Abstract: An experimental study establishing a technique for the contactless optical determination of the local plastic formability limit on the loss of stability of sheet metal has been conducted. The possibilities for the recording of the time instant and the place of the localisation of the deformation based on the changes in the optical images of the surface have been examined. An optical criterion for the determination of the time instance and the place of the loss of stability derived through a correlation analysis of the images has been proposed. The experimentally obtained results have been presented and analysed.

Keywords: stable formability limit, loss of stability, photogrammetry, correlation analysis, digital image correlation

Link:

PHOTOGRAMMETRIC TECHNIQUE FOR THE DETERMINATION OF THE MOMENT IN TIME AND THE PLACE OF THE LOSS OF STABILITY DURING THE PLASTIC DEFORMATION OF SHEET METAL

Spilko Hubenov, Georgi Stoilov

http://www.foibg.com/ijima/vol03/ijima03-04-p06.pdf