{ "cells": [ { "cell_type": "markdown", "metadata": {}, "source": [ "# Chapter 4:Torsion" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 4.2 page number 183" ] }, { "cell_type": "code", "execution_count": 1, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "The maximum shear due to torsion is 152.87 Mpa\n", "stress tensor matrix [[ 0. 152.9 0. ]\n", " [ 152.9 0. 0. ]\n", " [ 0. 0. 0. ]]\n" ] } ], "source": [ "#Given\n", "dia = 10 #diameter of shaft(A-C)\n", "c = dia/2 #mm - Radius\n", "T = 30 #N/mm -Torque in the shaft \n", "#Caliculations\n", "\n", "J = 3.14*(dia**4)/32 #mm4\n", "shear_T = T*c*pow(10,3)/J # The torsion shear in the shaft AC\n", "import numpy as np \n", "print \"The maximum shear due to torsion is \",round(shear_T,2),\"Mpa\"\n", "arr_T = np.zeros((3,3))\n", "arr_T[0][1]=round(shear_T,1) #arranging the elements in array\n", "arr_T[1][0]=round(shear_T,1)\n", "print \"stress tensor matrix\",(arr_T),\n", "\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 4.3 page number 184" ] }, { "cell_type": "code", "execution_count": 2, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "The maximum shear due to torsion is 43.15 Mpa\n", "The minimum shear due to torsion is 34.52 Mpa\n" ] } ], "source": [ "#Given \n", "dia_out = 20 #mm- outer diameter of shaft\n", "dia_in = 16 #mm- inner diameter of shaft \n", "c_out = dia_out/2 #mm - outer Radius of shaft \n", "c_in = dia_in/2 #mm - inner radius of shaft \n", "T = 40 #N/mm -Torque in the shaft \n", "#caliculations\n", "\n", "J = 3.14*((dia_out**4)- (dia_in**4))/32 #mm4\n", "shear_T_max = T*c_out*pow(10,3)/J # The maximum torsion shear in the shaft\n", "shear_T_min = T*c_in*pow(10,3)/J # The maximum torsion shear in the shaft\n", "print \"The maximum shear due to torsion is \",round(shear_T_max,2),\"Mpa\"\n", "print \"The minimum shear due to torsion is \",round(shear_T_min,2),\"Mpa\"\n", "\n", "\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 4.4 page number 187" ] }, { "cell_type": "code", "execution_count": 3, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "The Diameter of the shaft used is 15.26 mm\n" ] } ], "source": [ "#Given\n", "hp = 10 # horse power of motor \n", "f = 30 # given \n", "shear_T = 55 #Mpa - The maximum shearing in the shaft \n", "#caliculations\n", "\n", "T = 119*hp/f # N.m The torsion in the shaft \n", "#j/c=T/shear_T=K\n", "k = T*pow(10,3)/shear_T #mm3\n", "#c3=2K/3.14\n", "c = pow((2*k/3),0.33) #mm - The radius of the shaft \n", "diamter = 2*c #mm - The diameter of the shaft\n", "print \"The Diameter of the shaft used is\",round(diamter,2),\"mm\"\n", "\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 4.5 page number 188" ] }, { "cell_type": "code", "execution_count": 4, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "The Diameter of the shaft1 is 6.87 mm\n", "The Diameter of the shaft2 is 0.702590481015 mm\n" ] } ], "source": [ "#Given \n", "hp = 200 #Horse power\n", "stress_sh = 10000 #psi- shear stress\n", "rpm_1 = 20.0 # The rpm at which this shaft1 operates \n", "rpm_2 = 20000.0 # The rpm at which this shaft2 operates\n", "T_1= hp*63000.0/rpm_1 #in-lb Torsion due to rpm1\n", "T_2= hp*63000/rpm_2 #in-lb Torsion due to rpm1\n", "#caliculations \n", "\n", "#j/c=T/shear_T=K\n", "k_1= T_1/stress_sh #mm3\n", "#c3=2K/3.14\n", "c_1= pow((2*k_1/3),0.33) #mm - The radius of the shaft \n", "diamter_1 = 2*c_1 #mm - The diameter of the shaft\n", "print \"The Diameter of the shaft1 is\",round(diamter_1,2),\"mm\"\n", "\n", "#j/c=T/shear_T=K\n", "k_2= T_2/stress_sh #mm3\n", "#c3=2K/3.14\n", "c_2= pow((2*k_2/3),0.33) #mm - The radius of the shaft \n", "diamter_2 = 2*c_2 #mm - The diameter of the shaft\n", "print \"The Diameter of the shaft2 is\",diamter_2,\"mm\"\n", "\n", "\n", "\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 4.7 page number 193" ] }, { "cell_type": "code", "execution_count": 5, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "The maximum angle rotated is 0.0232628450106 radians \n" ] } ], "source": [ "#Given \n", "T_ab = 0 #N.m - torsion in AB \n", "T_bc = 150 #N.m - torsion in BC\n", "T_cd = 150 #N.m - torsion in CD\n", "T_de = 1150 #N.m - torsion in DE\n", "l_ab = 250 #mm - length of AB\n", "l_bc = 200 #mm - length of BC\n", "l_cd = 300 #mm - length of cd \n", "l_de = 500.0 #mm - length of de\n", "d_1 = 25 #mm - outer diameter \n", "d_2 = 50 #mm - inner diameter\n", "G = 80 #Gpa -shear modulus\n", "#Caliculations \n", "\n", "J_ab = 3.14*(d_1**4)/32 #mm4\n", "J_bc = 3.14*(d_1**4)/32 #mm4\n", "J_cd = 3.14*(d_2**4 - d_1**4)/32 #mm4\n", "J_de = 3.14*(d_2**4 - d_1**4)/32 #mm4\n", "rad = T_ab*l_ab/(J_ab*G)+ T_bc*l_bc/(J_bc*G)+ T_cd*l_cd/(J_cd*G)+ T_de*l_de/(J_de*G) # adding the maximum radians roteted in each module\n", "print \"The maximum angle rotated is \",rad,\"radians \" " ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 4.9 Pagenumber 196" ] }, { "cell_type": "code", "execution_count": 6, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "The Torsion at rigid end A is -141.72 N-m\n", "The Torsion at rigid end B is 1291.72 N-m\n" ] } ], "source": [ "#given \n", "#its a statistally indeterminant \n", "#we will take of one of the support \n", "#Given \n", "T_ab = 0 #N.m - torsion in AB \n", "T_bc = 150 #N.m - torsion in BC\n", "T_cd = 150 #N.m - torsion in CD\n", "T_de = 1150 #N.m - torsion in DE\n", "l_ab = 250 #mm - length of AB\n", "l_bc = 200 #mm - length of BC\n", "l_cd = 300 #mm - length of cd \n", "l_de = 500.0#mm - length of de\n", "d_1 = 25 #mm - outer diameter \n", "d_2 = 50 #mm - inner diameter\n", "#Caliculations \n", "\n", "J_ab = 3.14*(d_1**4)/32 #mm4\n", "J_bc = 3.14*(d_1**4)/32 #mm4\n", "J_cd = 3.14*(d_2**4 - d_1**4)/32 #mm4\n", "J_de = 3.14*(d_2**4 - d_1**4)/32 #mm4\n", "G = 80 #Gpa -shear modulus\n", "rad = T_ab*l_ab/(J_ab*G)+ T_bc*l_bc/(J_bc*G)+ T_cd*l_cd/(J_cd*G)+ T_de*l_de/(J_de*G) \n", "#now lets consider T_A then the torsion is only T_A\n", "# T_A*(l_ab/(J_ab*G)+ l_bc/(J_bc*G)+ l_cd/(J_cd*G)+ l_de/(J_de*G)) +rad = 0\n", "# since there will be no displacement \n", "T_A =-rad/(l_ab/(J_ab*G)+ l_bc/(J_bc*G)+ l_cd/(J_cd*G)+ l_de/(J_de*G)) #Torsion at A\n", "T_B = 1150 - T_A #n-m F_X = 0 torsion at B\n", "print \"The Torsion at rigid end A is\",round(T_A,2),\"N-m\"\n", "print \"The Torsion at rigid end B is\",round(T_B,2),\"N-m\"\n", "\n", "\n", "\n", "\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 4.12 Pagenumber 202" ] }, { "cell_type": "code", "execution_count": 7, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "The allowable torsion on the 8 bolt combination 27129600.0 N-m\n" ] } ], "source": [ "#Given\n", "dai_bc = 240 #mm- daimeter of '8'bolt circle \n", "dia = dai_bc/8 #Diameter of each bolt\n", "A = 0.25*(dia**2)*3.14 # Area of a bolt\n", "S_allow = 40 #Mpa - The maximum allowable allowable shear stress \n", "P_max = (S_allow)*A #N - The maximum allowable force \n", "D = 120.0 #mm - the distance from central axis \n", "T_allow =P_max*D*8 #N-m The allowable torsion on the 8 bolt combination \n", "print \"The allowable torsion on the 8 bolt combination\",T_allow ,\"N-m\"\n", "\n", "\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 4.15 page number 211" ] }, { "cell_type": "code", "execution_count": 8, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "the Equivalent Torsion constant is 1.97 in4\n" ] } ], "source": [ "#Given \n", "#AISC MANUALS\n", "#approximated by three narrow tubes \n", "#J = Bbt^3\n", "B = 0.33 # constant mentiones in AISC\n", "#three rods \n", "\n", "#rod_1\n", "t_1 = 0.605 #inch - Thickness \n", "b = 12.0 #inches - width \n", "J_1 = B*b*(t_1**3) #in4 - Torsion constant \n", "\n", "#rod_2\n", "t_2 = 0.605 #inch - Thickness \n", "b = 12 #inches - width \n", "J_2 = B*b*(t_2**3) #in4 - Torsion constant \n", "\n", "#rod_3\n", "t_3 = 0.390 #inch - Thickness \n", "b = 10.91 #inches - width \n", "J_3 = B*b*(t_3**3) #in4 - Torsion constant \n", "\n", "#Equivalent\n", "J_eq = J_1+J_2+J_3 #in4 - Torsion constant \n", "print \"the Equivalent Torsion constant is \",round(J_eq,2), \"in4\"\n", "\n", "\n", "\n", "\n" ] }, { "cell_type": "markdown", "metadata": {}, "source": [ "## Example 4.16 page number 214" ] }, { "cell_type": "code", "execution_count": 9, "metadata": { "collapsed": false }, "outputs": [ { "name": "stdout", "output_type": "stream", "text": [ "The maximum shear due to torsion is 345.23 Mpa\n", "The minimum shear due to torsion is 276.18 Mpa\n" ] } ], "source": [ "#Given \n", "dia_out = 10 #mm- outer diameter of shaft\n", "dia_in = 8 #mm- inner diameter of shaft \n", "c_out = dia_out/2 #mm - outer Radius of shaft \n", "c_in = dia_in/2 #mm - inner radius of shaft \n", "T = 40 #N/mm -Torque in the shaft \n", "#caliculations\n", "\n", "J = 3.14*((dia_out**4)- (dia_in**4))/32 #mm4\n", "shear_T_max = T*c_out*pow(10,3)/J # The maximum torsion shear in the shaft\n", "shear_T_min = T*c_in*pow(10,3)/J # The maximum torsion shear in the shaft\n", "print \"The maximum shear due to torsion is \",round(shear_T_max,2),\"Mpa\"\n", "print \"The minimum shear due to torsion is \",round(shear_T_min,2),\"Mpa\"" ] } ], "metadata": { "kernelspec": { "display_name": "Python 2", "language": "python", "name": "python2" }, "language_info": { "codemirror_mode": { "name": "ipython", "version": 2 }, "file_extension": ".py", "mimetype": "text/x-python", "name": "python", "nbconvert_exporter": "python", "pygments_lexer": "ipython2", "version": "2.7.10" } }, "nbformat": 4, "nbformat_minor": 0 }