A comprehensive experimental-numerical investigation on the bending response of laminated double channel beams in modular buildings

Abstract

Laminated channel steel beams enhance the interaction between adjacent beam components and thereby improve the structural integrity of steel modular buildings. However, the bending response of laminated steel channel beams has not been fully understood. In this study, a series of experimental tests and a finite element analysis (FEA) were conducted to investigate the superimposed bending behaviour of laminated channel beams. Four-point bending tests were performed on a simple laminated beam with interfacial friction (LFB), a strong laminated beam with interfacial friction and bolt connections (LFCB), and a single beam to derive the bending response of an independent bending beam (IBB) for comparison. The results show that the overall load bearing capacity and stiffness of LFB and LFCB are much higher than those of IBB. In addition, the neutral axes of strain distributions evaluated in the central section of each layer beam tend to approach interfaces. This becomes more evident as beams are more strongly connected. The interfacial mechanical behaviours of loads and slippage significantly influence the superimposed bending response of laminated beams. The interfacial connections between the channel beams have an important role in defining the position of neutral axes of laminated specimens, and the load bearing capacities calculated based on the mid-span stress models agree well with the experimental and numerical results.