a b s t r a c tBallistic performance, at effective strain rates of (10 4 -10 5 s À1 ), for polymeric dicyclopentadiene (pDCPD)was compared with two epoxy resin/diamine systems with comparable glass transition temperatures. The high rate response was characterized in terms of a projectile penetration kinetic energy, KE 50 , which describes the projectile kinetic energy at a velocity with a 50% probability of sample penetration. pDCPD showed superior penetration resistance, with a 300-400% improvement in ballistic energy dissipation, when compared with the structural epoxy resins. In addition, unlike typical highly crosslinked networks that become brittle at low temperatures, the improved pDCPD performance occurred over a very broad temperature range (À55 to 75°C), despite exhibiting a glass transition temperature characteristic of structural resins ($142°C). In addition to the high T g , pDCPD exhibited a room temperature glassy storage modulus of 1.7 GPa, offering the potential to circumvent the common structural versus energy dissipation trade-off encountered with conventional crosslinked polymers. Quasi-static measurements suggested that the performance of pDCPD is phenomenologically related to higher fracture toughness and lower yield stress relative to typical epoxies, while molecular dynamics simulations suggest the origin is the lack of strong non-covalent interactions and the facile formation of nanoscale voids to accommodate strain in pDCPD.Published by Elsevier Ltd.

This work focuses on the mechanical performance of E-glass/fire retardant bisphenol A epoxy vinyl ester composites under compressive loads that are exposed to a one sided heat flux. The goals of the experimental work were to adequately characterize lamina off axis stiffness response at elevated temperatures, and to characterize the response of laminate specimens exposed to combined thermal and mechanical loading.A unique test was developed that exposed laminate coupon specimens to a one sided heat flux and mechanical load.Experiments were conducted in an effort to characterize the effect temperature has on the reversible off axis stiffness; this data would be used in the modeling of the laminate specimens exposed to the combined loading scenario. Modeling techniques that predict the time to failure and the strain history of vinyl ester samples subjected to a simultaneous compressive and thermal load is developed and compared against experimental data. Only reversible material property changes that are a function of temperature are accounted for in the modeling efforts. The modeling approaches agree reasonably well with experimental results that do not include the effects of elevated temperature creep.

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