Comparison of Double-Shearing and Coaxial Models for Pressure-Dependent Plastic Flow at Frictional Boundaries

2003 ◽  
Vol 70 (2) ◽  
pp. 212-219 ◽  
Author(s):  
S. Alexandrov
Keyword(s):  
Channel Flow ◽  
Friction Surface ◽  
Qualitative Difference ◽  
Strain Rate Tensor ◽  
Parallel Plates ◽  
Maximum Friction ◽  
Classical Plasticity ◽  
Pressure Independent ◽  
Pressure Dependent Plasticity ◽  
Friction Surfaces

The qualitative difference in solution behavior in the vicinity of maximum friction surfaces is demonstrated for two distinct models of pressure-dependent plasticity (the double-shearing and coaxial models) using closed-form solutions for planar flow through an infinite wedge-shaped channel and plane-strain compression of an infinite block between parallel plates. Singular velocity fields (some components of the strain rate tensor approach infinity at the friction surface) occur in the solutions based on the double-shearing model. This is similar to behavior in the vicinity of maximum friction surfaces in classical plasticity of pressure-independent materials. A singular velocity field is also obtained in the solution based on the coaxial model for the problem of channel flow; but, in contrast to the double-shearing model and classical plasticity, sticking must occur at this friction surface. For the problem of compression of a material obeying the coaxial model, no solution based on conventional assumptions exists with the maximum friction law. This is quite different from both the corresponding solution based on the double-shearing model and the channel flow solution based on the coaxial model.

Investigation of the formation of friction surface microgeometry of a wear-resistant coating during friction with a metal counterbody

2021 ◽  
pp. 147-152
Author(s):  
N.F. Struchkov ◽  
G.G. Vinokurov ◽  
O.N. Popov
Keyword(s):  
Statistical Model ◽  
Binomial Distribution ◽  
Friction Surface ◽  
Sliding Friction ◽  
Wear Particles ◽  
Wear Resistant ◽  
Wear Resistant Coatings ◽  
Frictional Interaction ◽  
Surface Microgeometry ◽  
Friction Surfaces

Were is researched the friction surfaces of wear-resistant coatings with modifying additives Al2O3 and metal counterbody made of ShH15 steel, and also reveals the factors that influence the formation of coating microgeometry of surface during sliding friction. A statistical model has been developed based on the binomial distribution of removed wear particles to describe the frictional interaction during friction of the coating with a metal counterbody.

In situ monitoring of friction surfaces and their sequence pattern analysis

2007 ◽  
Vol 366 (1865) ◽  
pp. 665-671 ◽  
Author(s):  
S Kano ◽  
H Homma ◽  
S Sasaki ◽  
H Shimura
Keyword(s):  
Laser Pulse ◽  
Friction Surface ◽  
Optical Microscope ◽  
Carbon Steels ◽  
In Situ Monitoring ◽  
Plate Motion ◽  
Surface Pattern ◽  
Size And Shape ◽  
Motion Speed ◽  
Friction Surfaces

Friction occurs between solid surfaces, and even sometimes on lubricated surfaces. To understand tribological subjects, it is important to know the changes that occur in friction surfaces. In this study, a laser strobe technique is applied to a friction surface observation. The recorded surface images were analysed using pattern-matching methods and their correlations are discussed. A test using pin-on-plate methods with carbon steels was performed using a reciprocating motion speed of 10 Hz for 4.9 N. A pulsed laser light (Nd:YAG SHG=532 nm, 5 ns per pulse) was irradiated onto the friction surface. It was induced using an optical microscope that was located just to the side of the pin. The laser pulse was synchronized with the plate motion, which was a trigger of the laser pulse. The surface image was stored for every cycle. These sequences were calculated and their correlations were analysed as a function of the surface pattern and the friction track size and shape. Analysis revealed that some groups were distinguishable as parameters of the damage size and shape.

scholarly journals FEM Analysis of Dynamic Soil-Pile-Structure Interaction in Liquefied and Laterally Spreading Ground

2013 ◽  
Vol 29 (3) ◽  
pp. 733-755 ◽  
Author(s):  
Dongdong Chang ◽  
Ross Boulanger ◽  
Scott Brandenberg ◽  
Bruce Kutter
Keyword(s):  
Fem Analysis ◽  
Pile Group ◽  
Fe Model ◽  
Plasticity Model ◽  
Dense Sand ◽  
Structure Interaction ◽  
Centrifuge Tests ◽  
Centrifuge Models ◽  
Pressure Independent ◽  
Pressure Dependent Plasticity

A two-dimensional nonlinear dynamic finite element (FE) model was developed and calibrated against dynamic centrifuge tests to study the behavior of soil-pile-structure systems in liquefied and laterally spreading ground during earthquakes. The centrifuge models included a simple structure supported on pile group. The soil profiles consisted of a gently sloping clay crust over liquefiable sand over dense sand. The FE model used an effective stress pressure dependent plasticity model for liquefiable soil and a total stress pressure independent plasticity model for clay, beam column elements for piles and structure, and interface springs that couple with the soil mesh for soil-structure interaction. The FE model was evaluated against recorded data for eight cases with same set of baseline parameters. Comparisons between analyses and experiments showed that the FE model was able to approximate the soil and structural responses and reproduce the lateral loads and bending moments on the piles reasonably well.

A Micro-Channel Flow and Heat Transfer Study by Lattice Boltzmann Method

2003 ◽  
Author(s):  
Ru Yang ◽  
Chin-Sheng Wang
Keyword(s):  
Heat Transfer ◽  
Lattice Boltzmann Method ◽  
Channel Flow ◽  
Lattice Boltzmann ◽  
Slip Flow ◽  
Navier Stokes ◽  
Micro Channel ◽  
Parallel Plates ◽  
Boltzmann Method ◽  
Good Agreement

A Lattice Boltzmann method is employed to investigate the flow characteristics and the heat transfer phenomenon between two parallel plates separated by a micro-gap. A nine-velocity model and an internal energy distribution model are used to obtain the mass, momentum and temperature distributions. It is shown that for small Knudsen numbers (Kn), the current results are in good agreement with those obtained from the traditional Navier-Stokes equation with non-slip boundary conditions. As the value of Kn is increased, it is found that the non-slip condition may no longer be valid at the wall boundary and that the flow behavior changes to one of slip-flow. In slip flow regime, the present results is still in good agreement with slip-flow solution by Navier Stokes equations. The non-linear nature of the pressure and friction distribution for micro-channel flow is gieven. Finally, the current investigation presents a prediction of the temperature distribution for micro-channel flow under the imposed conditions of an isothermal boundary.

scholarly journals Technological support of selective transfer on friction surface

2021 ◽  
Vol 2021 (5) ◽  
pp. 35-39
Author(s):  
Viktor Hohlov
Keyword(s):  
Friction Surface ◽  
Selective Transfer ◽  
Roughness Parameters ◽  
Processing Methods ◽  
Technological Support ◽  
Friction Surfaces

Dependences for the computation of roughness parameters and their technological support essential for selective transfer on friction surfaces are offered. Processing methods which should be used for their fulfillment are shown.

Technology of sliding friction surface machining based on hard wear-resistant coating use taking into account technological inheritance impact

2020 ◽  
Vol 2020 (12) ◽  
pp. 31-38
Author(s):  
Tatiana Mihalenko
Keyword(s):  
Wear Resistance ◽  
Friction Surface ◽  
Sliding Friction ◽  
Quality Parameters ◽  
Surface Machining ◽  
Technological Support ◽  
Coating Application ◽  
Technological Inheritance ◽  
Theoretical Investigations ◽  
Friction Surfaces

The matters of technological support of wear-resistance for sliding friction surfaces are considered. The results of experimental theoretical investigations of modes impact of preliminary machining, coating application and sliding friction surfaces finishing upon their quality parameters are shown.

Sign in / Sign up

Export Citation Format

Share Document