Novel Comparison of Structural Damping in Composites Across Resin Systems and Scales: Article No. 120810

Vibration behavior of composite materials is important for aerospace, automotive, and energy generation applications. Specifically, structural damping governs vibration amplitudes and affects reliability and performance. To analyze the effects of different resins, this work characterizes coupon damping of traditional epoxy (Westlake RIMR135/RIMH1366), thermoplastic (Arkema Elium 188 O), and polyester covalent adaptable network (PECAN, developed at the National Laboratory of the Rockies) resin systems across uniaxial glass fiber, biaxial glass fiber, and infused balsa wood. These broad coupon tests across resins and materials with a validated and refined approach represent a significant and novel contribution. This work applies coupon tests and the modal strain energy approach to predict a 4.2x to 5.2x increase in damping for the Elium resin compared to the epoxy resin. This is inline with previous 13 m experiments and establishes new confidence by building up from the coupon-level understanding. Conversely, PECAN and epoxy coupons exhibit similar damping. Suspected aging effects are reported across resins with a notable 20% decrease in damping for some Elium coupons. Notably, the damping predictions based on coupon tests are made at an estimated 13x cost reduction and 13x time reduction compared to prototyping and testing composite structures at the 13 m scale.