Rédiger un PREreview

In this study, the mechanical and fracture behavior of AISI 304 austenitic stainless steel sheets was investigated using a crystal plasticity finite element method (CPFEM). Two types of microstructures were analyzed: a random configuration with equiaxed grains and a textured configuration with elongated grains, resulting from severe cold rolling. Polycrystalline geometries were generated using a Voronoi tessellation algorithm in MATLAB and implemented in ABAQUS. The hardening parameters for each microstructure were identified through calibration by matching experimental and simulated uniaxial stress–strain curves. Results revealed that the aspect ratios of the grains (length and width relative to thickness) significantly affect the macroscopic fracture strain. Increasing the grain length-to-thickness ratio l/dl/dl/d led to a reduction in fracture strain, while increasing the grain width-to-thickness ratio w/dw/dw/d enhanced strain uniformity and delayed fracture. Comparisons between the two microstructures showed that the textured configuration consistently exhibited lower ductility due to higher dislocation density and limited slip system activation. Grain-level fracture analysis demonstrated that increasing the number of grains reduced the standard deviation of local fracture strain and improved deformation uniformity. Additionally, textured microstructures exhibited earlier formation of shear bands at lower strain levels, indicating a lower forming limit. These findings provide valuable insights into the relationship between grain morphology, crystallographic texture, and formability in metal sheets. The results can be applied to optimize microstructural design for improved ductility in high-strain-rate forming processes.