Mixed-mode loading analysis on the lap shear specimen test per ASTM D1002

Shear loading capability of adhesive joints is an important criterion of adhesives. Adhesives show the highest strength when they are loaded in shear condition. ASTM D1002 is the standard test method to evaluate the shear strength of the adhesives. This method is popular due to the simplicity of the test, easy to replicate, and the consistency of the testing results.; Due to the material elastic mismatch and the eccentricity of the test setup, a mixed mode loading is introduced to the adhesive joint. This thesis performed a detail study about the behavior of the adhesive joint, tested by ASTM D1002 method. A conventional fracture mechanics theory is utilized. A crack is embedded in the lap shear specimen adhesive joint and tested on the tensile test machine. From the experimental result, it is shown that the specimen is also experienced tensile loading. There is an indication that the final failure is due to cleavage loading. The result of the experiment and the effect of the mixed mode loading are studied in detail.; A modified test setup to minimize the mixed mode loading was used to validate the current failure theory. The specimen will be modified in a way to minimize the tensile loading applied to the specimen. This thesis provides a better understanding of adhesives behavior under different loading conditions. This knowledge will also be beneficial in designing a good adhesive joint.