Numerical investigation of collapse behavior of steel-concrete composite frames containing corrugated webs with and without openings

As an alternative to flat webs (FWs), corrugated webs (CWs) in composite beams have been employed extensively in steel construction systems. However, the collapse behavior of steel-concrete composite frames containing CW beams has not yet been studied and requires urgent investigation. In this study, numerical models were developed to explore the collapse behavior of these composite frames in an internal column removal scenario. Subsequently, the verified modeling methods were used to conduct a comparative study on the collapse resistance performance of models containing FW and CW beams with and without openings to explore the evolution of their collapse behavior. The results reveal that the load-resisting mechanisms of the composite frames containing FW and CW beams are substantially different. The total resistance of the composite frames containing FW beams is a result of both flexural and catenary action, whereas that of the frames containing CW beams is mainly a result of flexural action only. Appropriate openings on the beam web can intensify the catenary action. Furthermore, an extensive numerical parametric study of the composite frames containing CW beams was conducted to elucidate the effect of key parameters, such as the corrugate shape, type, and angle, on the collapse behavior. The effects of the opening type, diameter, end distance, and spacing on the collapse behavior of these frames is also investigated. Finally, three strategies for improving the bearing capacity of the composite frames containing CW beams with openings are proposed: reinforcement by stub tubes, kinked plates, and a skin diaphragm. The results reveal that all these strategies can substantially improve the bearing capacity.