What non-destructive techniques assess internal cracks in granite artworks?

Granite artworks, prized for their durability and beauty, can develop internal cracks over time due to stress, weathering, or structural flaws. Detecting these defects without damaging the artwork requires advanced non-destructive testing (NDT) techniques. Here are the most effective methods:

1. Ultrasonic Testing (UT): High-frequency sound waves are transmitted through the granite. Cracks disrupt the wave propagation, revealing their location and size.

2. Infrared Thermography: Thermal imaging detects temperature variations caused by cracks, highlighting subsurface defects.

3. Ground-Penetrating Radar (GPR): Electromagnetic waves map internal structures, identifying cracks and voids.

4. Acoustic Emission Testing: Monitors stress-induced acoustic signals to pinpoint active crack growth.

5. X-ray Computed Tomography (CT): Provides 3D imaging of internal cracks, though less common due to cost and equipment requirements.

These techniques ensure the preservation of granite artworks while accurately assessing their structural integrity.