Nonlinear Analysis of a RC Structure for Different Damping Models

Abstract

Damping is an important property of the structure as it helps in the dissipation of vibratory energy which is generally caused by the dynamic loads acting on the structure. Limiting the response amplitudes that are caused due to imposed vibrations is always challenging for the structure’s stability and safety. Three types damping models; viscous damping, structural damping and coulomb friction damping are proposed so far in the literature. Among these models viscous damping is highlighted due to the fact of high energy dissipation in the structure. In the present analysis, comparison of these three damping models in a G+5 RCC structure with respect to the energy dissipation by considering strain energy. The structure is analysed for the response amplitudes for the different damping models. The damping coefficient present in the structure is identified using linear time history analysis. Non-linear time history analysis is performed using time stepping methods to assess the response amplitudes of the structure. Using the non- linear responses, the amount of energy dissipated in each model and the loss factors are estimated. Also, the energy dissipations in the structure are compared for two different ground motions. Viscous damping model is found to be the suitable model in reducing effect of vibrations coming to the structure. For the structure having viscous damping model, frequency response curves of response amplification and phase angle are plotted. Therefore, non-linear behaviour of the structure can be estimated to some extent.