Failure Analysis of a Diesel Engine Connecting Rod

摘要

A failure investigation has been conducted on a diesel engine connecting rod. The fracture occurred at the small head of the connecting rod. Visual and scanning electron microscopy observations show that a lot of axial grooves appear on the internal surface close to the fracture and the fatigue cracks initiated from the axial grooves. Fractography indicates that the multiple-origin fatigue fracture is the dominant failure mechanism. The machining or assembling process was responsible for the formation of the axial grooves.