Effects of Applied Stress and Temperature on the Nonlinear Elastic Properties of Graphite Fibers

摘要

The nonlinear elastic behavior of a series of pitch-based graphite fiber bundles was determined by using a new measurement method that uses laser-generated ultrasound over ranges of temperature and static tensile stress. From these data, plots are presented of the Young's modulus versus stress and temperature. The modulus increases with static tensile stress and decreases with temperature. These results are important for characterizing the elastic behavior of composites in which these fibers are used. Some possible mechanisms for explaining the observed effects are discussed.