Nonlinear analysis of reinforced concrete shells using layered elements with drilling degree of freedom

This paper presents a nonlinear finite element procedure for the analysis of reinforced concrete shells using the four-node quadri-lateral flat-shell element with drilling rotational stiffness. A layered approach is used to discretize, through the thickness, the behavior of the concrete and the behavior of the reinforcement. The analysis takes into account material nonlinearity by incorporating tensile, compressive, and shear models of cracked concrete, in addition to a model for the reinforcing steel. Using the smeared-crack method, the cracked concrete is treated as an orthotropic nonlinear material. The steel reinforcement is assumed to be in a uniaxial stress state and to be smeared in a layer. The constitutive models, which cover the loading, unloading, and reloading paths, and the developed finite element procedure predicts with reasonable accuracy the behavior of reinforced concrete shells subjected to different types of loading. The proposed numerical method for nonlinear analysis of reinforced concrete shells is verified by comparison with reliable experimental results.