Question 7.4: Hoist Chain Failure Analysis A chain used to hoist heavy loa......
Hoist Chain Failure Analysis
A chain used to hoist heavy loads fails. Examination of the failed link indicates considerable deformation and necking prior to failure. List some of the possible reasons for failure.
This description suggests that the chain failed in a ductile manner by a simple tensile overload. Two factors could be responsible for this failure:
1. The load exceeded the hoisting capacity of the chain. Thus, the stress due to the load exceeded the ultimate tensile strength of the chain, permitting failure. Comparison of the load to the manufacturer’s specifications will indicate that the chain was not intended for such a heavy load. This is the fault of the user!
2. The chain was of the wrong composition or was improperly heat-treated. Consequently, the yield strength was lower than intended by the manufacturer and could not support the load. This may be the fault of the manufacturer!