Comparative Study of Concrete Models in OpenSEES for Performing Nonlinear Analysis

Acknowledging the strength deterioration of Reinforced Concrete (RC) structures under nonlinear loading, along with the structural response at the ultimate load, the response throughout the analysis is of due importance for reliable nonlinear dynamic analysis. Hence, while selecting the material models for structural modelling for nonlinear analysis, it is required to strike a balance between computational efficiency and realistic representation of material response. Here, an eight storeyed RC wall-frame building, designed according to Indian design codes IS-456:2000 and IS-13920:2016, is analysed through Incremental Dynamic Analysis (IDA). Three different structural models are modelled and analysed using three different concrete models using the open source computer program OpenSEES, viz. Concrete01, Concretre02 and Concrete07. The IDA results are compared in order to study the merits and demerits of the considered concrete models. It is found that Concrete02 ensures better numerical stability than Concrete07 and also predicts the dynamic response of concrete better than Concrete01.