Complex Mode Superposition Method Considering the Effect of Multiple Fold Eigenvalue in Seismic Design

Abstract eng:
When structures possess multiple fold eigenvalues, the orthogonality among different modes no longer exists in most cases. Therefore, in this paper, transfer function method independent of orthogonal relation is adopted to analyze the dynamic response based on theory of linear algebra and complex variable function, the dynamic response analysis method in time domain is derived, which is suitable for both non-classically and classically damped linear system with multiple fold eigenvalues. In addition, the structural response spectrum is introduced successfully and the CCQC algorithm is deduced, which can consider the effect of multi-fold-eigenvalues. The applicability of the deduced formula is verified through Newmark integration computation of liner structure subjected to prescribed earthquake motion. Meanwhile, the results show that, for the structure with multiple fold eigenvalues, the calculation errors will be fairly large if simply neglecting the effect of multiple fold eigenvalues. Finally, it is pointed out that the method derived in this paper is suitable for computing seismic responses of MDOF classical or non-classical damping linear system with or without multiple eigenvalues.

• Export as: BibTeX | MARC | MARCXML | DC | EndNote | NLM | RefWorks
• Add to your basket