Uncertainty assessment of digital image correlation method in dynamic applications

Even though digital image correlation (DIC) is a widely used optical full field measurement method, it still needs further performance investigations, when it comes to dynamic conditions. Dealing with a moving target, causes a motion effect (i.e. blurring) on the acquired images. This factor is an important source of uncertainty that needs to be quantified. Therefore, the present study aims to perform a systematic uncertainty assessment of DIC method in general dynamic applications. The study focuses on 2D DIC. In the case of 3D DIC similar problems will arise and therefore, a complete understanding of two dimensional conditions will be of great help to further studies which deal with 3D conditions. The whole work can be divided in to two parts. In the first part, a method to simulate the motion effect on a reference image is proposed to be applied. This method allows simulating the acquired images in a real dynamic test and estimating the measurement uncertainty caused by the motion effect. Using this technique, the uncertainty of DIC measurement is estimated. The second part of the study aimed to validate the simulation technique. Therefore, several tests are conducted by imposing harmonic motion to a target, in different frequencies and amplitudes. The results show good agreement between the experiments and the simulations, proving the introduced technique to be an effective method for motion induced uncertainty estimation.