Control of fatigue delamination growth

This Ph.D. is part of the H2020 DACOMAT-project.

Initial imperfections are present in composite structures as soon as the product leaves the production floor. In the case of glass fibre wind turbine blades, this is for example in the form of large voids. These may in turn lead to delaminations, which grow throughout service life of the product. The EU project DACOMAT aims to accept these imperfections and to focus on developing composite materials which tolerate them.

The aim of the proposed phd study is to investigate and control delamination propagation in com-posite structures. Specifically, fatigue delamination will be considered as this is one of the critical failure drivers of composite structures [1]. Previous experimental [2] and numerical [3] studies found that inter-face strength is a key parameter for inducing multiple cracks (see fig. 1) and that each new crack may increase fracture resistance. Ongoing tests show that lamina interface properties may be influenced by plasma treating the glass fibres prior to infusion. It is hypothesized that such surface treatment may be used to control the formation of multiple cracks in a delamination sensitive region, such as a ply-drop. Experimental tests are planned to test this hypothesis and serve as a basis for validating a numerical model.


Daan Jonas Hottentot Cederløf
PhD student
DTU Wind Energy
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