1214 Modeling of Materials with Internal Structure or Mechanism

Yun-Che Wang, National Cheng Kung University
Sergei Alexandrov, Russian Academy of Sciences; Beihang University
Physical responses of materials under external disturbances, such as mechanical deformation, thermal loading or electromagnetic excitation, are of particular importance to the scientific community and industrial applications. Modern materials may contain specifically designed internal structure or mechanism to exhibit unusual overall physical behavior, such as negative Poisson’s ratio, extreme viscoelastic modulus or negative index of refraction. It is known that negative Poisson’s ratio can be achieved in foams with re-entrant cell structures, or in materials with rigid rotation units as a deformation mechanism. Extreme viscoelastic modulus may be achieved through the interaction between negative-stiffness and positive-stiffness phases. Negative index of refraction has been widely studied via the effects of internal resonance in the metamaterial community. Although homogenization theories for elastic, plastic, inelastic or coupled-field properties have long successful histories, the overall properties of the materials may exhibit unique properties that are unprecedentedly studied, due to the effects of their internal structure or mechanism. The internal structure, also known as microstructure, may be that for functionally graded materials or other composite materials, such as foams, polycrystalline metals, metal matrix composites or composite systems. The internal mechanism may be solid-solid phase transitions, which may give rise to negative stiffness, or metamaterials containing micro-resonators. Qualitative or quantitative modeling of such materials or searching for their unique roles in industrial applications may shed light on the developments of future emerging technologies. This minisymposium aims to discuss all computational aspects of the materials with internal structure or mechanism at the continuum or atomic levels for their mechanical responses and multiphysical responses. The mechanical responses include, but not limited to, elastic, plastic, thermal or viscoelastic properties. The multiphysical responses include, but not limited to, piezoelectric, pyroelectric or magneto-electric properties. Numerical methods, such as finite element/difference methods, phase field methods or molecular dynamics simulations, are traditional workforce in the realm of computational materials science. Novel solution methods based on analytical-solution procedures with considerations of non-affine deformation are also welcome.