Experimental Study and Finite Element Analysis on Load-Bearing Performance of Corrugated Steel–Concrete Composite Arch Structures

This study compares the mechanical characteristics of an arched corrugated steel–concrete composite structure (CSC), a concrete-only structure (C), and a corrugated steel-only structure (CS) through loading tests. By integrating three-dimensional numerical simulation analysis, it systematically investigates the load-bearing performance, deformation characteristics, and failure mechanisms of the three structures. The test results indicate that the ultimate bearing capacity of CSC reached 216 kN, representing increases of 517% and 52% compared with C and CS, respectively. The overall flexural stiffness and ductility were significantly enhanced, and the ultimate bearing capacity exceeded the linear superposition of the individual capacities of C and CS, demonstrating a positive synergistic force. A three-dimensional finite element numerical model was established. Finite element analysis was conducted under boundary and loading conditions identical to those used in the loading tests. The results indicate that the relative error between the simulated and experimental ultimate bearing capacities did not exceed 2.3%. The load–displacement curves exhibited a variation trend basically consistent with the experimental results, demonstrating that the model can reflect the actual mechanical behavior and failure evolution process of the structure with reasonable accuracy. The damage distribution maps elucidate the three-stage damage evolution pattern of the composite structure: damage initiates at the corrugated steel–concrete contact interface, subsequently propagates upward through the concrete, and ultimately extends to the concrete surface, causing cracking and interfacial delamination and leading to structural failure. Finally, to simplify the finite element numerical analysis procedure and improve computational efficiency, three equivalent modeling schemes for the composite structure were proposed. Comparative analysis revealed that when the composite structure was equivalent to a homogeneous novel composite material structure, the deviation in ultimate bearing capacity between the equivalent structure and the test specimen was controlled within 16%, and the maximum displacement deviation was controlled within 1.35%, while the deformation characteristics remained in good agreement. The proposed equivalent method can provide a reference for equivalent modeling in the design and FE numerical analysis of similar composite structures.