The ASTM D3165 test technique is used to determine the strength qualities of adhesives in shear when single-lap-joint laminated assemblies are tension-loaded. This test method can be used to create design parameters for bonded assemblies in the joint configuration that closely simulates the actual joint configuration of multiple bonded assemblies.
This test method can also be used as a quality control test for laminated assemblies throughout the manufacturing process. Single-lap tests can be used to compare and select adhesives or as bonding procedures for fatigue and environmental changes susceptibility with caution because various adhesives may react differently at different joints.
The test specimen is prepared in accordance with ASTM D3165, in a room with a relative humidity of 50% and a temperature of 23°C. The specimen is then pinned or, if jaws are used, placed in the testing machine’s grips so that the outer 25.4 mm of each end is in contact with the jaws and the long axis of the test specimen coincides with the direction of applied pull through the grip assembly’s centerline. At a rate of 8.3 to 9.7 MPa per minute of shear area, the force is applied to the specimen. Until it fails, the load is maintained. To approximate this loading rate, a free crosshead speed is employed.
Video 01: ASTM D3165 Adhesive failure test on a bonded joint
According to the ASTM D3165, the recommended length of the specimen’s lap is 0.50 ± 0.01 in. (12.7 ± 0.3 mm).
According to ASTM D3165, each specimen’s load at failure, as well as the nature and extent of the failure, is recorded. The shear area of all failed loads is measured in megapascals (pounds-force per square inch).
The ASTM D3165 test technique is used to determine the strength qualities of adhesives in shear when single-lap-joint laminated assemblies are tension-loaded.