A model reduction method for fast finite element analysis of continuously symmetric waveguides

摘要: Abstract This paper presents a model reduction strategy for fast finite element analysis of continuously symmetric elastic waveguides. Accounting continuous symmetry, the initial three-dimensional problem is first reduced to two-dimensional quadratic eigenvalue based on semi-analytical method. has be solved repeatedly at multiple frequencies determine modal properties waveguide as functions frequency (e.g. dispersion curves). Although two-dimensional, such becomes costly when size increases. In this paper, specific basis proposed project matrix operators problem. built from complex eigenvectors computed maximum analysis, enriched by cut-off eigenvectors, and then post-processed through QR decomposition. Numerical results are presented three critical test cases, involving high-frequency viscoelastic loss, curve veering phenomena, or leakage loss respectively. The method turns out simple implement, fast, accurate spectrum, including attenuated waves. time needed build model, prior its solution, remains short (roughly equal single iteration full model). Once reduced, can more than 50 times faster