Micro-damage initiation evaluation of z-pinned laminates based on a new three-dimension RVE model

Abstract Z-pinning is an effective method to increase the delamination resistance of composite laminate. To optimize the design of z-pinned reinforced composite material, the paper proposes a new three-dimension RVE model for z-pinned laminates based on the manufacturing process, which involves the evolution of microstructures inside the laminate. First, an insertion and curing simulation is conducted by the finite element method to obtain an initial three-dimension microstructure RVE grid. Then, use the Delaunay triangulation method to regenerate the grids of resin-rich zone, matrix layer and steel z-pin. Finally, the regenerated grid is transformed into a finite element RVE model. Local material properties and local fiber orientation are determined by the Chamis model and grid geometries, respectively. Periodic boundary conditions are defined to confirm deformation compatibility and continuous stress. The RVE model is used to investigate the effects of z-pinned process parameters on the in-plane compressive strength and micro-damage evolution of laminates, and is eventually verified by the experimental results.