Application of Electronic Speckle Pattern Interferometry to measure thermal strains of thin layered structures


  • Mircea Cristian Dudescu


speckle interferometry, thermal strain, coefficient of thermal expansion


Applications of the Electronic Speckle Pattern Interferometry (ESPI) for the determination of the coefficient of thermal expansion (CTE) and thermal behaviour of a thin layered foils is investigated in this paper. A heating system was designed for applying thermal load and ESPI technique delivers the full-field thermal deformation fields of the test sample due to the change in temperature. The normal strain is calculated for full-field analysis of thermal expansion of the specimen. For validation, the CTE of an aluminium sample is determined and compared with the textbook value, validating the proposed experimental set-up and the sensitivity and accuracy of the applied experimental technique. The CTE and stress concentration at interface due to thermal loads of a layered thin structure consisting of two different materials is measured. The results reveal that the ESPI is a proper and effective tool for full-field thermal behaviour analysis and CTE measurement.


HAN, B., WU, Z., CHO, S., Measurement of thermal expansion coefficient of flexible substrate by moire interferometry, Experimental Techniques, 25, 3, pp. 22?25, 2001.

BING, P., HUI-MIN, X., TAO, H., ASUNDI, A., Measurement of coefficient of thermal expansion of films using digital image correlation method, Polym. Test., 28, 1, pp. 75?83, 2009.

WANG, Y.G., TONG, W., A high resolution DIC technique for measuring small thermal expansion of film specimens, Opt. Laser Eng., 51, 1, pp. 30?33, 2013.

LIU, Z., GAO, J., Deformation-pattern-based digital speckle correlation for coefficient of thermal expansion evaluation of film, Opt. Express, 19, 18, pp. 17469?17479, 2011.

MONTANINI, R., FRENI, F., Non-contact measurement of linear thermal expansion coefficients of solid materials by infrared image correlation, Meas. Sci. Technol., 25, 1, p. 015013(8), 2014.

ZHENG, F., TAN, Y., LIN, J., DING, Y., ZHANG, S., Study of non-contact measurement of the thermal expansion coefficients of materials based on laser feedback interferometry, Rev. Sci. Instrum., 86, 4, p. 043109, 2015.

WU, E., CHEN, S., TSAI, C.Z., KAO, N., Mechanical behavior of flip chip packages under thermal loading, in: Micro- and Opto-Electronic Materials and Structures: Physics, Mechanics, Design, Reliability, Packaging (Eds: E. Suhir, Y.C. Lee, C.P. Wong), Springer, 2007, pp. B651-B676.

DUDESCU, C., NAUMANN, J., STOCKMANN, M., NEBEL, S., Characterisation of thermal expansion coefficient of anisotropic materials by Electronic Speckle Pattern Interferometry, Strain, 42, 3, pp. 197–205, 2006.

ASTM E228-11, Standard test method for linear thermal expansion of solid materials with a pushrod dilatometer, ASTM International, West Conshohocken, PA, 2011,