Displacement component-based modeling of reinforced concrete columns in SAP2000: Validation against experimental and OpenSees results

Abstract

Accurate estimation of lateral displacement in reinforced concrete (RC) columns is essential for performance-based seismic assessment. Total lateral displacement consists of flexural, bar-slip, and shear deformation components; however, commercial structural analysis platforms such as SAP2000 generally consider only flexural deformation, which may lead to overestimation of stiffness and inaccurate prediction of deformation capacity in non-ductile members. Although advanced nonlinear finite element platforms such as OpenSees explicitly represent these mechanisms, their implementation typically requires considerable modeling expertise and computational effort. This study presents a displacement component-based modeling framework within SAP2000 to represent flexural, bar-slip, and shear deformations through a component-based plastic hinge formulation. Rather than proposing new analytical formulations, the framework provides a practical and reproducible implementation strategy for representing individual deformation mechanisms within a commercial structural analysis platform. The proposed methodology is validated against the cyclic responses of an experimental database comprising 24 RC column specimens and is further compared with fiber-based OpenSees simulations in terms of lateral load–displacement response, stiffness degradation, and hysteretic behavior. The results demonstrate good agreement with the experimental responses, indicating that the proposed framework can effectively represent the nonlinear cyclic response of RC columns while explicitly accounting for the contributions of individual deformation mechanisms. The proposed methodology offers a practical intermediate nonlinear assessment approach between simplified engineering models and computationally demanding distributed-plasticity simulations for the seismic performance evaluation of existing RC structures.