Fastener Failure Modes in Automotive and Aerospace: Fatigue, Corrosion, Loosening & More
Fatigue Failure Bolts and screws in vehicles and aircraft almost invariably fail by fatigue under repeated loading. Fatigue cracks usually initiate at stress concentrators (often the first thread engaged by the nut or a sharp root) and grow slowly with each load cycle. According to experts, insufficient preload or lost clamp force is a key cause: if a bolt isn’t tightened enough (or loses tension), cyclic loads create tensile stress fluctuations that initiate cracks[1][2]. Once a crack reaches a critical size, the bolt breaks suddenly (often without warning) under normal [...]