Optical Measurement Methods
Shearography
Laser Interferometry for NDT
Shearography is a non-destructive optical inspection method for detecting surface and subsurface defects in materials and structures. By analyzing deformation under slight load, it enables fast, full-field inspection — particularly for composite and lightweight components.
Measurement principle
For a measurement, a controlled load — thermal, vacuum, mechanical, or dynamic — is applied to slightly deform the material, revealing hidden defects. Rather than measuring absolute displacement, shearography evaluates deformation gradients across the surface. Defects such as delaminations, disbonds, or core damage disrupt the local strain field and appear as distinct anomalies in the interferometric image.
Key Advantages
- Non-contact and non-destructive testing (NDT)
- Full-field, real-time inspection
- High sensitivity to subsurface defects
- Suitable for production environments
- Especially effective for composites and sandwich structures
Application Areas
Shearography is commonly applied in aerospace for inspecting composite structures such as wings and fuselage panels, in the automotive industry for testing tires and lightweight materials, and in wind energy for evaluating rotor blades. It is also used for quality control of bonded or layered materials, detection of delaminations and disbonds, and inspection of pressure vessels and pipelines. Explore the examples below to see typical application scenarios.
