Quantitative comparison between experimental measurements and CP-FEM predictions of plastic deformation in a tantalum oligocrystal. (March 2015)

• Record Type: Journal Article
• Authors: Lim, Hojun; Carroll, Jay D.; Battaile, Corbett C.; Boyce, Brad L.; Weinberger, Christopher R.
• Is Part Of: International journal of mechanical sciences. Volume 92(2015)
• Page Start: 98
• Page End: 108
• Publication Date: 2015-03
• Subjects: Tantalum -- Crystal plasticity -- Strain field -- Texture -- EBSD -- DIC; Mechanical engineering -- Periodicals; Génie mécanique -- Périodiques; Mechanical engineering; Maschinenbau; Mechanik; Zeitschrift; Periodicals; 621.05
• DOI: 10.1016/j.ijmecsci.2014.12.010
• Languages: English
• ISSNs: 0020-7403

Abstract

Abstract: Quantitative comparisons of experimental measurements and model predictions are crucial to validate and improve material models as well as to understand underlying physical phenomena. In this work, we used a recently developed in situ technique combining high resolution digital image correlation (HR-DIC) and electron backscatter diffraction (EBSD) to obtain intergranular surface strain fields and crystal rotations. These measurements were compared to predictions from a crystal plasticity-finite element method (CP-FEM) simulation. To accurately reproduce the initial grain morphology in the CP-FEM simulation without assumptions regarding the sub-surface microstructure, a coarse columnar-grained tantalum specimen was used. Experimental data was projected onto the finite element mesh to compare measured and simulated data on a point-wise basis. It is shown that model predictions of both surface strain fields and crystal rotations agree reasonably well with HR-DIC and EBSD measurements at various applied strains. This procedure provides an objective and quantitative methodology to evaluate the model-experiment agreement and allows for testing of various model parameters to improve the model. Abstract : Highlights: CP-FEM simulations of Ta oligocrystals were quantitatively compared with experimental intragranular measurements. Model predictions of surface strain fields showed good agreement with HR-DIC measurements. Model predictions of surface crystal rotations showed good agreement with EBSD measurements.