DISK-SHAPED COMPACT TENSION & COMPACT TENSION TESTS ON QUASI-BRITTLE THICK CELLULAR STRUCTURAL ADHESIVE: EXPERIMENTAL AND NUMERICAL ANALYSES
This paper deals with fracture mechanics analysis to study and understand the effect of density on the crack initiation resistance of a thick cellular structural adhesive. Disk-shaped compact tension and compact tension samples of two different densities have been fractured and analyzed. The crack opening has been stabilized making possible the crack growth resistance curve computation. The behavior of the material has then been shown to be quasi-brittle. A numerical simulation of the tests using finite elements and virtual crack closure technique has been performed to extract the evolution of an equivalent elastic crack length associated to the measurable sample elastic stiffness decrease along the test. The resistance curve has then been estimated by applying the equivalent linear elastic fracture mechanics.