AN ANALYSIS OF THE STRESS-STRAIN STATE OF REINFORCED CONCRETE BEAM CROSS-SECTIONS SUBJECTED TO BIAXIAL BENDING

Abstract

This paper presents a simple analytical method for determining the stress-strain state of reinforced concrete (RC) beams subjected to biaxial bending. A simple supported beam with three input load values applied at two positions is used in this study. The beam cross-section is divided into numerous elements and then the stress-strain state at the centre of these elements is analysed. The material behaviour of concrete and rebar are both simulated using a bilinear model. The results of this method are compared and verified with a three-dimensional finite element approach. The results indicate that the proposed method is easy to implement and its performance is comparable to a numerical simulation method.  The stress-strain state, location, and shape of the neutral axis, as well as the shape of the compressive and tensile area can be extracted using the proposed method. This method can also present the position and length of the crack in the cross-section. Moreover, this method ensures accurate evaluation when selecting materials and the initial layout of the rebars. The testing and evaluation of the accuracy of the material selection can be completed by using this proposed method. Also, the method can be applied to RC beams with different cross-sections and complex loading.