A novel modular CFS composite frame-wall structure: Experimental investigation and numerical analysis

Abstract

Due to the advantages with short-time installation and waste reduction, modular structures are promising. In the process of applying cold-formed steel (CFS) structures in multi-rise buildings, the combination of steel frames and CFS walls can improve the lateral performance of the structures. A novel modular CFS composite frame-wall structure was proposed, which was comprised by modular steel frames and modular CFS shear walls. Five full-scale modular CFS frame-wall components derived from the composite structures were tested under cyclic loads. The layout of sheathings, configuration of CFS diagonal bracings and door openings were varied to study their effects on lateral performance of the modular CFS composite structures. The results indicate the modular steel frames and CFS shear walls can do well in working cooperatively. The bearing capacity of the specimens with sheathings is more than twice that of the specimens without sheathings. In contrast, the effect of the diagonal bracings is not so significant due to the failure of the screw in the ends. Besides, the simplified models based on equivalent line elements was put forward and verified by experiments. A 6-story CFS composite frame-wall archetype structure was designed and its 3D numerical model was built on basis of the mentioned above simplified approaches. The nonlinear time-history analyses were carried out to evaluate the seismic response of the structures. Results show that the inter-story drifts of the designed structures under the earthquake waves of collapse levels are less than the drift limits 1/50. The designed structures have good seismic performance.