YCE: a provider of applied structural engineering solutions
Wind blades are subject to adverse weather conditions such as lightning strikes and wind erosion.
All repairs are carried out at height; YCE Repair System guarantees that maintenance and repair activities meet the following general technical criteria:
Duration: The repair must be able to offer a service life at least equal to the original state of the blade, maintaining its integrity under the same fatigue loads and environmental conditions. Repairs by adhesive bonding must not significantly degrade over time.
Stiffness: The repair should allow the original composite structure to maintain its optimum stiffness strength. The repair must permit only minimal changes to the load paths.
Surface finishing: The surface finishing of the repair must keep the aesthetic appearance, UV resistance, resistance to chemicals and the aerodynamic properties of the original construction.
The repair activities are carried out according to the following technical standards:
– Deutsches Institut für Bautechnik – DIBt -, Berlin Richtlinie für Windenergieanlagen, März 2004
– Det Norske Veritas – Design and manufacture of wind turbine blades, offshore and onshore wind turbines, October 2010
– Germanischer Lloyd – Guideline for the Certification of Wind Turbines, Edition 2010
YCE Repair System: priorities of blade repair design
Extraordinary shell damage and YCE repair techniques
Structural damage to spar and composite sandwich laminates
Erosion and cosmetic damage
Most wind blades, even the newest designs, are damaged by lightning strikes. Apart from the immediate damage caused by the lightning (the formation of plasma that burns the sacrificial layer of the blade), overheating caused by the intensity of the current through the earthing system causes the vaporization of the water that found its way inside the blade.
The instantaneous transformation of this water into gas and its immediate expansion cause mechanical damage to the tip area.
YCE research has developed a retrofit that improves LPS (Lightning Protection System): YCE LPS RETROFIT®.
YCE LPS RETROFIT® prolongs the lifecycle of the blades by extending the electrical attraction area of the receptor, mechanically strengthening the blade tip and improving the Lightning Protection System.