Viscoelastic characterization of high fiber content filament wound polyurethane matrix composites

Elastomeric matrix composites (EMCs) consisting of a polyurethane matrix un idirectionally reinforced with high volume fractions of high strength fiber s have interesting and unique mechanical properties such as high strength a nd stiffness in the fiber direction and high ductility perpendicular to the fibers. The aim of this investigation is to explore the quasi-static mecha nical properties of glass and carbon filer EMCs in the direction transverse to the fibers and to measure and model the creep of the monolithic matrix material and the transverse creep of the glass EMC. In the quasi-static tes ts, glass and carbon EMCs followed a monotonic stress-strain curve that was essentially Aat from approximately 1-2% to over 10% strain. The maximum st resses obtained in the quasi-static tests were approximately 3.5 and 7 MPa in the carbon and glass EMCs, respectively. The monolithic matrix and the g lass EMC loaded transversely to the fibers both showed highly nonlinear cre ep behaviors. The former creep behavior was modeled successfully with a sta ndard power law expression. The nonlinear creep behavior of the glass ER IC cannot Le modeled with a standard power law expression, possibly due to cr eep damage.