Ultraviolet Single-Camera Stereo-Digital Image Correlation for Deformation Measurement up to 2600 °C

Background

In the mechanical testing of high-temperature structural materials, ultra-high temperature deformation measurement is very necessary and very challenging.

Objective

To overcome the challenge of using single-camera stereo-digital image correlation (stereo-DIC) for ultra-high-temperature measurement.

Methods

An ultraviolet single-camera stereo-DIC system combining active UV illuminations, an ultraviolet camera, a single UV narrow bandpass filter, a reflective prism and two reflectors was established. In addition, two types of high temperature speckle patterns were prepared A tensile test of C/C composites at 2600 °C was conducted to verify the effectiveness and accuracy of the developed technology.

Results

The ultraviolet single-camera stereo-DIC system has excellent resistance to thermal radiation. As well, the two types of speckle patterns are available at 2600 °C. And the values of elastic modulus calculated by the developed technology and high-temperature extensometer are very close to each other, and the relative errors are less than 7%.

Conclusions

The well matched strain results with high-temperature extensometer data demonstrates that the ultraviolet single-camera stereo-DIC is an effective ultra-high temperature deformation measurement technology and has great potential in characterizing the deformation response of materials at ultra-high temperatures.