{ "metadata": { "name": "" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 8:Combined Loadings" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.1 Page No 408" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Given\n", "di=4*12 #inch, diameter\n", "ri=di/2.0 #Radius\n", "t=0.5 #inch, thickness\n", "sigma=20.0 #Ksi, stress\n", "\n", "#Calculation\n", "#Cylindrical Pressure Vessel\n", "p1=(t*sigma)/ri #sigma = pr/t\n", "#Spherical Vessel\n", "p2=(2*t*sigma)/(ri) #sigma = pr/2t\n", "\n", "#Display\n", "print\"The maximum internal pressure the cylindrical pressure vessel can sustainis\",round(p1*1000,0),\"psi\"\n", "print\"The maximum internal pressure a spherical pressure vessel can sustain is\",round(p2*1000,0),\"psi\"\n", "\n", " " ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The maximum internal pressure the cylindrical pressure vessel can sustainis 417.0 psi\n", "The maximum internal pressure a spherical pressure vessel can sustain is 833.0 psi\n" ] } ], "prompt_number": 20 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.2 Page No 414" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Determine stress at point B and C\n", "\n", "#Given\n", "P = 15000.0 #N, force,\n", "a = 40.0 #mm, length\n", "b = 100.0 #mm, breadth\n", "\n", "#CAlculation\n", "#Normal Force\n", "A = a*b #Area\n", "sigma = P/A\n", "#Bending Moment\n", "I = (a*b**3)/12.0 #I = (1/12)*bh**3\n", "M = P*(b/2.0) \n", "c = b/2.0\n", "sigma_max =(M*c)/I\n", "\n", "#Superposition\n", "x = ((sigma_max-sigma)*b)/((sigma_max+sigma)+(sigma_max-sigma))\n", "sigma_b = (sigma_max-sigma)\n", "sigma_c = (sigma_max + sigma)\n", "\n", "#Display\n", "print\"The state of stress at B is(tensile)\",sigma_b,\"psi\"\n", "print\"The state of stress at C is (compressive)\",sigma_c,\"psi\"\n", "\n", "\n", " \n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The state of stress at B is(tensile) 7.5 psi\n", "The state of stress at C is (compressive) 15.0 psi\n" ] } ], "prompt_number": 21 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.3 Page No 415" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Calculate the stress\n", "\n", "#Given:\n", "ri =24 #inch, radius\n", "t = 0.5 #inch\n", "ro = ri+t\n", "sp_wt_water = 62.4 #lb/ft**3\n", "sp_wt_steel = 490 #lb/ft**3\n", "l_a = 3 #m depth of point A from the top\n", "\n", "#Internal Loadings:\n", "import math\n", "v = (math.pi*l_a)*((ro/12.0)**2 - (ri/12.0)**2)\n", "W_st = sp_wt_steel*v\n", "p = sp_wt_water*l_a #lb/ft**2,Pascal's Law\n", "p_=p*0.0069 #psi\n", "#Circumferential Stress:\n", "sigma1 = (p_*ri)/t\n", "#Longitudinal Stress:\n", "A_st = (math.pi)*(ro**2 - ri**2)\n", "sigma2 = W_st/A_st\n", "\n", "#Display:\n", "print\"The state of stress at A (Circumferential)\",round(sigma1,0),\"KPa\"\n", "print\"The state of stress at A (Longitudinal) \",round(sigma2,1),\"KPa\"\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The state of stress at A (Circumferential) 62.0 KPa\n", "The state of stress at A (Longitudinal) 10.2 KPa\n" ] } ], "prompt_number": 30 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.4 Page No 417" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Determine the state of stress\n", "\n", "#Given\n", "y_c = 125/1000.0 #m, length\n", "x_c = 1.5 #m\n", "y_b = 1.5 #m\n", "x_b = 6.0 #m\n", "udl = 50.0 #kN/m, force per unit length\n", "l_udl = 2.5 #m\n", "l = 250/1000.0 #m\n", "width = 50/1000.0 #m \n", "\n", "\n", "#Internal Loadings:\n", "N = 16.45 #kN\n", "V = 21.93 #kN\n", "M = 32.89 #kNm\n", "\n", "#Stress Components:\n", "#Normal Force:\n", "A = l*width\n", "sigma1 = N/(A*1000)\n", "#Shear Force:\n", "tou_c = 0\n", "#Bending Moment:\n", "c = y_c\n", "I = (1/12.0)*(width*l**3)\n", "sigma2 = (M*c)/(I*1000)\n", "#Superposition:\n", "sigmaC = sigma1+sigma2\n", "\n", "#Display:\n", "print\"The stress due to normal force at C \",round(sigma1,2),\"MPa\"\n", "print\"The stress due to shear force at C \",tou_c,\"MPa\"\n", "print\"The stress due to bending moment at C \",round(sigma2,1),\"MPa\"\n", "print\"The resultant stress at C \",round(sigmaC,1),\"MPa\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The stress due to normal force at C 1.32 MPa\n", "The stress due to shear force at C 0 MPa\n", "The stress due to bending moment at C 63.1 MPa\n", "The resultant stress at C 64.5 MPa\n" ] } ], "prompt_number": 31 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.5 Page No 418" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Given:\n", "r = 0.75*10 #mm, radius\n", "f_x =40000 #N, force along x\n", "f_y =800 #N force along y\n", "l1 = 0.8 #mm\n", "l2 = 0.4 #mm\n", "\n", "#Stress Components:\n", "#Normal Force:\n", "A1 =l1*l2\n", "sigma1 = f_x/A1 #stress = P/A\n", "\n", "#Bending Moment:\n", "M_y1 = 8000 #N\n", "c1 = l2/2.0\n", "I1 = (1/12.0)*(l1*l2**3)\n", "sigma_A1 = (M_y1*c1)/I1 \n", "M_y2 = 16000 #N\n", "c2 = l2\n", "I2 = (1/12.0)*(l2*l1**3)\n", "sigma_A2 = (M_y2*c2)/I2 \n", "\n", "#Resultant:\n", "res_normal= -sigma1-sigma_A1-sigma_A2\n", "\n", "#Display:\n", "\n", "print\"The stress due to normal force at A \",sigma1/1000,\"KPa\"\n", "print\"The stress due to bending moment 8KN at A \",sigma_A1/1000,\"KPa\"\n", "print\"The stress due to bending moment 16KN at A \",sigma_A2/1000,\"KPa\"\n", "print\"The resultant normal stress component at A \",res_normal/1000,\"KPa\"\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The stress due to normal force at A 125.0 KPa\n", "The stress due to bending moment 8KN at A 375.0 KPa\n", "The stress due to bending moment 16KN at A 375.0 KPa\n", "The resultant normal stress component at A -875.0 KPa\n" ] } ], "prompt_number": 38 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.7 Page No 420" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Calculate Stress at A\n", "\n", "#Given:\n", "P = 500 #lb, load\n", "r=0.75 #inch, radius\n", "#Stress Components:\n", "\n", "#Normal Force:\n", "import math\n", "A = math.pi*r**2\n", "sigma = P/A\n", "\n", "#Bendng Moments:\n", "M_x =7000 #lb\n", "cy = r\n", "Ix = (1/4.0)*math.pi*(r**4) \n", "sigma_max_1 = (M_x*cy)/Ix \n", "\n", "M_y = P*l_bc/2.0\n", "cx = l_bc/2.0\n", "Iy = (1/12.0)*(l_ab*l_bc**3) #I = (1/12)*(bh**3)\n", "sigma_max_2 = (M_y*cx)/Iy #sigma = My/I\n", "#Superposition\n", "sigmaf=round(sigma/1000,3)+round(sigma_max_1/1000,1)\n", "\n", "#Display:\n", "print\"The normal stress at corner A \",round(sigma/1000,3),\"ksi\"\n", "print\"The normal stress at point A for Bending Moment \",round(sigma_max_1/1000,1),\"ksi\"\n", "print\"The normal stress at point A for Superimposition \",round(sigmaf,1),\"ksi\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The normal stress at corner A 0.283 ksi\n", "The normal stress at point A for Bending Moment 21.1 ksi\n", "The normal stress at point A for Superimposition 21.4 ksi\n" ] } ], "prompt_number": 50 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 8.8 Page No 421" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Determine the state of stress at point A\n", "\n", "#Given\n", "r=0.75 #radius,inch\n", "V=800 #Forca, lb\n", "\n", "#Calculation\n", "#shear force\n", "import math\n", "Q=(4*r/(3*math.pi))*(0.5*(math.pi*r**2))\n", "Ix=(1/4.0)*math.pi*(r**4) \n", "tau=V*Q/(Ix*2*r)\n", "#Since point A is on neutral axis\n", "sigmaA=0\n", "T=11200 #lb inch, force \n", "Iy=(1/2.0)*math.pi*(r**4) \n", "sigma_a=T*r/Iy\n", "#Superimposition\n", "sigmayzA=tau+sigma_a\n", "\n", "\n", "#Result\n", "print\"The stress for shear stress distribution is\",round(tau/1000,3),\"ksi\"\n", "print\"The stress for Bending moment is\",sigmaA,\"ksi\"\n", "print\"The stress for torque\",round(sigma_a/1000,2),\"ksi\"\n", "print\"The stress for Superimposition \",round(sigmayzA/1000,1),\"ksi\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The stress for shear stress distribution is 0.604 ksi\n", "The stress for Bending moment is 0 ksi\n", "The stress for torque 16.9 ksi\n", "The stress for Superimposition 17.5 ksi\n" ] } ], "prompt_number": 67 } ], "metadata": {} } ] }