Non-linear dynamic analysis to assess the seismic performance of cross-laminated timber structures

Abstract

Timber structures are widely recognized to perform very well under strong ground motions. A non-linear dynamic analysis can be carried out to assess their seismic performance for design purposes, as allowed by the current regulations. When dealing with timber structures, however, the difficulties typically involved by this very powerful method of analysis may increase and sometimes become even overwhelming. The reasons are mainly due to insufficient experimental data, lack of standard constitutive models for timber connections and inadequate support provided by the current seismic codes. The key aspects related to modelling the non-linear behaviour of modern timber structures with particular focus to the crucial role of connections are analyzed in this paper. By referring to a case-study building made by solid cross-laminated (X-Lam) timber panels and designed according to the Eurocodes, the path that the designer has to undertake when carrying out a time-history non-linear analysis of a X-Lam timber structure is put in evidence, while some simplified assumptions are suggested and justified. A concentrated plasticity three-dimensional model is adopted where the hysteretic behaviour of connections is implemented by exploiting experimental data available from the literature. Three suites of earthquake records are considered in the investigation. The paper aims to give structural engineers some useful hints to carry out non-linear dynamic analyses of cross-laminated timber structures for design purposes.