Analysis of Shear Panel Elements Using Improved Fixed Strut Angle Model Based on Plane-Stress Element

The behaviour of reinforced concrete (RC) member can be evaluated by employing a reasonably accurate constitutive relationship and element type in the finite element (FE) framework. Important components like columns, beams and shear wall in an RC structure can be analysed in the FE framework by using a plane-stress element. In general, RC members are subjected to the combination of axial, shear, flexure, and torsional loading. Hence, it is necessary to use constitutive models which can consider the effects of combined loading. This work focuses on implementing an improved fixed strut angle model in finite element framework to analyse shear panels under combined shear and axial loads. The proposed procedure is based on secant stiffness based iterative formulations and employs constitutive relationships which consider the concrete softening and tension stiffening. The material models and the equilibrium conditions based on the fixed strut angle model were implemented into MATLAB based FE framework. The reliability of the proposed analytical model is checked against the experimental results available in the literature. Moreover, it is essential to use efficient material constitutive relationships which can be effectively implemented in a finite element framework without compromising the accuracy of the predictions. A comprehensive analytical study is carried, wherein predictions were obtained using different combinations of material models. Comparison of the results shows that the predictions of the proposed model agree well with the test results.