{ "metadata": { "name": "", "signature": "sha256:54c92a13ce853ac5fe5325a355c839b097f01e81340aa957e3602b8ea43de184" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter8-Axisymmetrically Loaded Members" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex1-pg239" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#calculate pressure and for longitudinal stress \n", "di=0.3 ##m\n", "de=0.4 ##m\n", "v=0.3\n", "sigmathetamax=250*10**6 ##Pa\n", "p0=0.\n", "pi=0.\n", "\n", "##solution a:\n", "a=0.15\n", "b=0.2\n", "r=a\n", "##sigmathetamax=pi*((b**2+a**2)/(b**2-a**2))\n", "pi=sigmathetamax*((b**2-a**2.)/(b**2+a**2.))\n", "print'%s %.2f %s'%(\"in Pa is= \",pi,\"\")\n", "\n", "##solution b:\n", "r=a\n", "##sigmathetamax=-2*p0*(b**2/(b**2-a**2))\n", "p0=-(-sigmathetamax)*((b**2.-a**2.)/(2.*b**2.))\n", "print'%s %.2f %s'%(\"in Pa is= \",p0,\"\")\n", "\n", "##solution c:\n", "u=((a**3*pi)/(b**2-a**2))*(0.7+1.3*(b**2./a**2.))\n", "print'%s %.2f %s'%(\"in per E meter is= \",u,\"\")\n", "sigmaz=(pi*a**2-p0*b**2)/(b**2-a**2)\n", "print'%s %.2f %s'%(\"for longitudinal stress is\",sigmaz,\"\")\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "in Pa is= 70000000.00 \n", "in Pa is= 54687500.00 \n", "in per E meter is= 40650000.00 \n", "for longitudinal stress is -35000000.00 \n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex2-pg241" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#calculate pressure \n", "sigmayp=340. ##MPa\n", "tauyp=sigmayp/2. ##MPa\n", "print'%s %.2f %s'%(\"in MPa is=\",tauyp,\"\")\n", "a=0.1 ##m\n", "b=0.15 ##m\n", "v=0.3 \n", "##pi=4*p0\n", "##sigmatheta=(pi*(a**2+b**2)-2*p0*b**2)/(b**2-a**2)\n", "##sigmatheta=1.7*pi\n", "\n", "##sloution a: maxi principal stress theory\n", "sigmatheta=1.7\n", "pi=sigmayp/sigmatheta\n", "print'%s %.2f %s'%(\"in MPa is= \",pi,\"\")\n", "\n", "##sloution b: maxi shearing stress theory\n", "##(sigmatheta-sigmar)/2=1.35*pi\n", "pi=tauyp/1.35\n", "print'%s %.2f %s'%(\"in MPa is= \",pi,\"\")\n", "\n", "##solution c: energy of distortion theory\n", "sigmar=-1\n", "sigmayp1=math.sqrt(sigmatheta**2+sigmar**2-sigmatheta*sigmar)##*pi\n", "print(sigmayp1)\n", "pi=sigmayp/sigmayp1\n", "print'%s %.2f %s'%(\"in MPa is=\",pi,\"\")\n", "\n", "##solution d: maxi principal strain theory\n", "##(sigmatheta-v*sigmar)/E=sigmayp/E\n", "pi=sigmayp/(sigmatheta-v*sigmar)\n", "print'%s %.2f %s'%(\"in MPa is= \",pi,\"\")\n", "\n", "##solution e: octahedral shearing stress theory:\n", "pi=(math.sqrt(2.)*sigmayp)/math.sqrt((sigmatheta-sigmar)**2.+sigmar**2.+(-sigmatheta)**2)\n", "print'%s %.2f %s'%(\"in MPa is= \",pi,\"\")\n", "\n", "\n", "\n", "\n", "\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "in MPa is= 170.00 \n", "in MPa is= 200.00 \n", "in MPa is= 125.93 \n", "2.36431808351\n", "in MPa is= 143.80 \n", "in MPa is= 170.00 \n", "in MPa is= 143.80 \n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex3-pg243" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#calculate contact pressure and tangential stresses in the outer cylinder\n", "a=0.15 ##m\n", "b=0.2 ##m\n", "c=0.25 ##m\n", "E=200*10**9. ##Pa\n", "delta=0.0001 ##m\n", "140 ##MPa\n", "\n", "p=((E*delta)/8.)*(((b**2.-a**2.)*(c**2.-b**2.))/(2.*(b**2.)*(c**2.-a**2.)))\n", "print'%s %.2f %s'%(\"the contact pressure in Pa is= \",p,\"\") ## textbook ans is wrong\n", "\n", "p=12.3*10**6\n", "sigmatheta=p*((b**2+c**2.)/(c**2.-b**2.)) ## where r=0.2\n", "print'%s %.2f %s'%(\"tangential stresses in the outer cylinder in Pa is= \",sigmatheta,\"\")\n", "sigmatheta1=(2*p*b**2)/(c**2-b**2) ## where r=0.25\n", "print'%s %.2f %s'%(\"tangential stresses in the outer cylinder in Pa is= \",sigmatheta1,\"\")\n", "sigmatheta3=-(2*p*b**2)/(b**2-a**2) ## where r=0.15\n", "print'%s %.2f %s'%(\"tangential stresses in the inner cylinder in Pa is= \",sigmatheta3,\"\")\n", "sigmatheta4=-p*((b**2.+a**2.)/(b**2.-a**2.)) ## where r=0.2\n", "print'%s %.2f %s'%(\"tangential stresses in the inner cylinder in Pa is= \",sigmatheta4,\"\")\n", "\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "the contact pressure in Pa is= 307617.19 \n", "tangential stresses in the outer cylinder in Pa is= 56033333.33 \n", "tangential stresses in the outer cylinder in Pa is= 43733333.33 \n", "tangential stresses in the inner cylinder in Pa is= -56228571.43 \n", "tangential stresses in the inner cylinder in Pa is= -43928571.43 \n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex4-pg246" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#calculate radial displacement of disk and shaft\n", "dn=0.1 ##m\n", "do=0.5 ##m\n", "t=0.08 ##m\n", "w=6900*(2*math.pi/60.) ##rpm\n", "row=7.8*10**3##Ns**2/m**4\n", "E=200*10**9 ##Pa\n", "v=0.3\n", "b=0.05\n", "c=0.25\n", "\n", "\n", "##solution a:\n", "##ud=((0.05*3.3*0.7)*(0.0025+0.0625-(1.3/3.3)*0.0025+(1.3/0.7)*0.0625)*row*w**2)/(8*E)\n", "ud=((0.05*3.3*0.7)*(b**2+c**2-(1.3/3.3)*b**2+(1.3/0.7)*c**2))/(8)\n", "print'%s %.4f %s'%(\"radial displacement of the disk in meter is= \",ud,\"\")\n", "\n", "##us=((0.05*0.7)*(3.3*0.0025-1.3*0.0025)*row*w**2)/(8*E)\n", "us=((0.05*0.7)*(3.3*b**2-1.3*b**2))/(8)\n", "print'%s %.6f %s'%(\"radial displacement of the shaft in meter is= \",us,\"\")\n", "delta=(ud-us)*row*w**2./E\n", "print(delta)\n", "\n", "##solution b:\n", "##p=E*delta*(c**2-b**2)/(2*b*c**2)\n", "p=E*delta*(c**2-b**2)/(2*b*c**2)\n", "print'%s %.2f %s'%(\"in Pa is= \",p,\"\")\n", "sigmathetamax=p*(c**2+b**2)/(c**2-b**2)\n", "print'%s %.2f %s'%(\"in Pa is= \",sigmathetamax,\"\")\n", "\n", "##solution c:\n", "sigmathetamax=3.3*(b**2.+c**2.-(1.9/3.3)*b**2.+c**2.)*row*w**2./8.\n", "print'%s %.2f %s'%(\"in Pa is= \",sigmathetamax,\"\")\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "radial displacement of the disk in meter is= 0.0026 \n", "radial displacement of the shaft in meter is= 0.000022 \n", "5.24957318528e-05\n", "in Pa is= 100791805.16 \n", "in Pa is= 109191122.25 \n", "in Pa is= 211764600.73 \n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex5-pg250" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#calculate sigma theta and sigma \n", "ti=0.075 ##m\n", "to=0.015##m\n", "a=0.05##m\n", "b=0.25##m\n", "delta=0.05 ##mm\n", "w=6900*(2*math.pi/60.) ##rpm\n", "s=1.\n", "row=7.8*10**3##Ns**2/m**4\n", "E=200. ##GPa\n", "\n", "##solution a:\n", "t1=ti*a**s\n", "print'%s %.4f %s'%(\"t1 is=\",t1,\"\")\n", "t1=to*b**2.\n", "print'%s %.4f %s'%(\"t1 is=\",t1,\"\")\n", "##(ti/to)=(t1*a**-s)/(t1*b**-s)=(b/a)**s\n", "c=(b/a)**s\n", "\n", "(ti/to)==c\n", "print'%s %.2f %s'%(\"ti/t0 is=\",c,\"\")\n", "m1=-0.5+math.sqrt((0.5)**2+(1+0.3*1))\n", "print'%s %.2f %s'%(\"m1 is=\",m1,\"\")\n", "m2=-0.5-math.sqrt((0.5)**2.+(1.+0.3*1.))\n", "print'%s %.2f %s'%(\"m2 is=\",m2,\"\")\n", "\n", "##sigmar=0=(c1/t1)*(0.05)**m1+(c2/t1)*(0.05)**(m2)-0.00176*row*w**2 ## r=0.05\n", "##sigmar=0=(c1/t1)*(0.25)**m1+(c2/t1)*(0.25)**(m2)-0.0439*row*w**2 ## r=0.25\n", "\n", "c1=t1*0.12529*row*w**2.\n", "print'%s %.2f %s'%(\"c1 is=\",c1,\"\")\n", "c2=t1*-6.272*10**-5*row*w**2\n", "print'%s %.2f %s'%(\"c2 is=\",c2,\"\")\n", "\n", "r=0.05\n", "sigmar=(0.12529*r**0.745-6.272*10**-5*r**(-1.745)-0.70*r**2)##*row*w**2\n", "print'%s %.5f %s'%(\"sigmar is= \",sigmar,\"\")\n", "\n", "sigmatheta=(0.09334*r**0.745+1.095*10**-4*r**(-1.745)-0.40*r**2)##*row*w**2\n", "print'%s %.2f %s'%(\"sigmatheta is= \",sigmatheta,\"\")\n", "\n", "##solution b:\n", "r=0.05\n", "##ur=(r*sigmatheta)/E\n", "ur=(r*sigmatheta)\n", "print'%s %.7f %s'%(\"ur is= \",ur,\"\")\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "t1 is= 0.0037 \n", "t1 is= 0.0009 \n", "ti/t0 is= 5.00 \n", "m1 is= 0.74 \n", "m2 is= -1.74 \n", "c1 is= 478341.11 \n", "c2 is= -239.46 \n", "sigmar is= 0.00001 \n", "sigmatheta is= 0.03 \n", "ur is= 0.0014711 \n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Ex6-pg251" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#calculate pressure\n", "b=0.25 ##m\n", "w=6900.*(2*math.pi/60.) ##rpm\n", "t1=0.075 ##m\n", "t2=0.015 ##m\n", "row=7.8*10**3##Ns**2/m**4\n", "c1=t1\n", "\n", "x=t2/t1\n", "print(x)\n", "\n", "##(t2/t1)==(c1*exp(-(row*w**2/2*sigma)*b**2))/c1\n", "##exp(-(row*w**2/2*sigma)*b**2)=x\n", "##log(x)=-(row*w**2*b**2/2*sigma)\n", "y=2.*math.log(x)\n", "print(y)\n", "sigma=-(row*w**2.*b**2.)/y\n", "print'%s %.2f %s'%(\"in Pa is= \",sigma,\"\")\n", "\n", "##t=c1*exp(-row*(w**2/2*sigma)*r**2)\n", "z=row*(w**2./(2.*sigma))\n", "print(z)\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "0.2\n", "-3.21887582487\n", "in Pa is= 79072562.70 \n", "25.7510065989\n" ] } ], "prompt_number": 2 } ], "metadata": {} } ] }