TC11钛合金微动疲劳裂纹萌生预测分析

摘要

In order to solve the fretting fatigue failure problem of dovetail joints between blade and disk in aero-engine, a prediction model was introduced to predict the fretting fatigue crack initiation location, orien⁃tation, and life. Based on the critical plane theory and the damage mechanism, a fretting damage parameter CSE was proposed by taking consideration of the dominant factors. The control parameter CSE predicted crack initiation of a fretting specimen, and the results confirmed the validity of the prediction model by the comparison of the predicted and the actual failure situations of titanium alloy TC11 specimen.%针对航空发动机叶片与盘榫连接结构简化模型的微动失效形式，建立了基于临界平面法预测微动疲劳裂纹萌生的控制模型。该模型引入综合考虑多种微动疲劳影响因素的微动损伤参量CSE（微动综合损伤参量），建立了微动疲劳特性的分析流程，对微动疲劳裂纹的萌生方向、位置和寿命进行了估算。应用CSE控制模型，对失效的TC11钛合金微动疲劳试件的裂纹萌生进行预测，通过比较不同损伤参量的预测结果，验证了CSE预测裂纹萌生的有效性。