Deformation behaviour of materials studied by digital image correlation method
Summary
To understand deformation behaviour related to intrinsic and extrinsic properties of materials, not only experiments using precise machines and sensors but also deep interpretation of the deformation curves, specimen geometries, and specific testing conditions are important. Digital Imaging Correlation (DIC) is a technique which can be applied for the study of crack propagation and material deformation in real-world applications.Contactless sensing DIC optical method for tracking and image registration technique allows accurate 2D and 3D measurements of gauge section of specimens during tensile testing. The additional data obtained during testing allow to understand more deeply whole deformation process including calculations of local elongation, local contraction and redistribution of strain fields on the surface of the specimens.Objectives
- To apply DIC method for 2D and 3D measurements of gauge section of cylindrical specimens during tensile testing.
- To use the data obtained by the DIC method to evaluate the effect of various treatments on deformation behaviour of ferritic-pearlitic steel.
Schema of 3D digital image correlation method for cylindrical tensile specimenAchievements
- Measurements and calculations of 3D strain fields in x and y direction and shear strains in xy direction by the DIC method on the surface of the hydrogenated and annealed specimens tested to fracture. Monitoring of highly no-uniform deformation with extensive necking and determination of local maximum strains in the necked region.
- Calculations of stress-strain curves assuming engineering, uniform, non-uniform and local deformation of the gauge section based on the measurements of elongation and reduction of area by the DIC method during entire tensile deformation.
- Calculations of work hardening rates for the uniform, non-uniform and local deformations.
- Determination of the effect of hydrogenation and annealing on room temperature tensile deformation behaviour of ferritic-pearlitic steel based on the experimental data obtained by the DIC method.
Additional reading
ŠTAMBORSKÁ, M. – LAPIN, J. – BAJANA, O. – LOSERTOVÁ, M. Tensile deformation behavior of ferritic-pearlitic steel studied by digital image correlation method. In Kovové materiály, 2015, Vol. 53, No. 6, p. 399-407. (Current Contents, Scopus, WOS). ISSN 0023-432X.LOSERTOVÁ, M. - ŠTAMBORSKÁ, M. - LAPIN, J. - MAREŠ, V. Comparison of deformation behavior of 316L stainless steel and Ti6Al4V alloy applied in traumatology. In Metalurgija, 2016, vol. 55, no. 4, p. 667-670. ISSN 0543-5846.
ŠTAMBORSKÁ, M. – LAPIN, J. – BAJANA, O. Effect of hydrogenation on deformation behaviour of ferritic-pearlitic steel studied by digital image correlation method. In Kovové materiály, 2016, Vol. 54, No. 6, pp.397-406. (Current Contents, Scopus, WOS). ISSN 0023-432X.
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