Acoustic emission during fracture of short glass fiber reinforced poly-vinyl chloride-

The fracture mechanics approach and acoustic emission (AE) analysis have been coupled in an investigation of slow crack growth of short fiber reinforced poly(vinyl chloride). It was found that AE occurs during less than one percent of the time of crack growth suggesting that so-called continuous crack propagation is based on discontinuous microscopic damage. The time dependence of various AE parameters exhibits a good linear relationship with crack speed. For a unit of newly created fracture surface, a constant amount of acoustic energy is released independent of crack speed. At very low speeds, below 3.10 to the minus 3 power mm/s, a change in mechanism from pure matrix related to fiber related crack growth is observed, which is also reflected by a change in the amplitude distribution of the AE events.