High speed ultraviolet digital image correlation (UV-DIC) for dynamic strains at extreme temperatures

Area of Science:

• Materials Science
• Optical Engineering
• Experimental Mechanics

Background:

• Digital Image Correlation (DIC) is a non-contact method for measuring surface displacements and strains.
• High-temperature DIC is challenged by blackbody radiation, which saturates camera sensors.
• Existing ultraviolet (UV) DIC methods are limited by slow camera speeds.

Purpose of the Study:

• To investigate the feasibility of high-speed UV-DIC at extreme temperatures.
• To overcome the speed limitations of conventional UV-DIC systems.
• To enable accurate strain measurements in materials under high-temperature dynamic conditions.

Main Methods:

• A UV intensifier was coupled with a high-speed camera for UV-DIC measurements.
• Experiments included quasi-static thermal expansion and high-temperature vibration tests.
• System performance was evaluated at temperatures up to 1600°C and frame rates of 5000 fps.

Main Results:

• The UV-DIC system successfully performed measurements at temperatures up to 1600°C and 5000 fps.
• Achieved speeds are over 100 times faster than previously reported UV-DIC systems.
• Measurements with the UV intensifier were noisier but enabled operation above camera saturation limits.

Conclusions:

• The developed high-speed UV-DIC system significantly advances the capability for dynamic strain measurement at extreme temperatures.
• This technology opens new possibilities for material characterization under harsh conditions.
• Further optimization may be needed to reduce noise introduced by the UV intensifier.