{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Chapter 13: Creep and Stress Rupture" ] }, { "cell_type": "markdown", "metadata": { "collapsed": true }, "source": [ "### Example 13.1, Engineering Creep, Page No. 461" ] }, { "cell_type": "code", "execution_count": 1, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "\n", "-----------------------------------------------------------\n", "\n", "Temperature\tCreep Strength, psi\tWorking Stress, psi\n", "\n", "------------------------------------------------------------\n", "\n", "1100 F\t\t\t30000\t\t\t10000\n", "\n", "\n", "1500 F\t\t\t4000\t\t\t1333\n", "\n" ] } ], "source": [ "\n", "#variable declaration\n", "sf=3;\n", "per=1/1000;\n", "T=[1100, 1500];\n", "C=[30000, 4000]; \n", "W=[0, 0];\n", "#calculation\n", "W[0]=C[0]/sf;\n", "W[1]=C[1]/sf;\n", "\n", "#result\n", "print('\\n-----------------------------------------------------------\\n');\n", "print('Temperature\\tCreep Strength, psi\\tWorking Stress, psi\\n');\n", "print('------------------------------------------------------------');\n", "print('\\n1100 F\\t\\t\\t%i\\t\\t\\t%i\\n')%(C[0],W[0]);\n", "print('\\n1500 F\\t\\t\\t%i\\t\\t\\t%i\\n')%(C[1],W[1]);" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "### Example 13.2, Engineering Creep, Page No. 461" ] }, { "cell_type": "code", "execution_count": 4, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "\n", "Activation Energy = 157867 cal/mol\n", "\n", "\n", "\n", "Note: Calculation Errors in book\n" ] } ], "source": [ "\n", "\n", "from math import log\n", "\n", "#variable declaration\n", "def C(f):\n", " return (f-32)*5/9;\n", "R=1.987;\n", "T2=1300;\n", "T1=1500;\n", "\n", "#calculation\n", "T2=C(T2)+273.15;\n", "T1=C(T1)+273.15;\n", "e2=0.0001;\n", "e1=0.4;\n", "Q=R*log(e1/e2)/(1/T2-1/T1);\n", "\n", "#result\n", "print('\\nActivation Energy = %g cal/mol')%(Q)\n", "print('\\n\\n\\nNote: Calculation Errors in book');" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "### Example 13.3, Prediction of long time properties, Page No. 464" ] }, { "cell_type": "code", "execution_count": 3, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "\n", "At T = 1200 F, P = 41500\n", "At T = 1600 F, P = 51500\n", "And from the master ploy of Astroploy, corresponding stress required are sigma = 78000 psi and sigma = 11000 psi\n" ] } ], "source": [ "\n", "from math import log10\n", "\n", "#variable declaration\n", "t=10**5;\n", "C1=20;\n", "T1=1200;\n", "T2=1600;\n", "\n", "#calculation\n", "P_1200=(T1+460)*(log10(t)+C1);\n", "P_1600=(T2+460)*(log10(t)+C1);\n", "\n", "#result\n", "print('\\nAt T = 1200 F, P = %g\\nAt T = 1600 F, P = %g\\nAnd from the master ploy of Astroploy, corresponding stress required are sigma = 78000 psi and sigma = 11000 psi')%(P_1200,P_1600);" ] } ], "metadata": { "kernelspec": { "display_name": "Python 2", "language": "python", "name": "python2" }, "language_info": { "codemirror_mode": { "name": "ipython", "version": 2 }, "file_extension": ".py", "mimetype": "text/x-python", "name": "python", "nbconvert_exporter": "python", "pygments_lexer": "ipython2", "version": "2.7.10" } }, "nbformat": 4, "nbformat_minor": 0 }