THE COMPLEX-COMPLETE-QUADRATIC-COMBINATION (CCQC) METHOD FOR SEISMIC RESPONSES OF NON-CLASSICALLY DAMPED LINEAR MDOF SYSTEM

摘要

In this paper, for non-classically damped linear multiple degrees of freedom system with complex modes, the CCQC method for calculation of maximum seismic responses of structures based on response spectra is deduced following similar procedures as the wellknown CQC method, in which new modal displacement-velocity and velocity correlation coefficients are involved besides the modal displacement correlation coefficient in normal CQC formula. The new real value form formula of CCQC method not only is as concise as that of normal CQC method but also has explicit physical meaning. The results obtained from CCQC approach are discussed and verified in example through step by step integration computation under a prescribed earthquake motion input. From examplary analyses, it may be pointed that the CCQC algorithm normally gives conservative outcome and that the forced mode uncoupling approach has good approximation even the discussed examplary structures are strongly non-proportional.