Comparison of the lateral force-resisting mechanisms of steel MiC structures with full-strength and partial-strength inter-module joints: Experimental and numerical analysis

The modular integrated construction (MiC) approach can significantly transform the construction industry owing to its efficiency, quality, and sustainability. It is believed that steel MiC structures with full-strength inter-module joints can provide better structural behavior than those with partial-strength inter-module joints at the expense of construction efficiency. Therefore, the effects of different joint properties on the critical behavior of steel MiC structures must be investigated, particularly the lateral force-resisting mechanisms, such that guidelines for selecting connecting techniques can be established. To this end, two steel MiC frame specimens with upper and lower steel modules connected via welding and bolting, which can be regarded as two frames with full-strength and partial-strength joints, are experimentally tested. Furthermore, extensive numerical analyses are conducted to investigate the lateral behavior. It is found that compared with the welded specimen, the bolted specimen indicates a significantly lower initial stiffness owing to the shear behavior of the bolted joints. The lateral resistance of the welded specimen can be accurately evaluated by a global failure mechanism comprising plastic hinges formed at the ends of beams and columns. By contrast, the failure mechanism of the bolted specimen depends on the strength of the joints.