Investigation of Modelling Approaches for Non-Linear Analysis of Reinforced Concrete Frames

This paper presents explicit evaluation of the safety and reliability of structures to obtain the actual performance of the structure numerically which will finally help designers to not only protect life, but also to minimize damage of the structures to an acceptable level. To do so, nonlinear finite element analysis of the frame is conducted, and results from lumped plasticity and continuum-based modelling approaches were compared with documented experimental results. The capability of each numerical model to capture the load deformation relationship and failure pattern is studied. Moreover, a parametric study is performed for selection of suitable material model which could depict the actual response of the frame for both considered numerical modelling tools. From this study, the analysis result of the lumped plasticity based model in SAP2000 was seen to be more realistic to the experiment result when the user-defined hinge model with confined nonlinear concrete property, non-linear rebar property with consideration of crack section as per the codal provision was performed. The frame remodeled with continuum mechanics based approach in LS-DYNA modelling tool could capture the experimental results with higher accuracy. In addition, among several material models available, Continuous surface cap model is recommended to be used for quasi-static analysis of structures since it can capture the performance of structure with significant accuracy.