Effect of Additively Manufactured Resin Rich Layers on Mechanical Properties of Glass Fiber Reinforced Thermoset Resins

Fiber reinforced composites (FRCs) have seen a considerable growth in the past fifty years. Despite their low cost, lightweight and good in-plane properties, FRCs suffer from poor out-of-plane properties and delamination tendency. One strategy to improve out-of-plane properties is the incorporation of resin rich layers (RRL) between fiber layers to increase the toughness of the composite parts. However, these structures are challenging and difficult to manufacture using traditional lay-up methods. Additive manufacturing (AM) is a novel way of manufacturing complex multi-material parts that cannot be produced using traditional methods. In this study, we demonstrate an AM method of controlling the thickness of the RRL domains to quantify RRL effects on mechanical properties, such as fracture toughness In this work, we demonstrate the use of digital light processing (DLP) to produce FRCs with a novel methacrylate based resin and random discontinuous glass fiber (RDGF) mats with controlled RRL layers. Results show that increases with RRL thickness without significantly reducing composite stiffness or strength Overall, AM is a useful tool for manufacturing composite parts with spatially resolved RRLs and motivates future technologies for the design of damage tolerant parts.