Crystal Plasticity Simulations

Understanding the influence of microstructural behavior of materials on their macroscopic response requires a synergistic approach combining in-situ experiments and multi-scale modeling using crystal plasticity approaches. Modeling approaches have a complementary role to in-situ experiments, and after proper validation these models can go beyond the limits of the experimental techniques to provide a deeper understanding of the material behavior. One such experimental-modeling synergistic approach was recently proposed. This multi-scale modeling approach combines finite element modeling at the macroscale and crystal plasticity modeling using the computationally efficient elasto-viscoplastic fast Fourier transform (EVP-FFT) model at the microscale. At the macroscale, finite element modeling is used to simulate complex engineering parts and predict their mechanical behavior. The FE predicted stresses or strain rates can then be used as macroscopic boundary conditions to drive the EVP-FFT model. At the microscale, the EVP-FFT model captures the influence of elastic/plastic anisotropy, texture, defect activity and grain neighborhood effects on the macroscopic material response. The modeling procedure is validated at the macroscale using the results of mechanical tests and at the microscale using in-situ diffraction and/or microscopy studies.

In a series of recent works, within the framework of our ERC project MULTIAX, the combined FE-FFT approach with experimental validation was highly successful in providing a comprehensive understanding of the macroscopic and microscopic response of 316L austenitic stainless steel cruciform samples subjected to different biaxial loads.

Study of lattice strain evolution during biaxial deformation of stainless steel using a finite element and fast Fourier transform based multi-scale approach
Upadhyay M V, Van Petegem S, Panzner T, Lebensohn R A, Van Swygenhoven H
Acta Materialia 118, 28-43 (2016).

Intergranular Strain Evolution During Biaxial Loading: A Multiscale FE-FFT Approach
Upadhyay M V, Capek J, Van Petegem S, Lebensohn R A, Van Swygenhoven H
JOM 69, 839-847 (2017).

Stresses and Strains in cruciforms samples deformed in tension
Upadhyay M V, Panzner T, Van Petegem S, Van Swygenhoven H
Experimental Mechanics 57, 905-920 (2017).