Seismic Performance of WUF-W Moment Connections According to Access Hole Geometries

Abstract

The welded unreinforced flange-welded web (WUF-W) moment connection is an all-welded moment connection, which is one of the prequalified connections for the special moment frame (SMF) specified in AISC 358-10. However, previous experimental studies reported that WUF-W connections with a beam depth of 890 mm failed as a result of brittle beam flange fracture and did not satisfy the requirement for the SMF connection specified in AISC 341-10. In this study, a finite element analysis (FEA) was conducted to investigate the cause of the brittle failure in the WUF-W connection. This study observed that the brittle failure occurred in WUF-W connections was mainly attributed to the access hole geometry. This study proposed the improved access hole geometry to prevent brittle failure from WUF-W connections. To verify the analysis results, this study conducted an experimental test using one WUF-W connection specimen with an improved access hole geometry.