FEM-Based Assessment of Steel-Lightweight Concrete-Steel Sandwich Composite Beams for FPSO Applications: Behavior, Failure, and Design

Abstract This study explores the cracking behavior of steel-lightweight concrete-steel (SCS) sandwich composite beams with shear connectors through finite element analysis (FEA) using DIANA FEA software. Originally developed by DNV for marine vessel construction, SCS panels offer advantages such as reduced weight, simplified manufacturing, fire insulation, sound and vibration damping, and enhanced impact resistance. Despite proven applications in building and bridge construction, their adoption in marine applications requires further development. The numerical model incorporates the nonlinear stress-strain behavior of steel and concrete, as well as bond-slip interactions at the steel-concrete interface. Key performance metrics, including load-deformation curves, crack opening, and failure modes, are analyzed to assess the structural behavior of SCS beams. The results inform a preliminary design approach for SCS beams, addressing the current lack of specific design rules. The proposed simplified method demonstrates safe and accurate predictions, offering a foundation for broader applications in building and offshore industries. This work underscores the potential of SCS systems as an innovative structural solution, advancing their feasibility and commercialization.