Modelling of damage accumulation and failure of structural members subjected to strong seismic actions

摘要

Following the total Lagrangian approach, an incremental formulation for three-dimensional Timoshenko beam element taking into account large displacements and rotations is developed. For the failure analysis of reinforced concrete structural members, subjected to extreme loads, a new elastoplastic damage constitutive model is proposed on the level of cross-sectional variables. The model is based on the concept of the yield surface and associated flow rule. The effects of softening and strength deterioration are accounted for by the introduction of damage variables. To assure the objectivity of the numerical simulation a non-local treatment of damage variables is implemented. Comparison to different experimental results on biaxial cyclic tests is performed. Numerical results demonstrate that the proposed model effectively reproduces softening, strength deterioration, coupling between different components of the generalized force vector and other nonlinear effects accompanying the inelastic structural response under three-dimensional seismic loading.