Numerical simulation for structural behaviour of stainless steel web cleat connections

Abstract

A finite element model for predicting the moment-rotation curves of stainless steel web cleat connections is developed, and validated by test data. The effects of several parameters (i.e., number of bolts, gage distance of angles, thickness of angles, and types of stainless steel) on the moment-rotation curves of stainless steel web cleat connections are investigated using the validated finite element models. The stiffness and ultimate moment of stainless steel web cleat connections increase as the angle thickness or number of bolts increases, and they decreases as the gage distance of angles increases. S22053 stainless steel web cleat connections exhibit a higher stiffness and moment resistance than S30408 and S31608 stainless steel web cleat connections. Chen and Kishi's model can accurately predict the moment-rotation curves of stainless steel web cleat connections, but the initial stiffness and ultimate moment capacity calculated from Kishi and Chen are not ideal. An empirical formula for calculating the initial stiffness of web cleat connections is proposed. Compared with the test data for the initial stiffness, the average error of the proposed formula is only 14.67%, making it more accurate than existing models. The finite element analysis results indicate that current yield line mechanisms for the angle may not reflect the behaviour of the angle. A new yield line mechanism for the angle is proposed on the basis of stress distribution in the angle at the ultimate strength state. An analytical model for estimating the ultimate moment capacity of web cleat connections is derived. The proposed formula produces a more accurate prediction than the existing formulas, as the average error of the ultimate moment capacity between the estimated values and test data is only 6.00%. Good agreement between the proposed model and the moment-rotation curves of the test data is observed. Design recommendations for the structural behaviour of stainless steel web cleat connections are provided.