Application of digital image correlation technique to dynamic measurement of the velocity field in the deformation zone in cold rolling

Experimental determination of the velocity distribution in the deformation zone is of significant importance to investigate the metal flow in both the conventional and asymmetric rolling processes. In this paper, a whole-field method based on the digital image correlation has been investigated and applied to cold rolling. The system reported in this paper can dynamically measure the velocity distribution in the deformation zone. Various rolling parameters have been obtained from the recorded images, including the neutral point location and neutral angle, forward and backward slips, the length of the contact arc, etc. Based on these parameters, the coefficient of friction can also be obtained. The principle of operation and a description of the system are given. Rolling tests carried out on an experimental rolling mill are described and results are presented to demonstrate the feasibility of the proposed method. (C) 2002 Elsevier Science Ltd. All rights reserved.