Experimental study and finite element simulation of novel nap-core sandwich composite

Modeling methods for a new type of structural composite - lightweight nap-core sandwich - are presented. The material has its nap-core based on cup-shaped knitted fabric impregnated and cured with a thermosetting resin, which is versatile and possesses noted mechanical properties. However, the complexity of the nap-core's underlying geometries and constituents makes the finite element simulation of it a challenging task. The authors are proposing a number of approaches. At first, the nap-core is modeled at the macroscopic scale as a 3D-shaped thin shell whose input material parameters have been determined through laboratory tests. In the next approach, the nap-core is modeled from the mesoscopic scale whereby its effective material parameters are acquired from a cost-effective homogenization scheme given to its fibrous representative volume element. Ultimately, the analysis of the experimental results and the simulation results proves the appropriateness of the simulation methods.