X-Ray Stress Determination in a Single Lap- Joint Containing a Debonded Region^*

Abstract

XRD has been found to be a useful technique for investigating both surface and interior stresses in. adhesive bonded joints. For the interior stresses, to gain access to the joint interface, adherends were chosen such that one adherend was relatively transparent to the X-radiation used and the other was not. Incident X-rays then penetrated the first adherend and the adhesive, and were diffracted from just below the surface of the second adherend.In prior work it was shown that the measured stresses due to an applied load agreed quite well with stresses calculated for the same joint using the TEXGAP-2D finite element program, except at one extremity of the bond. One explanation proposed for the discrepancy was that a small debond was present at this extremity. In the present study, therefore, an investigation was made of a joint contfli'nitig an intentional debond at this extremity.