Damping capabilities of reinforced concrete components in the beyond design range from the identification to a critical review of common best-practices

International audienceWhen attempting to predict the seismic response of reinforced concrete (RC) structures, a trade-off has to be found between a realistic representation of the dissipations through material law and a numerically more efficient modelling with a controlled computational demand such as a Rayleigh-type damping model. Anyway, constitutive laws only describe internal dissipation and actually need a complementary dissipation term often chosen as a proportional damping matrix to take into account external dissipation sources such as interactions with the environment. Decoupling these two contributions in global dissipation measurement from experimental tests is still challenging. To address this problem, a numerical study based on an experimentally identified structural model is here presented. To this end, an experimental campaign has been carried out on RC beams set up on the AZALEE shaking table of the TAMARIS facility operated by the French Alternative Energies and Atomic Energy Commission (CEA). In this paper, the experimental campaign is briefly presented. Then, a parametric model is formulated and identified from the experimental results. Third, numerical dynamic experiments are carried out in order to assess the influence of several parameters on the energy dissipation and on the equivalent viscous damping ratio through two different methods. The validity of these results is assessed on a numerical case where a nonlinear model and an equivalent linear model are compared with each other. Experimental results of dynamic tests are also used as reference in order to estimate the additional viscous damping necessary to take into account the whole energy dissipation