鸟撞飞机风挡数值模拟研究

Numerical Simulation of Bird Impact on Aircraft Windshield

目前,鸟撞是威胁航空安全的重要因素之一,飞机风挡抗鸟撞是飞机安全飞行的重要保证。首先介绍了鸟撞飞机风挡的研究现状,利用LS-DYNA3D对鸟撞飞机风挡进行数值模拟,通过建立飞机全尺寸圆弧风挡模型及鸟体简化模型,计算得到风挡结构的变形、位移、有效应力、可能发生破坏的位置、鸟体水平与垂直方向速度、加速度等数据结果。仿真结果表明,鸟撞飞机风挡是发生在毫秒量级的非线性冲击动力学行为,整个撞击过程约5.6 ms,在T=1.8 ms时刻,风挡承受的有效应力最大,为8.304×10~7Pa,鸟体垂直方向加速度达到1.5228×10~4m/s^2。同时,通过选取风挡三个网格单元,得到位移及有效应力变化历程,综合考虑位移和应变结果可知风挡正中心为受到鸟撞后最危险的部位,利用数值模拟方法进行鸟撞风挡分析,可减小时间成本,提高分析问题工作效率,为飞机风挡鸟撞适航验证提供更有效的方法。

At present,the bird strikes is one of the important factors that threaten aviation safety,and aircraft windshield anti-bird strike is an important guarantee for aircraft safety flight. Firstly,the research status of the bird＇s windshield is introduced. The numerical simulation of the bird ＇s windshield is carried out by using LS-DYNA3 D. The deformation,displacement and effective stress of the windshield structure,the possible damage to the location,bird body level,vertical direction speed,acceleration and other data results are calculated by establishing the full-size circular windshield model and the bird body simplified model. The simulation results show that the wind impact of the aircraft is in the order of millisecond nonlinear dynamic behavior. The whole impact process is about 5. 6 ms; while T = 1. 8 ms,the effective stress on the windshield,which reaches 8. 304 × 10^7 Pa,is maximum,and the vertical acceleration of birds is 1. 5228 × 10^4m/s^2. At the same time,by selecting the three grid elements of the windshield,the displacement and the effective stress change process are obtained. The displacement and strain results show that the center of the windshield is the most dangerous part of the bird; and analyzing the windshield by the numerical simulation method can reduce the cost of time,improve the efficiency of the problem,and provide a more effective method for airworthiness.