Existence, Energy Identity, and Higher Time Regularity of Solutions to a Dynamic Viscoelastic Cohesive Interface Model

The peeling behavior of a thin film bonded to a substrate is investigated by using the cohesive interface model. We compare the peeling processes of film/substrate interfaces with three different geometric shapes, including a flat interface, a curved interface of sinusoidal shape, and a wavy interface with two-level sinusoidal hierarchy. The effect of the peeling angle on the maximal peeling strength is also examined. It is demonstrated that the peeling strength can be significantly improved by introducing a hierarchical wavy morphology at the film/substrate interface. This study may be helpful for the design of film/substrate systems with enhanced mechanical properties.

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A note on traction continuity across an interface in a geometrically non-linear framework

Mathematics and Mechanics of Solids ◽

10.1177/1081286518766980 ◽

2018 ◽

Vol 24 (8) ◽

pp. 2478-2496 ◽

Cited By ~ 3

Author(s):

Ali Javili

Keyword(s):

Spatial Configuration ◽

Three Dimensional ◽

Interface Model ◽

Cohesive Interface ◽

Interface Models ◽

Linear Framework ◽

Non Linear ◽

Spatial Configurations ◽

Elastic Interface ◽

General Interface

The objective of this contribution is to elaborate on the notion of “traction continuity” across an interface at finite deformations. The term interface corresponds to a zero-thickness model representing the interphase between different constituents in a material. Commonly accepted interface models are the cohesive interface model and the elastic interface model. Both the cohesive and elastic interface models are the limit cases of a generalized interface model. This contribution aims to rigorously analyze the concept of the traction jump for the general interface model. The governing equations of the general interface model in the material as well as spatial configurations are derived and the traction jump across the interface for each configuration is highlighted. It is clearly shown that the elastic interface model undergoes a traction jump in both the material and spatial configurations according to a generalized Young–Laplace equation. For the cohesive interface model, however, while the traction field remains continuous in the material configuration, it can suffer a jump in the spatial configuration. This finding is particularly important since the cohesive interface model is based on the assumption of traction continuity across the interface and that the term “traction” often refers to the spatial configuration and not the material one. Thus, additional care should be taken when formulating an interface model in a geometrically non-linear framework. The theoretical findings for various interface models are carefully illustrated via a series of two-dimensional and three-dimensional numerical examples using the finite element method.

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Parametric Studies of Nonlinear Damping Behavior of APS Thermal Barrier Coatings Based on Cohesive Interface Model

Volume 7: Structures and Dynamics, Parts A and B ◽

10.1115/gt2012-69343 ◽

2012 ◽

Author(s):

Yong Chen ◽

Wei Dong

Keyword(s):

Thermal Barrier Coatings ◽

Turbine Blades ◽

Ceramic Coatings ◽

Nonlinear Damping ◽

Contact Friction ◽

Thermal Barrier ◽

Interface Model ◽

Damping Properties ◽

Barrier Coatings ◽

Cohesive Interface

Thermal barrier coatings (TBCs) could reduce the temperature of the turbine blades and allow them working at higher temperatures, which leads to higher durability and reliability of turbine blades, and improves engine performance and fuel efficiency. Recent researches shown that thermal barrier coatings have very good damping properties, which means it could also improve the high cycle fatigue (HCF) life of the turbine blades. Previous studies found that damping of air plasma spray (APS) thermal barrier coatings exhibit non-linearities (amplitude-dependent) due to its microstructures, which consists of several layers of splats with inter- and intra-microstructural micro-cracks. The main purpose of this paper is on the application of a bilinear cohesive interface model to simulate the microstructural features, the damage process and the contact friction between the interfaces of microstructural faults in APS ceramic topcoat. A representative volume element (RVE) model which coupled with the cohesive interface model is built and parametric relations, in terms of interface strength and stiffness, vibration amplitude and vibration cycles, are computed in this paper for understanding the effect of interfacial degradation, de-bonding, sliding, and contact friction between the interfaces of microstructural faults on the nonlinear damping properties. The calculation results could provide a fundamental understanding of the mechanisms responsible for the observed nonlinear energy dissipation and damping properties in APS ceramic coatings.

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