Image analysis of plastic deformation in the fracture of paper

A new imaging technique has been developed to characterise the outer plasti c deformation field resulting from a fracture process in a sample of deep D ouble-Edge Notched Tension (DENT) geometry. This technique has the ability to measure strains of less than 0.1%. Commercial copy paper samples were us ed during the establishment of this technique. The results indicate that th e plastic deformation field for fracture in the CD direction is more signif icant than that for fracture in the MD direction.