折叠机翼的结构动力学建模与降阶方法分析

Structural Dynamic Modeling and Model Reduction analysis of a Folding Wing

针对折叠机翼的结构动力学建模问题,为了实现动力系统的可观性和可控性,结合有限元分析中的模态综合法,以及控制理论中的内平衡准则实现了对折叠机翼的模型降阶。对比分析了不同阶次的降阶模型的频率响应与在MSC.NASTRAN中建立的模型的频率响应发现:在频率较低时,两种模型的频率响应曲线基本吻合;在频率较高时,频率响应曲线具有一定的差异。但是通过提高降阶模型的阶次,可以改善高频时的频率响应的差异。对比结果表明,上述降阶方法是有效且合理的,得到的降阶模型不仅阶数较低,而且具有可观且可控的优点。上述低阶模型对于结构动力学特性的分析以及控制系统的优化设计均具有积极的意义。

For the structural dynamic model of a folding wing, a model reduction was achieved based on modal synthesis method in finite element analysis and balanced model reduction method in control theory. The frequency re- sponses of the reduced order model with different orders and those of the model established in MSC. NASTRAN were compared：The frequency responses of two models have a good agreement at a lower frequency while there is a slight difference in frequency response at a higher frequency. However, the higher order model reduced model can improve this difference. Comparative results show that this reduction method is effective and reasonable. The reduction model was obtained with the characteristics of low order, controllability and observability. This model of low order plays an important role in structural dynamic analysis and design of control systems.