Influence of cell size on out of plane stiffness and in-plane compliance character of the sandwich beam made with tunable PCTPE nylon honeycomb core and hybrid polymer nanocomposite skin

Sandwich structures with honeycomb core find specific application in impact resistance and energy absorption applications. However, such studies were limited to cores with metallic honeycomb, which had limited energy absorption abilities apart from extrinsic weight. The current work aims to fabricate hybrid sandwich beams made with PCTPE (Plasticized Co-polyamide Thermoplastic Elastomer) nylon using Fused Filament Fabrication (FFF). The cell size was varied from 10 to36 mm with a variation of longest diagonal. The face sheets were prepared with High-density polyethylene (HDPE) matrix with equal loading of Graphite nanoplatelet and Nano-diamond hybrid filler system. The face sheets were joined to honeycomb core to prepare sandwich panel with tailored made adhesive. It was observed that during out of the plane test, for 10 mm cell the SEA (specific energy absorption) was 1.15 kJ/kg, which decreased upto and 69% for 36 mm respectively. During the in-plane flexural test, the minimum flexural modulus showed by 36 mm longest diagonal cell was 31 MPa, which had increased further by 24, 50, 62, 67 and 76% for 27, 21, 15, 12 and 10 nun respectively, indicating elastic nature and damping ability of sandwich beam. The free vibration analysis was performed on by taking cantilever configuration. The experimentally obtatned results were then validated using-Ansys-14 slmulation. was concluded that PCTPE nylon core exhibited dual properties of stiffness and compliance for the period of out-plane testing and in-plane respectively, with a threshold limit of 36 mm cell size.