Investigation on the inelastic torsional response of asymmetric-plan buildings

Many studies on the seismic performance of asymmetric-plan buildings have clearly shown how much such types of structures, due to their coupled roto- translational response, are vulnerable when excited by a lateral ground motion. Efforts have been spent in past investigations for identifying the sources of the in- plan irregularity and for evaluating contribute and effects of rotations to the seismic response. While the elastic behaviour has been studied extensively, general conclu- sions in the field of the inelastic range are still lacking. The aim of the present investigation is to contribute to the current understanding of still unclear aspects of the nonlinear seismic behaviour of asymmetric-plan buildings, as the influence on their torsional response of both the in-plan resistance distribution and the seismic action intensity. In order to achieve these scopes, results from nonlinear dynamic analysis on single-storey frame buildings characterized by different strengths distributions and excited by ground motions of increasing intensities are presented.