Accuracy evaluation of digital image correlation method

(Investigation of random patterns and photographic conditions)

Abstract

The measurement accuracy of strains and strain rates by digitak image correlation method (DIC) is investigated. Displacement distribution of non-deformed stationary object are measured by DIC using various focal lengths and F-numbers. Mean values and standard deviations of the strain and strain rate are evaluated. As a result, it is found that increase of the focal length reduces measurement accuracy and tends to be inversely proportional to observation magnification.