Seismic behavior of an innovative bolted connection with dual-slot hole for modular steel buildings

Although a significant advantage for modular steel buildings (MSBs) is suitable for rapid construction, the un-expected installation error and initial defects of components in the construction site may lead to the failure of rapid assembly or even connection between modules. Aiming at the error sensitivity problem of module splicing, this paper proposes a new type of bolted connection with dual-slot hole and two kinds of connection strength-ening methods, including diagonal brace strengthening and flange strengthening. To proceed, tests on four full-scale connections with cyclic loads were performed for seismic behavior. The test results presented the speci-mens' failure mode, strength and stiffness properties, ductility, and energy dissipation capacity. Following that, the finite element model was validated against test data, and the influence of slot hole size and displacement effect was discussed. Finally, the hysteretic model was given. The results indicated that the proposed connection has reliable load-bearing, stable energy dissipation, and fast splicing capacity. The connection may be classified as semi-rigid type according to the stiffness feature for the structural behavior of MSBs. Both diagonal brace and flange strengthening can effectively improve the connections' load-bearing capacity but weaken the energy dissipation capacity. The research results could serve as an effective reference for the inter-module bolted connection design of MSBs.