2024/12/14 by Mousavi, Seyed Ali, Shokrollahi, Hassan, Sabouri, Hadi
paper · doi:10.60664/jsm.2024.1130323
This study investigates the flexural behavior of sandwich structures composed of glass fiber-reinforced composite laminates. The cores and matrices of these composites consist of Polyamide (PA), a thermoplastic polymer, which renders them recyclable and, in certain cases, repairable. Three-point bending tests were conducted on the sandwich structures, and the extensive results were thoroughly examined. The sandwich panel cores exhibit three distinct structures: honeycomb, re-entrant auxetic, and sinusoidal ligament. Various parameters were analyzed, including the absorbed energy by the structures, flexural stress on the laminates, shear stress on the cores, and the force-to-weight ratio. Notably, the re-entrant auxetic structure with a 2 mm cell thickness outperformed the other structures in terms of energy absorption and force-to-weight ratio corresponding to failure. Furthermore, the flexural tests revealed interesting differences among the core structures. The results show that the re-entrant auxetic and honeycomb structures exhibited greater brittleness compared to the sinusoidal ligament structure. Additionally, the sinusoidal ligament structure demonstrated an approximately 10% load increase as the thickness increased from 1.5 to 2 millimeters. Moreover, the displacement at the point of failure increased by approximately 17% for the sinusoidal ligament and about 30% for the re-entrant auxetic. These findings contribute valuable insights into the design and optimization of sandwich structures for various engineering applications.