A Numerical Method to Estimate the Collapse Pressure of a 2-D Steel-Concrete-Steel Sandwich Ring

Abstract Offshore floating wind turbines must be designed to withstand harsh loading conditions. To date, many spar substructures use steel cylinders with concrete ballast to achieve the required strength and stability. The presence of these two materials raises the idea of formulating a steel-concrete-steel sandwich configuration, which could potentially reduce cost. To further explore such new structural concepts, this work proposes a meshless collapse load algorithm for sandwich structures under hydrostatic pressure. First, the spar structure is modeled as a 2-D sandwich ring under plane-strain condition. As for material properties, our model assumes the von Mise yield criterion can be applied to both ductile steel and brittle concrete materials. The J2 flow theory of plasticity with isotropic hardening will be used after the material has yielded. The principle of minimum potential energy is used to construct a system of equations. The solution will be solved incrementally and iteratively with integration points generated by the Gauss-Legendre method. In the end, the present work is validated with commercial finite element software, Abaqus. The results agree well with each other, which shows the potential of this method for rapid generation of multiple geometries and quick solution times to explore more spar designs.