DIC Calibration Methods

Methods for quantifying DIC measurement uncertainty in an industrial environment
DIC Measurement uncertainty

We evaluated the state-of-the-art for quantifying measurement uncertainty of digital image correlation and assessed potential candidate techniques for evaluating the uncertainty during 1:1 aircraft scale optical strain and displacement measurements.

From there we developed two specific methods for experiments performed in industrial situations. The methods can be performed at the time of the test and quantify measurement uncertainty in the whole measurement volume in a manner that is relevant to the validation of predictive numerical models. This step significantly improves the quality of laboratory-based DIC measurements.

The first method is based on using a calibration plate in front of the test object and a rigid body displacement of the camera system. The methodology is illustrated in this video. A typical result is displayed in the figure below.

The second method uses an LCD screen in front of the test object which displays simulated speckle patterns that are numerically deformed to represent planar strain states. The methodology is illustrated in this video.

 

/documents/1583244/0/MU_DIC/ee0f0ec2-0750-44e1-ae54-12f581d78b07?t=1553533914670
Deviations of position data from DIC measurement after calibrating the system in front of the test object. They form the basis for estimating the DIC measurement uncertainty.