Investigation of various concrete materials to simulate seismic response of RC structures

This paper focuses on the performance evaluation of several concrete models in reinforced concrete (RC) structures subjected to seismic loading. Despite many studies conducted on implementing different characteristics of concrete in constitutive models, there is an essential need for investigating the ability of these models in predicting the behavior of structures in seismic applications. In this paper, several developed plasticity-based constitutive models with the combination of fracture and continuum damage models are investigated for application in seismic loading conditions. Damage-based isotropic and anisotropic models and smeared cracking approach have been applied as complementary components of plasticity-based concrete models. Robustness assessment of various developed plasticity and damage, or plasticity and smeared crack concrete models are evaluated using a finite element based software, LS-DYNA and employing five concrete models as indicators of desired constitutive models, including MAT 084, representative of plasticity and smeared crack model, and MAT 159, MAT 072R3, MAT 272, and MAT 273, representatives of plasticity and different tensile/compressive damage models. This paper studies the cyclic behavior of structural components, including RC rectangular and T-shaped beams, short and slender columns, lightly and highly reinforced squat and slender shear walls, with and without boundary elements. The minimum number of parameters available in most of the experimental researches is used in the simulation of concrete models. Based on the analysis results, the strengths and weaknesses of five selected concrete models to predict the key characteristics of cyclic behavior of RC structures, including initial stiffness, peak strength, strain at peak strength, failure mode, stiffness degradation, and pinching are discussed. Some recommendations are also provided for modeling the RC structures.