Математическое моделирование особенностей эволюции напряженно-деформированного состояния в материале с покрытием

Abstract

The interfacial mechanisms of the stress concentration in materials with modified surface layers are investigated. A dynamic boundary-value problem in a plane-strain formulation is solved numerically by the finite-difference method. The geometry of a curvilinear interface corresponds to the configuration found experimentally and is explicitly accounted for in the calculations. Both the experimentally observed microstructure of a sample with an serrated coating-substrate interface and a model microstructure with an ideal sinusoidal shape of this boundary were considered. The constitutive model assumes that the modified surface layers are elastic, while the elasticity of the base material is followed by plastic flow which provides isotropic strain hardening. Serrated and wavy base material-surface layer interfaces observed experimentally are assigned explicitly in calculations. Two stages in the evolution of the stress concentration are found to occur due to irregular interfacial geometry. The stress concentration in near-interfacial regions turns out to depend on the parameters of sinusoidal wavy interface and coating thickness.