Micro- and Nanoscale Deformation Measurement of Surface and Internal Planes via Digital Image Correlation
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The digital image correlation (DIC) technique is successfully applied across multiple length scales through the generation of a suitable speckle pattern at each size scale. For microscale measurements, a random speckle pattern of paint is created with a fine point airbrush. Nanoscale displacement resolution is achieved with a speckle pattern formed by solution deposition of fluorescent silica nanoparticles. When excited, the particles fluoresce and form a speckle pattern that can be imaged with an optical microscope. Displacements are measured on the surface and on an interior plane of transparent polymer samples with the different speckle patterns. Rigid body translation calibrations and uniaxial tension experiments establish a surface displacement resolution of 1 μm over a 5×6 mm scale field of view for the airbrushed samples and 17 nm over a 100×100 μm scale field of view for samples with the fluorescent nanoparticle speckle. To demonstrate the capabilities of the method, we characterize the internal deformation fields generated around silica microspheres embedded in an elastomer under tensile loading. The DIC technique enables measurement of complex deformation fields with nanoscale precision over relatively large areas, making it of particular relevance to materials that possess multiple length scales.
KeywordsDigital image correlation Nanoparticle Displacement measurement Multiscale Deformation
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- 2.Peters WH, Ranson WF (1982) Digital imaging techniques in experimental stress analysis. Opt Eng 21(3):427–431.Google Scholar
- 4.Peters WH, Ranson WF, Sutton MA, Chu TC, Anderson J (1983) Application of digital correlation methods to rigid body mechanics. Opt Eng 22(6):738–742.Google Scholar
- 13.Patel JK (2003) Digital image correlation for microscale and nanoscale deformation measurement. M.S. Thesis, University of Illinois at Urbana–Champaign.Google Scholar
- 16.Goodier JN (1933) Concentration of stress around spherical and cylindrical inclusions and flaws. Appl Mech 1(2):39.Google Scholar