A compact thick-adherend compressive-lap specimen (TACLS) for rapid shear testing of adhesives

Standard tests for adhesive bond characterization present several limitations. Conventional lap-joint specimens are easy to fabricate but exhibit complex stress distributions and stress singularities, while configurations approaching pure shear require complex specimens and specialized fixtures. This study investigates the stress state within the adhesive layer of a thick-adherend compressive-lap specimen (TACLS), formed by bonding two flat adherends side by side and loading the resulting coupon in compression along the adhesive mid-plane. The proposed concept combines simple specimen preparation with straightforward loading and is well suited for large-scale characterization of adhesive bonding systems.