Question

A flat plate of width 30 mm needs to be pinned down to another plate. Two pins are readily available - one of diameter 6 mm and the other of diameter 15 mm. Which of the two pins will you use if the only criterion for selection is reduced stress in the plate?

Answer 1

solution: pn3 O 6mm diameter ping assuming pindia = hale dia in plate. W=somm d=6mm w Old Let thickness bet and force applied P, then nominal stress one p = P =P (max) undt 200t 24t for W = 20 =0.2 stress concenloation factor kl 1= 2.52 tence actual max stress = I may Klex One 2-52xp 24t = 0.105 P 15 mm dia pin used W = 30mm d= 15mm let thickness be it then may nominal stress, on2=P - P (3045) 15t Kl2 e 2.45 hence actual max stress = may = 2.15* P for W = 15 = 0.5 15+ = oil 433P smce only criterion is reduced stress inplate so 6mm dia pin should be preferred