{ "metadata": { "name": "" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 4:Axial Load" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4.1 Page no 126" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Given\n", "a_ab = 1\t\t #inch**2, area\n", "a_bd = 2 \t\t #inch**2\n", "a_bc = a_bd\n", "p = 29\t\t\t #kN, load\n", "l_ab = 2\t\t #ft\n", "l_bc = 1.5 \t\t #ft\n", "l_cd = 1 \t #ft\n", "\n", "#Calculations\n", "#Internal Forces By method of Sections\n", "p_bc = 15 #kip\n", "p_cd = 7 #kip\n", "p_ab=9 #kip\n", "#Displacement\n", "d=(p_bc*l_ab*12/(a_ab*p*10**3))+(p_cd*l_bc*12/(a_bd*p*10**3))+(p_ab*l_cd*12/(a_bc*p*10**3))\n", "d_=p_cd*l_bc*12/(a_bd*p*10**3)\n", "\n", "#Display\n", "print\"The displacement of B relative to C is = +%1.3f mm\",round(d*10,4),\"inch\"\n", "print \"Displacement of B relative to C is\",round(d_,5),\"inch\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The displacement of B relative to C is = +%1.3f mm 0.0217 inch\n", "Displacement of B relative to C is 0.00217 inch\n" ] } ], "prompt_number": 11 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4.2 Page no 127" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Given\n", "a_ab = 400.0 #mm**2, area\n", "d_rod = 10.0 #mm\n", "r_rod = d_rod/(2*1000) #radius in m\n", "P = 80.0 #kN, load\n", "E_st = 200*(10**9) #Pa, pressure\n", "E_al = 70*(10**9) #Pa\n", "l_ab = 400.0 #mm, length of ab\n", "l_bc = 600.0 #mm length of bc\n", "\n", "#Calculations\n", "#Displacement\n", "#delta =PL/AE\n", "import math\n", "numerator1 = P*(10**3)*(l_bc/1000.0) \n", "denominator1 = (math.pi*r_rod**2*E_st)\n", "delta_cb = numerator1/denominator1 #to the right\n", "numerator2 = -P*(10**3)*(l_ab/1000.0) \n", "denominator2 = (a_ab* 10**-6 *E_al)\n", "delta_a = -numerator2/denominator2 #to the right\n", "delta_c = delta_a+delta_cb\n", "\n", "#Display\n", "print\"The displacement of C with respect to B = \",round(delta_cb,4),\"m\"\n", "print\"The displacement of B with respect to A = \",round(delta_a,4),\"m\"\n", "print'The displacement of C relative to A = ',round(delta_c*1000,2),\"mm\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The displacement of C with respect to B = 0.0031 m\n", "The displacement of B with respect to A = 0.0011 m\n", "The displacement of C relative to A = 4.2 mm\n" ] } ], "prompt_number": 16 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4.3 Page no 128" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Given\n", "d_ac = 20.0 #mm, ac diameter\n", "r_ac = d_ac/(2*1000)\t\t #radius in m\n", "d_bd =40.0 \t\t\t #mm\n", "r_bd = d_bd/(2*1000) \t\t#radius in m\n", "P = 90.0 \t\t\t\t#kN\n", "E_st = 200*(10**9) \t\t#Pa\n", "E_al = 70*(10**9) \t\t#Pa\n", "l_af = 200.0 \t\t\t#mm\n", "l_fb = 400.0 \t\t\t#mm\n", "l_bd = 300.0\t\t\t#mm\n", "l_ac = l_bd\n", "\n", "#Calculations\n", "#Internal Force\n", "P_ac = 60 #kN\n", "P_bd = 30 #kN\n", "#Displacement\n", "import math\n", "num1 = -(P_ac*10**3*(l_ac/1000.0))\n", "denom1 = math.pi* r_ac**2*E_st\n", "delta_a = -num1/denom1 \n", "delta_a = delta_a*1000 \n", "#Post BD delta = PL/AE\n", "num2 = -(P_bd*10**3*(l_bd/1000))\n", "denom2 = math.pi* r_bd**2*E_al\n", "delta_b = -num2/denom2 \n", "delta_b = delta_b*1000 \n", "delta_f = delta_b + (0.184)*(l_fb/(l_af+l_fb)) \n", "\n", "#Display\n", "print'The displacement of Post AC =',round(delta_a,3),\"mm downwards\"\n", "print'The displacement of Post BD =',round(delta_b,3),\"mm downwards\"\n", "print'nThe displacement of point F =',round(delta_f,3),\"mm downwards\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The displacement of Post AC = 0.286 mm downwards\n", "The displacement of Post BD = 0.102 mm downwards\n", "nThe displacement of point F = 0.225 mm downwards\n" ] } ], "prompt_number": 24 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4.5 Page no 139" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Given\n", "import math\n", "d_ab = 5 #mm, ab diameter\n", "A = (math.pi/4)*(d_ab/1000)**2\n", "gap = 1 #mm\n", "P = 20 #kN, pressure\n", "E_st = 200 #GPa\n", "l_ac = 0.4 #m\n", "l_cb = 0.8 #m\n", "l_ab = l_ac+l_cb\n", "\n", "#Calculations\n", "#Equilibrium\n", "# Eqn1 -Fa - Fb +P*10**3 = 0 \n", "#Compatibility\n", "delta_ba = gap/1000.0 #in m\n", "delta = delta_ba*(A*E_st*10**9) #delta_ba* Lac/AE \n", "\n", "#Eqn2 (L/AE)*Fa -(Lb/AE)*Fb = delta_ba\n", "#Solving Equations 1 and 2 by matrices\n", "Fa=16 #KN\n", "Fb=4.05 #KN\n", "\n", "#Display\n", "print\"The reaction force at A = \",Fa,\"kN\"\n", "print\"The reaction force at B = \",Fb,\"kN\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The reaction force at A = 16 kN\n", "The reaction force at B = 4.05 kN\n" ] } ], "prompt_number": 11 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4.6 Page no 140" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Given\n", "P = 9 \t\t #kip, load\n", "E_al = 10 #ksi, \n", "E_br = 15 # ksi\n", "h = 1.5 \t #ft\n", "ri = 1 \t #inch\n", "ro = 2 \t #inch\n", "\n", "#Calculations\n", "import math\n", "A = (math.pi*(ro**2 -ri**2))\n", "Ai = math.pi*ri**2\n", "#Equilibrium Eqn1 F_al +F_br = P\n", "#Compatibility\n", "coeff_F_br = (A*E_al)/(Ai*E_br) \n", "#Eqn2 F_al- (coeff_F_br*F_br) = 0\n", "#Solving equations 1 and 2 using matrices\n", "Fal=6 \n", "Fbr=3\n", "\n", "avg_stress_al = Fal/A \n", "avg_stress_br = Fbr/Ai \n", "avg_stress_al = avg_stress_al/1000\n", "avg_stress_br = avg_stress_br/1000\n", "\n", "#Display\n", "print\"The axial force experienced by Al = \",Fal,\"ksi\"\n", "print\"The axial force experienced by Brass = \",Fbr,\"ksi\"\n", "print'The average normal stress in Al = ',round(avg_stress_al*1000,3),\"ksi\"\n", "print'The average normal stress in Al Brass = ',round(avg_stress_br*1000,3),\"ksi\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The axial force experienced by Al = 6 ksi\n", "The axial force experienced by Brass = 3 ksi\n", "The average normal stress in Al = 0.637 ksi\n", "The average normal stress in Al Brass = 0.955 ksi\n" ] } ], "prompt_number": 7 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4.7 Page no 141" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Given\n", "P = 15\t\t #kN. load\n", "a_ab = 50 \t#mm**2, area\n", "a_ef =a_ab\n", "a_cd = 30 \t#mm**2, area\n", "l_ef = 0.5 \t#m, ef length\n", "l_ce = 0.4 \t#m\n", "l_ac = 0.4 \t#m\n", "\n", "#Calculations\n", "#In the y direction F_a +F_c +F_e = P\n", "#of moments -F_a(l_ac)+ P(l_ac/2) +F_e(l_ce) = 0\n", "\n", "#Compatibility equation for displacemnts\n", "coeff_Fc = (1/a_cd) #coefficient of Fc\n", "coeff_Fa = (0.5/a_ab) #coefficient of Fc\n", "coeff_Fe = (0.5/a_ef) #coefficient of Fc\n", "\n", "#Solving the 3 Equations\n", "F_a=9.52\n", "F_b=3.46\n", "F_c=2.02\n", "#Display\n", "print\"The force in rod AB = \",F_a,\"kN\"\n", "print'The force in rod CD = ',F_b,\"kN\"\n", "print'The force in rod EF = ',F_c,\"kN\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The force in rod AB = 9.52 kN\n", "The force in rod CD = 3.46 kN\n", "The force in rod EF = 2.02 kN\n" ] } ], "prompt_number": 10 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4.8 Page no 142" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Given\n", "r_o = 0.5\t\t #inch, outside radius\n", "r_i = 0.25\t\t#inch, inside radius\n", "l = 3 \t\t\t#inch\n", "one_turn =20 #threads per inch\n", "\n", "#calculations\n", "import math\n", "a_t = (math.pi)*(r_o**2 - r_i**2) #Area of thread\n", "a_b = (math.pi*(r_i**2))# Area of bolt\n", "# In Y direction F_b - F_t = 0\n", "\n", "#Compatibility\n", "half_turn = one_turn/2.0\n", "#Solving the two simultaneous equations for F_b and F_t\n", "F_b =11.22 #kip\n", "F_t = F_b\n", "stress_b = F_b/a_b\n", "stress_t = F_t/a_t\n", "F_b = F_b/1000.0\n", "F_t = F_t/1000.0\n", "\n", "#Display\n", "print'The stress in the bolt ',round(stress_b,1),\"ksi\"\n", "print'The stress in the screw ',round(stress_t,1),\"ksi\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The stress in the bolt 57.1 ksi\n", "The stress in the screw 19.0 ksi\n" ] } ], "prompt_number": 14 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4.9 Page no 144" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Given\n", "import math\n", "l_ab = 800 + 400\t\t#mm, ab length\n", "P = 20 \t\t \t#kN, load\n", "d = 5/1000.0 \t\t\t#m, diameter\n", "area = (math.pi/4.0)*d**2 \t#Cross sectional area\n", "l_bbdash = 1/1000.0\t\t#m\n", "E = 200.0 \t\t\t#GPa\n", "\n", "#Calculations\n", "#Compatibility\n", "delta_p = (P*10**3*0.4)/(area*E*10**9) #delta = PL/AE\n", "delta_b = delta_p-l_bbdash\n", "F_b = (delta_b*area*E*10**9)/(l_ab/1000.0)\n", "F_b = F_b/1000.0\n", "\n", "#Equilibrium\n", "F_a = P - F_b\n", "\n", "#Display\n", "print\"The reaction at A \",round(F_a,2),\"kN\"\n", "print'The reaction at B',round(F_b,2),\"kN\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The reaction at A 16.61 kN\n", "The reaction at B 3.39 kN\n" ] } ], "prompt_number": 22 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4.10 Page no 152" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Given\n", "T1 = 60\t\t #degree celcius\n", "T2 = 120\t\t#degress celcius\n", "l_ab = 0.5\t\t#m\n", "area =l_ab**2 \t#m**2\n", "alpha = 6.6*10**-6\t# per degree celcius\n", "E = 29*10**6 \t\t#kPa\n", "\n", "#Equilibrium\n", "#F_a = F_b = F\n", "del_T = T2-T1\n", "F = alpha*del_T*area*E #Thermal Stress Formula\n", "avg_normal_comp_stress = (F*10**-3)/area # sigma = F/A\n", "\n", "#Display\n", "print\"The force at A and B = \",F/1000,\"kip\"\n", "print'The average normal compressive stress = ',avg_normal_comp_stress,\"ksi\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The force at A and B = 2.871 kip\n", "The average normal compressive stress = 11.484 ksi\n" ] } ], "prompt_number": 27 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4.12 Page no 154" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Given\n", "area_sleeve = 600*10**-6 #m**2, area\n", "area_bolt = 400*10**-6 #m**2, area\n", "T1 = 15 #degree celcius\n", "T2 = 80 #degree celcius\n", "alpha_bolt = 12*10**-6 #per degree celcius\n", "alpha_sleeve = 23*10**-6 #per degree celcius\n", "l = 0.15 #m\n", "E_bolt = 200*10**9 #N/m**2 \n", "E_sleeve = 73.1*10**9 #N/m**2 \n", "\n", "#Equilibrium\n", "#F_s = F_b\n", "\n", "#Compatibility\n", "del_T = T2 - T1 \n", "delb_T = alpha_bolt*del_T*l \n", "delb_F = l/(area_bolt*E_bolt)\n", "dels_T = alpha_sleeve*del_T*l \n", "dels_F = l/(area_sleeve*E_sleeve)\n", "\n", "#delb_T + F_b*delb_F = dels_T + F_s*dels_F\n", "F_b = (dels_T-delb_T)/(delb_F+dels_F)\n", "F_b = F_b/1000 #in kN\n", "F_s= F_b\n", "\n", "#Display\n", "print\"The force experienced by sleeve and bolt, Fs=Fb \",round(F_s,1),\"kN\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The force experienced by sleeve and bolt, Fs=Fb 20.3 kN\n" ] } ], "prompt_number": 44 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4.13 Page no 165" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Given\n", "yiel = 250 #MPa, yield stress\n", "r = 4 #mm, radius\n", "width = 40 #mm\n", "thick = 2 #mm\n", "\n", "#a)\n", "r_h = r/(width - (2*r))\n", "w_h = width/(width - (2*r))\n", "K = 1.75\n", "area = (thick*(width - (2*r))*10**-6)\n", "P_y = (yiel*10**6*area)/K\n", "P_y = P_y/1000.0\n", "#b)\n", "P_p = (yiel*10**6*area)\n", "P_p = P_p/1000.0\n", "\n", "#Display\n", "print\"The maximum load P that does not cause the steel to yield \",round(P_y,2),\"kN\"\n", "print'The maximum load that the bar can support ',P_p,\"kN\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The maximum load P that does not cause the steel to yield 9.14 kN\n", "The maximum load that the bar can support 16.0 kN\n" ] } ], "prompt_number": 36 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 4.14 Page No:166" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Given:\n", "P = 60 #KN, load\n", "sigmaY= 420 #MPa, bending stress\n", "E = 70*10**6 #MPa\n", "l1 = 0.1 #m\n", "l2 = 0.3 #m\n", "r=0.005 #m \n", "\n", "#Maximum Normal Stress:\n", "#r_h = 6/20.0\n", "#w_h = 40/20.0\n", "#K = 1.6\n", "#from sec 4.4\n", "Fa=45\n", "Fb=15\n", "sigmaAC=(Fa/1000.0)/((math.pi)*r**2)\n", "sigmaCB=(Fb/1000.0)/((math.pi)*r**2)\n", "Fay=sigmaY*10**3*(math.pi)*r**2\n", "Fb=P-Fay\n", "if sigmaAC>sigmaY:\n", " print\"Calculate sigmaAC again\"\n", "else:\n", " print\"It is OK\" \n", "sigmaAC_=sigmaY\n", "sigmaCB_=Fb/1000.0/((math.pi)*r**2)\n", "if sigmaCB_