Experimental, numerical simulation and design methodology for a novel sleeve fully bolted joint in modular buildings

Modular construction has been widely adopted globally due to its significant construction efficiency and environmental benefits, demonstrating substantial market potential. To expand the application scope of modular construction and address the insufficient quantity and uneven distribution of urban sports facilities, the authors and their research team previously proposed a novel modular stadium building. As the connection joint is the most critical load-bearing component in this novel structural system, the authors developed an innovative internal sleeve-full bolt connection joint and investigated the mechanical performance of T-shaped and cruciform connection joints. To comprehensively explore the mechanical behavior of this novel joint, this study investigates the lateral mechanical performance of the proposed connection joint through experimental testing, numerical simulation, and theoretical analysis, based on prior research. First, the structural design of the novel joint was analyzed, and full-scale static tests were conducted on the joint specimens. Experimental results were used to establish validated numerical models for refined analysis. To identify factors influencing the initial stiffness and ultimate bearing capacity of the joint, finite element parametric analyses were performed on the internal sleeve thickness, stiffener thickness, and beam-column cross-sectional dimensions. Finally, a simplified analytical model was developed, and theoretical design formulas for the novel joint were derived. The prediction errors of the theoretical formulas were mostly below 10 %, confirming their applicability in engineering design. Additionally, a design procedure for the joint was provided. The research findings and methodologies presented in this paper can serve as a reference for related studies and contribute to the advancement of modular construction technology. • A novel modular building and its internal sleeve all-bolt joint are introduced. • Full-scale tests on the novel joint were conducted to investigate its lateral mechanical performance. • The finite element parametric analysis of the novel inner sleeve fully bolted joint is carried out, and design suggestions are given. • The theoretical calculation formula for the novel joint was derived, and the design procedure was provided.