Mixed mode fracture characterization of brittle and semi-brittle adhesives using the SCB specimen

• Published in: International journal of adhesion and adhesives 2020-09, Vol.101, p.102629, Article 102629
• Main Authors: Ajdani, Arsalan, Ayatollahi, Majid R., Akhavan-Safar, Alireza, Martins da Silva, Lucas Filipe
• Format: Article
• Language: English
• Subjects: Adhesion tests; Adhesive joints; Adhesives; Brittle fracture; Cantilever beams; Correlation analysis; Data reduction; Digital imaging; Energy measurement; Energy release rate; Failure analysis; Finite element method; Flexing; Fracture mechanics; Measurement methods; Measurement techniques; Mechanical properties; Mixed-mode fracture energy; Semi-circular bend; Strain measurement
• ISSN: 0143-7496; 1879-0127
• DOI: 10.1016/j.ijadhadh.2020.102629

Fracture mechanics and damage mechanics are widely used to predict the mechanical behavior of adhesive joints. The critical energy release rate is one of the most important parameters in these models. In practice, most adhesive joints experience mixed mode loading conditions. Therefore, mixed mode fracture energy measurement plays an important role in adhesive joint failure analysis. A new test method for mixed mode fracture energy measurement of brittle and semi-brittle adhesive joints is presented in this paper using semi-circular bend specimens. A data reduction scheme based on a finite element analysis is suggested and finite element results are validated by digital image correlation strain measurement technique. The fracture envelops obtained from the proposed specimen are compared to double cantilever beam (DCB), single leg bending (SLB) and, end-notched flexure (ENF) test results. Good agreement between the new specimen and the classic energy measurement methods is observed.