Elastoplastic material model for nonlinear analysis of planar RC structures under cyclic loadings

Abstract

This paper presents what is believed to be the first successful attempt to apply an elastoplastic material model to planar reinforced concrete under cyclic loads. The model treats an element of reinforced concrete in biaxial stress states, and provides for the cracking and crushing of concrete, opening and closing of previously formed cracks, and yielding of steel reinforcement. The model offers both computational efficiency and an adequate level of accuracy.A rectangular plane stress finite element with three degrees-of-freedom per node, two translations, and an in-plane rotation is employed to discretize the continuum. The presence of rotational degrees-of-freedom at nodes allows an application of the proposed model to the analysis of coupled shear walls and shear wall – frame systems.When the nonlinear finite element analysis results are compared with the experimental response of a shear panel and a shear wall subject to reversed cyclic loads, a good comparison is achieved. The analytical results for the shear panel are also compared with those obtained by other investigators using a degrading nonlinear material model, and a close correspondence is obtained.