• Tomotsugu Shimokawa, Kanazawa University
• Takahiro Shimada
• Ryosuke Matsumoto
• Hajime Kimizuka

The main purpose of this mini-symposium is to discuss to what extent macroscopic mechanical properties of crystalline materials can be understood by a bottom-up approach based on the nanoscale dynamics of defects. We also discuss the novel functions by focusing on the interplay between mechanical properties and other physical properties at the nano/defect scale. Crystalline materials generally contain hierarchical characteristic lengths such as Burgers vector, dislocation structure size, and grain size and also have heterogeneous structures such as variety of slip systems due to crystal structure, hard and soft composite structures, and grain size gradients; therefore, it is not easy to understand the mechanical properties only based on the frame works of the conventional established lattice defect theories. For this reason, nanoscale computer simulations that can deal with the dynamics of atomic structures are undoubtedly a promising approach. The interpretation of mechanical properties of virtual materials based on complex and nonlinear phenomena due to nanoscale dynamics of lattice defect through computer simulations is expected to lead to an essential understanding of the mechanisms of mechanical properties of various real crystalline materials, but unfortunately not all of them have been successful. This means that there are still some problems to be solved to understand macroscopic mechanical (and correlation to other physical) properties in a bottom-up manner based on nanoscale defect mechanics. In this symposium, we will discuss the future direction of nanomechanics and related physical phenomena of microscopic defects by sharing the cutting-edge trends and challenges of bottom-up approaches through various talks on, but not limited to the following topics:

• Heterogeneous-, Nanostructure-, Gradient-materials
• Ab initio, Molecular dynamics, Kinematic Monte Carlo, Dislocation dynamics, Phase field, Continuum mechanics
• Structural and mechanical properties of defects and their physical properties and functions
• Dislocation, Grain boundary, Disinclination, Deformation twin, Shear band, Kink band, and Topological defects
• Unique defect structures and mechanics due to non-uniform structures
• Defect interactions
• Nucleation mechanism of non-elastic deformation modes