Compressive performance of three-dimensional multilevel sandwich composite structures

This study reports a two-dimensional bi-directional E-glass woven fabric preform structure is converted into a three-dimensional sandwich composite structure with the help of wooden molds and matrix material. One to three levels of sandwich composite are prepared with a rectangular core configuration by keeping the specimen’s constant dimensions. A second multilevel sandwich composite sample set is developed with hexagonal, square, and triangular core configurations, maintaining length, width, height, and weight constant. The developed composite samples are characterized by their compressive properties. For single, double, and triple-level sandwich composites with rectangular cores, it is found that increasing the number of levels led to an increase in compressive load capacity, with triple-level structures exhibiting the highest strength. However, an increase in the number of levels resulted in a decrease in specific compressive load. Additionally, the energy absorption capacity increases as the number of levels increases. In the case of multilevel sandwich composites with triangular, square, and hexagonal core, the triangular core demonstrated the highest compressive strength and energy absorption capacity compared to square and hexagonal configurations. The failure modes of the sandwich composite structure have also been discussed. The results indicate that the sandwich composite’s compressive, energy absorption properties, and failure modes depend on many parameters, such as the number of levels, core structure, free wall length, face sheet length, and loading direction. The findings of this study will provide valuable insights into potential applications and performance of these advanced sandwich structures, enabling improved design and optimization for specific engineering applications across diverse industries.