Cyclic Behavior of WUF-W Connections Predicted using FE Analyses with Accurate Material Hardening Models

Abstract

Welded unreinforced flange-welded web (WUF-W) connections are one of prequalified connections specified in AISC 358-16 (2016) for special and intermediate moment frames. The cyclic behavior of the WUF-W connections varies according to many different parameters such as panel zone strength ratio, beam span-to depth ratio, access hole geometry, and beam-column strength ratio. The cyclic behavior of the connections has been often investigated using experimental tests. The cyclic behavior of the connections has been often investigated using experimental tests. However, it is difficult to conduct tests considering all combinations of individual design and detail parameters because of excessive cost and time. The objective of this study was to construct the FE model with an accurate material model for predicting the cyclic behavior of WUF-W connections. The material model was constructed with a combination of one isotropic and three kinematic hardening models based on combined hardening model. The particle swarm optimization was used to precisely determine the constituent parameter values of the material model for steel materials. The cyclic behavior of WUF-W connections was accurately simulated using the proposed FE model. Strain distribution and local flange bucking shape were also precisely predicted using the model.