脉冲子结构与有限元刚-弹混合连接的子结构方法

航天器结构的日益复杂庞大对系统级的动力学建模仿真以及进一步的结构优化提出了巨大挑战。为提高动力学求解效率,通常引用动态子结构方法。本文利用适于处理瞬态冲击问题的脉冲子结构(IBS)方法,并对其进行改进,将基于脉冲响应函数(IRF)的子结构与有限元建立的子结构综合,同时考虑刚性、弹性以及刚-弹混合连接情形下的子结构综合格式。通过3个数值算例,验证了方法的正确性。最后将刚-弹混合连接下的子结构方法应用到月球探测器软着陆的动态响应预测,结果表明该方法适于对月球探测器软着陆动态响应进行高精度快速预测,并且可以应用于月球探测器的局部动力学结构优化。

A substructure method for coupling impulse response functions with finite element models via rigid-elastic joints

The complexity and size of spacecraft have brought great difficulties and challenges to system level dynamics simulation and design optimization. In order to improve the computing efficiency, dynamic substructuring method is introduced. This paper uses the impulse-based substructuring (IBS) method, an efficient approach in transient dynamic simulating, and adapts the original methods by coupling impulse response functions (IRF) with finite element models through rigid-elastic joints. The validity of these coupling ways which include rigid-only, elastic-only and rigid-elastic joints is separately demonstrated by three numerical examples. Besides, the coupling way by rigid-elastic joints is applied to the transient dynamic simulation of soft landing of the lunar lander. The results show that this method is suitable for the simulation of soft landing for lunar landers with great efficiency and precision. Furthermore, this method can be applied to the lunar lander's local structure optimization.