The effect of inter-connection properties on the lateral behaviour of moment-frame modular steel structures

Abstract Recently, there has been a push for the adoption of pre-fabricated modular units in constructing low to high-rise buildings mainly due to the reduction of material waste and construction time. These units are manufactured in a factory and then transported to the construction site for assembly through inter-connections to create a building block. The unique nature of these inter-connections is crucial for the structural performance of modular buildings as they provide modular structure integrity. Despite the growing popularity of modular construction, there is a limited number of published studies examining how inter-connection mechanical characteristics influence the lateral performance of moment-frame modular structures. The stiffness of inter-connections plays a crucial role in determining the overall rigidity of these structures, indicating the importance of studying their impact on the seismic performance of moment-frame modular buildings. The objective of this study is to investigate the impact of inter-connection mechanical characteristics on the lateral performance of moment-frame modular buildings using nonlinear static analysis. For this purpose, three frames with four, eight, and twelve storeys are assumed for analysis. Various inter-connections with different stiffness properties are considered in the nonlinear static analysis. Three performance levels are taken into account, and the responses of the structures at these levels are assessed and compared based on different inter-connection mechanical properties. The findings suggest that a decrease in inter-connections' stiffness results in a reduction of lateral capacity up to around 32.98% for the structural base shear.