Load carrying capacity of novel semi-interlocking inter-modular connections in modular buildings

Inter-modular connections are vital for ensuring load sharing, transfer efficiency, and structural integrity in prefabricated modular buildings under extreme loading conditions. The existing intermodular connections in steel buildings face several challenges, including insufficient lateral load resistance, inability to reuse, higher costs, and longer installation times. Therefore, this study aims to develop a semi-interlocking bolted plate connection designed for modular buildings, offering enhanced assembly efficiency and structural performance at a lower cost. Two types of semi-interlocking inter-modular connections were developed to improve compatibility with common steel modular building sections and typical modular arrangements. Monotonic loading tests, including compressive, tensile, and shear tests, were performed to assess the connections’ load-bearing capacities and deformation characteristics. The experimental results demonstrated that the connections have sufficient compressive and tensile capacities compared to the axial capacity of the column. Moreover, the shear capacity of the connections is nearly 10% higher than that of traditional bolted connections and 50% higher than existing inter-modular connections, while ensuring ease of construction. The connection performed adequately in axial and shear capacities, enabling the required or exceeding standard design capacities. Moreover, the connections were nearly 40% less costly than most of the industry's existing partially interlocking connections. The findings suggest that the proposed semi-interlocking connection is a viable solution for advancing the modular construction industry.