Tensile mechanical behavior of T300 and M40J fiber bundles at different strain rate

Tensile mechanical behavior of T300 fiber bundles and M40J fiber bundles ha ve been studied in the strain rate range from 0.001 1/s to 1300 1/s and com plete stress strain curves were obtained. Results show that both ultimate s trength and failure strain of two materials are strain rate insensitive, an d T300 fiber and M40J fiber can be regarded as strain rate insensitive mate rials. On basis of the fiber bundles model and the statistic theory of fibe r strength, single Weibull distribution model and bimodal Weibull distribut ion model have been developed to describe mechanical behavior of fiber bund les. And a method for determine the statistic parameters of fibers by tensi le tests of fiber bundles is established, too. The simulated stress strain curves from the model are in good agreement with the test data. Simulated r esults show that the strength of T300 fiber can be described by single Weib ull distribution function, and the strength of M40J fiber should be describ ed by bimodal Weibull distribution function. (C) 2001 Kluwer Academic Publi shers.