wind turbines

There are 268,000 wind turbines spinning around the world at the end of 2014, which equates to a capacity of 370 GW globally. As the turbines age, the number of mechanical failures is likely to increase rapidly. Therefore, there is a clear market need to develop novel techniques that can meet the requirements of inspecting wind turbine blade on-site the wind tower so that structural failure and catastrophic consequences can be avoided.
Current competitive non-destructive testing (NDT) techniques such as visual inspection, thermography, acoustic emissions or ultrasound require skilled personnel or "workshop environment" conditions in order for the inspection to be carried out successfully or do not meet the existing safety standards. Shearography has been accepted as a valuable non-contact NDT technique in a variety of industrial sectors. However, those shearography systems normally work on a stable condition such as in a lab or a specifically designed test facility. The condition on a wind tower is totally different in that the wind turbine blade will never be completely stationary even when the wind turbine is parked because wind will never stop completely.