Experimental and numerical investigations on large-scale concrete-filled double-steel-plate composite structures

Abstract Concrete-filled double-steel-plate composite (CDC) technology is commonly used in residential and bridge structures to achieve higher structural stiffness and strength. However, CDC technology has rarely been used in structures with large-scale sections, such as bridge towers and submarine tunnels before. Experimental and numerical studies were conducted to develop a novel large-scale CDC structure system and investigate its mechanical performance. Three full-scale four-point bending specimens were designed to represent the real compatible functioning and buckling performance of a CDC structure and were tested to failure. Significant events and failure modes of all specimens were distinguished and analyzed. Finite element analysis (FEA) models were established to simulate the performance of the specimens. Details of connectors and plate buckling were considered in the FEA models. Numerical load–displacement results were consistent with the experimental results, which demonstrated that the CDC structure specimens exhibited higher strength and stiffness compared to reinforced concrete (RC) specimens. The FEA models produced results that agreed well with the experimental load-slide results and strain distribution. The concrete and steel plate in the CDC specimen functioned compatibly before the ultimate state was reached. The plane assumption is applicable when designing the large-scale CDC structures. The pull-out resistance of the connectors can be designed according to the yield strength of the steel plate to guarantee the compatible functioning of the CDC structures. The FEA models and conclusions derived from the study can be used to aid the design and further investigations of the CDC structures.