The behavior of II/III mixed-mode delamination in laminated composites and potential savings in Aerospace regarding verification processes

Delamination is recognised as the most critical damage process in laminated composites: even a simple, single plane defect can result in multi-plane delamination growth (delamination migration) which is often associated to other secondary processes such as intralaminar or translaminar damage. In previous research, the link between the mode III component and delamination migration was established [9]. However, the exact mode-mixity at which this migration occurs needs to be investigated further. This project will determine the effect of load introduction on the migration threshold in II/III mixed-mode delamination. The test method that will be used is a 6-point bending plate [10] that relies on bending moments to induce mixed-mode delamination. The tests will be instrumented with acoustic emission to capture, if possible, the onset of resin microcracking. The test will then be interrupted for detailed fractographic analysis at the crack front. These will give an insight of the role of bending on the fracture process of mode II-III on multi-angled interfaces.Outgoin