直升机金属动部件的寿命管理

针对某型直升机动部件承受高频低幅振动载荷的特点，探讨安全寿命和损伤容限相结合的寿命控制方法。以直升机的金属主桨叶为例，采用飞行空测载荷数据编制的实测统计载荷谱，通过Miner线性累积损伤理论计算得到裂纹形成寿命与风险率的关系。同时考虑裂纹扩展寿命对降低风险率的贡献，通过断裂力学分析计算出应力强度因子、损伤容限临界裂纹尺寸，建立主桨叶损伤容限分析的工程计算模型，得到裂纹扩展寿命(检查周期)与风险率的关系。

LIFE MANAGEMENT OF HELICOPTER METALLIC DYNAMIC COMPONENTS

Helicopter dynamic components experience high cycle fatigue loads in practically every flight regime. In order to improve the reliability and reduce the operating costs of helicopters, an increasing emphasis is being placed on the development of damage tolerance in life management of helicopter dynamic components. The technique which combines safety life and damage tolerance is being carried out for metallic main rotor blades of a helicopter. The crack initiation lives for different risks of failure were obtained with Miner nominal stress rule with load spectrum based on the usage statistics. A fracture analysis is performed for crack growth, the stress intensity and the critical crack size were obtained. The crack growth lives relevant to the inspection intervals for different risks of failure were obtained using Forman model.