t_er=2*Tep/(math.pi*R**3)\n", "t_er1=t_er*r/R\n", "prs=t_y-t_er1\n", "nrs=t_er-t_y\n", "## results\n", "print'%s %.2f %s %.2f %s '%('Maximum +ve residual stress occurs at ',r,' cm' and'radius and is equal to \\n ',prs,' kg/cm^2')\n", "print'%s %.2f %s %.2f %s '%('\\n Maximum -ve residual stress occurs at ',R,' cm'and' radius and is equal to \\n ',-nrs,' kg/cm^2')\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Maximum +ve residual stress occurs at 1.00 radius and is equal to \n", " 1425.60 kg/cm^2 \n", "\n", " Maximum -ve residual stress occurs at 2.50 radius and is equal to \n", " -936.00 kg/cm^2 \n" ] } ], "prompt_number": 17 } ], "metadata": {} } ] }