Previous research has shown that the high strain rate performance of thermosetting polymer systems is strongly correlated to three characteristics: the relaxation behavior with respect to the polymer Tg, the molecular weight between crosslinks (Mc), and the fracture toughness (KIC). Using different thermosetting systems as template networks, the molecular architecture can be altered to target these criteria and compared as polymer-only and fiber reinforced composites under high strain rate impact testing. It is hypothesized that by combining these fundamental characteristics, a design space is created for performance optimization, particularly for reducing the damage area caused by delamination while retaining energy absorption over a broad range of temperatures. Here, epoxy and ring-opening metathesis (ROMP) resins were used to fabricate fiber reinforced composites with plain weave S-2 glass fibers using VARTM. The resultant composites were tested under high strain rate impact over a temperature range of -50°C to 75°C and were compared to composites made from conventional, structural epoxy resins. While greatly altering the energy absorption mechanisms for polymer systems, the effect of the mentioned underlying performance characteristics was not as straightforward for fiber reinforced composites. This work seeks to clarify how resin architecture can affect not only the resistance to impact, but also the damage and deformation mechanisms observed and the residual mechanical integrity of fiber reinforced composites.
2025-04-09 09:00:00
