Collapse behavior and resistance mechanisms of steel modular buildings with corrugated walls: experimental, numerical, and analytical insights

Abstract

This paper investigates the collapse behavior and resistance mechanisms of steel modular buildings (SMBs) with corrugated steel walls under the scenario of two edge module loss. The study employs experimental methods to examine critical aspects of the specimen, including failure modes, load-displacement behavior, wall deformations, structural component displacements, and strain development in beams and columns. A validated finite element model is utilized to further explore the contributions of wall panels to structural collapse resistance and to evaluate the influence of wall corrugation configurations on the load-bearing capacity of SMBs. Based on the experimental findings, a simplified analytical method is proposed to estimate the specimen's peak load. The results indicate that the load-displacement response progresses through four distinct stages, with the peak load reaching approximately 2.2 times the yield load. After wall failure, the structural resistance initially decreases but subsequently recovers due to the catenary action in the short module beams. The final failure mode is characterized by the separation of the short wall panel from the module frame, tensile failure in the long wall panel, and flange fracture in the short beam. During large deformations, compression between the two adjacent long beams results in a final relative displacement of approximately 12 mm. Both short and long wall panels contribute significantly to the collapse resistance during small deformations, each accounting for over 40%. However, as displacement increases, the short wall panel's contribution becomes dominant due to the stronger restraints provided by the module frame.