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An incremental mode‐superposition for non‐linear dynamic analysis
Author(s) -
Mohraz Bijan,
Elghadamsi Fawzi E.,
Chang ChiJen
Publication year - 1991
Publication title -
earthquake engineering and structural dynamics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.218
H-Index - 127
eISSN - 1096-9845
pISSN - 0098-8847
DOI - 10.1002/eqe.4290200507
Subject(s) - superposition principle , bilinear interpolation , damping matrix , direct integration of a beam , response analysis , mathematical analysis , modal analysis , mathematics , modal , truncation (statistics) , control theory (sociology) , structural engineering , engineering , computer science , stiffness matrix , finite element method , statistics , control (management) , artificial intelligence , chemistry , polymer chemistry
Abstract This paper uses an incremental mode‐superposition procedure to compute the inelastic dynamic response of multi‐degree‐of‐freedom systems. A damping matrix proportional to the instantaneous properties is used throughout the analysis. The non‐linear response of several shear type plane and space frames with elastic‐plastic and bilinear column properties subjected to ground excitation was computed by both the incremental mode‐superposition and the direct integration of the coupled equations of motion. When all modes are considered, the responses computed by the incremental mode‐superposition are identical to those from the direct integration. Fewer modes can also be used to compute the response with reasonable accuracy by performing the modal truncation for each time increment. The study shows that incorporating instantaneous damping in non‐linear dynamic analysis is relatively simple and requires less computational time than the direct integration.