A heavyduty pump assembly is bolted to the base frame with a

A heavy-duty pump assembly is bolted to the base frame with a total apparent contact area of 425 cm^2 (identified in red in the drawing). The mounting brackets and the base frame are made of Type 20 grey cast iron. Estimate the average force that should be generated by tightening the bolts to allow 20% of apparent contact surface to actually develop contact.

Solution

average force on the pump

F

from standard table

tensile stress = 150MPa

ultimate strength = 456N/mm²

yield strength= 295N/mm²

elastice limit =240N/mm²

the average force is the shearing force of the bolts

shear force = load/area

load acting is 456

force = 456*150/425

160KN