professor, Technion—Israel Institute of Technology, Haifa,
Results of an experimental study of the influence of strain rate, temperature, and humidity on the mechanical behavior of a graphite/epoxy fiber composite are presented. Three principal strengths (longitudinal, transverse, and shear) and four basic moduli (longitudinal, transverse, axial shear, and major Poisson's ratio) of a unidirectional graphite/epoxy (T300/5208) composite were studied as functions of strain rate, temperature, and humidity. Each test was performed at a constant tensile strain rate in an environmental chamber providing simultaneous temperature and humidity control. Before being tested, specimens were given a moisture preconditioning treatment at 60°C. Values for the matrix-dominated moduli and strength were significantly influenced by both environmental and rate parameters, whereas the fiber-dominated moduli were not. However, the longitudinal strength was significantly influenced by temperature and moisture content. A qualitative explanation for these observations is presented.
Paper ID: CTR10755J