The Laser Interlaminar Reinforcement of Continuous Glass Fiber Composites

Abstract

Inter-laminar crack initiation and propagation is a major mode of failure in laminate fiber reinforced composites. A laser reinforcement process is developed to bond layers of glass fabric prior to the vacuum assisted transfer molding of laminate composites. Glass fabric layers are bonded by fusing a dense glass bead to fibers within the laser focal volume, forming a 3D reinforcement architecture. Coupled heat transfer and viscous flow modeling is used to capture the temperature and morphology evolution of glass during the reinforcement process under experimentally observed conditions. Mode I double cantilever beam testing is performed to quantify the effects of laser inter-laminar reinforcements on composite delamination resistance.Post mortem high resolution imaging of the fracture surface is used to characterize the toughening mechanism of the inter-laminar reinforcements. Improved delamination resistance of laser reinforced composites derives from crack arrest and deflection mechanisms, showing a positive correlation to the reinforcement thickness.

Interlaminar Toughening of GFRP—Part I: Bonding Improvement Through Diffusion and Precipitation

“…Other researchers used different methods to achieve composite toughening. Tan et al used laser to bond layer of fabric by fusing a dense glass bead [7,8]. Groleau et al used the blends with nylon particles [9].…”