Optics and Lasers in Engineering vol:48 issue:10 pages:978-986
In this contribution it is discussed whether it is possible to measure the coefficient of thermal expansion (CTE) of steel with the aid of the digital image correlation (DIC) technique. DIC is first used to obtain reference values of the CTE of well-known steels (S235 and SS304) on simple geometries (rectangular blocks) in the low temperature interval (up to 120°C). Although the strains that occur in this process are small, the CTE can be determined with good accuracy if enough photos are available. The influence of the different parameters that control the correlation process showed no influence on the results. The values for the CTE are compared to available literature references and strain gauge measurements. The technique is extended to measure in a higher temperature interval (up to 600°C) and three-dimensional geometries (tubular samples) and a third material (SS409). It is shown that also in these cases, the obtained results are reliable.