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diff --git a/Machine_Design_by_U_C_Jindal/23-BRAKES.ipynb b/Machine_Design_by_U_C_Jindal/23-BRAKES.ipynb new file mode 100644 index 0000000..6140bdc --- /dev/null +++ b/Machine_Design_by_U_C_Jindal/23-BRAKES.ipynb @@ -0,0 +1,371 @@ +{ +"cells": [ + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "# Chapter 23: BRAKES" + ] + }, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 23.1: B23_1.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"// sum 23-1\n", +"clc;\n", +"clear;\n", +"W=20e3;\n", +"m=W/9.81;\n", +"//diameter of brake drum\n", +"Db=0.6;\n", +"p=1;\n", +"Vi=1;\n", +"Vf=0;\n", +"D=1;\n", +"R=0.5;\n", +"wi=Vi/R;\n", +"wf=0;\n", +"w=1;\n", +"Vav=0.5;\n", +"S=2;\n", +"t=S/Vav;\n", +"//angle turned by by hoist drum=theta\n", +"theta=0.5*wi*t;\n", +"K.E=0.5*m*Vi^2;\n", +"P.E=2*W;\n", +"T.E=K.E+P.E;\n", +"T=T.E/theta;\n", +"P=wi*T*10^-3;\n", +"Rb=Db/2;\n", +"Ft=0.5*T*p/Rb;\n", +"u=0.35;\n", +"N=Ft/u;\n", +"//contact area of brake lining=A\n", +"A=N/p;\n", +"b=0.3*Db;\n", +"L=A*10^-6/(b);\n", +"//angle subtended at brake drum centre=theta2\n", +"theta2=2*(asin(L/Db));\n", +"theta2=theta2*180/%pi; // converting radian to degree\n", +"\n", +" // printing data in scilab o/p window\n", +" printf('T is %0.1f Nm ',T);\n", +" printf('\n P is %0.4f kW ',P);\n", +" printf('\n b is %0.2f m ',b);\n", +" printf('\n L is %0.3f m ',L);\n", +" printf('\n theta2 is %0.0f deg ',theta2);\n", +" \n", +"\n", +"\n", +"" + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 23.2: B23_2.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"// sum 23-2\n", +"clc;\n", +"clear;\n", +"b=80;\n", +"t=2;\n", +"theta=225*%pi/180;\n", +"u=0.22;\n", +"//F1/F2=e^(u*theta)\n", +"//let F1/F2=x;\n", +"x=exp(u*theta);\n", +"//maximum tensile stress in steel tape is siga\n", +"siga=60;\n", +"A=b*t;\n", +"F1=siga*A;\n", +"F2=F1/x;\n", +"r=0.2;\n", +"T=(F1-F2)*r;\n", +"OA=30;\n", +"OB=100;\n", +"OC=350;\n", +"P=((F2*OB)+(F1*OA))/OC;\n", +"OA=F2*OB/F1;\n", +"\n", +" // printing data in scilab o/p window\n", +" printf('F1 is %0.0f N ',F1);\n", +" printf('\n F2 is %0.1f N ',F2);\n", +" printf('\n T is %0.2f Nm ',T);\n", +" printf('\n OA is %0.2f mm ',OA);\n", +" " + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 23.3: B23_3.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"// sum 23-3\n", +"clc;\n", +"clear;\n", +"theta=%pi/3;\n", +"r=160;\n", +"u=0.3;\n", +"pmax=0.9;\n", +"b=40;\n", +"R=(4*r*sin(theta))/((2*theta)+sin(2*theta));\n", +"//frictional torque is T\n", +"T=2*u*pmax*b*(r^2)*sin(theta);\n", +"T=2*T*10^-3;\n", +"Rx=0.5*pmax*b*r*((2*theta)+(sin(2*theta)))*10^-3;\n", +"Ry=u*Rx;\n", +"\n", +" // printing data in scilab o/p window\n", +" printf('T is %0.2f Nmm ',T);\n", +" printf('\n R is %0.3f mm ',R);\n", +" printf('\n Rx is %0.3f kN ',Rx);\n", +" printf('\n Ry is %0.2f kN ',Ry);" + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 23.4: B23_4.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"// sum 23-4\n", +"clc;\n", +"clear;\n", +"d=320;\n", +"r=d/2;\n", +"b=50;\n", +"u=0.3;\n", +"pmax=1;\n", +"c=115*2;\n", +"// From to fig. 23-9, distance OA=R is calculated.\n", +"R=sqrt(115^2+66.4^2);\n", +"C=115*2;\n", +"theta1=0;\n", +"theta2=120*%pi/180;\n", +"theta0=120*%pi/180;\n", +"thetamax=%pi/2;\n", +"Tr=u*pmax*b*r^2*(cos(theta1)-cos(theta2))/sin(thetamax)*10^-3;\n", +"//the notation 'r' is used for moments of right hand shoe, similarly 'l' for the left shoe.\n", +"Mfr=u*pmax*b*r*(4*r*(cos(theta1)-cos(theta2))+(R*(cos(2*theta1)-cos(2*theta2))))/(4*sin(thetamax))*10^-3;\n", +"Mpr=pmax*b*r*R*((2*theta0)-(sin(2*theta2)-(sin(theta1))))/(4*sin(thetamax))*10^-3;\n", +"F=(Mpr-Mfr)/c*10^3;\n", +"//Mpl+Mfl=F*c;\n", +"x=F*c*10^-3;\n", +"y=(Mpr/pmax)+(Mfr/pmax);\n", +"pmax2=x/y;\n", +"Tl=pmax2*Tr;\n", +"Mpl=pmax2*Mpr;\n", +"Mfl=pmax2*Mfr;\n", +"T=Tl+Tr;\n", +"\n", +" // printing data in scilab o/p window\n", +" printf('Tr is %0.0f Nm ',Tr);\n", +" printf('\n Mf is %0.2f Nm ',Mfr);\n", +" printf('\n Mp is %0.2f Nm ',Mpr);\n", +" printf('\n Tl is %0.1f Nm ',Tl); \n", +" printf('\n Mfl is %0.2f Nm ',Mfl);\n", +" printf('\n Mpl is %0.2f Nm ',Mpl);\n", +" printf('\n F is %0.1f N ',F);\n", +" printf('\n T is %0.1f Nm ',T);\n", +" \n", +" //The difference in the answers are due to rounding-off of values.\n", +" \n", +" " + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 23.5: B23_5.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"// sum 23-5\n", +"clc;\n", +"clear;\n", +"m=1100;\n", +"V=65*5/18;\n", +"t=4;\n", +"r=0.22;\n", +"mb=12;\n", +"C=460;\n", +"S=0.5*V*t;\n", +"//Total kinetic energy TE=K.E(vehicle)+K.E(rotating parts).\n", +"TE=((0.5*m*(V^2))+(0.1*0.5*m*(V^2)));\n", +"E=TE/4;\n", +"w=V/r;\n", +"theta=S/r;\n", +"T=E/theta;\n", +"delT=E/(mb*C);\n", +"\n", +" // printing data in scilab o/p window\n", +" printf('S is %0.2f m ',S);\n", +" printf('\n E is %0.2f Nm ',E);\n", +" printf('\n T is %0.2f Nm ',T);\n", +" printf('\n delT is %0.2f ',delT);\n", +" \n", +"//The difference in the answers are due to rounding-off of values." + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 23.6: B23_6.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"// sum 23-6\n", +"clc;\n", +"clear;\n", +"T=35000;\n", +"u=0.4;\n", +"p=0.7;\n", +"r=200;\n", +"N=T/(u*r)\n", +"b=sqrt(N/p);\n", +"l=b;\n", +"//2theta = theta2\n", +"theta2=2*asin(l/(2*r));\n", +"F=u*N;\n", +"P=((250*N)-(u*N*80))/550;\n", +"Ry=N-P;\n", +"Rx=u*N;\n", +"R=sqrt(Rx^2+Ry^2);\n", +"w=2*%pi*100/60;\n", +"// Rate of heat generated is Q\n", +"Q=u*N*w*r/1000;\n", +"\n", +" // printing data in scilab o/p window\n", +" printf('N is %0.1f N ',N);\n", +" printf('\n b is %0.0f mm ',b);\n", +" printf('\n P is %0.1f N ',P);\n", +" printf('\n R is %0.2f N ',R);\n", +" printf('\n Q is %0.2f J/s ',Q);\n", +"\n", +"//The answer to Rate of heat generated 'Q' is calculated incorrectly in the book." + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 23.7: B23_7.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"// sum 23-7\n", +"clc;\n", +"clear;\n", +"Vi=20*5/18;\n", +"Vf=0;\n", +"m=80;\n", +"pmax=1;\n", +"u=0.1;\n", +"S=50;\n", +"KE=0.5*m*Vi^2;\n", +"N=KE/(u*S*2);\n", +"t=sqrt(N/(pmax*3));\n", +"b=3*t;\n", +"\n", +" // printing data in scilab o/p window\n", +" printf('KE is %0.1f Nm ',KE);\n", +" printf('\n N is %0.2f N ',N);\n", +" printf('\n t is %0.1f mm ',t);\n", +" printf('\n b is %0.1f mm ',b);\n", +"\n", +"//The difference in the answers are due to rounding-off of values." + ] + } +], +"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 +} |