An iterative scheme of flexibility‐based component mode synthesis with higher‐order residual modal compensation

Abstract

An Iterative Flexibility‐based Component Mode Synthesis (IF‐CMS) is presented for the model reduction of partitioned structural dynamic systems via localized Lagrange multipliers. A distinct IF‐CMS feature is the inclusion of hierarchical residual flexibility at each iteration, resulting in considerably improved accuracy compared with the classical Craig–Bampton (CB) CMS method. The present IF‐CMS method does not increase the number of substructural modes during the hierarchical iteration process. In particular, to alleviate ill‐conditioning during the iteration steps, the proposed IF‐CMS method adopts the so‐called (qd, α, ub)‐formulation by condensing Lagrange multipliers from the original F‐CMS method. The performance of the proposed method is evaluated through numerical examples, which illustrates improved accuracy over existing CMS methods.

A Parallel Approach of the Enhanced Craig–Bampton Method

“…The main idea of the proposed method can be extended to other iterative CMS methods with higher order residual flexibility, both primal and dual assemblies [22,32,33]. It should be noted that blockwise and decoupled formulations are prerequisites to achieve the parallel computations of iterative methods.…”

Efficient calculation of higher order time history response derivatives by substructuring method

“…Go et al (2020) proposed a family of Craig–Bampton methods considering the higher order residual flexibility for discarded mode compensation by using O’Callahan’s approximation or adding generalized coordinate vectors containing unknown eigenvalues. An iterative procedure is also employed to consider the contribution of discarded modes accurately (Chung et al, 2021). The aforementioned research focuses on improving the accuracy of substructuring method to calculate eigensolutions and eigensensitivity.…”