Cyclic performance and numerical analysis of dry-assembled CFS composite walls filled with high-strength foam concrete

In order to improve the assembly rate of cold-formed steel (CFS) housing structural systems, this paper proposes two novel dry assembly forms for flange and web connections. Cyclic loading tests were conducted to investigate the effects of the flanges and different connection methods on the failure mode, bearing capacity, stiffness, energy consumption and ductility of the prefabricated CFS foamed concrete shear walls (PCFS-FCSWs). The findings indicated that the damage to the PCFS FCSWs was predominantly concentrated in the web region between the vertical joints. The shear forces in the webs were successfully transferred to the flanges via the connectors and bolts. The presence of flanges increased the compressive and deformation capacity of the specimens, and delayed the degradation of stiffness. The bearing capacity of PCFS-FCSWs was inferior to that of the cast-in-place wall, although their deformability and energy consumption were superior. Compared with the web spliced specimen, the load-bearing capacity and total energy consumption of the specimen assembled with L-shaped connectors increased by 22.8% and 50.4%, respectively. The finite element modelling (FEM) results demonstrated that the minimum principal stress trace in the webs of PCFS-FCSWs was distributed along the diagonal. The stresses at the bottom of the flanges were distributed parabolically and there was a shear lag effect. Finally, a simplified model for predicting the shear bearing capacity of PCFS-FCSWs was proposed, considering the effects of cladding panels, flanges and assembly joints. The findings provide valuable insights for the promotion and application of dry-assembled CFS composite walls in seismic zones.