Dynamic analysis of inelastic primary-secondary systems

Two methods are proposed to compute the response of inelastic composite pri mary-secondary systems by a decomposition into undamped substructure modes. The first method is based on an iterative syntheses, where interface condi tions as well as inelastic deformations of the substructures are treated as additional fictious loadings and their intensities are calculated in an it erative process. Alternatively, only modal coupling of tuned modes is consi dered, thus, restricting the application to coupled systems with a modal se condary to primary mass ratio much smaller than one. The dynamic behavior o f oscillators attached to frames with various inelastic substructure proper ties is investigated, which are excited by the north-south component of the El Centro earthquake sample, Results derived by the proposed methods are c ompared to decoupled analyses to estimate their capability with respect to inelastic substructural behavior and non-classical damping. (C) 1999 Elsevi er Science Ltd. All rights reserved.