Fracture Mechanics Tests in Adhesively Bonded Joints: A Literature Review

Fracture mechanics characterization tests for adhesive joints are analyzed and reviewed in order to understand their advantages and disadvantages. Data reduction techniques for analytical methods are summarized to understand the improvements implemented in each test. Numerical approaches are also used complementing tests information. Both linear and non-linear methods to obtain the fracture energy release rate are presented. Pure mode I and mode II tests are described. Simple mixed-mode tests, varying only the specimen geometry, with limited mode-mixity are also presented. Performing a wider mode-mixity range requires sophisticated apparatus that are studied in detail. There is no general agreement about the test suitability for mixed-mode fracture assessment of adhesive joints. A universal test that can easily be performed and give accurate results is essential to optimize the expensive testing at the design stage.