Modified Iterative-Order-Reduction Substructuring Method with Interface Boundary Reduction

Abstract

The iterative-order-reduction (IOR) substructuring method is an efficient model order reduction (MOR) technique for estimating eigenvalues and eigenvectors in large-scale structural systems. However, it can be computationally expensive when applied to models with highly refined meshes and a substantial number of substructures because it retains all the interface degrees of freedom (DOF), which increase the size of the reduced structural matrices. Moreover, the reduced structural matrices may suffer from ill-conditioning after a certain number of iterations, potentially yielding inaccurate results. This paper presents a modified IOR substructuring method that integrates interface boundary reduction to reduce the size of the original IOR substructuring model by decreasing the number of interface DOF. The performance of the proposed method is demonstrated through a comprehensive numerical comparison with the original IOR substructuring and other widely used MOR techniques, including the Craig–Bampton, enhanced Craig–Bampton, and iterated improved reduced system with a substructuring scheme. The results show that the proposed method achieves comparable accuracy while significantly reducing the computational time and memory usage.