鸟撞高速飞机风挡若干问题的冲击动力学研究

AN IMPACT DYNAMICS INVESTIGATION ON SOME PROBLEMS IN BIRD STRIKE ON WINDSHIELDS OF HIGH SPEED AIRCRAFTS

对鸟撞飞机风挡的动态响应问题作了冲击动力学的分析研究。由航空有机玻璃在应变率10^(-4)s^(-1)～10~3s_(-1)和温度-60～100℃的试验研究表明其本构关系的应变率效应和温度效应是不可忽略的。由铸镁合金的试验研究则表明其表观的应变率敏感性与铸态缺陷所引起的试验数据分散性相比是可忽略的。用特征线数值法对撞击界面载荷特性的计算分析表明,撞击载荷与结构动态响应间的耦合作用是不可忽视的。

Some problems of the dynamic response of aircraft windshields to bird-strike are investigated from the view-point of impact dynamics. The experimental results of an aeronautical PMMA tested at the strain-rates of 10-4 s-1 to 103 s-1 and the temperatures of - 60℃ to 100℃ are given, and a nonlinear thermo-viscoelastic constitutive equation for it is suggested. The experimental results of a cast magnesium alloy tested at the strain-rates of 10-4s-1 to 103s-1 are also given, and an apparent nonlinear elasto-plastic constitutive equation is suggested. The character of impact loading is analysed numerically by a characteristics method, and it is shown that the determination of impact loading is coupled with the determination of dynamic response of structure. It is found that the effects of constitutive characters of both bird and windshields on the impact loading, in general, can not be neglected.