含硬α缺陷钛合金风扇盘失效风险影响因素研究

摘要

Probabilistic risk assessment (PRA) of life limited parts, which are extremely critical to engine safety level, is one of the most significant problems for civil aero-engine airworthiness certification. A PRA methodology based on fracture mechanics was introduced and used to assess a titanium fan disk with hardαanomalies in it. A sensitivity analysis of three factors which strongly affect disks' failure was carried out, and the result shows that load is more sensitive than anomaly distribution and fracture toughness of the disk. There is little influence of fracture toughness with 10％variation on the failure risk.%对于民用航空发动机而言,限寿件对发动机的结构完整性以及整机安全水平有着极其重要的影响,对限寿件进行概率风险评估是发动机适航取证过程中面临的重要问题之一.文章基于国际通用断裂力学的限寿件概率风险评估方法,利用该方法对含硬α缺陷的钛合金轮盘进行失效风险分析,并就影响风险值的载荷、断裂韧度以及缺陷等三个重要参数进行了敏感性分析.分析结果表明,相对于缺陷和材料的断裂韧度而言,载荷的变动对盘的失效风险值影响最为显著,缺陷大小次之,而断裂韧度在10％范围内变动对失效风险值的影响几乎可以忽略.