Elevated Temperature Optical Microscopy DIC

  • Kevin B. ConnollyEmail author
  • W. Carter Ralph
Conference paper
Part of the Conference Proceedings of the Society for Experimental Mechanics Series book series (CPSEMS)


When determining the microstructural performance of new materials, such as composites and additively manufactured parts, it is necessary to understand their full-scale behavior. Since non-homogeneous materials are being used more often in critical applications, understanding their microstructural response is becoming more important. Digital Image Correlation (DIC) has proven to be invaluable in characterizing the small-scale performance of non-homogenous materials, but presents a number of challenges for certain tests. One such area is determining the local strain behavior for non-homogeneous micro-scale materials as the part is heated. Using DIC on a sample at elevated temperatures must deal with optical distortions caused by uneven heating of the air above the part. Using DIC at a microstructural level is difficult due to the limited depth of field, which can cause a loss of focus and difficulty in generating an appropriate speckle pattern. To examine the microstructural thermal response both of these difficulties must be overcome simultaneously. Southern Research has developed methods and apparatus to allow optical DIC to be used over a range of temperatures and microscopic fields of view. This paper will address how each of the problems was overcome in the apparatus design and testing method as well as show results validating the technique.


Strain measurement Digital image correlation Thermal strain Optical microscopy Surface preparation 


  1. 1.
    Chu, T.C., Ranson, W.F., Sutton, M.A., Peters, W.H.: Applications of digital image correlation techniques to experimental mechanics. Exp. Mech. 25(3), 232–244 (1985)CrossRefGoogle Scholar
  2. 2.
    Kammers, A.D., Daly, S.: Digital image correlation under scanning electron microscopy: methodology and validation. Exp. Mech. 53(9), 1743–1761 (2013)CrossRefGoogle Scholar
  3. 3.
    Ralph, W.C., Raiser, G.F.: Assembly level digital image correlation under reflow and thermal cycling conditions. In: Proceedings of the 63rd Electronic Components & Technology Conference, Las Vegas, NV, pp. 2223–2227, 28–31 May 2013Google Scholar

Copyright information

© The Society for Experimental Mechanics, Inc. 2019

Authors and Affiliations

  1. 1.Southern Research InstituteBirminghamUSA

Personalised recommendations