{ "metadata": { "name": "chapter 15.ipynb" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter no.15:Thin Cyclindrical Shell" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem no 15.1,Page no.351" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of variables\n", "\n", "D=0.8 #m #Diameter of Shell\n", "L=3 #m #Length of shell\n", "t=0.01 #m #thickness of metal\n", "E=200*10**9 #Pa \n", "p=2.5*10**6 #Pa #Internal Pressure\n", "m=4 #Poisson's ratio\n", "\n", "#Calculation\n", "\n", "sigma_1=p*D*(2*t)**-1 #N/m**2 #Hoop stress\n", "sigma_2=p*D*(4*t)**-1 #N/m**2 #Longitudinal stress\n", "\n", "e_1=1*E**-1*(sigma_1-sigma_2*m**-1) #Hoop strain\n", "e_2=1*E**-1*(sigma_2-sigma_1*m**-1) #Hoop strain\n", "\n", "d=e_1*D*100 #cm #Increase in Diameter\n", "l=e_2*L*100 #cm #Increase in Length\n", "\n", "dell_v=2*e_1+e_2 #Volumetric strain\n", "V=dell_v*pi*4**-1*D**2*L*10**6 #cm**3 #Increase in Volume\n", "\n", "#Result\n", "print\"Change in Diameter is\",round(d,3),\"cm\"\n", "print\"Change in Length is\",round(l,3),\"cm\"\n", "print\"Change in Volume is\",round(V,2),\"cm**3\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Change in Diameter is 0.035 cm\n", "Change in Length is 0.037 cm\n", "Change in Volume is 1507.96 cm**3\n" ] } ], "prompt_number": 13 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem no 15.2,Page no.352" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of variables\n", "\n", "D=0.8 #m #iameter of water main\n", "h=100 #m #Pressure head\n", "w=10*10**3 #N/m**3 #Weight of Water\n", "sigma_t=20*10**6 #MPa #Permissible stress\n", "\n", "#Calculation\n", "\n", "p=w*h #N/m**2 #Pressure of inside the main\n", "t=p*D*(2*sigma_t)**-1*100 #m #Thcikness of metal\n", "\n", "#Result\n", "print\"The Thickness of metal is\",round(t,2),\"cm\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The Thickness of metal is 2.0 cm\n" ] } ], "prompt_number": 21 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem no 15.3,Page no.352" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of variables\n", "\n", "p=2*10**6 #MPa #Steam Pressure\n", "t=0.02 #m #thickness of boiler plate\n", "sigma_t=120*10**6 #MPa #Tensile stress\n", "sigma_l=120*10**6 #MPa #Longitudinal stress\n", "rho=0.90 #% #Efficiency of Longitudinal joint\n", "rho_e=0.40 #% #Efficiency of circumferential joint\n", "\n", "#Calculations\n", "\n", "D_1=sigma_t*2*t*rho*p**-1 #Diameter of boiler \n", "D_2=sigma_l*4*t*rho_e*p**-1 #Diameter of boiler \n", "\n", "#Max diameter of boiler is equal to minimum value of diameter\n", "\n", "#Result\n", "print\"Maximum diameter of boiler is\",round(D_2,2),\"m\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Maximum diameter of boiler is 1.92 m\n" ] } ], "prompt_number": 29 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem no 15.4,Page no.352" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of variables\n", "\n", "L=0.9 #m #Length of cyclindrical shell\n", "D=0.2 #m #Internal Diameter\n", "t=0.008 #m #thickness of metal\n", "dV=20*10**-6 #m**3 #Additional volume\n", "E=200*10**9 #Pa \n", "m=1*0.3**-1 #Poissoin's ratio\n", "\n", "#Calculations\n", "\n", "V=pi*4**-1*D**2*L #Volume of cyclinder\n", "\n", "#Let X=2*e_1+e_2\n", "X=dV*V**-1 #Volumetric strain (Equation 1)\n", "\n", "#e_1=p*D*(2*E*t)**-1*(1-1*(2*m)**-1) #Circumferential strain\n", "#e_2=p*D*(2*E*t)**-1*(1*2**-1-1*(2*m)**-1) #Circumferential strain\n", "\n", "#substituting above values in equation 1 we get\n", "p=X*E*t*(D*((1-1*(2*m)**-1)+(1*4**-1-1*(2*m)**-1)))**-1*10**-3 #KN/m**2 #Pressure exerted by fluid\n", "sigma_t=p*D*(2*t)**-1 #KN/m**2 #hoop stress\n", "\n", "#Result\n", "print\"Pressure Exerted by Fluid on the cyclinder is\",round(p,2),\"KN/m**2\"\n", "print\"Hoop stress is\",round(sigma_t,2),\"KN/m**2\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Pressure Exerted by Fluid on the cyclinder is 5956.68 KN/m**2\n", "Hoop stress is 74458.45 KN/m**2\n" ] } ], "prompt_number": 41 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem no 15.5,Page no.353" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of variables\n", "\n", "t=0.015 #m #Thickness of plate\n", "sigma_t=120*10**6 #Pa #tensile stress\n", "sigma_l=120*10**6 #Pa #Longitudinal stress\n", "rho=0.7 #% #Efficiency of longitudinal joints\n", "rho_l=0.3 #% #Efficiency of circumferential joints\n", "p=2*10**6 #Pa #Internal pressure\n", "D=1.5 #m #shell diameter\n", "\n", "#Calculations (Part-1)\n", "\n", "D_1=sigma_t*2*t*rho*p**-1 #m \n", "D_2=sigma_l*4*t*rho_l*p**-1 #m \n", "\n", "#Thus max diameter of shell is min of above two cases\n", "\n", "#Calculations (Part-2)\n", "\n", "p_1=sigma_t*2*t*rho*D**-1*10**-6 #MPa\n", "p_2=sigma_l*4*t*rho_l*D**-1*10**-6 #MPa\n", "\n", "#Thus Internal pressure is min of above two cases\n", "\n", "#Result\n", "print\"Max Permissible Diameter of shell is\",round(D_2,2),\"m\"\n", "print\"Max Permissible Internal Pressure is\",round(p_2,2),\"MPa\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Max Permissible Diameter of shell is 1.08 m\n", "Max Permissible Internal Pressure is 1.44 MPa\n" ] } ], "prompt_number": 8 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem no 15.6,Page no.354" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of variables\n", "\n", "L=3 #m #Length\n", "D=1 #m #Internal Diameter\n", "t=0.015 #m #thickness\n", "p=1.5*10**6 #Pa #Internal pressure\n", "E=200*10**9 #Pa \n", "m=1*0.3**-1 #Poissoin's ratio\n", "\n", "#Calculations\n", "\n", "sigma_t=p*D*(2*t)**-1*10**-6 #MPa #Hoop stress\n", "sigma_l=p*D*(4*t)**-1*10**-6 #MPa #Longitudinal stress\n", "\n", "dD=(p*D**2*(2*t*E)**-1*(1-1*(2*m)**-1))*10**2 #cm #Change in Diameter\n", "dL=p*D*L*(2*t*E)**-1*(1*2**-1-1*m**-1)*10**2 #cm #Change in Length\n", "\n", "V=pi*4**-1*D**2*L #Volume \n", "dV=p*D*(2*t*E)**-1*(5*2**-1-2*(m)**-1)*V*10**6 #cm #Change in Volume\n", "\n", "#Result\n", "print\"The circumferential stresses induced is\",round(sigma_t,2),\"MPa\"\n", "print\"The Longitudinal stresses induced is\",round(sigma_l,2),\"MPa\"\n", "print\"The change in dimension are:D is\",round(dD,3),\"cm\"\n", "print\" :L is\",round(dL,4),\"cm\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "0.02125\n", "The circumferential stresses induced is 50.0 MPa\n", "The Longitudinal stresses induced is 25.0 MPa\n", "The change in dimension are:D is 0.021 cm\n", " :L is 0.015 cm\n" ] } ], "prompt_number": 26 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem no 15.7,Page no.355" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of variables\n", "\n", "L=0.9 #m #Length of cyclinder\n", "D=0.4 #m #Diameter \n", "t=0.006 #m #thickness\n", "p=5*10**6 #Pa #Pressure\n", "E=100*10**9\n", "m=3 #Poissoin's ratio\n", "k=2.6*10**9 #Pa #Bulk modulus\n", "\n", "#Calculations\n", "\n", "#Let X=dV_1*V_1**-1\n", "X=p*(0.4-2*0.006)*(2*t*E)**-1*(5*2**-1-2*m**-1) #Volumetric strain\n", "dV_1=round(X,5)*pi*4**-1*0.388**2*L #cm**3 #Increase in volume of cyclinder\n", "V_1=pi*4**-1*0.388**2*L #VOlume\n", "dV_2=p*k**-1*V_1 #DEcrease in volume of oil due to increase in pressure\n", "\n", "dV=(dV_1+dV_2)*10**6 #Resultant additional space \n", "\n", "#Result\n", "print\"additional quantity of oil to be pumped is\",round(dV,2),\"cm**3\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "additional quantity of oil to be pumped is 519.62 cm**3\n" ] } ], "prompt_number": 23 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem no 15.8,Page no.356" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of variables\n", "\n", "A=1600*(3600)**-1 #Kg/sec #Amount of steam generated\n", "v=0.24 #m**3/kg #specific volume of steam\n", "sigma_t=4*10**6 #MPa #Tensile stress\n", "V_1=30 #m/s #Velocity of steam\n", "p=1*10**6 #Pa #Steam pressure\n", "\n", "#Calculation\n", "\n", "V=A*v #m**3/s #volume of steam \n", "D=(V*(pi*4**-1*V_1)**-1)**0.5*100 #Diameter of pipe\n", "t=p*D*(2*sigma_t)**-1 #Thicknes of pipe\n", "\n", "#Result\n", "print\"Diameter of boiler is\",round(D,2),\"cm\"\n", "print\"Thickness of steel plpe is\",round(t,2),\"cm\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Diameter of boiler is 6.73 cm\n", "Thickness of steel plpe is 0.84 cm\n" ] } ], "prompt_number": 43 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem no 15.9,Page no.359" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of variables\n", "\n", "P=14*10**3 #N #Axial pull\n", "dL=0.0084 #cm #Elongation\n", "L=0.25 #m #Length\n", "p=7*10**6 #Internal pressure\n", "dL_2=0.0034 #cm #Longation\n", "d=0.0475 #m #Internal diameter \n", "D=0.05 #m #External Diameter\n", "m=0.25\n", "\n", "#Calculation\n", "\n", "t=(D-d)*2**-1 #thickness od tube\n", "A=pi*4**-1*(D**2-d**2) #Area of tube\n", "sigma=P*A**-1 #stress\n", "e=dL*(L)**-1 #strain\n", "E=sigma*e**-1 #Modulus of Elasticity\n", "sigma_1=p*d*(2*t)**-1 #Hoop stress\n", "sigma_2=p*d*(4*t)**-1 #Longitudinal stress\n", "\n", "m=-(sigma_1*(dL_2*L**-1*E-sigma_2)**-1) #POissoin's ratio\\\n", "\n", "#Let X=1*m**-1\n", "X=1*m**-1 #Poissoin's ratio\n", "\n", "#Result\n", "print\"The value of Poissoin's ratio is\",round(X,3)\n", " " ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The value of Poissoin's ratio is 0.277\n" ] } ], "prompt_number": 28 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem no 15.10,Page no.357" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of variables\n", "\n", "D=0.8 #m #Diameter\n", "t=0.01 #m #Thickness \n", "p=5*10**6 #Pa #Pressure\n", "m=1*0.25**-1\n", "E=200*10**9 #Pa\n", "\n", "#Calculations\n", "\n", "sigma_1=5*10**6*0.8*(4*0.01)**-1 #stress\n", "sigma_2=sigma_1\n", "e_1=sigma_1*E**-1-sigma_2*(m*E)**-1 #strain\n", "e_v=3*e_1\n", "V=4*3**-1*pi*(D*2**-1)**3 #m**3 tress\n", "dell_v=e_v*V*10**6 #cm**3\n", "\n", "#Result\n", "print\"Volume of additional Fluid\",round(dell_v,3),\"cm**3\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Volume of additional Fluid 301.593 cm**3\n" ] } ], "prompt_number": 37 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem no 15.11,Page no.358" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "d=0.3 #m #Diameter\n", "D=0.003 #m #Diameter of steel wire\n", "t=0.006 #m #thickness\n", "sigma_w=8*10**6 #Pa #Stress\n", "p=1*10**6 #Pa #Internal pressure\n", "E_s=200*10**9 #Pa #Modulus of Elasticity for steel\n", "E_c=100*10**9 #Pa #Modulus of Elasticity for cast iron\n", "m=1*0.3**-1\n", "\n", "#Calculations\n", "\n", "sigma_p=(sigma_w*pi*2**-1*d)*(2*t)**-1 #compressive hoop stress\n", "sigma_l=p*d*(4*t)**-1 #Longitudinal stress\n", "\n", "#when internal presure is apllied Let sigma_w_1=Tensile in wire and sigma_p_1=tensile hoop in wire\n", "#sigma_p_1*2*t+sigma_w_1*2*d**-1*pi*4**-1*d**2=p*D\n", "\n", "#After substituting values and further simplifying we get\n", "#1.2*sigma_p_1+0.471*sigma_w_1=3000 Equation 1\n", "\n", "#1*E_c**-1(sigma_p_1-sigma_1*m**-1+sigma_p)=1*E_s**-1(sigma_w_1-sigma_w)\n", "\n", "#After substituting values and further simplifying we get\n", "#sigma_p_1-0.5*sigma_w_1=1.36*10**6 \n", "#sigma_p_1=0.5*sigma_w_1-3.39*10**6 Equation 2\n", "\n", "#From Equation 2 substituting value of sigma_p_1 in Equation 1\n", "\n", "\n", "sigma_w_1=(40.68*10**3+0.3*10**6)*(10.71238*10**-3)**-1\n", "sigma_p_1=0.5*sigma_w_1-3.39*10**6\n", "\n", "#Let X=sigma_p_1 and Y=sigma_w_1\n", "X=sigma_p_1*10**-6 #MPa #Stresses in pipe\n", "Y=sigma_w_1*10**-6 #MPa #Stresses in wire\n", "\n", "#Result\n", "print\"Stress in the pipe is\",round(X,2),\"MN/m**2\"\n", "print\"Stress in the wire is\",round(Y,2),\"MN/m**2\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Stress in the pipe is 12.51 MN/m**2\n", "Stress in the wire is 31.8 MN/m**2\n" ] } ], "prompt_number": 29 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Problem no 15.12,Page no.359" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initilization of variables\n", "\n", "D=0.038 #m #External Diameter\n", "d=0.035 #m #Internal Diameter\n", "d_1=0.0008 #m #Steel wire diameter\n", "p=2*10**6 #pa #Pa #Internal Pressure\n", "sigma_t_1=7*10**6 #Pa #Circumferential stress\n", "#E_s=1.6*E_s\n", "m=0.3\n", "\n", "#Calculation\n", "\n", "t=(D-d)*2**-1 #m Thickness \n", "\n", "#sigma_t*2*t=pi*d*2**-1*sigma_w\n", "#From Above equation we get\n", "\n", "#sigma_t=0.419*sigma_w (Equation 1)\n", "\n", "sigma_w_1=(p*d-sigma_t_1*2*t)*(2*d_1**-1*pi*4**-1*d_1**2)**-1 #stress in wire\n", "sigma_l=p*d*(4*t)**-1 #Longitudinal stress in tube\n", "\n", "#Now Equating equations of strain in tube and wire we get\n", "sigma_w=-(1.6*(sigma_t_1-sigma_l*m)-sigma_w_1)*1.67**-1*10**-6\n", "\n", "#Result\n", "print\"The Tension at which wire must have been wound is\",round(sigma_w,2),\"MPa\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The Tension at which wire must have been wound is 20.0 MPa\n" ] } ], "prompt_number": 30 } ], "metadata": {} } ] }