Performance of inter-module connection with a pegged tenon for composite modular buildings with CFST columns

Abstract

The global rise of modular building, with its standardized manufacturing, faster construction, and superior quality, has been a significant trend. Steel-concrete composite modular buildings are emerging as a promising solution to address the increasing capacity demand resulting from the growing design height of modular buildings in various applications, including residential buildings, hotels, and offices. The use of concrete-filled steel tubular (CFST) columns effectively increases the capacity of modular units. However, this also results in higher load demand for inter-module connections, posing a significant challenge for conventional designs. This paper introduces a new tenon-connected inter-module connection for composite modular buildings, in which the tenon is pegged with tightening bolts driven through it perpendicularly. This innovative design offers a reliable load path to ensure continuity between the connected columns, while also allowing for easy assembly. An experimental test was conducted on six full-scale connection specimens to study their structural performance under monotonic loading. Four distinct failure modes were observed, and the corresponding load-displacement relation and strain distribution were thoroughly evaluated. A detailed finite element analysis (FEA) model was developed and validated against test data, which was then used to conduct a parametric study to investigate the influence of key parameters on the connection performance. The study revealed that variations in the column, brace, and tenon parameters greatly influenced the connection failure mode and loading capacity. The findings of this study provided a reference for the safe design of novel inter-module connections for composite modular buildings.