HIGH-STRAIN RATE PROPERTIES OF CYCOM-5920 1583 CLOTH GLASS/EPOXY COMPOSITES/

Polymer matrix composites offer excellent properties such as high spec ific strength and stiffness, which make them attractive for many naval , aerospace, and automotive applications. Although they are candidate materials for many applications where high strain rate loading is prob able, little is known of the material responses to shock loading for m ost composite materials. Because mechanical properties vary significan tly with strain rate, the use of static properties in the analysis and design of structures that undergo dynamic loadings can, on one hand, lead to a very conservative overweight design or, on the other hand, c an lead to designs that fail prematurely and unexpectedly. The use of dynamic material properties will ensure the design of composite struct ures, which are weight efficient and structurally sound when they are subjected to dynamic loads. A split Hopkinson pressure bar is used to obtain compressive mechanical properties of Cycom 5920/1583, an uniaxi al cloth, E-glass/rubber toughened epoxy composite being used presentl y by the Electric Boat Division of General Dynamics for undersea struc tures, Yield stress, yield strain, ultimate stress, ultimate strain, a nd modulus of elasticity values are presented and analyzed wherein the strain rates vary from 60 to 1150 s(-1).