{ "metadata": { "name": "", "signature": "sha256:38d29ad436c9255138372fb573a0261c5aeb8d664f2491fbf03a71e42b1c4783" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 23: Wings" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 23.1 Pg.No.609" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from __future__ import division\n", "from sympy import solve, symbols, pprint\n", "import math\n", "y=symbols('y')\n", "\n", "B1=B6=2580\n", "B2=B5=3880 #Boom areas (mm^2)\n", "B3=B4=3230\n", "\n", "l1=200\n", "l2=230 #dimensions shown in Fig 23.3 (mm)\n", "l3=165\n", "\n", "Mx=300*10**6 #bending moment (N.mm)\n", "My=0\n", "\n", "Ixx=2*(B1*l3**2+B2*l2**2+B3*l1**2)\n", "sigma_z=Mx/Ixx*y\n", "\n", "print \"direct stress in booms sigma_z = %s\" %(sigma_z)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "direct stress in booms sigma_z = 0.370651791174781*y\n" ] } ], "prompt_number": 8 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 23.2 Pg.No.612" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from __future__ import division\n", "from sympy import solve, symbols, pprint\n", "import math\n", "import numpy as np\n", "\n", "T=11.3*10**6 # torque applied (N.mm)\n", "G_REF=27600 #(N/mm^2)\n", "A1=258000\n", "A2=355000 #areas in table\n", "A3=161000\n", "\n", "#t*12=G/G_REF*t\n", "t12=24200/G_REF*1.22\n", "t12i=27600/G_REF*2.03\n", "t13=t24=24200/G_REF*1.22 #G and thickness taken from table ex23.2 Pg.No.612\n", "t35=t46=t56=20700/G_REF*0.92\n", "t34=27600/G_REF*1.63\n", "\n", "# del12=ds/t*12\n", "del12=1650/t12\n", "del12i=508/t12i\n", "del13=del24=775/t13\n", "del34=380/t34 #lengths taken from table\n", "del35=del46=508/t35\n", "del56=254/t56\n", "\n", "\n", "a=np.array([[del12+del12i,-del12i,0,-2*A1*G_REF],[-del12i,del12i+del13+del24+del34,-del34,-2*A2*G_REF],[0,-del34,del35+del46+del34+del56,-2*A3*G_REF],[A1,A2,A3,0]])\n", "b=np.array([0,0,0,5.65*10**6])\n", "x=np.linalg.solve(a,b)\n", "print \"shear stress distribution is as follows\"\n", "print \"q1=%1.1f N/mm\"%(x[0])\n", "print \"q2=%1.1f N/mm\"%(x[1])\n", "print \"q3=%1.1f N/mm\\n\"%(x[2])\n", "print \"dO_dz=%1.2e \"%(x[3])" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "shear stress distribution is as follows\n", "q1=7.1 N/mm\n", "q2=8.9 N/mm\n", "q3=4.2 N/mm\n", "\n", "dO_dz=7.36e-07 \n" ] } ], "prompt_number": 27 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 23.3 Pg.No.616" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from __future__ import division\n", "from sympy import solve, symbols, pprint\n", "import math\n", "import numpy as np\n", "\n", "A1=265000\n", "A2=213000\n", "A3=413000\n", "\n", "G_REF=27600\n", "Sy=86.8*10**3\n", "t78=3*27600/27600*1.22\n", "del78=1270/t78\n", "t12=t56=1.22\n", "del12=del56=1023/t12\n", "t23=1.63\n", "del23=1274/t23\n", "t34=2.03\n", "del34=2200/t34\n", "del38=57\n", "del84=95\n", "del87=347\n", "del27=68\n", "del75=106\n", "del16=330/1.63\n", "Ixx=809*10**6 #From example 23.1\n", "\n", "qb27=-99.4;qb16=-45.5;qb65=0;qb57=95.5;qb38=-69.8;qb48=69\n", "\n", "\n", "a=np.array([ [del34+del84+del38,-del38,0,-2*A1*G_REF], [-del38,del23+del38+del87+del27,-del27,-2*A2*G_REF], [0,-del27,del56+del27+del75+del12+del16,-2*A3*G_REF], [2*A1,2*A2,2*A3,0] ])\n", "b=np.array([-10488,-2561,7426,19736700])\n", "x=np.linalg.solve(a,b)\n", "\n", "qs01=5.5\n", "qs02=10.2\n", "qs03=16.5\n", "\n", "q34=qs01\n", "q23=qs02\n", "q12=qs03\n", "q61=-qb16+qs03\n", "q57=qb57-qs03\n", "q72=-qb27-qs02\n", "q48=qb48+qs01\n", "q83=-qb38-qs01\n", "\n", "print \"shear flows distribution is as follows :\"\n", "print \"q34=%1.2f N/mm\"%(q34)\n", "print \"q23=q87=%1.2f N/mm\"%(q23)\n", "print \"q12=q56=%1.2f N/mm\"%(q12)\n", "print \"q61=%1.2f N/mm\"%(q61) \n", "print \"q57=%1.2f N/mm\"%(q57)\n", "print \"q72=%1.2f N/mm\"%(q72)\n", "print \"q48=%1.2f N/mm\"%(q48)\n", "print \"q83=%1.2f N/mm\\n\"%(q83)\n", "\n", "print \"rate of twist = %1.1e rad/mm\"%(x[3])" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "shear flows distribution is as follows :\n", "q34=5.50 N/mm\n", "q23=q87=10.20 N/mm\n", "q12=q56=16.50 N/mm\n", "q61=62.00 N/mm\n", "q57=79.00 N/mm\n", "q72=89.20 N/mm\n", "q48=74.50 N/mm\n", "q83=64.30 N/mm\n", "\n", "rate of twist = 1.1e-06 rad/mm\n" ] } ], "prompt_number": 8 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 23.4 Pg.No.618 " ] }, { "cell_type": "code", "collapsed": false, "input": [ "from __future__ import division\n", "from sympy import solve, symbols, pprint\n", "import math\n", "import numpy as np\n", "\n", "#Boom areas\n", "B=[600,900,600,600,900,600]\n", "Pz=[0,0,0,0,0,0]\n", "y=[54.56,54.56,54.56,-54.56,-54.56,-54.56]\n", "Ixx=4*600*90**2+2*900*90**2\n", "Ixy=0\n", "Mx=1.65*10**6\n", "My=0\n", "\n", "a=np.array([[1700,-1520],[72000,144000]])\n", "b=np.array([3942,690726])\n", "x=np.linalg.solve(a,b)\n", "print \"\\nqs0I = %2.1f N/mm\\n\"%(x[0])\n", "print \"\\nqs0II = %2.1f N/mm\\n\"%(x[1])" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "\n", "qs0I = 4.6 N/mm\n", "\n", "\n", "qs0II = 2.5 N/mm\n", "\n" ] } ], "prompt_number": 21 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 23.5 Pg.No.622" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from __future__ import division\n", "from sympy import solve, symbols, pprint\n", "import math\n", "import numpy as np\n", "from sympy import integrate\n", "z=symbols('z')\n", "\n", "E=69000 #youngs modulus (N/mm^2)\n", "G=25900 #shear modulus (N/mm^2)\n", "t=2 #thickness (mm)\n", "B=[650,1300,650,650,1300,650] #boom area\n", "q0=[9.6,-5.8,50.3,-5.8,9.6,54.1,73.6]\n", "Sy0=44.5*10**3\n", "Sy1=1\n", "Mx0=-44.5*10**3*(2000-z)\n", "Mx1=-(2000-z)\n", "Ixx=81.3*10**6\n", "int_q0q1_Gt=1/G/t/Sy0*(q0[0]**2*250*t+q0[1]**2*500*t+q0[2]**2*250+q0[5]**2*250+q0[6]**2*250)\n", "\n", "delta=integrate(Mx0*Mx1/E/Ixx,(z,0,2000))+integrate(int_q0q1_Gt,(z,0,2000))\n", "print \"deflection at free end of the two cell = %2.2f mm\"%(delta)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "deflection at free end of the two cell = 23.58 mm\n" ] } ], "prompt_number": 70 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 23.6 Pg.No.624" ] }, { "cell_type": "code", "collapsed": false, "input": [ "from sympy import solve, symbols, pprint\n", "import math\n", "import numpy as np\n", "from sympy import integrate\n", "\n", "T=10*10**6 #torque subjected (N.mm)\n", "l1=800 \n", "l2=200 #lengths shown in Fig23.17 (mm)\n", "l3=1500\n", "A=l2*l1\n", "\n", "\n", "q=T/2/A\n", "S=T/l1\n", "q1=S/l2\n", "P=S*l3/2/l2\n", "\n", "a=np.array([[1,-1],[1,1]])\n", "b=np.array([31.3,62.5])\n", "q=np.linalg.solve(a,b)\n", "\n", "print \"shear flow :\"\n", "print \"q1=%2.2f N/mm\"%(q1)\n", "print \"q2=%2.2f N/mm\"%(q[0])\n", "print \"q3=%2.2f N/mm\\n\"%(q[1])\n", "\n", "print \"flange loads :\"\n", "print \"P(st.4500) = 0\"\n", "print \"P(st.3000) = %2.2f N (compression)\"%(l3*q[0]-l3*q[1])\n", "print \"P(st.2250) = %2.1f\"%(46875-l3/2*q1)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "shear flow :\n", "q1=62.50 N/mm\n", "q2=46.90 N/mm\n", "q3=15.60 N/mm\n", "\n", "flange loads :\n", "P(st.4500) = 0\n", "P(st.3000) = 46950.00 N (compression)\n", "P(st.2250) = 0.0\n" ] } ], "prompt_number": 84 } ], "metadata": {} } ] }