High rate response of elastomeric coatings for wind turbine blade erosion protection evaluated through impact tests and numerical models

• Published in: International journal of impact engineering 2023-09, Vol.179, p.104643, Article 104643
• Main Authors: Jespersen, Kristine Munk, Eftekhar, Mohammadali, Frost-Jensen Johansen, Nicolai, Bech, Jakob Ilsted, Mishnaevsky, Leon, Mikkelsen, Lars Pilgaard
• Format: Article
• Language: English
• Subjects: High strain rates; Leading-edge erosion; Viscoelastic materials; Wind turbine blades
• ISSN: 0734-743X
• DOI: 10.1016/j.ijimpeng.2023.104643

The high strain rate (above ∼104/s) behavior of an elastomer is characterized using low strain rate (below ∼101/s) dynamic mechanical thermal analysis and time–temperature superposition. This approach is validated using high strain rate ball impact experiments and finite element predictions of ball deformations and rebound speeds. The ball impact experiments are performed by shooting 6 mm rubber balls with a controlled impact speed of 50–170 m/s at steel and polyurethane targets. An explicit axisymmetric finite element model of the ball impact experiment is established in the commercial code Abaqus. The validated material properties are used to model the viscously dissipated energy and the corresponding temperature increase in the polyurethane target. The region with the largest dissipated energy in the target material is predicted to be in a ring around the impact center with a radius of approximately 1 mm. This region corresponds well to locations of early damage initiation observed in the impact fatigue experiments for similar materials. The predictions are confirmed by the observed temperature distributions using thermal camera imaging of the rubber ball impact experiment. The experimental setup was developed for impact fatigue testing of anti-erosion coatings for the leading-edges of wind turbine blades. [Display omitted] •Time temperature superposition of DMA data for high strain rate modeling parameters.•Method to validate hyper- and viscoelastic material model for impact on elastomers.•FE model for prediction of localized dissipation heating during impact.