Crystal plasticity simulations help to understand the local deformation behavior of multi-phase materials based on the microstructural attributes. The results of such simulations are mainly dependent on the Representative Volume Element (RVE) size and composition. The effect of RVE thickness on the changing global and local stress and strain is analyzed in this work for a test case of dual-phase steels in order to identify the minimal RVE thickness for obtaining consistent results. voxel representative volume elements are constructed by varying grain size and random orientation distribution in DREAM-3D. The constructed RVEs are sliced in depth up to 1, 5, 10, 15, 20, 25, 30, 40, and 50 layers to construct different geometries with increasing thickness. Crystal plasticity model parameters for ferrite and martensite are taken from already published data and assigned to respective phases. Although the global stress/strain behavior of different RVEs is similar (<5% divergence), the local stress/strain partitioning in RVEs with varying thickness and grain size shows a considerable variation when statistically compared. It is concluded that two-dimensional (2D) RVEs can be used for crystal plasticity simulations when global deformation behavior is of interest. Whereas, it is necessary to consider three-dimensional (3D) RVEs, which have a specific thickness and number of grains for determining stabilized and more accurate local deformation behavior. This estimation will help researchers in optimizing the computation time for accurate mesoscale simulations.
13 September 2019 in International Journal for Numerical and Analytical Methods in Geomechanics
Summary: We provide a brief review of the results obtained by Booker and Savvidou in their original 1985 paper describing the consolidation around a point heat source embedded in a fluid‐saturated porous medium. Although it gained a lot of attention in recent years, mainly as a benchmark problem for numerical codes, the analytical expressions for normal and shear stresses could not be confirmed to be correct. In this manuscript, we verify the expressions for temperature, pressure, and displacement and derive new expressions for the stress tensor withstanding numerical verification using the scientific open‐source thermo‐hydro‐mechanical‐chemical (THMC) simulator OpenGeoSys.
1 March 2021 in International Journal of Rock Mechanics and Mining Sciences