Deformation Measurement Technique

In general, deformation measurement technology is the determination of contour, shape and profiling of an object deformed under load.  At the Institute of Fluid Mechanics and Aerodynamics, this technique is used to determine the load and deformation of systems under aerodynamic load. In addition to established methods, which work via direct contact with the test object, contactless imaging measurement methods have become established in recent years. The main advantage is the possibility of investigating an entire simultaneous measurement field without distorting the behavior of the target by direct contact.  Dynamic processes can also be recorded in this way. Usually, several cameras are used to record the object to be measured from different perspectives and thus measure the three-dimensional extension. The methods for determining the 3D surface of the measurement object (correlation between stereo images) and the 3D deformation vector fields (correlation between images under different loads) are based on established cross correlation algorithms, which are also used in Particle Image Velocimetry (PIV). In addition to the evaluation methods, various hardware systems can also be used in corresponding arrangements for PIV and deformation measurement technology. In order to successfully identify the image information, digitally interpretable, artificial patterns are required on the target which are usually sprayed or projected onto the target.
At the Institute of Fluid Mechanics and Aerodynamics, these methods are being pursued particularly in the following areas:
  • Extension and adaptation of the digital evaluation methodology
  • Improvement of contour recognition for complex wing-geometries
  • Development of a method for identification by means of a naturally existing texture
  • Extension of known methods for the evaluation of large deformations
  • High-speed deformation measurements