A thermo-mechanical cohesive zone model accounting for mechanically energetic Kapitza interfaces

Abstract

a b s t r a c tInterfaces can play a dominant role in the thermo-mechanical response of a body. The importance of interfaces is more pronounced as the problem scale decreases since the interface area to the bulk volume ratio grows. The objective of this contribution is to study computational aspects of modeling thermomechanical solids containing mechanically energetic, geometrically non-coherent Kapitza interfaces under cyclic loading. The interface is termed energetic in the sense that it possesses its own energy, entropy, constitutive relations and dissipation. To date, classical thermo-mechanical cohesive zone models do not account for elastic interfaces. Therefore we propose a novel interface model that couples the classical cohesive zone formulation to the interface elasticity theory under the Kapitza assumption within a thermomechanical framework. In other words, such an interface model allows for discontinuities in geometry, temperature and normal stress fields, while not permitting a jump in the normal heat flux across the interface.The equations governing a fully non-linear transient problem are given. They are solved using the finite element method. The results are illustrated through a series of three-dimensional numerical examples for various interfacial parameters. In particular, a comparison is made between the results of the classical thermo-mechanical cohesive zone model and our novel (cohesive + energetic Kapitza) interface formulation.

Coupled thermally general imperfect and mechanically coherent energetic interfaces subject to in-plane degradation

“…(12) to vanish. A degrading LC interface can be modeled as in [20] by removing the second term in the last integral, due to the fact that the jump of normal heat flux across interface vanishes (see relation 10 2 ). The finite element implementation is now given in Appendix A.…”

“…We point out that the thermally GI interface presented here may be specialized to all the other types of thermal interfaces. For further details on the different types of thermal imperfections see [20,21,28,33] and references therein.…”

A general thermodynamical model for adhesive frictional contacts between viscoelastic or poro-viscoelastic bodies at small strains

“…Anyhow, from the engineering point of view, a detailed analysis of related variational formulations of interface cohesive models was developed in [21]. Another related and thermodynamically based approach for general imperfect interfaces was proposed and numerically studied in [24,29,30], considering e.g. an interface temperature different from the temperatures of adjacent bulks, cf.…”

Non-coherent energetic interfaces accounting for degradation

“…Due to the above features, these interfaces are labeled elastic or energetic. For further details see for instance, [12,20,22,29,30,36,39,[43][44][45][46][48][49][50]54,58,82,84] and ref-erences therein. The effect of interface energetics, e.g.…”