Yes
Earthquake response spectrum is the most popular tool in the seismic analysis and design of
structures. In the case of combined primary-secondary (P-S) systems, the response of the supporting P
substructure is generally evaluated without considering the S substructure, which in turn is only required
to bear displacements and/or forces imposed by the P substructure (¿cascade¿ approach). In doing so,
however, dynamic interaction between the P and S components is neglected, and the seismic-induced
response of the S substructure may be heavily underestimated or overestimated. In this paper, a novel
CQC (Complete Quadratic Combination) rule is proposed for the seismic response of linear light S
substructures attached to linear P substructures. The proposed technique overcomes the drawbacks of the
cascade approach by including the effects of dynamic interaction and different damping in the
substructures directly in the cross-correlation coefficients. The computational effort is reduced by using
the eigenproperties of the decoupled substructures and only one earthquake response spectrum for a
reference value of the damping ratio.