Thermomechanical Properties of Polymers at High Rates of Strain

Abstract

The dissipation of mechanical energy within a polymer in a relatively short timescale can cause softening of temperature dependant materials and at high strain-rates this effect is more pronounced.In the present study, tests have been performed on a bisphenol A epoxy resin, LY-564, at strain-rates of approximately 2500s.' using a Split Hopkinson Pressure Bar in compression.Temperature measurement has been carried out using a fast response infra-red radiometer developed at Oxford which is able to measure the surface temperature rise of a material during high rate tests.The temperature data shows three distinct slopes.Significant rises in temperature of approximately 50°C have been recorded during high rate compression tests.Rkum6: La dissipation de I'dnergie mecanique dans un polymkre durant une courte periode peut causer une diminution de durete pour les materiaux qui dependent de la temperature et A des vitesses de deformation dlevde cet effet est plus prononce.Dans la prtsente etude, des tests ont etC effectues sur I'epoxy resine bisphenole A, LY-564, a des vitesses de deformation de 2500s.' en utilisant une barre de compression Hopkinson.Les m e s a s de temp6rature ont Btt effectutes en utilisant un radiomttre infrarouge A rkponse rapide developpe A Oxford capable de mesurer I'augmentation de temperature de surface d'un materiau durant les tests A haute temperature.Les d o ~6 e s de temperature montrent trois pentes distinctes.Des augmentations significatives de temperature d'approximativement 50°C ont Ctt enregistr6es durant les tests de compression A vitesse BlevCe.