{ "metadata": { "name": "", "signature": "sha256:2286c67a37dc36a4b2463b6ff90eb31f4de0251dedc09d4493cdbe015dfacf59" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter06 : Levers" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "sum 6-1 : page 296" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import sqrt, pi\n", "Del=10 \n", "k=500 \n", "W=k*Del \n", "#Let load arm be l1\n", "l1=200 \n", "#Let effort arm be l2\n", "l2=500 \n", "P=W*l1/l2 \n", "Ro=sqrt(W**2+P**2) \n", "Ta=40 \n", "d=sqrt(Ro*4/(2*pi*Ta)) \n", "d=10 \n", "pb=10 \n", "d1=sqrt(Ro/(pb*1.5)) \n", "d1=20 \n", "l=1.5*d \n", "t=10 \n", "T=Ro*4/(2*pi*d1**2) \n", "M=(Ro/2*(l/2+t/3))-(Ro/2*l/4) \n", "sigb=32*M/(pi*d1**3) \n", "sigmax=(sigb/2)+sqrt((sigb/2)**2+T**2) \n", "P=Ro/(l*d1) \n", "D=2*d1 \n", "\n", "# Output\n", "print \"d1 is %0.1f mm \"%d1 \n", "print \"D is %0.1f mm \"%D" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "d1 is 20.0 mm \n", "D is 40.0 mm \n" ] } ], "prompt_number": 10 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "sum 6-2 : page 297" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import sqrt, pi\n", "d1=80 \n", "p=0.981 \n", "Ta=40 \n", "siga=80 \n", "pa=15 \n", "W=pi*(d1**2)*p/4 \n", "P=W/8 \n", "Ws=W-P \n", "d=sqrt(W*4/(pi*2*Ta)) \n", "l=1.5*d \n", "D=2*d \n", "T=W/(2*pi*pa**2/4) \n", "M1=P*(700-87.5-(D/2)) \n", "h=50 \n", "b=h/4 \n", "Z=b*h**2/6 \n", "sigb=M1/Z \n", "pmax=80 \n", "T=2465.6/h**2 \n", "pmax=(sigb/2)+sqrt((sigb/2)**2+T**2) \n", "\n", "# Output\n", "print \"h is %0.2f mm \"%h \n", "print \"pmax is %0.2f MPa \"%pmax\n", " \n", "#The difference in the value of pmax is due to rounding-off the digits." ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "h is 50.00 mm \n", "pmax is 74.43 MPa \n" ] } ], "prompt_number": 11 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "sum 6-3 : page 303" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import sqrt, pi\n", "P=((4*360)+(2*360))/900 \n", "Fv=4-2 \n", "Fh=P \n", "Fr=sqrt(Fv**2+Fh**2) \n", "P1=4*0.36/0.9 \n", "Rf=sqrt(4**2+1.6**2) \n", "d=sqrt(Rf*10**3/(15*1.25)) \n", "d=16 \n", "l=1.25*d \n", "T=Rf*10**3*4/(2*pi*d**2) \n", "D=2*d \n", "M1=Rf*10**3*(360-(D/2)) \n", "pa=15 \n", "h=80 \n", "b=h/4 \n", "Z=b*h**2/6 \n", "sigb=M1/Z \n", "T=4310/(b*h) \n", "pmax=(sigb/2)+sqrt((sigb/2)**2+T**2) \n", "\n", "# Output\n", "print \"P is %0.1f KN \"%P \n", "print \"pmax is %0.2f MPa \"%pmax" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "P is 2.0 KN \n", "pmax is 69.53 MPa \n" ] } ], "prompt_number": 12 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "sum 6-4 : page 304" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import sqrt, pi\n", "l=360 \n", "P=400 \n", "Mh=2*P*l/3 \n", "sigb=50 \n", "l1=60 \n", "d=(Mh*32/(pi*l1))**(1/3) \n", "d=30 \n", "L=420 \n", "siga=60 \n", "H=20 \n", "B=H/3 \n", "Mx=P*(L-H/2) \n", "Tx=2*P*l/3 \n", "sigb1=Mx*18/H**3 \n", "Td=P/(B*H) \n", "Tr=17.17*Tx/H**4 \n", "T=Tr+Td \n", "sigmax=(sigb1/2)+sqrt((sigb1/2)**2+T**2) \n", "Tmax=sqrt((sigb1/2)**2+T**2) \n", "T=P*L \n", "M=P*(l1+(2/3*l)) \n", "Te=sqrt(T**2+M**2) \n", "Ta=40 \n", "D=(Te*16/(pi*Ta))**(1/3) \n", "D=round(D) #Rounding off \n", "# Output\n", "print \"d is %0.1f mm \"%d \n", "print \"D is %0.1f mm \"%D" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "d is 30.0 mm \n", "D is 1.0 mm \n" ] } ], "prompt_number": 13 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "sum 6-5 : page 306" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import sqrt, pi\n", "l2=300 \n", "l=450 \n", "P=400 \n", "Mx=2*P*l2/3 \n", "siga=80 \n", "dh=(Mx*32/(pi*siga))**(1/3) \n", "dh=22 \n", "L=(2*l2/3)+l \n", "T=P*L \n", "Ta=40 \n", "d=(T*16/(pi*Ta))**(1/3) \n", "d=35 \n", "d1=1.6*d \n", "Th=T*16*d1/(pi*(d1**4-d**4)) \n", "l1=1.5*d \n", "My=P*(L-(d1/2)) \n", "B=dh \n", "H=sqrt(3.66*75) \n", "H=30 \n", "Mz=P*l1/2 \n", "Te=sqrt(T**2+Mz**2) \n", "d2=(Te*16/(pi*Ta))**(1/3) \n", "d2=32 \n", "b=d/4 \n", "b=round(b)\n", "t=d/6 \n", "t=round(t)\n", "# Output\n", "print \"d is %0.1f mm \"%d \n", "print \"dh is %0.1f mm \"%dh \n", "print \"d1 is %0.1f mm \"%d1 \n", "print \"l1 is %0.1f mm \"%l1 \n", "print \"d2 is %0.1f mm \"%d2 \n", "print \"b is %0.1f mm \"%b \n", "print \"t is %0.1f mm \"%t " ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "d is 35.0 mm \n", "dh is 22.0 mm \n", "d1 is 56.0 mm \n", "l1 is 52.5 mm \n", "d2 is 32.0 mm \n", "b is 8.0 mm \n", "t is 5.0 mm \n" ] } ], "prompt_number": 14 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "sum 6-6 : page 307" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from math import sqrt, pi\n", "L=450 \n", "P=700 \n", "T=P*L \n", "Ta=50 \n", "d=(T*16/(pi*Ta))**(1/3) \n", "d=32 \n", "d1=1.6*d \n", "d1=52 #Rounding off to nearest whole number\n", "l1=1.25*d \n", "My=P*(L-d1/2) \n", "sigb=65 \n", "H=(My*18/sigb)**(1/3) \n", "H=45 \n", "B=H/3 \n", "T1=P/(B*H) \n", "sigmax=(sigb/2)+sqrt((sigb/2)**2+T**2) \n", "Mx=P*l1/2 \n", "Te=sqrt((T)**2+(Mx**2)) \n", "d2=(Te*16/(pi*Ta))**(1/3) \n", "d2=d2+6 \n", "d2=round(d2)\n", "# utput\n", "print \"d is %0.1f mm \"%d \n", "print \"d1 is %0.1f mm \"%d1 \n", "print \"l1 is %0.1f mm \"%l1 \n", "print \"B is %0.1f mm \"%B \n", "print \"H is %0.1f mm \"%H \n", "print \"d2 is %0.1f mm \"%d2 " ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "d is 32.0 mm \n", "d1 is 52.0 mm \n", "l1 is 40.0 mm \n", "B is 15.0 mm \n", "H is 45.0 mm \n", "d2 is 7.0 mm \n" ] } ], "prompt_number": 15 } ], "metadata": {} } ] }