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author | nice | 2014-09-15 12:50:58 +0530 |
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committer | nice | 2014-09-15 12:50:58 +0530 |
commit | 2792e8d6ecab454e3cb8fb1ea1f26f1613bc1e1c (patch) | |
tree | 680c46833c53f5ecbbceb773bec170a89ac94152 /Theory_Of_Machines/ch9.ipynb | |
parent | f77c828fecc4db415b42d5b0e28a75dd135476d4 (diff) | |
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diff --git a/Theory_Of_Machines/ch9.ipynb b/Theory_Of_Machines/ch9.ipynb new file mode 100755 index 00000000..bdb83c80 --- /dev/null +++ b/Theory_Of_Machines/ch9.ipynb @@ -0,0 +1,349 @@ +{ + "metadata": { + "name": "", + "signature": "sha256:0872fbc3ae91821d4330e3facbf2559c866bc6b64416332df388f5fee66480e0" + }, + "nbformat": 3, + "nbformat_minor": 0, + "worksheets": [ + { + "cells": [ + { + "cell_type": "heading", + "level": 1, + "metadata": {}, + "source": [ + "Chapter 9 : Mechanisms with Lower Pairs" + ] + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 9.1 Page No : 245" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "\n", + "# Variables:\n", + "c = 1.2\n", + "b = 2.7 \t\t\t#m\n", + "\n", + "#Solution:\n", + "#Calculating the inclination of the track arm to the longitudinal axis\n", + "alpha = math.tan(c/(2*b))*180/math.pi \t\t\t#degrees\n", + "\n", + "#Results:\n", + "print \" Inclination of the track arm to the longitudinal axis, alpha = %.1f degrees.\"%(alpha)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + " Inclination of the track arm to the longitudinal axis, alpha = 12.9 degrees.\n" + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 9.2 Page No : 251\n" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "\n", + "# variables\n", + "a = 180. - 160. # degrees\n", + "N = 1500. # r.p.m.; \n", + "m = 12. # kg ; \n", + "k = 0.1 # m\n", + "\n", + "# calculations\n", + "w = round(2*math.pi*N/60)\n", + "I = m*k**2\n", + "cos2theta = 2*math.sin(math.radians(a))**2/(2 - math.sin(math.radians(a))**2)\n", + "theta = math.degrees(math.acos(cos2theta))/2\n", + "dw1bydt = w**2*math.cos(math.radians(a)) * math.sin(math.radians(2*theta)) * math.sin(math.radians(a))**2 / ( 1 - math.cos(math.radians(theta))**2 * math.sin(math.radians(a))**2)**2\n", + "max_t = I * dw1bydt\n", + "\n", + "# results\n", + "print \"Maximum angular acceleration of the driven shaft : %.f rad/s**2\"%dw1bydt\n", + "print \"maximum torque required : %.f N-m\"%max_t\n", + "\n", + "\n", + "# answers are different because of rounding error. please check using calculator." + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "Maximum angular acceleration of the driven shaft : 3080 rad/s**2\n", + "maximum torque required : 370 N-m\n" + ] + } + ], + "prompt_number": 12 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 9.3 Page No : 252" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "\n", + "# Variables:\n", + "alpha = 18*math.pi/180 \t\t\t#radians\n", + "\n", + "#Solution:\n", + "#Maximum velocity is possible when\n", + "theta1 = 0.\n", + "theta2 = 180. \t\t\t#degrees\n", + "\n", + "#Calculating the angle turned by the driving shaft when the velocity ratio is unity\n", + "theta3 = math.cos(math.sqrt((1-math.cos(alpha))/(math.sin(alpha)**2)))*180/math.pi \t\t\t#degrees\n", + "theta4 = 180-theta3 \t\t\t#degrees\n", + "\n", + "#Results:\n", + "print \" Angle turned by the driving shaft when the velocity ratio is maximum, theta = %d degrees\\\n", + " or %d degrees.\"%(theta1,theta2)\n", + "print \" Angle turned by the driving shaft when the velocity ratio is unity, theta = %.1f degrees or\\\n", + " %.1f degrees.\"%(theta3,theta4)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + " Angle turned by the driving shaft when the velocity ratio is maximum, theta = 0 degrees or 180 degrees.\n", + " Angle turned by the driving shaft when the velocity ratio is unity, theta = 43.2 degrees or 136.8 degrees.\n" + ] + } + ], + "prompt_number": 2 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 9.4 Page No : 252" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "\n", + "# Variables:\n", + "N = 500. \t\t\t#rpm\n", + "\n", + "#Solution:\n", + "#Calculating the angular velocity of the driving shaft\n", + "omega = 2*math.pi*N/60.0 \t\t\t#rad/s\n", + "#Calculating the total fluctuation of speed of the driven shaft\n", + "q = 12./100*omega \t\t\t#rad/s\n", + "#Calculating the greatest permissible angle between the centre lines of the shafts\n", + "#alpha = math.cos((-(q/omega)+math.sqrt(0.12**2+4))/2.0)*180/math.pi\t\t\t#degrees\n", + "cosalpha =((-(q/omega)+math.sqrt(0.12**2+4))/2.0)\t\t\t#degrees\n", + "alpha = math.degrees(math.acos(cosalpha))\n", + "\n", + "#Results:\n", + "print \" Greatest permissible angle between the centre lines of the shafts, alpha = %.2f degrees.\"%(alpha)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + " Greatest permissible angle between the centre lines of the shafts, alpha = 19.64 degrees.\n" + ] + } + ], + "prompt_number": 15 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 9.5 Page No : 252" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "\n", + "# Variables:\n", + "N = 1200.\n", + "q = 100. \t\t\t#rpm\n", + "#Solution:\n", + "#Calculating the greatest permissible angle between the centre lines of the shafts\n", + "cosalpha = ((-(100./1200)+math.sqrt(0.083**2+4))/2)\n", + "alpha = math.degrees(math.acos(cosalpha)) #degrees\n", + "#Calculating the maximum speed of the driven shaft\n", + "N1max = N/cosalpha \t\t\t#rpm\n", + "#Calculating the minimum speed of the driven shaft\n", + "N1min = N*cosalpha\t\t\t#rpm\n", + "\n", + "#Results:\n", + "print \" Greatest permissible angle between the centre lines of the shafts, alpha = %.1f degrees.\"%(alpha)\n", + "print \" Maximum speed of the driven shaft, N1max = %d rpm.\"%(N1max)\n", + "print \" Minimum speed of the driven shaft, N1min = %d rpm.\"%(N1min)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + " Greatest permissible angle between the centre lines of the shafts, alpha = 16.4 degrees.\n", + " Maximum speed of the driven shaft, N1max = 1251 rpm.\n", + " Minimum speed of the driven shaft, N1min = 1151 rpm.\n" + ] + } + ], + "prompt_number": 24 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 9.6 page no : 253" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math\n", + "\n", + "# variables\n", + "N = 240. # r.p.m \n", + "w = 2 * math.pi * 240./60 #rad/s \n", + "alpha = 20 \n", + "m = 55. # kg ;\n", + "k = .150 \n", + "mm = 0.15 #m ; \n", + "T1 = 200. #N-m ; \n", + "theta = 45. # \u00b0 ; \n", + "q = 24. # r.p.m.\n", + "\n", + "# calculations\n", + "I = round(m * k**2,2) \n", + "dw1bydt = round(-(w**2)*math.cos(math.radians(alpha))*math.sin(math.radians(2*theta))*math.sin(math.radians(alpha))**2 / (1- math.cos(math.radians(theta))**2 * math.sin(math.radians(alpha))**2)**2,2)\n", + "T2 = I * dw1bydt\n", + "T = T1 + T2\n", + "Tdash = T*math.cos(math.radians(alpha))/(1-math.cos(math.radians(theta))**2 * math.sin(math.radians(alpha))**2)\n", + "cosapha = (-0.1+math.sqrt((0.1**2)+4))/2\n", + "alpha = math.degrees(math.acos(cosapha))\n", + "\n", + "# result\n", + "print \"T' = %.1f N-m\"%Tdash\n", + "print \"Alpha a = %.1f degrees\"%alpha\n", + "\n", + "# rounding off error" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "T' = 102.7 N-m\n", + "Alpha a = 18.0 degrees\n" + ] + } + ], + "prompt_number": 3 + }, + { + "cell_type": "heading", + "level": 2, + "metadata": {}, + "source": [ + "Example 9.7 Page No : 254" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "import math \n", + "\n", + "# Variables:\n", + "alpha = 20. \t\t\t#degrees\n", + "NA = 500. \t\t\t#rpm\n", + "\n", + "#Solution:\n", + "#Calculating the maximum speed of the intermediate shaft\n", + "NBmax = NA/math.cos(math.radians(alpha)) \t\t\t#rpm\n", + "#Calculating the minimum speed of the intermediate shaft\n", + "NBmin = NA*math.cos(math.radians(alpha)) \t\t\t#rpm\n", + "#Calculating the maximum speed of the driven shaft\n", + "NCmax = NBmax/math.cos(math.radians(alpha)) \t\t\t#rpm\n", + "#Calculating the minimum speed of the driven shaft\n", + "NCmin = NBmin*math.cos(math.radians(alpha)) \t\t\t#rpm\n", + "\n", + "#Results:\n", + "print \" Maximum speed of the intermediate shaft( NBmax) = %.1f rad/s.\"%(NBmax)\n", + "print \" Minimum speed of the intermediate shaft( NBmin) = %.2f rad/s.\"%(NBmin)\n", + "print \" Maximum speed of the driven shaft( NCmax) = %.2f rad/s.\"%(NCmax)\n", + "print \" Minimum speed of the driven shaft( NCmin) = %.1f rad/s.\"%(NCmin)\n" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + " Maximum speed of the intermediate shaft( NBmax) = 532.1 rad/s.\n", + " Minimum speed of the intermediate shaft( NBmin) = 469.85 rad/s.\n", + " Maximum speed of the driven shaft( NCmax) = 566.24 rad/s.\n", + " Minimum speed of the driven shaft( NCmin) = 441.5 rad/s.\n" + ] + } + ], + "prompt_number": 27 + } + ], + "metadata": {} + } + ] +}
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