Correlation between acoustic emission and gluing defects in conical joints

Introduction. Object of this work is to find out the presence and the entity of the gluing defects in conical steel couplings joint with anaerobic adhesive (Loctite 638) and interference by applying the acoustic emission (AE) technique. The adhesive defect, as shown in [1], influences a lot the releasing moment but it is very difficult to be discovered with the traditional non-destructive testing techniques once the parts are assembled. Because of these reasons, it was decided to correlate the AE signals recorded during the releasing tests with the defect entities and, if it’s possible, to foresee the final releasing moment of the couplings. Fundamental goal, therefore, is to verify if there is a correlation between the characteristic parameters of AE, the defect entities and the releasing load of the joint.