Direct floor response spectra for nonlinear nonstructural components

The method for the direct determination of floor acceleration spectra, previously developed by the authors, is extended in order to take into account the nonlinear component behaviour. In the case of a linear elastic response of both the primary structure and the component, the component may be exposed to very high accelerations during seismic actions. The component accelerations can be greatly reduced if the response of the structure and/or the component is nonlinear. Considerable research work on the effect of the nonlinearity of structures has already been performed, whereas relatively sparse information is available on the quantitative influence of the component nonlinearity on its response. In the paper, first, the results of a parametric study of floor acceleration spectra for nonlinear components are shown and discussed. Then, the proposed extension of the existing authors’ method is described and validated by test examples. In addition, an approximate approach for the estimation of floor acceleration spectra for nonlinear components by using an increased component damping value is presented. In the proposed method, floor acceleration spectra are, to a great extent, based on the theory of the dynamics of structures, and partly combined with empirical values and well established approaches for considering nonlinear effects. Floor acceleration (response) spectra explicitly take into account ground motion spectra and dynamic characteristics of buildings and components. The advantage of such an approach is its general applicability, which allows diverse design options.