Whilst in operation, wind turbines are prone to damage from external forces. The rotor blades on a wind turbine require regular inspection and maintenance to keep them in good condition.
Most rotor blades are constructed from glass fibre however a growing number of blades are using a hybrid of glass and carbon fibre to improve strength and stiffness while reducing weight.
Rotor blade damage
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The rotor blades can be subjected to bird strikes, lightning strikes where the carbon fibre in the blade structure can act as an electrical conductor, and leading edge corrosion caused by rain, hail, sand, insects and ice.
These factors can cause damage to the rotor blades and reduce the aerodynamic performance, resulting in decreased power production. Studies have shown leading edge corrosion can result in a drag increase of up to 500%, culminating in a decrease in annual energy output of 20%.
Challenges facing rotor blade repairs
Regular inspections can expose any faults or damage to the rotor blades before the turbine fails. This effectively minimises downtime caused by unanticipated repairs.
Technicians can inspect, clean and repair the rotor blades to ensure they are in good condition. When repairing the rotor blade, the technician is suspended from the rotor hub and works on the subject blade, which is stopped in the down position. Anchor lines may be deployed to the tower or around the blade.
A project overseer on the ground is responsible for resin preparation, control of cure parameters, and for keeping records for quality control purposes.
One of the most challenging aspects of repairing the rotor blades is curing the resin, where in some cases, it can take 24 hours for the resin to cure. This results in downtime and a loss of revenue.
Solutions for repairing wind turbine rotor blades
Araldite methacrylate structural adhesives can speed up the repair process for technicians. These adhesives have high strength and rapid curing with the ability to bond and repair different substrates such as composites, metals and thermoplastics. Methacrylates exhibit high lap shear strength comparable to epoxies and have good tensile strength.
Our recommended solutions are: Araldite 2021-1, Araldite 2022-1 and Araldite 2048-1. All products are available in 50ml and 380ml cartridges making them portable and convenient for field work. They provide accurate mixing and dispensing saving time and providing ease of repeatability. These adhesives can be used to repair leading edge erosion, small holes and surface defects.
A two component, toughened, rapid curing methacrylate adhesive with minimal pre-treatment. Ideal for rapid fixing and filling of small voids.
A two component, fast cure methacrylate adhesive offering non-sag and gap filling up to 4mm.
A two component, fast setting, flexible, methacrylate adhesive system that allows rapid attachment of parts.
For more information on adhesives for the wind industry, please get in touch.