A robust 3D constitutive law to describe the quasi-brittle materials behaviour under cyclic loading: application to the analysis of a 3D RC shearwall under cyclic loading
Résumé
The formulation of robust constitutive law that can handle the complex behaviour of quasi-brittle
materials such as concrete is still an open-question. Despite the fact that significant progresses have
been noticed over the last decades, further efforts are still needed when dealing with the case of
cyclic loadings [1,2]. This work aims at developing a new 3D constitutive law accounting for the
major features characterizing the concrete behaviour. A specific attention has been paid to the
strategy to describe the stiffness recovery when switching from tension to compression to preserve
both the numerical robustness of the formulation and a strong physical meaning. Based on
micromechanics consideration, smooth transitions including frictional sliding allows for a robust
damage deactivation. The proposed constitutive law has been implemented in the finite element
software Cast3M developed by the French Atomic Energy and Alternative Energies Commission
(CEA). After exposing some local results at the Gauss’ point level, a structure case study has been
carried out. In order to qualify both the relevancy and the numerical robustness of the proposed
constitutive law, a reinforced concrete (RC) shearwall tested within the framework of the French
national project CEOS.fr has been considered. Representative post-test simulations based on a 3D
finite element discretization have been carried out and the numerical results are compared with the
experimental data considering not only the monotonic case but also the cyclic reverse case. Based on
the numerical/experimental comparisons, the Authors are very confident in the formulation strategy
they considered in this work. Dynamic simulations should be performed in a close future to qualify
the relevancy of the proposed constitutive law.