Induction-excited thermography - A method to visualize defects in semi-structural adhesive bonds of car body structures

State-of-the-art automobile production uses semi-structural adhesive bonding to join hybrid materials. Examples of application in automobile production are sunroofs or windshields joined to the bodywork. This paper presents the capabilities/benefits of induction-excited thermography for non-destructive testing of semi-structural adhesively bonded components. This new quality control method offers robust, contactless and extensive testing of these bonds by a visualization of thermal irregularities in an induction-excited thermal heat transfer, caused by defects in the adhesive. By a proper adaptation of inductive excitation the detection of various defects of the adhesive seam, like delaminations, neckings and also zero volume defects, both at small sized specimen and at a large-surfaced reference application were realized.