|
With increasing requirements on the efficiency of aircraft engines and the application of advanced materials, the non-contact evaluation of the deformation and the vibration behaviour is of increasing interest. For optical deformation measurements at high surface speeds, motion blur becomes a critical uncertainty factor. A full-field measurement method for rotating components is proposed, in which in-situ high-resolution images can be acquired for digital image correlation. The measurements are carried out through an optical derotator, which allows rotational motion blur to be largely avoided. Optical image distortions due to the use of a dove-prism are considered and the effects are attempted to be minimized by an angle-precise triggering of the digital single-lens reflex camera. The measured deformations on a generic bladed disc under different rotational speeds up to 2500 RPM show a good correlation compared both to 3D digital image correlation measurements from ARAMIS as well as to numerical predictions. The results demonstrate that the approach is sound for measuring the deformation, whereas measurements at the circumference reveal the image distortion effects, posing that further steps are necessary for an investigation of the vibration behavior.
|
