Numerical investigation into the effect of passive energy dissipation in low-rise structures built on soft-soil sites

This paper presents a study into the effectiveness of passive energy dissipation systems in low-rise structures built on soft soil sites subjected to ground motions. In this technique designated energy dissipating devices (EDDs) are installed in the structure such that a portion of the energy originated from ground shaking is diverted to. This paper focuses on displacement-based EDD whose response is highly non-linear. The governing equations of a multi-degree of freedom lumped-mass model with force-displacement non-linearity described by the Bouc-Wen model are presented. Two parameters, namely the brace-EDD assembly to frame stiffness ratios S_r and the yield drift angles γ_y are identified to be influential and a parametric study is carried out using response history analyses. Results indicate that Sr plays an important role on overall structural response, with an increase in S_r generally result in more desirable performance. On the contrary γ_y plays a less significant role. Results presented in this study give an insight into the preliminary selection of EDD and brace properties.