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diff --git a/The_Theory_of_Machines_by_T_Bevan/8-Brakes_and_dynamometer.ipynb b/The_Theory_of_Machines_by_T_Bevan/8-Brakes_and_dynamometer.ipynb new file mode 100644 index 0000000..af019e1 --- /dev/null +++ b/The_Theory_of_Machines_by_T_Bevan/8-Brakes_and_dynamometer.ipynb @@ -0,0 +1,268 @@ +{ +"cells": [ + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "# Chapter 8: Brakes and dynamometer" + ] + }, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 8.1: Braking_trrques.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"\n", +"clc\n", +"//given\n", +"dia=12//in\n", +"r=dia/2\n", +"CQ=7//in\n", +"OC=6//in\n", +"OH=15//in\n", +"u=0.3\n", +"P=100//lb\n", +"phi=atan(u)\n", +"x=r*sin(phi)//in inches;radius of friction circle\n", +"a=5.82//from figure\n", +"Tb=P*OH*x/a//braking torque\n", +"printf('\nThe braking torque of the drum Tb= %.2f lb in\n',Tb)" + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 8.2: Braking_troque_applied_to_the_drum.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"\n", +"clc\n", +"//given\n", +"\n", +"OH=15//in\n", +"l=OH\n", +"u=0.3\n", +"P=100//lb\n", +"phi=atan(u)\n", +"//according to fig 170(b)\n", +"//for clockwise rotation\n", +"a=6//from figure\n", +"x=r*sin(phi)//in inches;radius of friction circle\n", +"Tb=P*l*x/a//braking torque on the drum\n", +"//for counter clockwise rotation\n", +"a1=5.5//in\n", +"Tb1=P*l*x/a1//braking torque on the drum\n", +"//according to figure 172(a)\n", +"//for clockwise rotation\n", +"a2=6.48//from figure\n", +"x=r*sin(phi)//in inches;radius of friction circle\n", +"Tb2=P*l*x/a2//braking torque on the drum\n", +"//for counter clockwise rotation\n", +"a3=6.38//in\n", +"Tb3=P*l*x/a3//braking torque on the drum\n", +"T1=ceil(Tb1)\n", +"T2=ceil(Tb2)\n", +"T3=ceil(Tb3)\n", +"printf('\nbraking torque on drum\nWhen dimensions are measured from fig 170(b)\nFor clockwise rotation= %.f lb in\nFor counter clockwise rotation= %.f lb in\nWhen dimensions are measured from fig 171(a)\nFor clockwise rotation= %.f lb in\nFor counter clockwise rotation= %.f lb in',Tb,T1,T2,T3)\n", +"\n", +"\n", +"" + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 8.3: Magnitude_of_force.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"\n", +"clc\n", +"//given\n", +"u=.35\n", +"Tb=500//lb.ft\n", +"rd=10//in\n", +"phi=atan(u)\n", +"x=rd*sin(phi)\n", +"//F*OD=R*a=R1*a\n", +"//R=R1\n", +"//2*R*x=Tb\n", +"OD=24//in\n", +"a=11.5//inches; From figure\n", +"F=Tb*a*12/(OD*2*x)\n", +"//from figure\n", +"HG=4//in\n", +"GK=12//in\n", +"HL=12.22//in\n", +"P=F*HG/GK\n", +"Fhd=HL*P/HG\n", +"printf('\na) Magnitude of P = %.f lb',P)\n", +"printf('\nb) Magnitude of Fhd = %.f lb',Fhd)" + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 8.4: force_required_to_support_load.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"\n", +"clc\n", +"//given\n", +"u=.3\n", +"theta=270*%pi/180\n", +"l=18//in\n", +"a=4//in\n", +"Di=15//in\n", +"Do=21//in\n", +"w=.5//tons\n", +"W=w*2204//lb\n", +"Q=W*Di/Do//required tangential braking force on the drum\n", +"k=%e^(u*theta)//k=T1/T2\n", +"p=Q*a/(l*(k-1))\n", +"printf('Least force required, P = %.f lb',p)" + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 8.5: Effort_applied.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"\n", +"clc\n", +"//given\n", +"n=12\n", +"u=.28\n", +"a=4.5//in\n", +"b=1//in\n", +"l=21//in\n", +"r=15//in\n", +"Tb=4000//lb\n", +"theta=10*%pi/180\n", +"//k=Tn/To\n", +"k=((1+u*tan(theta))/(1-u*tan(theta)))^n\n", +"Q=Tb*(12/r)\n", +"P=Q*(a-b*k)/(l*(k-1))//from combining 8.6 with k=e^u*theta\n", +"printf('The least effort required = P = %.1f lb',P)" + ] + } +, +{ + "cell_type": "markdown", + "metadata": {}, + "source": [ + "## Example 8.6: minimum_distance.sce" + ] + }, + { +"cell_type": "code", + "execution_count": null, + "metadata": { + "collapsed": true + }, + "outputs": [], +"source": [ +"clc\n", +"//given\n", +"w=9.5 //ft\n", +"h= 2 //ft\n", +"x=4 //ft\n", +"v=30//mph\n", +"V=1.46667*v//ft/s\n", +"u1=.1\n", +"u2=.6\n", +"g=32.2//ft/s^2\n", +"//a) rear wheels braked\n", +"fa1=(u1*(w-x)*g)/(w+u1*h)\n", +"fa2=(u2*(w-x)*g)/(w+u2*h)\n", +"sa1=V^2/(2*fa1)\n", +"sa2=V^2/(2*fa2)\n", +"//b) front wheels braked\n", +"fb1=u1*x*g/(w-u1*h)\n", +"fb2=u2*x*g/(w-u2*h)\n", +"sb1=V^2/(2*fb1)\n", +"sb2=V^2/(2*fb2)\n", +"//c) All wheels braked\n", +"fc1=u1*g\n", +"fc2=u2*g\n", +"sc1=V^2/(2*fc1)\n", +"sc2=V^2/(2*fc2)\n", +"k1=(x+u1*h)/(w-x-u1*h)//Na/Nb\n", +"k2=(x+u2*h)/(w-x-u2*h)//Na/Nb\n", +"printf('\nCoefficient of friction = 0.1\na) Minimum distance in which car may be stopped when the rear brakes are applied = %.f ft\nb) Minimum distance in which car may be stopped when the front brakes are applied = %.f ft\nc) Minimum distance in which car may be stopped when all brakes are applied = %.f ft\nCoefficient of friction = 0.6\na) Minimum distance in which car may be stopped when the rear brakes are applied = %.f ft\nb) Minimum distance in which car may be stopped when the front brakes are applied = %.f ft\nc) Minimum distance in which car may be stopped when all brakes are applied = %.f ft\n',sa1,sb1,sc1,sa2,sb2,sc2)\n", +"printf('Required ration of Na/Nb\nFor u1 = 0.1 -> %.3f\nFor u2 = 0.6 -> %.2f\n',k1,k2)" + ] + } +], +"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 +} |