Buckling behavior simulation of composite sandwich shells using finite element analysis

Today, many researchers have focused to use of composite materials in various industries. Most of the composites used in industry are structurally sandwich composites. Sandwich composites consist of three parts: shells, core and adhesive materials. Sandwich structures are mostly used where the weight and volume of the structure is superior to its strength. Therefore, if sandwich structures can be strengthened in some way without huge increase of weight, they will be a very good alternative for all types of metal and composite structures. One of the issues in the field of pressure vessels and composite bodies is the study of their endurance in the face of external pressure. Due to the creation of unstable buckling in tanks under external pressure, the buckling is always considered as the main mechanism of their failure.The current study aims to investigate the core of sandwich structures by modeling the tanks and bodies under external pressure of these structures using the finite element method. Two modes were examined for modeling: one with a solid foam core and the other with a honeycomb-shaped core (trapezoidal). Each of these modes was modeled in two distinct materials, as well as three various dimensions and sizes, which were first derived linearly by the first buckling mode for each of the modes; The problem was then nonlinearly analyzed for the most crucial situation with coefficient of initial geometric disturbances . By analyzing prior research in this subject, the results of finite element analysis were confirmed. The usage of sandwich composite constructions in the face of external pressure conditions, according to the findings, can be highly useful.