Acoustic emission in bonded elastomer discs subjected to uniform tension. II



The aim of this paper is to evaluate and analyze the growing and tearing mechanisms of existing microvoids within bonded elastomer discs using the acoustic emission (AE) technique. It was shown that the existing microvoids in the deformed disc are responsible for the reduction of the apparent modulus (M) of the elastomer disc, the stress softening, and the hysteresis when the material is subjected to triaxial stress conditions. A series of experiments performed in our laboratory confirmed the existence of microvoids within the deformed bonded unfilled nitrile rubber discs. Valuable information about the size of the deformed voids in the material was obtained using the frequency spectrum of the detected AE signals. More information on the tearing of voids was extracted from the count, event, amplitude, and duration time distribution of the received AE pulses.