基于经验模态分解和模型缩聚的动力响应重构方法研究

大型工程结构自由度数量巨大,采用现有基于全局有限元模型的时域方法重构此类结构动力响应效率低、计算难度大,因此,提出一种结合经验模态分解和模型缩聚的动力响应重构方法.基于模态综合法,将有限元全模型适当划分为多个子结构,通过坐标转换,得到自由度数目更少的超单元模型,结合带有间歇准则的经验模态分解法进行重构.由于该方法无需考...

DYNAMIC RESPONSE RECONSTRUCTION METHOD BASED ON EMPIRICAL MODE DECOMPOSITION AND MODEL CONDENSATION

In terms of performing the dynamic response reconstruction of large civil engineering structures, the efficiency and accuracy of the current time-domain method based on finite elements are low and poor. A dynamic response reconstruction method combining empirical modal decomposition and modal condensation is proposed. Based on the modal synthesis method, the whole finite element model is divided into several sub-structures, and a super-element model with less DOFs is obtained by coordinate transformations. The reconstruction is carried out by combining the empirical modal decomposition method with intermittent criterion. Without considering the boundary conditions of each substructure, this method effectively reduces the dimension of the mathematical matrix of the relevant physical parameters of the finite element model, greatly improves the computational efficiency of response reconstruction, and is suitable for the dynamic response reconstruction of civil engineering structures. The effectiveness of the reconstruction method is verified by a numerical example of a cantilever beam, and the influence of noise and the number of main modes on the reconstruction effect are studied. The results show that the noise level has some influence on the precision of reconstruction, and that the number of main modes has trivial influence on the precision of reconstruction.