Determination of initial interface debonding in tungsten fibre reinforced epoxy composite using photon emission and electric current fluctuation

Photon emission from an interface and electric current fluctuation between fibre and matrix were studied using a tungsten fibre reinforced epoxy pullo ut specimen, to determine the initial interface debonding event. Direct obs ervation of the interfacial debonding behaviour was carried out separately, for comparison with photon emission results and electric current measureme nts. Photon emission and electric current fluctuation were observed simulta neously, and the load at these events was nearly the same as that found at the onset of interface debonding by direct observation, Both techniques wer e found to be effective tools for determination of initial interface debond ing, because the behaviours originated from a discharge at the interface wh ich occurred just after the onset of debonding.