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 "cells": [
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   "cell_type": "markdown",
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   "source": [
    "# Ch:24 Rope drive"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## exa 24-1 - Page 635"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "n is 13    \n"
     ]
    }
   ],
   "source": [
    "from __future__ import division\n",
    "from math import sqrt, pi, exp, sin, asin\n",
    "P=150000#\n",
    "m=0.4#\n",
    "D=1.8#\n",
    "d=0.6#\n",
    "C=4.2#\n",
    "V=15#\n",
    "Fc=m*V**2#\n",
    "BL=44.81*10**3#\n",
    "FOS=35#\n",
    "F1=BL/FOS#\n",
    "theta=pi-(2*asin((D-d)/(2*C)))#\n",
    "beta=22.5*pi/180#\n",
    "u=0.13#\n",
    "x=u*theta/sin(beta)#\n",
    "F2=(F1-Fc)/exp(x)#\n",
    "n=P/((F1-F2)*V)#\n",
    "n=13#\n",
    "print \"n is %0.0f    \"%(n)#"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## exa 24-2 - Page 635"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      " annual FOS is 5.02    \n",
      "\n",
      " FOS neglecting bending load is 13.9    \n"
     ]
    }
   ],
   "source": [
    "from math import sqrt, pi\n",
    "W=1000#\n",
    "m=0.498#\n",
    "BL=78#\n",
    "d=12#\n",
    "Am=0.39*d**2#\n",
    "dw=sqrt(Am*4/(6*19*pi))#\n",
    "Ew=74.4*10**3#\n",
    "Ds=56*d#\n",
    "sigb=Ew*dw/Ds#\n",
    "Wb=sigb*pi*(d**2)/4*10**-3#\n",
    "l=20#\n",
    "Ws=m*l#\n",
    "a=1.2#\n",
    "Wa=a*(W/2+Ws)*10**-3#\n",
    "#Let the static load be Ps\n",
    "Ps=(W/2+Ws)*9.81*10**-3#\n",
    "#let the effective load  be Peff\n",
    "Peff=Ps+Wb+Wa#\n",
    "FOS1=BL/Peff#\n",
    "FOS2=BL/(5+0.612)#\n",
    "print \" annual FOS is %0.2f    \"%(FOS1)#\n",
    "print \"\\n FOS neglecting bending load is %0.1f    \"%(FOS2)#"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## exa 24-3 - Page 636"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "W is 28.224 kN   \n"
     ]
    }
   ],
   "source": [
    "d=12#\n",
    "sigut=1960#\n",
    "Pb=0.0025*sigut#\n",
    "Ds=480#\n",
    "F=Pb*d*Ds/2#\n",
    "W=F*2*10**-3#\n",
    "print \"W is %0.3f kN   \"%(W)#"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## exa 24-4 - Page 637"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {
    "collapsed": false
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "d is 12 mm   \n"
     ]
    }
   ],
   "source": [
    "from math import sqrt, pi\n",
    "sigut=1770#\n",
    "Pb=0.0018*sigut#\n",
    "W=4000#\n",
    "a=2.5/2#\n",
    "Ws=90*0.5#\n",
    "Wa=(W+Ws)*a/9.81#\n",
    "Weff=W+Wa#\n",
    "d=sqrt(Weff*2/(23*Pb))#\n",
    "d=12#\n",
    "print \"d is %0.0f mm   \"%(d)#"
   ]
  }
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