Applications of Shearography
Used in the Inspection of Wind Turbine Blades
The production of the blades of wind turbine includes some complex procedures. After the production of these blades, the inspection is very difficult because of their large size. The huge size of these blades requires fast and accurate inspection, which can cover several square meters in a small time.
The technique of shearography is used to inspect the specimen of huge sizes like these blades. It detects various defects occurred during the production processes such as delamination, kissing bonding, wrinkle, and debonding. The whole instrument gives its first reading within 5 minutes.
This technology provides maximum flexibility to the operator. It is also used for inspecting the helicopter’s blades similar to wind turbine blades.
Used for Inspecting Bonded Sandwich Structures with Foam Cores and Stiff Skins
A bonded sandwich structure is a structure that consists of stiff stainless steel skins and low-density foam cores. The defects in this structure are present mainly in between skin and core. They may also present in the bondline of the structure. These defecst are responsible for the passing of ambient air through them.
Shearography is found to be very useful to inspect such structures. It is used to detect the defects, and it also estimates the depth position in stiff areas.
Used in Aerospace Industries
A high quality inspection system is required in aerospace industries. A special branch of shearography, named robotics shearography, is used in various Jet manufacturing companies today. It’s a fully automatic system that was installed for the first time in 2008 . It is capable of inspecting 1-2 square metersper minute of material, which is a pretty good speed.
The system works in a vacuum chamber. The vacuum chamber is used to excite the parts of the structure. However, it also uses heat to deform the material, if required. It can supply heat up to 3Kw to the material at a time.