Study of fracture of specimens made of fiberglass plastic using acoustic-emission and strain measurements

The crack resistance of specimens made of a fiberglass plastic composite material has been studied. All specimens had approximately the same geometric dimensions. At the center of the specimens, there were 25-mm-long notches on both sides. The specimens were loaded with a static or cyclic load at a frequency f = 5 Hz. The tests were performed using acoustic-emission (AE) and strain gage measurements. The AE technique allowed stable localization of a flaw at an early stage of growth and made it possible to automate the measurement process. The strain gage measuring system was used to find deformations in the zones of localization of AE signals.