Evaluation of the effect of material selection and core geometry in thin-walled sandwich structures due to compressive strength using a finite element method

Sandwich panels are widely used in various applications due to their ability to support loads while maintaining a lightweight structure. This study employs finite element analysis (FEA) to evaluate the performance and strength of sandwich panels under compressive loads. The material choices and core shape of squared sandwich structures under compression are examined by FEA. Material variants include ASTM A36, AISI 1045, and AISI 52100, while core geometry configurations, such as circular, rectangular, and hexagonal, are analyzed to determine the optimal structural performance. Compression is executed by releasing an impactor weighing 350 kg at an initial velocity of 9.68 m/s, which is directed directly into the surface of the sandwich panel. The Johnson–Cook damage model is used to characterize the behavior of materials under damage conditions. It can be observed that core geometry governs collapse behavior more strongly than material types. Hexagonal cores deliver the most balanced crash performance, where concertina-type folding develops symmetrically, producing the flattest and longest force plateau and the highest specific energy absorption in all material types tested. A circular core exhibits the same hexagonal peak load in higher-strength steels while maintaining low-strain gradients. In contrast, a square core performs well in ductile, low-strength steels but rapidly loses efficiency as metal strength increases, as early localized buckling dominates its collapse.