// exa 6.4 Pg 171 clc;clear;close; // Given Data Sut=700;// MPa Syt=460;// Mpa F1BYF2=3;// ratio of tensions dg=300;// mm dp=400;// mm P=25;// kW N=600;// rpm alfa=20;// degree Km=1.5;// fatigue factor Kt=1.5;// shock factor tau_d1=0.30*Syt;// MPa tau_d2=0.18*Sut;// MPa tau_d=min(tau_d1, tau_d2);// MPa (taking minimum value) tau_d=0.75*tau_d;//MPa (Accounting keyway effect) // Pulley D // P= 2*%pi*N*T/60 T=P/(2*%pi*N/(60*1000));// N.m // (F1-F2)*dp/2=T SUB_F1F2 = T*2/dp;// N (where SUB_F1F2 = F1-F2) F2 = SUB_F1F2/(F1BYF2-1) ;// N (putting value of ratio) F1=F1BYF2*F2;// N F=F1+F2;// N // Gear B Ft=T*2/dg;// N Fr=Ft*tand(alfa);// N // Bearing Reactions //Vertical forces //RA*2*dg+Fr*dg=F*dg; RA=(F*dg-Fr*dg)/(2*dg);// N (downwards) RC=RA+Fr+F;// N (upwards) MA=0;MB_v=-RA*dg;// N.mm MC=-F*dg;// N.mm //Horizontal forces MB_h=Ft*2*dg/4;// N.mm //Resultant B.M at B MB=sqrt(MB_v**2+MB_h**2);// N.mm Mmax=MC;//N.mm T=T*1000;// N.mm // d**3=16/%pi/tau_d*sqrt((Km*M)**2+(Kt*T)**2) d=(16/%pi/tau_d*sqrt((Km*Mmax*1000)**2+(Kt*T)**2))**(1/3) printf('shaft diameter(using ASME Code) = %.1f mm. Use diameter = %.f mm.',d,d)