民用飞机应急断离连接件结构优化设计研究

Study on the Structural Optimization Design of the Emergency Breaking Connectors of Civil Aircraft

双剪切连接结构被广泛用于航空航天飞行器,其应急断离连接件的横向冲击性能对飞机结构的应急断离设计有重要影响。应急断离连接件的冲击断裂过程属于高度非线性的瞬态动力学问题,为了研究连接件的详细断裂过程,采用动力学有限元方法建立一超静定接头连接结构各接头应急断离连接件的完全热力耦合有限元模型,根据相关适航条例和飞机应急着陆工况拟定边界条件,对应急断离连接件进行冲击数值仿真,分析得到不同几何参数的连接件在不同冲击速率和冲击倾角下的吸能效率和断离载荷。研究表明应急断离连接件冲击断裂过程中吸收的能量随冲击速率和冲击倾角增大而增大,当冲击倾角超过一定范围连接件将无法实现应急断离。分析方法和仿真结果可以为应急断离连接件结构优化设计提供依据和参考。

Double shear connecting structure is widely used in aircraft structure, the lateral impact behaviors of the emergency breaking connectors have significant influences on emergency breaking away realization of aircraft structure. The fracture process of the connectors is a high nonlinear problem of transient dynamics. In order to study the detailed fracture process of the emergency breaking connectors, a fully thermo - mechanical coupled finite element model of each connecting joint was established based on the hyper static connecting structure and applied to the dy- namic simulations under different boundary conditions which were proposed according to the airworthiness regulations and emergency landing conditions of aircraft. The failure mode and energy absorption of different emergency breaking connectors were given. The results show that the energy absorption of the connectors increased with the increase of the impact velocity and impact angle. When the impact angle exceeds a certain range, the connectors are unable to re- alize the emergency breaking away process. The analysis methods and simulation results can give certain reference to the structural optimization design of the emergency breaking connectors.