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

Abstract

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 Method name: A novel method using a specially designed & coated bond-rig to improve the consistency and accuracy of sample lay-up when bonding samples for lap-shear testing, Keywords: Adhesion, Lap-shear, Tensile testing, Release coating, Automotive, Aerospace