Zikry group at NC State

Anyone run into the work of the Zikry group before? (http://www.mae.ncsu.edu/zikry/index.html) It looks like most of the work focuses on FCC materials but some ideas may apply to DISFRAC?  Haven't chased down any papers yet but here are some interesting sounding titles.

T. Kameda, and M.A. Zikry, (2006), Modeling of Grain-Boundary Effects and Intergranular and Trangranular Failure in Polycrystalline Intermetallics, Metallurgical and Materials Transactions A , 37A, 2107-2120

O. Rezvanian and M.A. Zikry (2007), Statistically Stored, Geometrically Necessary and Grain Boundary Dislocation Densities: Microstructural Representation and Modelling, Philosophical Transactions Of The Royal Society Of London. Series A, Mathematical, Physical And Engineering Sciences, 463/ 2087, 2833-2853

Jawad, F. F., & Zikry, M. A. (2009). The effects of grain-boundary orientations on failure behavior in FCC polycrystalline systems. International Journal of Damage Mechanics², 18(4), 341-369.

Shi, J., & Zikry, M. A. (2009). Grain-boundary interactions and orientation effects on crack behavior in polycrystalline aggregates. International Journal of Solids and Structures², 46(21), 3914-3925

Rezvanian, O., Zikry, M. A., & Rajendran, A. M. (2008). Microstructural modeling in F.C.C. crystalline materials in a unified dislocation-density framework. Materials Science & Engineering. A, Structural Materials: Properties, Microstructure and Processing², 494(1-2), 80-85

Ashmawi, W. M., & Zikry, M. A. (2002). Prediction of grain-boundary interfacial mechanisms in polycrystalline materials. Journal of Engineering Materials and Technology², 124(1), 88-96

grain boundary energy and strengths: values in the literature

• Qiao & Kong (2004) 25kJ/m work of separation of grain boundary, includes plastic dissipation.  Note units; this is per unit length grain boundary not per unit area of crack surface (or even per unit area of grain boundary).  This is used to compute the total fracture work to cross the grain boundary; 25 kJ/m * (persistent area per unit length grain boundary) = (units of kJ)
• Stec & Faleskog (2009) take the work of separation (excluding plastic deformation) to be 640 N/m in general.  Here the units are N/m = J/m^2 as necessary for their cohesive model applied to the grain boundary. They also employed values of Gamma_GB = 160, 320, & 1600 N/m.
• Stec & Faleskog (2009) cite the ideal ferrite strength = 12 GPa, but use sigma_max = 4.8 GPa to account for material defects and dissipation effects.