Investigation of mechanical performance of 3D woven spacer sandwich composites with different cell geometries

In this research, woven spacer fabrics with woven cross-links and having different cell geometries viz. rectangular, trapezoidal and triangular were produced, along with one spacer structure connected with core piles which were subsequently converted to their composite forms using vacuum assisted resin infusion molding (VARIM). The sandwich composites produced were analyzed for their quasi-static lateral compression and flexural performance to compare their load bearing capacity and energy absorbency. The rectangular spacer structure with double layer wall construction (RECTDL) sustained maximum specific compressive load among all the structures, followed by spacer structure connected with pile yarns (SPY). For structures with single layer wall constructions, rectangular spacer (RECTSL) had higher specific compressive load compared to triangular (TR) and trapezoidal (TPZ) spacer structures. The energy per unit volume absorbed by these structures was in the order of RECTDL > RECTSL > TR > TPZ. The specific bending load for these structures was in the order of RECTDL > RECTSL > SPY > TR > TPZ structures, and flexural stress for sandwich structures with woven cross-links was higher than the one connected with core piles. These results can be used to engineer woven cross-linked spacer fabric based sandwich composite structures with specific load bearing capability.