Tensile behaviour of a self-locking inter-module connection with spring-loaded plunger latches: A numerical study using ductile fracture simulation

Modular construction has an increasing recognition as a viable alternative to traditional methods due to its benefits, such as faster construction, improved quality control, and reduced material waste, all of which contribute to more sustainable practices within the building and construction sector. The recent development of a self-locking inter-module connection with spring-loaded plunger latches further enhances construction speed. A previous experimental study has highlighted the significant role of material fracture in determining the full-range connection behaviour. Using a robust finite element analysis (FEA) model that considers the ductile fracture of structural steel, the present study evaluates the connection performance across various geometric configurations. A practical framework is proposed to calibrate the required fracture parameters using standard tensile coupon and shear plate tests. The validated FEA model broadens the available data and allows further discussion about the interactions among parameters. The connection behaviour is characterised by 3 distinct failure modes related to critical component shifts among the protruded sleeve, recessed sleeve, and latch, each with unique responses. A simplified calculation method is developed to estimate the connection capacity, achieving an average ratio of predicted capacity over measured capacity of 0.99, with errors within ± 10 % for most data, demonstrating its high accuracy and reliability in predicting the failure mode and capacity of self-locking inter-module connections.