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diff --git a/Mechanics_Of_Material_by_J_M_Gere/11-Columns.ipynb b/Mechanics_Of_Material_by_J_M_Gere/11-Columns.ipynb new file mode 100644 index 0000000..0f47082 --- /dev/null +++ b/Mechanics_Of_Material_by_J_M_Gere/11-Columns.ipynb @@ -0,0 +1,444 @@ +{ +"cells": [ + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "# Chapter 11: Columns" + ] + }, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 11.1: EX11_1.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"E = 29000; // Modulus of elasticity in ksi\n", +"spl = 42 ; // Proportional limit in ksi\n", +"L = 25 ; // Total length of coloum in ft\n", +"n = 2.5 ; // factor of safety\n", +"I1 = 98 ; // Moment of inertia on horizontal axis\n", +"I2 = 21.7 ; // Moment of inertia on vertical axis\n", +"A = 8.25 ; // Area of the cross section\n", +"Pcr2 = (4*%pi^2*E*I2)/((L*12)^2) ; // Criticle load if column buckles in the plane of paper\n", +"Pcr1 = (%pi^2*E*I1)/((L*12)^2) ; // Criticle load if column buckles in the plane of paper\n", +"Pcr = min(Pcr1,Pcr2) ; // Minimum pressure would govern the design\n", +"scr = Pcr/A ; // Criticle stress\n", +"Pa = Pcr/n ; // Allowable load in k\n", +"disp('k',Pa,'The allowable load is ')\n", +" " + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 11.2: EX11_2.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"L = 3.25 ; // Length of alluminium pipe in m\n", +"d = 0.1 ; // Outer diameter of alluminium pipe\n", +"P = 100000; // Allowable compressive load in N\n", +"n =3 ; // Safety factor for eular buckling\n", +"E = 72e09 ; // Modulus of elasticity in Pa\n", +"l = 480e06 ; // Proportional limit\n", +"Pcr = n*P ; // Critic;e load\n", +"t = (0.1 - (55.6e-06)^(1/4) )/2 ; // Required thickness\n", +"// Above formula comes from solving following equation\n", +"// d2 = d ; d1 = d-2*t ; Pcr = n*P ; I = (%pi/64)*(d2^4-d1^4); Pcr = (2.406*%pi^2*E*I)/((L)^2) ;\n", +"tmin = t ;\n", +"disp('mm',tmin*1000,'The minimum required thickness of the coloumn is')\n", +"// Supplimentry calculatios \n", +"I = (%pi/64)*(d^4-(d-2*t)^4) ; // Moment of inertia\n", +"A = (%pi/4)*(d^2-(d-2*t)^2) ; // Area of cross section\n", +"r = sqrt(I/A);\n", +"s = L/r // slenderness ratio\n", +"scr = Pcr/A ; // Criticle stress " + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 11.3: Determination_of_longest_permissible_length_of_rod.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"P = 1500 ; // Load in lb\n", +"e = 0.45 ; // ecentricity in inch\n", +"h = 1.2 ; // Height of cross section in inch\n", +"b = 0.6 ; // Width of cross section in inch\n", +"E = 16e06 ; // Modulus of elasticity \n", +"del = 0.12 ; // Allowable deflection in inch\n", +"L = asec(1.2667)/0.06588 ; // Maximum allowable length possible\n", +"// Above formula comes from solving following equation\n", +"// Pcr = (%pi^2*E*I)/(4*(L)^2); I = (h*b^3)/12; del = e*(sec((%pi/2)*sqrt(P/Pcr))-1)\n", +"disp('inch',L,'The longest permissible length of the bar is')\n", +"\n", +"" + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 11.4: Calculation_of_compressive_stress_and_factor_of_safety.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"L = 25 ; // Length of coloum in ft\n", +"P1 = 320 ; // Load in K\n", +"P2 = 40 ; // Load in K\n", +"E = 30000 ; // Modulus of elasticity of steel in Ksi\n", +"P = 360 ; // Euivalent load\n", +"e = 1.5 ; // Ecentricity of compressive load\n", +"A = 24.1 ; // Area of the Cross section\n", +"r = 6.05 ; // in inch\n", +"c = 7.155 ; // in inch\n", +"sy = 42 ;// Yeild stress of steel in Ksi\n", +"smax = (P/A)*(1+(((e*c)/r^2)*sec((L/(2*r))*sqrt(P/(E*A))))); // Maximum compressive stress\n", +"disp('ksi',smax,'The Maximum compressive stress in the column ')\n", +"// Bisection method method to solve for yeilding\n", +"function [x] = stress(a,b,f)\n", +" N = 100;\n", +" eps = 1e-5;\n", +" if((f(a)*f(b))>0) then\n", +" error('no root possible f(a)*f(b)>0');\n", +" abort;\n", +" end;\n", +" if(abs(f(a))<eps) then\n", +" error('solution at a');\n", +" abort;\n", +" end\n", +" if(abs(f(b))<eps) then\n", +" error('solution at b');\n", +" abort;\n", +" end\n", +" while(N>0)\n", +" c = (a+b)/2\n", +" if(abs(f(c))<eps) then\n", +" x = c ;\n", +" x;\n", +" return;\n", +" end;\n", +" if((f(a)*f(c))<0 ) then\n", +" b = c ;\n", +" else\n", +" a = c ;\n", +" end\n", +" N = N-1;\n", +" end\n", +" error('no convergence');\n", +" abort;\n", +"endfunction\n", +"\n", +"deff('[y]=p(x)',['y = x + (0.2939*x*sec(0.02916*sqrt(x))) - 1012 '])\n", +"x = stress(710,750,p);\n", +"Py = x ; // Yeilding load in K\n", +"n = Py/P; // Factor of safety against yeilding\n", +"disp(n,'The factor of safety against yeilding is')\n", +"\n", +"\n", +" \n", +" \n", +" " + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 11.5: Calculation_of_allowable_axial_load_and_maximum_permissible_length.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"E = 29000; // Modulus of elasticity in ksi\n", +"sy = 36 ; // Yeilding stress in ksi\n", +"L = 20 ; // Length of coloumn in ft\n", +"r = 2.57 ; // radius of gyration of coloumn\n", +"K = 1 ; // Effetive Length factor\n", +"s = sqrt((2*%pi^2*E)/sy) // Criticle slenderness ratio (K*L)/r\n", +"s_ = (L*12)/r; // Slenderness ratio\n", +"// Part(a)\n", +"n1 = (5/3)+((3/8)*(s_/s))-((1/8)*((s_^3)/(s^3)));// Factor of safety \n", +"sallow = (sy/n1)*(1-((1/2)*((s_^2)/(s^2)))); // Allowable axial load\n", +"A = 17.6; // Cross sectional area from table E1\n", +"Pallow = sallow*A ; // Allowable axial load\n", +"disp('k',Pallow,'Allowable axial load is')\n", +"// Part (b)\n", +"Pe = 200 ; // Permissible load in K\n", +"L_ = 25 ; // Assumed length in ft\n", +"s__ = (L_*12)/r; // Slenderness ratio\n", +"n1_ = (5/3)+((3/8)*(s__/s))-((1/8)*((s__^3)/(s^3)));// Factor of safety \n", +"sallow_ = (sy/n1_)*(1-((1/2)*((s__^2)/(s^2)))); // Allowable axial load\n", +"A = 17.6 ; // Area of the cross section in^2\n", +"Pallow = sallow_*A // Allowable load\n", +"L1 = [24 24.4 25];\n", +"P1 = [201 194 190];\n", +"L_max = interpln([P1;L1],Pe); // Interpolation for getting the length correspondong to permissible load\n", +"disp('ft',L_max,'The maximum permissible length is')\n", +"" + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 11.6: Finding_the_minimum_required_thickness_for_a_steel_pipe_column.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"L = 3.6 ; // Length of steel pipe coloumn\n", +"d = 0.16 ; // Outer diameter in m\n", +"P = 240e03; // Load in N\n", +"E = 200e09; // Modulus of elasticity in Pa\n", +"sy = 259e06 ; // yeilding stress in Pa\n", +"Le = 2*L ; // As it in fixed-free condition\n", +"sc = sqrt((2*%pi^2*E)/sy); // Critical slenderness ratio\n", +"K = 2;\n", +"// First trial\n", +"t = 0.007; // Assumed thick ness in m\n", +"I = (%pi/64)*(d^4-(d-2*t)^4) // Moment of inertia\n", +"A = (%pi/4)*(d^2-(d-2*t)^2) // Area of cross section\n", +"r = sqrt(I/A) ; // Radius of gyration\n", +"sc_ = (K*L)/r ; // Slender ness ratio\n", +"n2 = 1.98 ; // From equation 11.80\n", +"sa = (sy/(2*n2))*(sc^2/sc_^2) // Allowable stress\n", +"Pa = sa*A ; // Allowable axial load in N\n", +"// Interpolation\n", +"t = [7 8 9];\n", +"Pa = [196 220 243];\n", +"t_min = interpln([Pa;t],240) ; // Interpolation for getting the minimum length\n", +"disp('mm',t_min,'The minimum required thickness of the steel pipe is')\n", +"" + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 11.7: Determination_of_the_minimum_required_outer_diameter_of_aluminium_tube.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"L = 16 ; // Effective length in inch\n", +"P = 5 ; // axial load in K\n", +"// Bisection method for solvong the quaderatic\n", +"function [x] = stress(a,b,f)\n", +" N = 100;\n", +" eps = 1e-5;\n", +" if((f(a)*f(b))>0) then\n", +" error('no root possible f(a)*f(b)>0');\n", +" abort;\n", +" end;\n", +" if(abs(f(a))<eps) then\n", +" error('solution at a');\n", +" abort;\n", +" end\n", +" if(abs(f(b))<eps) then\n", +" error('solution at b');\n", +" abort;\n", +" end\n", +" while(N>0)\n", +" c = (a+b)/2\n", +" if(abs(f(c))<eps) then\n", +" x = c ;\n", +" x;\n", +" return;\n", +" end;\n", +" if((f(a)*f(c))<0 ) then\n", +" b = c ;\n", +" else\n", +" a = c ;\n", +" end\n", +" N = N-1;\n", +" end\n", +" error('no convergence');\n", +" abort;\n", +"endfunction\n", +"\n", +"deff('[y]=p(x)',['y = 30.7*x^2 - 11.49*x -17.69 '])\n", +"x = stress(0.9,1.1,p);\n", +"d = x; // Diameter in inch\n", +"sl = 49.97/d ; // Slenderness ration L/r\n", +"dmin = d ; // Minimum diameter\n", +"\n", +"// The above equation comes from solving the following equationd for d\n", +"// S_allow = 13.7 - 0.23*(L/r) = P/ A ;\n", +"// A = (%pi/4)*(d^2-(d-2t)^2)\n", +"// I = (%pi/64)*(d^4-(d-2t)^4)\n", +"// r = sqrt(I/A)\n", +"disp('inch',dmin,'The minimum required outer diameter of the tube is')\n", +"\n", +"\n", +"\n", +"\n", +"\n", +"\n", +"\n", +"\n", +"\n", +"" + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 11.8: EX11_8.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"Fc = 11e06 ; // Compressive desing stress in Pa\n", +"E = 13e09 ; // Modulus of elasticity in Pa\n", +"// Part (a)\n", +"Kce = 0.3 ; \n", +"c = 0.8; \n", +"A = 0.12*0.16 ; // Area of cross section\n", +"Sl = 1.8/0.12 ; // Slenderness ratio\n", +"fi = (Kce*E)/(Fc*Sl^2) ; // ratio of stresses\n", +"Cp = ((1+fi)/(2*c)) - sqrt(((1+fi)/(2*c))^2-(fi/c)); // Coloumn stability factor \n", +"Pa = Fc*Cp*A ; // Allowable Axial load\n", +"disp('N',Pa,'The allowable axial load is')\n", +"// Part (b)\n", +"P = 100000; // Allowable Axial load\n", +"Cp_ = P/(Fc*A) ; // Coloumn stability factor\n", +"// Bisection method method to solve for fi\n", +"function [x] = stress(a,b,f)\n", +" N = 100;\n", +" eps = 1e-5;\n", +" if((f(a)*f(b))>0) then\n", +" error('no root possible f(a)*f(b)>0');\n", +" abort;\n", +" end;\n", +" if(abs(f(a))<eps) then\n", +" error('solution at a');\n", +" abort;\n", +" end\n", +" if(abs(f(b))<eps) then\n", +" error('solution at b');\n", +" abort;\n", +" end\n", +" while(N>0)\n", +" c = (a+b)/2\n", +" if(abs(f(c))<eps) then\n", +" x = c ;\n", +" x;\n", +" return;\n", +" end;\n", +" if((f(a)*f(c))<0 ) then\n", +" b = c ;\n", +" else\n", +" a = c ;\n", +" end\n", +" N = N-1;\n", +" end\n", +" error('no convergence');\n", +" abort;\n", +"endfunction\n", +"deff('[y]=p(x)',['y = ((1+x)/(2*c)) - sqrt(((1+x)/(2*c))^2-(x/c)) - Cp_ '])\n", +"x = stress(0.1,1,p); \n", +"fi_ = x \n", +"d_ = 0.12 ; // Diameter in m\n", +"L_max = d_*sqrt((Kce*E)/(fi_*Fc)); // Maximum length in m\n", +"disp('m',L_max,'The minimum allowable length is')\n", +"// Part (c)\n", +"b1 = [0.130 0.131 0.132]; // Two choices\n", +"Sl1 = 2.6./b1 // slenderness ratio\n", +"fi1 = (Kce*E)./(Fc*Sl1^2) // Ratio\n", +"Cp1 = ((1+fi1)/(2*c)) - sqrt(((1+fi1)/(2*c)).^2-(fi1/c)); // Coloumn stability factor \n", +"P1 = 11000.*Cp1.*b1^2 ; // Allowable atress \n", +"Pa1 = 125; // Given allowable stress\n", +"// Does not require display of result analysis has been shown for b = 0.131\n", +" " + ] + } +], +"metadata": { + "kernelspec": { + "display_name": "Scilab", + "language": "scilab", + "name": "scilab" + }, + "language_info": { + "file_extension": ".sce", + "help_links": [ + { + "text": "MetaKernel Magics", + "url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md" + } + ], + "mimetype": "text/x-octave", + "name": "scilab", + "version": "0.7.1" + } + }, + "nbformat": 4, + "nbformat_minor": 0 +} |