Frictional Contact Interface Research Articles

Analytical Formulation of Friction Interface Elements for Analysis of Nonlinear Multi-Harmonic Vibrations of Bladed Disks

An analytical formulation for the vectors of contact forces and the stiffness matrix of the nonlinear friction contact interface is developed for the analysis of multi-harmonic vibrations in the frequency domain. The contact interface elements provided here an exact description of friction and unilateral contact forces at the interacting surfaces, taking into account the influence of the variable normal load on the friction forces, including the extreme cases of separation of the two surfaces. Initial gaps and interferences at the contact nodes, which affect the normal force, as well as the unilateral action of the normal force at the contact surface, are all included in the model. The accurate calculation of the force vector and the tangent stiffness matrix provides a very reliable and fast convergence of the iteration process used in the search for the amplitudes of nonlinear vibrations of bladed disks. Numerical investigations demonstrate excellent performance with respect to speed, accuracy and stability of computation.

Transient scattering of SH waves from an inclusion with a unilateral frictional interface—a 2D time domain boundary element analysis

AbstractThis paper develops a 2D time domain boundary element method (BEM) to solve the transient SH‐wave scattering from an inclusion with a unilateral frictional interface. The incident SH‐wave is assumed strong enough to break friction so that localized slip takes place along the interface. The present problem is indeed a non‐linear boundary value problem since the mixed boundary conditions involve unknown intervals (the slip and stick zones). In order to determine the intervals, an iterative technique is developed. As an example, we consider the scattering of a circular cylinder embedded in an infinite solid. The numerical results of the interface traction and relative slip velocity are presented. Copyright © 2003 John Wiley & Sons, Ltd.

Transmission of elastic waves through a frictional contact interface between two anisotropic dissimilar media

The paper analyzes the reflection and refraction of elastic waves at a frictional contact interface between two anisotropic solids which are pressed together and at the same time loaded by the in-plane and anti-plane shearing tractions. Coulomb friction is supposed along the contact interface. The incident wave is assumed strong enough to break friction so that localized separation and slip occur, and therefore a global sliding may take place between the two solids. Using Fourier analysis, we manage to reduce the problem to a set of algebraic equations. An iterative procedure is developed to determine the slip, stick and separation zones. Numerical results of the interface tractions, the slip velocities, the global sliding velocities and the reflection/refraction coefficients are presented for a particular material combination. The harmonic generation due to boundary non-linearity and the coupling of the in-plane and anti-plane wave motions are discussed. The analysis is limited to the sub-critical angle incidence.

微小すべりを有する摩擦接触界面端部の応力特異性

Frictional contact interface edge appears in the fretting pair of a mechanical structure, and reduces its fatigue life. Due to the frictional force on the contact interface, the singular behavior at the edge is different from that of a bonded wedge, and is also different from that obtained by Hertz theory for elastic contact problems. In this paper, the singular stress field at a frictional contact interface edge is deduced theoretically. Based on the eigenequation which determines the singular order, the optimum geometry of the contact pad is discussed. Numerical analysis by using the boundary element method is also carried out to verify the theoretical results. It is found that the singularity depends not only on the material combination and the geometry shape of the frictional interface edge, but also on the coefficient of friction. Moreover, the singularity can be even stronger than 1/√r.

Transient dynamic analysis in layered structures with unilateral interfaces

Restricted accessMoreSectionsView PDF ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InRedditEmail Cite this article Stavroulakis Georgios E. and Antes Heinz 2001Transient dynamic analysis in layered structures with unilateral interfacesPhil. Trans. R. Soc. A.3592541–2555http://doi.org/10.1098/rsta.2001.0907SectionRestricted accessTransient dynamic analysis in layered structures with unilateral interfaces Georgios E. Stavroulakis Georgios E. Stavroulakis Carolo Wilhelmina Technical University, Institute of Applied Mechanics, Spielmannstr. 11, D-38106 Braunschweig, Germany Google Scholar Find this author on PubMed Search for more papers by this author and Heinz Antes Heinz Antes Carolo Wilhelmina Technical University, Institute of Applied Mechanics, Spielmannstr. 11, D-38106 Braunschweig, Germany Google Scholar Find this author on PubMed Search for more papers by this author Georgios E. Stavroulakis Georgios E. Stavroulakis Carolo Wilhelmina Technical University, Institute of Applied Mechanics, Spielmannstr. 11, D-38106 Braunschweig, Germany Google Scholar Find this author on PubMed Search for more papers by this author and Heinz Antes Heinz Antes Carolo Wilhelmina Technical University, Institute of Applied Mechanics, Spielmannstr. 11, D-38106 Braunschweig, Germany Google Scholar Find this author on PubMed Search for more papers by this author Published:15 December 2001https://doi.org/10.1098/rsta.2001.0907AbstractHighly nonlinear, unilateral effects on interfaces are accurately modelled within the framework of non–smooth mechanics. Unilateral contact and friction interactions are prototypes of the above–mentioned effects. Like all boundary–only nonlinearities, unilateral interfaces are most suitable candidates for the application of boundary–element techniques. Another, possibly more significant, reason for using this approach is the high accuracy of approximation for both boundary displacements and boundary tractions which is attained. Typical cases of unilateral interfaces are studied in this paper by the boundaryelement method. Among them, a unilateral contact interface which leads to LCPBEM (linear complementarity problem–boundary–element method) problems related to variational inequalities, a frictional contact interface which leads to ICP–BEM (implicit complementarity problem–boundary–element method) problems related to implicit variational inequalities, or quasi–variational inequalities and an adhesive interface which leads to CP–BEM (critical–point–boundary–element method) problems related to hemi–variational inequalities. Appropriate extensions and relevant theoretical questions are briefly discussed in a short appendix. Previous ArticleNext Article VIEW FULL TEXT DOWNLOAD PDF FiguresRelatedReferencesDetailsCited by Koutsianitis P, Tairidis G, Drosopoulos G, Foutsitzi G and Stavroulakis G (2016) Effectiveness of optimized fuzzy controllers on partially delaminated piezocomposites, Acta Mechanica, 10.1007/s00707-016-1771-6, 228:4, (1373-1392), Online publication date: 1-Apr-2017. This Issue15 December 2001Volume 359Issue 1789Theme Issue ‘Non-smooth mechanics’ compiled by F. G. Pfeiffer Article InformationDOI:https://doi.org/10.1098/rsta.2001.0907Published by:Royal SocietyPrint ISSN:1364-503XOnline ISSN:1471-2962History: Published online15/12/2001Published in print15/12/2001 License: Citations and impact Keywordscomplementarity problemswave propagationdynamic analysisnon-smooth mechanicsboundary elements

Anti-plane motion induced by a P or SV pulse at a frictional contact interface

Anti-plane motion induced by a P or SV pulse at a frictional contact interface

Re-polarization of elastic waves at a frictional contact interface—II. Incidence of a P or SV wave

This is Part II of a two-part paper which analyses the re-polarization of elastic waves at a frictional contact interface between two solids. The re-polarization of SH waves was solved in Part I by the use of the Fourier analysis. Here, in Part II, we consider the re-polarization of P or SV waves. It is assumed that the two solids are pressed together and, at the same time, loaded by anti-plane and in-plane shearing traction. If the incident wave is sufficiently strong, localized separation and slip may take place at the interface. As a result, the incident in-plane wave is re-polarized at the interface so that the anti-plane waves (SH waves) are induced. Using the method similar to that of Part I and considering the boundary conditions involving separation and slip, we manage to reduce the problem to a set of algebraic equations coupled with simple integral equations. An iterative method is developed based on the solution to the perfectly bonded interface. The locations and sizes of the separation and slip zones, the interface traction, the slip velocities, the global sliding velocities and the energy dissipation and partition are displayed for the case of two identical materials. It is found that the separation zones and the gaps are independent of the induced waves.

Propagation ofSHwaves in a layered half-space with a frictional contact interface

AbstractThe propagation of SH waves in a layered half-space with a frictional contact interface is considered. The incident wave is assumed to be sufficiently strong so that friction may be broken, and the local slip may take place at the interface. In the stick zones, both the displacements and stresses are continuous, while in the slip zones, the Coulomb friction model is adopted. The mixed boundary conditions lead to recurrence relations for the subcritical angle incidence or singular integral equations for the supercritical angle incidence. The extent and location of slip zones, which are unknown before the solution of the problem, are determined. The local slip velocities and the interface shearing tractions are calculated in detail for the subcritical angle incidence. The results show that the solution of the problem is dependent on the frequency of the incident wave due to the presence of the characteristic length—the thickness of the elastic layer. It is also found that, in some situations, there exist four slip zones instead of two over one representative period. All these features are quite different from those for infinite media.

Re-polarization of elastic waves at a frictional contact interface—I. incidence of an SH wave

This paper examines the interaction of an incident SH wave with a frictional contact interface between two solids which are pressed together. The incident wave is assumed strong enough to break friction so that localized slip takes place. It is also assumed that the solids are loaded by both anti-plane and in-plane shearing tractions which lead to a global sliding motion. An important and interesting phenomenon is that the incident SH wave is re-polarized at the interface so that the in-plane waves are induced because of the existence of the in-plane shearing traction. The present problem is indeed a nonlinear boundary value problem since the mixed boundary conditions involve unknown intervals (the slip and stick zones). Using Fourier analysis, we manage to reduce the problem to a set of algebraic equations coupled with simple integral equations. An iterative procedure is developed based on the solution to the welded interface. The locations and sizes of the slip zones, the interface shearing tractions, the slip velocities, the global sliding velocity and the energy dissipation and partition are displayed for the case of two identical materials. The present analysis is limited to the sub-critical angle incidence.

In-plane motion induced by an SH pulse at a frictional contact interface

In-plane motion induced by an SH pulse at a frictional contact interface

Heat extraction through a geothermal reservoir on an oblique fault plane

AbstractThe heat extraction through a geothermal reservoir on an oblique fault plane in the earth's crust is considered. The fault could be modelled mechanically as a frictional contact interface of two elastic bodies. The heat is recovered by circulating fluid through the reservoir, and then the surface of the reservoir is cooled by the fluid. The analysis is based on the two‐dimensional theory of quasi‐static thermoelasticity. It is concluded from numerical calculations that a geothermal reservoir can be created on an oblique fault plane, and the opened region, i.e. the fluid‐filled region, increases gradually with time during the heat extraction. Also discussed are the effects of the fluid pressure and the coefficient of friction on the behaviour of the reservoir.

A simple contact–friction interface element with applications to buried culverts

AbstractA simple friction–contact interface element is introduced which simulates frictional slippage, separation, and re‐bonding of two bodies initially mating at a common interface and subsequently deforming with an arbitrary static loading schedule. Constraint equations between initially mating node pairs and the general principle of virtual work are used to formulate the interface element for a finite element solution procedure. Some advantages of the interface element include; easy implementation intostandard finite element programs, direct determination of interface forces without round‐off problems, and the generality afforded by the virtual work formulation to include other non‐conservative models in the system.The application of the interface element to an idealized buried culvert problem illustrates that the model behaves properly. A second application, for a long‐span culvert installation with incremental soil loading, demonstrates the importance of modelling slippage at the culvert–soil interface in order to conform with experimental observations.

Energy relations for SH waves interacting with a frictional contact interface

The paper considers the partition of energy when an incident SH wave is reflected and refracted by a fricitonal contact interface that slips. The effect of applied shear tractions which cause a slow creeping motion is included in the analysis.