A Novel Finite Element Approach to Dynamics Analysis of Large Structures with Cyclic Symmetry Boundary Conditions

摘要

Many engineering structures exhibit periodic rotational symmetry for which computationally efficient solutions of the modal frequencies (eigenvalues) and mode shapes (eigenvectors) can be obtained by analyzing only a single substructure of the total structure. Current finite element method (FEM) implementation of these methods fall short of processing the doublet mode shapes associated with the duplicate frequencies which are inherent to these types of structures. This paper demonstrates how to efficiently combine these doublets into one mode shape and how to determine the worst-case phase angle orientation of this combined mode shape. With this information the structural evaluations of these types of structures can be more efficiently performed.