open access publication

Article, 2023

Structural transverse cracking mechanisms of trailing edge regions in composite wind turbine blades

In: Composite Structures, ISSN 0263-8223, 1879-1085, Volume 308, Page 116680, 10.1016/j.compstruct.2023.116680

Contributors (2)

Miao, Xing-Yuan (0000-0001-6972-1541) [1] Chen, Xiao (0000-0001-6726-4068) (Corresponding author) [1]

Affiliations

  1. [1] Technical University of Denmark
  2. [NORA names: DTU Technical University of Denmark; University; Denmark; Europe, EU; Nordic; OECD]

Abstract

Macro-scale crack transverse to the blade length direction is one of the typical damage types observed in the trailing edge regions of wind turbine rotor blades. In this work, the mechanisms of such transverse cracks and their failure characteristics under ultimate static loading are investigated numerically by high-fidelity three-dimensional finite element modelling. Composite failure, foam crushing, and adhesive tunnelling crack are captured in the finite element model. The effects of load directions, material properties of foam cores and adhesives on the formation and development of transverse cracks, as well as longitudinal cracks along the intersection between spar cap and sandwich panels are examined in detail under ultimate static loading. We find that under static loading, the formation of macro-scale transverse cracks is a buckling-driven process. The transverse cracks occur in load directions that can result in severe buckling deformation when the trailing edge is dominated by compressive loading. The buckling resistance can be increased by replacing low stiffness foam cores in sandwich panels with high stiffness ones so that the transverse cracking process is mitigated. The effects of adhesive materials on the buckling resistance are minor and thus the formation of transverse cracks is not affected by the material properties of adhesive materials.

Keywords

adhesive materials, adhesives, blades, cap, characteristics, composite failure, composite wind turbine blade, compressive loading, core, cracking process, cracks, crushing, damage types, deformation, detail, development, direction, edge, edge region, effect, element model, element modelling, failure, failure characteristics, finite element model, finite element modelling, foam core, formation, intersection, length direction, load direction, loading, longitudinal cracks, material properties, materials, mechanism, model, modelling, one, panel, process, properties, region, resistance, rotor blades, sandwich panels, spar cap, static loading, three-dimensional finite element modelling, trailing edge, trailing-edge region, transverse, transverse cracks, tunneling cracks, turbine blades, turbine rotor blades, types, typical damage types, wind turbine blades, wind turbine rotor blades, work