{ "metadata": { "name": "CH7" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 7: Dislocation and Strengthening Mechanisms" ] }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 7.1 Page no 183" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "u1=1\n", "v1=1\n", "w1=0\n", "u2=0\n", "v2=1\n", "w2=0\n", "u3=-1\n", "v3=1\n", "w3=1\n", "\n", "import math\n", "phi=math.acos((u1*u2+v1*v2+w1*w2)/(math.sqrt((u1**2+v1**2+w1**2)*(u2**2+v2**2+w2**2))))\n", "lam=math.acos((u3*u2+v3*v2+w3*w2)/(math.sqrt((u3**2+v3**2+w3**2)*(u2**2+v2**2+w2**2))))\n", "sigma=52 #in MPa, Tensile stress\n", "tr=sigma*math.cos(phi)*math.cos(lam)\n", "trc=30 #in MPa Critical resolved shear stress\n", "sy=trc/(math.cos(phi)*math.cos(lam))\n", "\n", "print\"(a)The resolved shear stress is \",round(tr,2),\"MPa\"\n", "print\"(b)Yield strength is\",round(sy,1),\"MPa\"\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(a)The resolved shear stress is 21.23 MPa\n", "(b)Yield strength is 73.5 MPa\n" ] } ], "prompt_number": 19 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Example 7.2 Page no 194" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "df=12.2 #Final dia in mm\n", "di=15.2 #Initial dia in mm\n", "\n", "CW = ((di**2-df**2)/di**2)*100\n", "ts=340 #in Mpa tensile strength, from fig 7.19 (b)\n", "duc=7 #in % Ductility from fig 7.19 (c)\n", "\n", "print\"Percent Cold Work is \",round(CW,1),\"%\"\n", "print\"Tensile strength is\",ts,\"MPa\"\n", "print\"Ductility is \",duc,\"%\"\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Percent Cold Work is 35.6 %\n", "Tensile strength is 340 MPa\n", "Ductility is 7 %\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 3, "metadata": {}, "source": [ "Design Example 7.3 Page no 199" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "di=6.4 #Initial dia in mm\n", "df=5.1 #Final dia in mm\n", "\n", "CW = ((di**2-df**2)/di**2)*100\n", "dmid = math.sqrt(df**2/(1-0.215))\n", "\n", "print\"Cold work is \",round(CW,1),\"%\"\n", "print\"But required ductility and yield strength is not matched at this cold work\"\n", "print\"Hence required Cold work is 21.5 %\"\n", "print\"Hence original diameter for second drawing is \",round(dmid,1),\"mm\"\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Cold work is 36.5 %\n", "But required ductility and yield strength is not matched at this cold work\n", "Hence required Cold work is 21.5 %\n", "Hence original diameter for second drawing is 5.8 mm\n" ] } ], "prompt_number": 11 }, { "cell_type": "code", "collapsed": false, "input": [], "language": "python", "metadata": {}, "outputs": [] } ], "metadata": {} } ] }