ACCELERATION OF AGING IN GRAPHITE/BISMALEIMIDE AND GRAPHITE/THERMOPLASTIC COMPOSITES

摘要

Short term sequenced creep compliance test procedures were used to characterize the aging of two polymeric composites (IM7/K3B, IM7/5260) at temperatures below the glass transition. The applicability of these procedures to account for both physical and chemical aging was discussed. Master curve data from these tests along with the associated time shift rate were used as input to a predictive methodology based upon linear viscoelasticity and the effective time theory. Long term compliance predictions were made to illustrate the differences between thermoset and thermoplastic composites and to demonstrate how time shifts can be used to help characterize the aging process. Results indicate acceleration of aging will be affected by test temperature, ply orientation and material system and that these parameters all play a role in determining the long term behavior.