Shear Stiffness of Concrete by Finite Elements

A mathematical model for the shear transfer across cracks in reinforced concrete is reviewed and used as a guide to identify the main parameters involved in the shear transfer phenomenon. The mathematical model is used as the basis for the statistical analysis of the available experimental data. This statistical analysis provides a simple expression for the prediction of the shear slip along a penetrating crack caused by the transfer of the shear force in the presence of a known normal force and of an initial crack width. This expression is utilized within the context of nonlinear finite element analysis to modify the shear rigidity terms of the constitutive law of concrete upon cracking, on an integration point basis. Verification analyses conducted demonstrate the capability of the proposed finite element model to reproduce experimental results. The proposed approach is applicable to loading conditions that do not cause failure by shear.