A concept for defining the mixed-mode behaviour of tough epoxy film adhesives by single specimen design
Research output: Contribution to journal › Article › Scientific › peer-review
|Number of pages||18|
|Journal||Journal of Adhesion Science and Technology|
|Publication status||E-pub ahead of print - 2020|
|Publication type||A1 Journal article-refereed|
Fracture modes I and II interact in mixed-mode loading conditions, and the interaction is typically taken into account using a mixed-mode fracture criterion. In this work, a concept for defining the criterion is developed through an experimental-numerical simulation analysis. The mixed-mode behaviour for the criterion is tested and analysed with a single specimen design. The design of the specimen simplifies the measurement when complex test arrangements and preparations for various specimen geometries are excluded in practice. Here, the mixed-mode fracture behaviour of the specimen is analysed in detail using digital image correlation (DIC). The DIC data are used in collaboration with a finite element–based crack onset analysis, including the virtual crack closure technique, in order to consider the typical simplifications and their effects on the mixed-mode criterion. As a benchmark case, the fracture criterion is determined for an epoxy film adhesive FM 300-2 using the developed approach. The developed approach was shown to be feasible and effective for defining the mixed-mode fracture criterion. The determined Power law criterion’s exponents were below unity, which points out that the common (presumed) exponent values in the current literature are actually unconservative.
- adhesive, mixed-mode testing, epoxy, virtual crack closure technique, digital image correlation