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A priori analysis of a higher-order nonlinear elasticity model for an atomistic chain with periodic boundary condition. (English) Zbl 1511.65130

Summary: Nonlinear elastic models are widely used to describe the elastic response of crystalline solids, for example, the well-known Cauchy-Born model. While the Cauchy-Born model only depends on the strain, effects of higher-order strain gradients are significant and higher-order continuum models are preferred in various applications such as defect dynamics and modeling of carbon nanotubes. In this paper we rigorously derive a higher-order nonlinear elasticity model for crystals from its atomistic description in one dimension. We show that, compared to the second-order accuracy of the Cauchy-Born model, the higher-order continuum model in this paper is of fourth-order accuracy with respect to the interatomic spacing in the thermal dynamic limit. In addition we discuss the key issues for the derivation of higher-order continuum models in more general cases. The theoretical convergence results are demonstrated by numerical experiments.

MSC:

65N30 Finite element, Rayleigh-Ritz and Galerkin methods for boundary value problems involving PDEs
65D32 Numerical quadrature and cubature formulas
65D05 Numerical interpolation
65N12 Stability and convergence of numerical methods for boundary value problems involving PDEs
65N15 Error bounds for boundary value problems involving PDEs
35J30 Higher-order elliptic equations
74B20 Nonlinear elasticity
74E15 Crystalline structure
82D20 Statistical mechanics of solids
82D80 Statistical mechanics of nanostructures and nanoparticles
81V45 Atomic physics