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

BackgroundIn the mechanical testing of high-temperature structural materials, ultra-high temperature deformation measurement is very necessary and very challenging.ObjectiveTo overcome the challenge of using single-camera stereo-digital image correlation (stereo-DIC) for ultra-high-temperature measurement.MethodsAn 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 degrees C was conducted to verify the effectiveness and accuracy of the developed technology.ResultsThe ultraviolet single-camera stereo-DIC system has excellent resistance to thermal radiation. As well, the two types of speckle patterns are available at 2600 degrees 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%.ConclusionsThe 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.