Question

A tractor drawbar is connected to an implement as shown below. The tractor pulls with a force of 50 kN that must be transmitted by the shear bolt. (a) Calculate the shear stress in the bolt if the bolt diameter is 19 mm. (b) Calculate the percent increase in the shear stress if the bolt diameter is reduced to 16 mm. (8 Pts.) Bolt Shear planes Drawbar

Answer 1

From figure therefore sigma F_x = 0 p = tau times A + tau times A p = 2 tau times A tau = p/2 A = 50 KN /2 times pi/4 times 19^2 mm^2 = 88.17 N mm^2 tau = 88.2 mpa if d^1 = 16 mm the tau_1 p/2a_1 = 50 kn/2 times pi/4 times 16^2 = 124.34 N/mm^2 tau-1 = 124.34 mpa therefore % pncrease in tau = tau^1 - tau /tau times 100 = [124.34 - 38.2/28.20] times 100 = 41% % increase in tau = 41%