Fracture rate dependency of an adhesive under dynamic loading

Abstract Adhesive joints are widely developed in aeronautic and automotive design applications. When subjected to impact loading, the rate sensitivity of adhesively bonded joints becomes a subject of interest. In this study, the Mode I fracture behavior of an aeronautic adhesive is characterized. Double Cantilever Beam tests are performed under various displacement rates. A new protocol is developed to accurately measure the fracture toughness. The corrected beam theory with effective crack length is extended to measure the energy release rate during the crack growth stage. The main advantage of this new protocol is to accurately determine the crack speed without a direct experimental error. The validity of the analysis scheme is discussed considering dynamic effects. The crack speed measurement is validated by comparison to a conventional camera monitoring. The crack velocity is found to decrease with the crack length, while the fracture toughness remains unchanged.