Digital image correlation (DIC) is a non-intrusive, optical measurement technique that is generally used to analyze the displacement and deformation of a surface. It was invented in the early 1980s and has become a standard technique when it comes to structural surface measurements.
Surface images are captured by one or more cameras at different points of time. By the use of correlation algorithms, the movement of individual surface features can be tracked. The resulting displacement field allows the evaluation of the surface deformation or motion under load or even the calculation of the observed object's strain, stress, and other mechanical properties.
In wind tunnel testing, the measurement technique is a valuable tool for the determination of a model’s structural behavior under aerodynamic loads. It is of particular importance for aeroelastic experiments, where the fluid-structural interaction can induce strongly varying loads accompanied by model vibration or motion.
Another application field of DIC is the assessment of the often-made assumption of a highly rigid wind tunnel model. In particular for high-fidelity aerodynamic measurements, this assumption should be verified, for example by structural measurements using DIC.
Editor: Tim Korthäuer (M.Sc.)
Publications:
- Korthäuer T, Accorinti A, Scharnowski S, Kähler CJ (2023) Experimental investigation of transonic buffeting, frequency lock-in and their dependence of structural characteristics. Journal of Fluids and Structures, Under Review
- Korthäuer T, Accorinti A, Scharnowski S, Kähler CJ (2023) Effect of Mach number and pitching eigenfrequency on transonic buffet onset. AIAA Journal, 61(1):112–124
- Korthäuer T, Accorinti A, Scharnowski S, Kähler CJ (2023) The effect of structural characteristics on frequency lock-in in transonic buffeting flows. AIAA SCITECH 2023 Forum, page 1195
- Accorinti A, Baur T, Scharnowski S, and Kähler CJ (2022) Experimental investigation of transonic shock buffet on an OAT15A profile. AIAA Journal, 60(11):6289–6300