Fracto-emission from single fibres of Kevlar

Fracto-emission (FE) is the emission of particles (e.g. electrons, ions and photons) during and following fracture. In this paper, we present data on electron emission (EE) and positive ion emission (PIE) from the tensile fracture of Kevlar single fibers. The fibers were initially fractured in pure tension, where a stranded form of fracture was observed, often with multiple peaks spread over several hundred microseconds. The loading condition was then changed by stretching and breaking the fibers over a dull metal edge. With this change in the loading, different forms of fracture were observed, each with distinctive forms of emission curves. When fracture was accompanied by extensive fibril formation, total emission was high and both EE and PIE decay times were long relative to fractures in which little fibril formation occurred. The results of this study suggest that FE has some applicability as a tool for the detection of fracture mechanisms of single fibers.