Question

The plate shown below is fastened to the fixed member by three 10mm diameter rivets. Compute the value of load P so that the average shearing stress in any rivet does not exceed 70 MPa.

Note that the 75m in the figure is really 75 mm. I need complete solutions so that i can learn how it is silved, im having problem about finding its centroid(or it does not need it)?

St件8 (1 Long BodRuper) ) The plate shown beloy is tastened to the fixed menber by three l0-mm-diamoler riets. Comoute average shearing siress in any ret does not TO MPo 7503 125㎜

Answer 1

Given that the plate is fastened to the fired member by 3 members of 10mm diameter rivets tau shearing stress > 70mpa finding the location of centroid of rivets x_g = 2/3 times 150 = 50 centroid divides the medians in the distance of centroid from the base is 50mm r1 is the radial distance from the center of gravity centroid to the first rivet and third rivet r1 = squareroot (75) ^2 + (xg) ^2 = 75^2 + 50^2 = 90.138mm r2 = 150-x_g = 150-50 = 100mm j = sigma AS^2 = 1/4pi(10^2) [2r_1^2 + r^2_2 + xg^2] = 1/4pi[10^2][2(90.138) ^2 + 100^2 + 50^2] = 179685.7 mm^4 t = 100p + 125p the critical rivets are at a distance r1 from cg t_max = tp/t 70 = 225p 90.138/179685.7 = 620.18n