飞机通风窗运动机构的抗鸟撞分析

Analysis of Anti Bird-strike for Aircraft Ventilation Window with Motion Mechanism

适航要求通风窗结构不能被鸟撞穿,鸟体不能进入飞机内部。相对于固定的通风窗结构在分析中只考虑强度因素,运动机构支持的通风窗还必须考虑结构刚度,避免由于大的变形出现缝隙而使鸟体进入飞机内部。基于PAM-CARSH软件,结合SPH方法,巧妙选择梁元节点自由度模拟机构转动副,对通风窗进行数值模拟,找到结构在强度和刚度上的薄弱部位,并进行结构改进。分析计算结果显示,改进后的结构能够满足鸟撞的强度和刚度要求。

The airworthiness for the flight safety requires that the ventilation window is the good enough to pre- vent the bird-striking and bird cannot enter the aircraft. Compared with fixed window structure that only taken into account the strength design, the stiffness of the moving ventilation window should be considered as well. Based on the PAM-CARSH software, the numerical model for the ventilation window under bird-striking was established, in which the bird was modeled with SPH element and the mechanism of revolute pair was modeled by selecting the freedom of beam element. The deformation behavior of the ventilation window with motion mechanism can be well described. Based on the simulation results, weak part of the structure is found and final corrected structure can well meets the requirements of both strength and stiffness in the airworthiness design.