Assessing Different Modeling Approaches for a Four-Story Reinforced Concrete Building

OpenSees and Perform3D models of a four-story reinforced concrete building tested on the E-Defense earthquake simulator were created in accordance with ASCE 41–17 provisions. The computational models differed in the techniques used to simulate the hysteretic response of beam-column joint, column, and wall elements. OpenSees building models followed lumped plasticity and distributed plasticity (fiber section) approaches. In OpenSees fiber section models, columns and walls were discretized using force-based fiber section elements with 5 integration points and Gauss Lobatto integration, while beams were modeled with zero-length hinge elements at member ends. The stress-strain behaviour of steel elements in the fiber section model was adjusted so the minimum and maximum strain limits would cause loss of lateral load capacity at a rotation similar to the capping point in the backbone curve specified in ASCE 41. Calculated performance metrics were compared with measured responses for strong motion records used in the tests. The output of OpenSees and Perform3D models were compared to show the difference in calculated deformation obtained with different analysis engines and modeling techniques. Analyses showed that approaches that capture bi-directional moment-axial interaction provided significantly different estimates of response than lumped-plasticity. Models that accounted for bi-axial interaction of column moments resulted in larger estimates of column rotation and damage.