Prediction models for the initial rotational stiffness and ultimate plastic moment for a double split tee connection

Abstract

As a partially restrained connection, a double split tee connection has demonstrated various behavioral characteristics based on the combination of T-stub thickness, high-strength bolt gauge distance, and beam and column stiffness ratio, among other characteristics. Accordingly, many researchers have proposed an analysis model that would determine the behavioral characteristics, stiffness, and strength of a double split tee connection by selecting T-stub thickness and high-strength bolt gauge distance as parameters. However, such a model has not yet been proven to be accurate due to complicated stress distribution, contact and bearing phenomena, as well as prying action on high-strength bolts. Therefore, this study proposed an improved prediction model for the initial rotational stiffness and ultimate plastic moment to implement double split tee connections in the domestic steel structures market. Toward this end, this study performed the three-dimensional nonlinear finite element analysis, and validated the proposed model by comparing and reviewing its test results from the works of other researchers.