Relation between acoustic emission analysis during cure cycle and bonded joints performances,

In 1993, a research program was started and developed in JRC Diagnostic and Reliability laboratories to assess the possibility to predict the structural behaviour of adhesive joints monitoring acoustic emission (AE) during the cure cycle leading to their production. Cure cycles have therefore been performed, either respecting the standards and guidelines established for the adherent materials, adhesive layer, timing, temperatures, or instead modifying one or more of these factors. The latter situation would presumably produce a joint which is unsuitable for use or at least with non-ideal characteristics. The idea was that acoustical activity during the different cycles should be discernible from a statistical point of view, presenting a relation with the quality of the joints finally produced. From experimental data some evaluation criteria were sorted out and a possible outlining of on-line joints’ quality control through AE concepts is provided.