Improved consistency of bond-line thickness when conducting single lap-shear joint tests

This article details a method for improving the consistency of bond-line thickness during lap-shear sample preparation. This includes the schematic for a lap-shear sample test rig and consideration for controlled variation of the bond-line thickness for up to ten pairs of samples at a time. Concerns regarding the curing of the samples when held on a large heat reservoir are addressed through direct measurement of the bond-rig temperature in combination with the cure chamber temperature. Additionally, the application of a release coating to the bond-rig has been demonstrated to improve ease of sample removal for the bond-rig, minimizing potential damage to the lap-shear sample set before testing. The release coating provides a clean surface for subsequent sets of samples, ensuring an even surface and reducing cleaning and degradation of the machined geometries of the rig. Overall, the proposed bond-rig provides: • Increased bond-line uniformity; • Up to ten samples prepared in a batch; • Option to apply a release coating to improve usability and minimize cleaning.