A method for detecting defects in adhesive joints AND DEVICE FOR ITS IMPLEMENTATION

摘要

FIELD: physics.;SUBSTANCE: in adhesive joints used in car assembly, ultrasonic pulses are transmitted to an article using a separate-combined transducer; reflected ultrasonic pulses are received and converted to echo signals; distribution of bottom echo signals are analysed on the screen of an ultrasonic flaw detector; the relationship between change in amplitude of bottom echo signals and the thickness of the non-metallic layer at standard parameters of adhesion of the non-metallic layer to the metallic layer on samples is determined, wherein the device is calibrated using samples imitating the "glass-adhesive-metal" joint with artificial defects. The amplitude of the bottom echo signals is adjusted. Further, ultrasonic pulses are transmitted to the joint; echo signals reflected from boundaries of the joint are received and then used to determine the number of joints, wherein to increase sensitivity and accuracy of inspection, the overall spectrum of the full echo signal from the adhesive-metal boundary and the tail end of the echo signal from the glass-adhesive boundary is used; the sweep range is then adjusted so that all bottom echo signals are within the screen of the ultrasonic flaw detector; further, the sweep range for all bottom echo signals is analysed and presence of a defect is indicated by presence of an echo signal pulse.;EFFECT: high sensitivity and accuracy of inspecting continuity and thickness of an adhesive joint in glued glass-adhesive-metal structures.;2 cl, 6 dwg