Abstract

In this paper, a data-driven approach to dislocation-mediated plasticity is presented. Within a dislocation density-based plasticity model incorporating effective disorder temperature, we analyze mechanical test data for various metals under diverse loading conditions and use large scale least squares method to determine the parameters of the theory. This approach enables accurate predictions of stress-strain behavior and temperature evolution for crystals under simple shear, tension/compression, and torsion over a broad range of strain rates and temperatures, where traditional crystal plasticity models fail. Furthermore, it captures size and Bauschinger effects, work hardening, and thermal softening. Next, we model notch-like defects to explore shear band instabilities, with predictions accurately matching Marchand and Duffy's experiments over a broad range of strain rates and temperatures.  Finally, we apply this approach to the brittle-ductile transition, predicting fracture toughness in tungsten across a range of temperatures – consistent with the experimental findings of Gumbsch.

Prof. Le Khanh Chau

Le Khanh Chau is a Senior Researcher at Ton Duc Thang University (Vietnam), with a distinguished academic background from renowned institutions, including Moscow State University and St. Petersburg State University. His research expertise encompasses smart and functionally graded materials, nonlinear vibration, wave propagation, thermodynamic dislocation theory, fracture mechanics, and micromechanics. He is internationally recognized with over 120 publications in leading journals and the authorship of the acclaimed Springer monograph "Vibrations of Shells and Rods". His prior experience includes faculty appointments in Germany and extensive international collaborations. He demonstrated passion for mentorship, having successfully supervised over 50 graduate and postgraduate students.