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 "metadata": {
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  "signature": "sha256:01311d1278cad60b1c0d60099bb705f52b2b4566cc66cef72df1eddeb97f8ca1"
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 "worksheets": [
  {
   "cells": [
    {
     "cell_type": "heading",
     "level": 1,
     "metadata": {},
     "source": [
      "Ch:16 Power screws"
     ]
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "exa 16-1 - Page 450"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "from math import atan, pi, sqrt, tan\n",
      "d=30#\n",
      "W=20*10**3#\n",
      "r1=8#\n",
      "r2=16#\n",
      "p=6#\n",
      "u1=0.2#\n",
      "u2=0.15#\n",
      "dm=d-(p/2)#\n",
      "alpha=atan(p/(pi*dm))#\n",
      "phi=atan(u1)#\n",
      "rm=(r1+r2)/2#\n",
      "Ttr=W*((dm*tan(alpha+phi)/2)+(u2*rm))#\n",
      "Ttr=Ttr*10**-3#\n",
      "print \"Ttr is %0.3f Nm     \"%(Ttr)#\n",
      "#The answer to Ttr is slightly different than in the book due to rounding-off of values."
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "Ttr is 110.148 Nm     \n"
       ]
      }
     ],
     "prompt_number": 1
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "exa 16-2 - Page 451"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "from math import cos\n",
      "d=50#\n",
      "W=20*10**3#\n",
      "r1=10#\n",
      "r2=30#\n",
      "p=7#\n",
      "u1=0.12/cos(15*pi/180)#\n",
      "u2=0.15#\n",
      "dm=d-(p/2)#\n",
      "alpha=atan(3*p/(pi*dm))#\n",
      "phi=atan(u1)#\n",
      "rm=(r1+r2)/2#\n",
      "Tr=W*((dm*tan(alpha+phi)/2)+(u2*rm))#\n",
      "Tr=Tr*10**-3#\n",
      "Te=W*((dm*tan(phi-alpha)/2)+(u2*rm))#\n",
      "Te=Te*10**-3#\n",
      "n=dm/2*tan(alpha)/(dm*tan(alpha+phi)/2+(u2*rm))#\n",
      "L=0.30#\n",
      "Ph=Tr/L#\n",
      "print \" Tr is %0.2f Nm     \"%(Tr)#\n",
      "print \"\\n Te is %0.3f Nm     \"%(Te)#\n",
      "print \"\\n n is %0.4f      \"%(n)#\n",
      "print \"\\n Ph is %0.2f N     \"%(Ph)#\n",
      "#The answers to Tr, Te and Ph is slightly different than in the book due to rounding-off of values."
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        " Tr is 187.49 Nm     \n",
        "\n",
        " Te is 51.691 Nm     \n",
        "\n",
        " n is 0.3489      \n",
        "\n",
        " Ph is 624.96 N     \n"
       ]
      }
     ],
     "prompt_number": 2
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "exa 16-3 - Page 452"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "d=30#\n",
      "W=5*10**3#\n",
      "p=5#\n",
      "rm=45/2#\n",
      "u1=0.15/cos(14.5*pi/180)#\n",
      "u2=0.15#\n",
      "dm=d-(p/2)#\n",
      "alpha=atan(p/(pi*dm))#\n",
      "phi=atan(u1)#\n",
      "Tr1=W*((dm*tan(alpha+phi)/2)+(u2*rm))#\n",
      "Tr1=Tr1*10**-3#\n",
      "n1=dm/2*tan(alpha)/(dm*tan(alpha+phi)/2+(u2*rm))#\n",
      "T1=W*((dm*tan(phi-alpha)/2)+(u2*rm))#\n",
      "T1=T1*10**-3#\n",
      "n2=dm/2*tan(alpha)/(dm*tan(phi-alpha)/2+(u2*rm))#\n",
      "u2=0.02#\n",
      "Tr2=W*((dm*tan(alpha+phi)/2)+(u2*rm))#\n",
      "Tr2=Tr2*10**-3#\n",
      "n3=dm/2*tan(alpha)/(dm*tan(alpha+phi)/2+(u2*rm))#\n",
      "Te=W*((dm*tan(phi-alpha)/2)+(u2*rm))#\n",
      "Te=Te*10**-3#\n",
      "n4=dm/2*tan(alpha)/(dm*tan(phi-alpha)/2+(u2*rm))#\n",
      "print \" Tr1 is %0.3f Nm     \"%(Tr1)#\n",
      "print \"\\n n1 is %0.4f      \"%(n1)#\n",
      "print \"\\n T1 is %0.3f Nm     \"%(T1)#\n",
      "print \"\\n n2 is %0.4f      \"%(n2)#\n",
      "print \"\\n Tr2 is %0.3f Nm     \"%(Tr2)#\n",
      "print \"\\n n3 is %0.4f      \"%(n3)#\n",
      "print \"\\n Te is %0.3f Nm     \"%(Te)#\n",
      "print \"\\n n4 is %0.4f      \"%(n4)#\n",
      "  \n",
      "  #The answer to T1 is misprinted in the book."
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        " Tr1 is 31.456 Nm     \n",
        "\n",
        " n1 is 0.1265      \n",
        "\n",
        " T1 is 23.307 Nm     \n",
        "\n",
        " n2 is 0.1707      \n",
        "\n",
        " Tr2 is 17.156 Nm     \n",
        "\n",
        " n3 is 0.2319      \n",
        "\n",
        " Te is 9.007 Nm     \n",
        "\n",
        " n4 is 0.4418      \n"
       ]
      }
     ],
     "prompt_number": 3
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "exa 16-4 - Page 453"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "d=28#\n",
      "P=300#\n",
      "L=180#\n",
      "p=8#\n",
      "r1=16#\n",
      "r2=46#\n",
      "rm=(r1+r2)/2#\n",
      "u1=0.12#\n",
      "u2=0.15#\n",
      "dm=d-(p/2)#\n",
      "alpha=atan(p/(pi*dm))#\n",
      "phi=atan(u1)#\n",
      "T=P*L#\n",
      "F=T/((dm*tan(alpha+phi)/2)+(u2*rm))#\n",
      "F=F*10**-3#\n",
      "print \"F is %0.3f kN     \"%(F)#"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "F is 7.299 kN     \n"
       ]
      }
     ],
     "prompt_number": 4
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "exa 16-5 - Page 453"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "d=25#\n",
      "p=8#\n",
      "F=392.4#\n",
      "L=250#\n",
      "l=p*2#\n",
      "u=0.14#\n",
      "dm=d-(p/2)#\n",
      "alpha=atan(l/(pi*dm))#\n",
      "phi=atan(u)#\n",
      "T=dm*tan(alpha+phi)/2#\n",
      "M=F*L#\n",
      "P=M/T*10**-3#\n",
      "print \"P is %0.1f kN     \"%(P)#"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "P is 23.6 kN     \n"
       ]
      }
     ],
     "prompt_number": 5
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "exa 16-6 - Page 454"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "d=52#\n",
      "W=2.2*10**3#\n",
      "p=8#\n",
      "r1=15#\n",
      "r2=30#\n",
      "rm=(r1+r2)/2#\n",
      "u1=0.15/cos(14.5*pi/180)#\n",
      "dm=d-(p/2)#\n",
      "alpha=atan(p/(pi*dm))#\n",
      "phi=atan(u1)#\n",
      "Ts=W*dm*tan(alpha+phi)/2#\n",
      "u2=0.12#\n",
      "Tc=u2*W*rm#\n",
      "T=10**-3*(Ts+Tc)#\n",
      "N=40#\n",
      "w=2*pi*N/60#\n",
      "P=T*w*10**-3#\n",
      "To=W*dm/2*tan(alpha)#\n",
      "n=To/(T*10**3)#\n",
      "print \"P is %0.2f KW     \"%(P)#\n",
      "print \"\\nn is %0.4f      \"%(n)#"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "P is 0.07 KW     \n",
        "\n",
        "n is 0.1659      \n"
       ]
      }
     ],
     "prompt_number": 6
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "exa 16-7 - Page 455"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "alpha=atan(2*0.2/(pi*0.9))#\n",
      "u1=0.15#\n",
      "phi=atan(u1)#\n",
      "P=200#\n",
      "L=250#\n",
      "Tt=P*L#\n",
      "W=10*10**3#\n",
      "u2=0.15#\n",
      "x=Tt/W#\n",
      "d=x/0.1716#\n",
      "d=30#\n",
      "p=6#\n",
      "dr=0.8*d#\n",
      "d=24#\n",
      "p=5#\n",
      "dr=d-p#\n",
      "dm=d-(p/2)#\n",
      "print \"d is %0.0f mm     \"%(d)#\n",
      "print \"\\np is %0.0f mm     \"%(p)#"
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        "d is 24 mm     \n",
        "\n",
        "p is 5 mm     \n"
       ]
      }
     ],
     "prompt_number": 7
    },
    {
     "cell_type": "heading",
     "level": 2,
     "metadata": {},
     "source": [
      "exa 16-8 - Page 456"
     ]
    },
    {
     "cell_type": "code",
     "collapsed": false,
     "input": [
      "FOS=3#\n",
      "sigut=380#\n",
      "Ta=0.577*sigut/FOS#\n",
      "d=25#\n",
      "Tus=460#\n",
      "Ps=pi*d*Tus#\n",
      "siga=127#\n",
      "dr=sqrt(Ps*4/(pi*siga))#\n",
      "d=30#\n",
      "p=6#\n",
      "dr=d-p#\n",
      "dm=d-(p/2)#\n",
      "u1=0.15#\n",
      "alpha=atan(p*2/(pi*dm))#\n",
      "phi=atan(u1)#\n",
      "T=Ps*dm*tan(alpha+phi)/2#\n",
      "T1=16*T/(pi*dr**3)#\n",
      "sigc=4*Ps/(pi*dr**2)#\n",
      "sigmax=sigc/2+sqrt((sigc/2**2)+(T1**2))#\n",
      "Tmax=sqrt((sigc/2**2)+(T1**2))#\n",
      "n=tan(alpha)/tan(alpha+phi)#\n",
      "Uo=Ps/2#\n",
      "Ui=Uo/n#\n",
      "wav=pi/2#\n",
      "wmax=2*wav#\n",
      "I=Ui*2/wmax**2#\n",
      "k=0.4#\n",
      "Ir=0.9*I*10**-3#\n",
      "m=Ir/k**2#\n",
      "R=0.4#\n",
      "rho=7200#\n",
      "a=sqrt(m/(2*pi*R*rho))#\n",
      "T=T*10**-3#\n",
      "print \" T is %0.3f Nm     \"%(T)#\n",
      "print \"\\n n is %0.4f      \"%(n)#\n",
      "print \"\\n a is %0.5f mm      \"%(a)#\n",
      "  \n",
      "#The difference in the answers of T is due to rounding-off of values."
     ],
     "language": "python",
     "metadata": {},
     "outputs": [
      {
       "output_type": "stream",
       "stream": "stdout",
       "text": [
        " T is 145.242 Nm     \n",
        "\n",
        " n is 0.4751      \n",
        "\n",
        " a is 0.04894 mm      \n"
       ]
      }
     ],
     "prompt_number": 8
    }
   ],
   "metadata": {}
  }
 ]
}