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A subspace iteration algorithm for the eigensolution of large structures subject to non‐classical viscous damping
Author(s) -
Gmür Thomas,
Schorderet Alain
Publication year - 2000
Publication title -
international journal for numerical methods in engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.421
H-Index - 168
eISSN - 1097-0207
pISSN - 0029-5981
DOI - 10.1002/1097-0207(20001210)49:10<1267::aid-nme5>3.0.co;2-m
Subject(s) - computation , eigenvalues and eigenvectors , unitary transformation , dissipative system , algorithm , mathematics , subspace topology , quadratic equation , iterative method , inverse , transformation (genetics) , matrix (chemical analysis) , damping matrix , convergence (economics) , krylov subspace , mathematical analysis , geometry , finite element method , physics , stiffness matrix , structural engineering , engineering , materials science , chemistry , composite material , quantum , biochemistry , quantum mechanics , gene , economic growth , economics
This paper describes an efficient and numerically stable algorithm for accurately computing the solutions of the quadratic eigenproblem associated to non‐proportionally viscously damped structures characterized by symmetric matrices. Combining the simultaneous inverse iteration with a generalized Rayleigh–Ritz analysis, the proposed procedure is well suited for extracting the subset of the lowest natural frequencies, the corresponding subcritical damping ratios and the mode shapes of large dissipative systems with non‐classical viscous damping. The iterative process exploits the specific nature of non‐proportionally damped structures, takes full advantage of the banded configuration of the structural matrices involved in the eigenproblem, avoids the computation of the left eigenvectors and circumvents the use of complex algebra owing to a unitary transformation strategy. An academic test case and an industrial numerical example are presented to highlight the effectiveness of the algorithm. Copyright © 2000 John Wiley & Sons, Ltd.