Flexural behavior of laminated H-beams in modular constructions: Numerical and analytical studies

Modular steel construction (MSC) has become an important development direction of the construction industry thanks to the faster construction speed and recyclability. The laminated steel beam is one of the key structure characteristics of MSC, which can enhance the structural integrity by strengthening the interaction between the adjacent beams in vertically stacked modules. In this study, numerical and analytical studies were carried out to explore the flexural behavior and design method of the laminated H-beams in MSC. Firstly, finite element models were established and verified based on the previous experimental study on flexural behavior of the laminated square steel tube beams and laminated channel steel beams. Afterwards, finite element analysis was conducted on flexural behavior of the laminated H-beams with different connecting bolts. The results showed that the flexural capacity and stiffnesses of the laminated H-beams were significantly improved by increasing the number of the connecting bolts in the bending-shear sector. The flexural behavior of the laminated H-beams was discussed including the failure mode, load-deflection curves and slippage of the superimposed surface to reveal the co-bending mechanism. In addition, parametric analysis was performed to reveal the influence of the position, number and diameter of the connecting bolts on flexural behavior of the laminated H-beams. Finally, a theoretical model on flexural capacity of the laminated H-beams was developed to determine the neutral axis and derive the flexural capacity of the laminated H-beams. The calculation formulas were verified to be reliable by comparing the theoretical analysis results with the numerical ones. The present study is beneficial to consummating the mechanical behavior and design method of MSC.