The Ultrasonic NDT of Adherent Area between Metal and Nonmetal Surfaces and the Prediction of Its Destruction Strength

A new approach so-called multi-reflection scanning method by transvers ultrason-ic wave is described for the NDT of adherend between metal and.nonmetal surfaces.Accord-ing to the adherent state,the destruction strength can be predicted by Bayesian inference. A skew probe scanning on the metal side is used to transform the longitudinal wave,dis-patched by a PZT transducer,after entering the metal layer into transversal.Then the lat-ter propagates in a zigzag path along the adhesive layer.The reflected wave strength are de-tected and integrated with respect to time.The relation between the adherent area along thescanned path and the time integral of reflected wave magnitude is founded. The prediction model by Bayesian inference has been studied.As the adhesive process isfixed,the relation batween the destruction strength of a part versus the measured adherentarea proportion and their distribution can be established.Practice shows that,even the rateof spoilage as high as 60%,the software can strictly judge