Improved measure of beam-to-column joint rotation in steel frames

The behavior of beam-to-column joint rotation in a steel frame has been shown to have significant effects on the internal force distribution and the global deformation response. However, approaches to experimentally quantify the joint rotation are not well established. This fact impairs the applicability and comparability of research results on joint mechanical behavior. This paper compares different measurement methods in the research literature on beam-to-column joint rotation in steel frames, and proposes improved approaches for the experimental quantification of the rotation of welded joint and welded-flange-bolted-web (WFBW) joints. The feasibility and accuracy of the proposed methods are demonstrated by the comparison of results from simplified frame analysis with those from finite element analysis on both partial and complete structural levels. ► In this study methods to quantify joint rotation in a steel frame are discussed. ► Three measure and calculation methods are proposed. ► We conduct frame finite element analysis to verify the accuracy of the three methods. ► The proposed methods have satisfied accuracy to predict the structural deformation.