Failure Modes and Bearing Capacity of High-Strength-Steel-Bearing-Type Bolted Connections

Bearing-type bolted connections are frequently used for steel structure connections and are typically small when used to connect high-strength steels. However, studies on the failure mode and ultimate bearing capacity of high-strength-steel-bearing-type bolted connections are, to our best knowledge, limited. To address this gap, experiments and numerical analysis were carried out to investigate bearing-type bolted connections with end distances and edge distances ranging from one time the bolt hole diameter to two times the bolt hole diameter. Eighteen specimens were fabricated using Q460, Q550, and Q690 alloys. The results showed that the specimens exhibited three failure modes: net cross-sectional; tearout; and splitting failures, where end distance and edge distance were two controlled parameters that determined the failure modes. This study introduces a novel data-driven method that leverages accumulated data from finite element models to accurately quantify the boundaries of various failure modes. It eliminates the requirement for numerous assumptions in complex mechanical derivations, specifically when deriving splitting failure boundaries resembling the bending of deep beams. Consequently, this method provides a reliable and feasible alternative for evaluating failure modes in specimens. It was demonstrated that the net cross-sectional failure could be avoided when end distance equaled one time the bolt hole diameter, indicating that it is feasible to lower the minimum of end distance to one time the bolt hole diameter. The ultimate bearing capacity with nonet cross-sectional failure increased linearly with end distance and nonlinearly with edge distance. Ultimate bearing capacity calculation methods for different failure modes considering end distance and edge distance, were proposed, and their accuracy was verified using experimental results from other studies.