Multi-Link viscoelastic contact model for numerical simulation of seismic pounding between adjacent structures

A special multi-link viscoelastic (MLV) finite element contact model is devised and calibrated in this study to reproduce Jankowski’s non-linear viscoelastic analytical model in time-history analyses including the effects of seismic pounding. The MLV model is constituted by an in-series assemblage of n linear dampers and n associated in-parallel linear springs. Its response is based on the sequential activation and disconnection of the dampers, following the variation of the time-variable interpenetration depth δ(t) between the colliding structures. This way, the resulting equivalent damping coefficient c(t) of the assemblage becomes a function of δ(t), and thus the relation between c(t) and δ(t) can be easily reproduced in piece-wise linear form in the finite element computation. Detailed information on the practical implementation of the MLV model in time-history seismic analyses, as well as on the calibration of relevant geometrical and mechanical parameters, are offered in the paper, based on the results of a simple case study, represented by a couple of one-storey colliding reinforced concrete frames.