Digital image correlation method for measuring deformations of vinyl chloride-coated metal multilayer sheets

Abstract

A three-dimensional (3D) digital image correlation (DIC) method is presented for measuring the deformations of vinyl chloride-coated metal (VCM) multilayer sheets and their composites. The calculations and the principle of strain and deformation measurements using the DIC method are described. A VCM multilayer sheet consists of a substrate [steel plate cold commercial (SPCC) and steel plate cold elongation (SPCE)] and a clad (a VCM film). The corresponding deformations of VCM deep-drawing multilayer sheets (SPCE as a substrate and a VCM film as a clad), VCM nondeep-drawing multilayer sheets (SPCC as a substrate and a VCM film as a clad), nondeep-drawing substrates (SPCC), deep-drawing substrates (SPCE) and clads (VCM films) were captured along the x- and y-directions in uniaxial tension experiments and using the DIC method. The maximal measured strains along the x-direction for the VCM deep-drawing multilayer sheets, VCM nondeep-drawing multilayer sheets, nondeep-drawing substrates, deep-drawing substrates and clads were, respectively, 637.835%, 132.210%, 31.688.632%, 107.102%, and 118.937%. The maximal measured strains along the [Formula: see text]-direction were 739.028%, −11.174%, −9.678%, −13.273% and 12.120%, respectively. These data show that the mechanical properties of VCM multilayer sheets are better than those of their substrates and clads. The effectiveness and accuracy of the presented DIC method for VCM multilayer sheet measurements were confirmed in a series of experiments.