Question

3. A cantilever spring is subjected to a concentrated load P varying continuously from upward to P, downward. You are given the following data. Sy = 850 MPa: Se = 175 MPa; b = 8 mm, h = 10 mm, k, = 2; n = 2. Use Soderberg criterion and reliability goal of 50%. a. Identify all the possible factors/conditions that affect the failure of the beam. [4 Marks] b. Identify all the factors that affect calculation of endurance limit and calculate the same. (10 Marks) c. Solve for the largest load P, that can be applied on the beam (5 Marks) 200 mm

Answer 1

@ Pmax 2 Po Puina Pop -s since there is a step & fillet present at x2 gaamm from free end of cantilever beams, there is stress Concentration m is is peser present. presen pre since there is musimum wall; But due to stress Concer at Step & fillet section is highest. -)goy critical section is step & fillet , stresses. Concentration stress to ve 200 mm. at x section fillet step & is caran - fig. shows moment & acting at shear force Critical section at which failione ewill shear stress - Thans verse is equivalent force due to shear Porce-Couple System compared to very small soi, we moment. Bending stress due to bending stress. in stress at shear rise can neglect factor concentration ; to stress stress concentration ses Due is calculated by calculated by is Fillet laceding of fatigue effect of effect of B & Combined Rector. & stress concentration Match sensitivity by fatigue both is determined factor Re of safety factor on Jegg ama depends is load based. Allowable And Bs application of on type we needed se z 175 mpa the endurance limits factors that affect finish factor o surface ). kaz surface polished atc Assuming " (@ Kb 2 size factor 2, de - Ba 107. factor 2 ode e size 7.62 dez 0.808. where

de 2 0.808 x5 1048 . de 2 7.227 mm n-0.107 7.221 @ @ © ...Kb el 0056 SI sos Kb zt) Ke 2 loading factor 21 Rgs Temperature 421 4 factors It Her reliability lous Effects for bending loud. for room temperature for 50% reliability e Rector Effects Miscellaneous kes kg 2 1 50, corrected endurance limits ses kako kc Kj Rete se en 2 luce cxcxcel X 175 12175 mpa Answer De © Bending stress (Maximum) is given by ke 32M 662 Kft te & Muense 20. 2xPo im Muina -0.2xPoa 0.1 po mm 0.05 Po MM Sos Mma 0-2 Po t (moni Po) 0.2 Po farl Poe . 15 Po mm & Oma Kf 6 MM sol, bas kf 2 6 mg

Acc. to saterberg critérion, Be ba tbm at syk. куб MG бе хри” 2x6xo. 15 (о (03 K16 мм x bИ И ахбхоод хоо Бохко 15 х 4 х 13 " 1. Po 2 36-3914 NK Answer o