All questions warth 5 paints each 11 Stress concentrations D

All questions warth 5 paints each 11 Stress concentrations Develop os polished smooth surlaces increase rapidly under stark loading 5) ron alloys ditter throm aluminum in that b. a are always more ductile b are much less susceptible to fangue e can be sined for infinibe ife s have coupon ess C. Ampily crack inducing bend ngsses 2) A fatigue coupon specimen made from AIS 130 stainless stheel (quenched and tempened to 400 F) fails in 160,000 cycles What stres eas applied? t. None of the above 6) endurance strength of a machined Ai 0 sest coupon is a120 ks b 1s0 si b. 33.5ks c. 1000 ks d. None of the above 100 ksi None of the ahove 3) Vielding imp es: s, Plastic deformation below elastic imt b. Elastic stress proportional to curvature c Loading beyond the elastic limit d. Linear spring defining elasticity distortian energy failure analysis b C. improved shear stress falure prediction betber coerelation with normal stress None of the above 4) A connecting eod design uses a new theory d. more conservatihe chromium steel which capable of 260 ksi ubimate strength Given Marin factors of 0.158 and 0.907, the connecting rod\'s endurance limit is? 8 8) steel machine part diffiers from their coupon machine part difers from their coupon steel specimens because a Marin factors increase endurance 14.3 ks strength Different meteras ave generaly used for steel 5-N curves b18.6 ks b 100ks None of the above d· C. Diflerent surface treatment is used d. All of the above

Solution

1. C: Stress concentration is found for fluctuating loads, rough surfaces, internal cracks, abrupt changes in section etc. A crack is developed where the stress concentration is localised, thereby tending to fracture.