The Role of Wear in the Initiation of Thermoelastic Instabilities of Rubbing Contact

1973 ◽  
Vol 95 (1) ◽  
pp. 71-75 ◽  
Author(s):  
T. A. Dow ◽  
R. A. Burton
Keyword(s):  
Thermal Expansion ◽  
Contact Pressure ◽  
Material Properties ◽  
Frictional Heating ◽  
Oscillatory Behavior ◽  
Two Dimensional ◽  
Infinite Body ◽  
Operating Variables ◽  
Uniform Value

Thermoelastic instability of rubbing contact results from the interaction of thermal expansion, frictional heating, and conduction of heat away from the contact zone. These interactions are modified by wear, which is shown to damp the growth of disturbances in contact pressure from a nominal uniform value. In some cases the presence of wear is found to give rise to oscillatory behavior where portions of the rubbing surfaces alternately rise and drop in temperature. These effects are analyzed for the case of a two-dimensional scraper or blade moving normal to its edge, which presses against the surface of a stationary semi-infinite body. The roles of material properties and operating variables are delineated in terms of dimensionless parameters appropriate to the system.

Thermoelastic Effects in Frictionally Heated Line Contact of Slablike Bodies

1978 ◽  
Vol 100 (1) ◽  
pp. 136-141 ◽  
Author(s):  
S. R. Heckmann ◽  
R. A. Burton
Keyword(s):  
Thermal Expansion ◽  
Elastic Deformation ◽  
Elevated Temperatures ◽  
Frictional Heating ◽  
Line Contact ◽  
Two Dimensional ◽  
Sliding Speed ◽  
Thermoelastic Effects ◽  
Dimensional Models ◽  
Realistic Geometry

Many sealing configurations incorporate the geometry of line contact on bluff, slablike bodies. When sliding speed is sufficiently high along or across the line of contact, instabilities may arise from interactions of thermal expansion, elastic deformation and frictional heating. These lead to concentrated contact with elevated temperatures and pressures. Previous studies have been largely restricted to two-dimensional models of such contact. The present study shows how those earlier results must be modified to apply to the more realistic geometry, and show also that the principal features of the interactions are the same in both geometries.

scholarly journals Effect of Material Properties in Certain Thermoelastic Contact Problems

1998 ◽  
Vol 65 (4) ◽  
pp. 889-893 ◽  
Author(s):  
D. Joachim-Ajao ◽  
J. R. Barber
Keyword(s):  
Contact Area ◽  
Material Properties ◽  
Frictional Heating ◽  
Contact Problems ◽  
Plane Boundary ◽  
Two Dimensional ◽  
Sliding Speed ◽  
Transient Problems ◽  
Contact Loads ◽  
Single Material

When two conforming bodies slide against each other, frictional heating and thermoelastic distortion generally causes the contacting surfaces to become convex and hence leads to a reduction in the size of the contact area. It is shown that, under such circumstances, the contact area is independent of the applied contact loads and the thermal and mechanical fields are linearly proportional to these loads. For two-dimensional problems involving a plane boundary, it is shown that there is a reduced dependence on material properties and in the case of a single material, the solution depends only on a single parameter which can be interpreted as a dimensionless sliding speed. These results extend to both steady-state and transient problems and therefore also characterize the critical sliding speed above which the system is unstable.

Role of Material Properties in the Finite Element Solution for Three-Dimensional Composites—A Sensitivity Study

1995 ◽  
Vol 209 (2) ◽  
pp. 157-160
Author(s):  
H-B Hellweg ◽  
M A Crisfield
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Material Properties ◽  
Three Dimensional ◽  
Transversely Isotropic ◽  
Sensitivity Study ◽  
Two Dimensional ◽  
Element Analysis ◽  
The Impact

Three-dimensional material test data for orthotropic laminae are difficult to obtain. Consequently, various simplifications are made for the material properties of individual layers in a finite element analysis, ranging from the assumption of transversely isotropic layers to applying two-dimensional material data in a three-dimensional analysis. In order to investigate the impact and validity of such simplifications, the sensitivity of the stresses and deformations in a finite element analysis on the material properties was investigated.

The role of gas flow distributions on CO2 mineralization within monolithic cemented composites: coupled CFD-factorial design approach

2021 ◽  
Author(s):  
Iman Mehdipour ◽  
Gabriel Falzone ◽  
Dale Prentice ◽  
Narayanan Neithalath ◽  
Dante Simonetti ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Factorial Design ◽  
Material Properties ◽  
Gas Flow ◽  
Design Approach ◽  
Processing Conditions ◽  
Gas Processing ◽  
Co2 Mineralization

Optimizing the spatial distribution of contacting gas and the gas processing conditions enhances CO2 mineralization reactions and material properties of carbonate-cementitious monoliths.

Magnetoelastic coupling, negative thermal expansion, and two-dimensional magnetic excitations in FeAs

2021 ◽  
Vol 103 (9) ◽  
Author(s):  
J. L. Niedziela ◽  
L. D. Sanjeewa ◽  
A. A. Podlesnyak ◽  
L. DeBeer-Schmitt ◽  
S. J. Kuhn ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Negative Thermal Expansion ◽  
Two Dimensional ◽  
Magnetic Excitations ◽  
Magnetoelastic Coupling

scholarly journals A methodology for hygrothermal modelling of imperfect masonry interfaces

2021 ◽  
pp. 174425912198938
Author(s):  
Michael Gutland ◽  
Scott Bucking ◽  
Mario Santana Quintero
Keyword(s):  
Boundary Conditions ◽  
Material Properties ◽  
Structural Integrity ◽  
Bulk Material ◽  
Weather Conditions ◽  
Masonry Wall ◽  
Two Dimensional ◽  
Liquid Transport ◽  
Imperfect Contact ◽  
Moisture Contents

Hygrothermal models are important tools for assessing the risk of moisture-related decay mechanisms which can compromise structural integrity, loss of architectural features and material. There are several sources of uncertainty when modelling masonry, related to material properties, boundary conditions, quality of construction and two-dimensional interactions between mortar and unit. This paper examines the uncertainty at the mortar-unit interface with imperfections such as hairline cracks or imperfect contact conditions. These imperfections will alter the rate of liquid transport into and out of the wall and impede the liquid transport between mortar and masonry unit. This means that the effective liquid transport of the wall system will be different then if only properties of the bulk material were modelled. A detailed methodology for modelling this interface as a fracture is presented including definition of material properties for the fracture. The modelling methodology considers the combined effect of both the interface resistance across the mortar-unit interface and increase liquid transport in parallel to the interface, and is generalisable to various combinations of materials, geometries and fracture apertures. Two-dimensional DELPHIN models of a clay brick/cement-mortar masonry wall were created to simulate this interaction. The models were exposed to different boundary conditions to simulate wetting, drying and natural cyclic weather conditions. The results of these simulations were compared to a baseline model where the fracture model was not included. The presence of fractures increased the rate of absorption in the wetting phase and an increased rate of desorption in the drying phase. Under cyclic conditions, the result was higher peak moisture contents after rain events compared to baseline and lower moisture contents after long periods of drying. This demonstrated that detailed modelling of imperfections at the mortar-unit interface can have a definitive influence on results and conclusions from hygrothermal simulations.

scholarly journals Role of fluctuations in the yielding transition of two-dimensional glasses

2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Misaki Ozawa ◽  
Ludovic Berthier ◽  
Giulio Biroli ◽  
Gilles Tarjus
Keyword(s):  
Two Dimensional
Sign in / Sign up

Export Citation Format

Share Document