Non-linear deformational analysis of reinforced concrete frame

Abstract

The paper presents the algorithm and some results of deformational non-linear analysis of reinforced concrete frame system taking into consideration of nonlinearity of materials. The nonlinearity of materials means the use of nonlinear models of concrete and reinforcement, stress-strain relationships of concrete and reinforcement are taken according to diagrams illustrated in Russian codes. The algorithm of deformational non-linear analysis has two stages. In the first stage, the relationship between element cross-sectional stiffness and internal forces was established. In the second stage, the structural analysis software SAP2000 was used for calculation of internal forces with the results received in the first stage. The results were investigated with a gradual increase of load values according to the relationship between element cross-sectional stiffness and internal forces. This helps to observe the places of formation of plastic hinges. From there some comments and recommendations were proposed to evaluate the criterion of limit state in structural analysis.