某柴油机曲轴单拐疲劳试验件断裂失效分析

Fracture Failure Analysis of Single-Throw Crankshaft Fatigue Test Piece for a Diesel Engine

针对某柴油机曲轴单拐平台弯曲疲劳试验中,曲轴圆角处发生非正常断裂现象,建立曲轴疲劳破坏故障树,从试验载荷过大、曲轴本体结构设计强度不足、曲轴制造缺陷等方面进行排查。最终确定导致曲轴单拐圆角失效的主要原因为圆角表面存在氧化腐蚀坑。分析结果为曲轴设计、生产过程控制及后续质量验收提供了重要依据。

During the bending fatigue bench test of a diesel engine single-throw crankshaft, abnormal fracture occurred at the corner of the crankshaft. A fault tree for fatigue failure of crankshaft was established. The main reasons are investigated from the aspects of excessive test load, insufficient strength of crankshaft structure and defects of crankshaft manufacturing. And the main reason for the failure at the corner of the single-throw turned out to be oxidative corrosion pits on the surface of the corner. The research provides good reference to the design, manufacturing, and quality acceptance of crankshafts.