Direct and inverse cohesive law identification of hardwood bonded joints with 1C-PUR adhesive using DCB test

Fracture characterisation under mode I loading of Eucalyptus globulus Labill. bonded joints with one-component polyurethane adhesive (1C-PUR) is addressed in this work. The objective is to estimate the cohesive law representative of the fracture behaviour of these joints. A direct , two inverse procedures were employed to determine the softening laws. The direct method is based on local measurement of crack tip displacements using digital image correlation in the course of Double Cantilever Beam (DCB) tests, while the inverse methods rely on load-displacement data and on load-crack tip opening displacement relations by finite element modelling. It was verified that consistent results can be obtained from the three methodologies leading to the conclusion that the classical inverse procedure is the most appealing one owing to its simplicity.

Automated summary

The fracture characterization of Eucalyptus globulus Labill. bonded joints with one-component polyurethane adhesive (1C-PUR) under mode I loading is investigated in this study. The objective is to estimate the cohesive law that represents the fracture behavior of these joints. Two inverse procedures and a direct method are utilized for determining the softening laws, with the direct method based on the measurement of crack tip displacements using digital image correlation during Double Cantilever Beam (DCB) tests. It is concluded that consistent results can be obtained from all three methodologies, with the classical inverse procedure being the most appealing due to its simplicity.