Operational modal analysis for linear time-varying continuous dynamic structure based on LMPCA

摘要

Based on the theory of "time-frozen", this paper proposes a novel operational modal analysis (OMA) for linear time-varying structure using limited memory principal component analysis (LMPCA). Compared with modal coordinate decomposition of non-stationary response signals for linear time-varying continuous beam structure, it is found that PCA can be decomposed to extract time-varying instantaneous modal parameters, which reveal structure characteristics in limited memory window length L. Numerical simulations results on a cantilever beam with slow time-varying mass are presented to verify the TV instantaneous natural frequencies and modal shapes identification capability of the LMPCA.