Analytical and Design Method for the Global Stability of Modular Steel Buildings

Abstract

Modular steel buildings (MSBs) are an innovative form of prefabricated buildings with many advantages related to the factory-manufactured construction process. However, technical issues in the global stability design remain ambiguous and induce either unsuitable or uneconomical results without understanding the effect of intermodule connections appropriately. In this study, one practical theoretical equation to determine the buckling length factor for the sway-permitted MSB was derived from a sub-assembly considering pinned or rigid inter-module connections. A large number of finite element models were then used to numerically validate the effectiveness of the theoretical equation and explore the main influencing factors including both intermodule connections and height-to-width ratios. Results indicated that the intermodule connections should be carefully considered when the floor beams are obviously larger than ceiling beams, and theoretical results can be accurate enough when the height-to-width ratios remain within 3.0. Moreover, the second-order analysis method for MSB was also performed by using nonlinear buckling analyses and then compared with the buckling length method to verify the previous findings. Finally, the criterion in selecting the proper stability design procedure for MSB was discussed in depth.