Parametrisation of Uniform Deformation in Ductile Metals Using Digital Image Correlation Technology

This paper presents a novel measurement method that aims to qualitatively and quantitatively assess uniform deformation during displacement- and force-controlled tensile tests of ductile metals. The method utilizes digital image correlation technology to record the strain distribution during tensile testing, followed by the calculation of the floating root mean square (RMS) value of the strain amplitude along the specimen axis. By implementing this approach, the RMS-based profiles of strain amplitude are identified in different metals and alloys, including austenitic stainless steels, structural steel, copper, and aluminium alloys. Moreover, the proposed method holds potential for predicting important deformation characteristics such as distribution of intensive plastic zones, necking effect, and delocalization effect. Thus, it establishes a link between macroscale and microscale during the analysis of plastic deformation behaviour. The effectiveness of the new method is compared with existing strain and strain-rate methods. The novel approach demonstrates promising advantages in the context of the identification of metal-forming parameters.