Improved design basis for large wind turbine blades
Finite element models were used for studying the buckling behaviour of a box girder, tested to failure in Phase 1 of this project
Purpose: The overall purpose of the project is to develop some more rational research-based design methods for large wind turbine blades. Models of specific failure modes, identified in wind turbine blades, are developed. Programme: The project contains both experimental and modelling work, ranging from mechanics of materials to structural behaviour. Three topics are in focus: 1) Compression strength of composites. 2) Fracture mechanics strength of adhesive-bonded joints. 3) Joints or transitions between uneven materials Anticipated results: Better basis for modelling of buckling and compression failure of fibre composites, interaction between different scales. Demonstration of fracture mechanics approach for adhesive-bonded joints. Clarification of general problems and possible solutions for joining different composite materials
The major results of Phase 2 of a project concerning the development of new design methods for wind turbine blades are summarised. Finite element models were used for studying the buckling behaviour of a box girder, tested to failure in Phase 1 of this project. The deformation behaviour of a box girder section subjected to transverse forces was investigated experimentally and by modelling. Buckling-driven delamination of planar specimens was studied on experimentally and by modelling. A novel approach was proposed for the determination of mixed mode cohesive laws for large-scale crack briding problems. The normal and shear stresses of the cohesive laws were obtained from data of the fracture resistance and the normal and tangential displacements of the cohesive zone. Delamination of a thin layer bonded to an elastic substrate close to corners and edges was also analysed. Results for the shape of the interface crack front and critical stress for steady-state delaminstion were obtained
Key figures
Category
Participants
| Partner | Subsidy | Auto financing |
|---|---|---|
| Danmarks Tekniske Universitet (DTU) | 3,35 mio. DKK | |
| Aalborg Universitet (Fredrik Bajers Vej) | ||
| LM Glasfiber A/S | ||
| VESTAS WIND SYSTEMS A/S |
Contact
P. O. Box 49
DK-4000 Roskilde, Denmark
www.risoe.dtu.dk
Sørensen, Bent F. (Ph.d., seniorforsker), 46775700, materials@risoe.dk
Øvr. Partnere: AAU. Inst. for Bygningsteknik; BYG-DTU; AAU. Inst. for Maskinteknik; LM Glasfiber A/S; Vestas Wind System A/S
