Non-Linear Dynamic Analysis of Reinforced Concrete Shells under Seismic Load

Abstract

Details of a finite element non-linear dynamic analysis on a reinforced concrete (RC) containment shell of a nuclear power plant subjected to seismic load is presented in this work. A three-dimensional (3D) 20-noded brick finite element is used for spatial discretisation. The concrete in compression is modeled using a modified Drücker-Prager elasto-plastic constitutive law. This constitutive law includes the strain rate sensitive effect, which is considered to be suitable for transient loading. Cracking of concrete is modeled by using a smeared approach and the tension-stiffening effect is considered by a strain-softening rule. A model based on fracture mechanics, using the concept of constant fracture energy release, is used to relate the strain softening effect to the element size in order to guaranty mesh independency in the numerical prediction. The reinforcement is also represented by a smeared approach and a classical elasto-plastic material model is adopted for reinforcing steel bars. Finally, results obtained with the present numerical model are compared with those obtained by other authors in terms of time history of displacements and cracking patterns.