In the immediate future, wind power will provide more electricity than any other technology based on renewable and low-emission energy sources. As a result, the size of offshore wind turbines has increased to harvest more wind energy in order to achieve the 2050 EU carbon neutral targets. The use of composites opens great prospects in the design and manufacture of the wind turbine blades due to their optimization versatility but composites perform poorly under impact and are sensitive to environmental factors. To combat this, blade manufacturers employ polymer-based surface coatings, caps or tapes to protect the composite structure. However, it is the repeated impact of rain droplets combined with the high blade tip speed, which are mostly contributing to the erosion of wind turbine blades [1]. The hindering of leading-edge erosion could be obtained through its multilayer material optimization i.e. Leading Edge Protection LEP [2]. Both the surface erosion and the intra-layer adhesion are affected by the shock wave propagation through the thickness of the LEP system produced from the collapsing water droplet after impact [3]. It is necessary to increase the interfacial fracture toughness resistance of the multy-layered system from the surface to the interface boundaries to damp the surface damage and avoid subsurface delamination [4]. Therefore, validated models considering the developed multicomplex stress states and the material degradation due to environmental loads are required for design purposes toward anti-erosion protection performance. This investigation summarizes the review of the current literature conducted in the framework of the IEA Wind TCP (International Energy Agency Wind Technology Collaboration Programme) - Task 46 Erosion of wind turbine blades [5]. It focuses on two main issues: firstly, the LEP material configuration used in industry considering the blade integration technology and, secondly, the modelling techniques and numerical procedures currently used to predict both wear surface damage and interface delamination failure. This work will allow for the identification of gaps within the research that can be explored during IEA Wind Task 46.

Laser-assisted tape placement (LATP) and thermoplastic composites (TPCs) pre-impregnated (prepreg) tapes are a promising combination of technologies; given the in-situ capabilities of the TPCs and the high degree of automation achievable with LATP. However, laminate quality, measured as final void content, tends to decrease when increasing placement speed. Heating and consolidation windows in LATP of TPCs are very short, especially when increasing the placement speed. For TPCs, resin flow is heavily influenced by melt viscosity above melting temperature (Tm). Therefore, the degree of intimate contact (Dic) resulting from the compaction phase can be significantly influenced by the tape’s degree of melt at the end of the heating phase. Due to melting being a kinetically controlled process[1,2], both temperatures and times above Tm need to be considered. The relationship between the degree of melt, both through thickness and in time, prior to compaction and the final Dic has not been explored yet. In this study, the final Dic and degree of melt of a CF/PEEK tape as a function of heating power, heating length and placement speed will be evaluated and correlated. The experimental investigation will consist of calorimetric data on melting kinetics of the polymer, and LATP experiment runs with different process parameters. Simulations of the thermal history (see Figure 1) and melting in the heating phase will be performed and validated with experiments. The research aims to understand the melting behaviour of the tapes during the heating stage in LATP, its dependence on the process parameters, and how it affects the final Dic and laminate quality.