The Nonstationary Contact Problem of Thermoelasticity for a Ring in the Presence of a Reinforcing Layer on the Friction Surface

2019 ◽  
pp. 447-455
Author(s):  
V. I. Kolesnikov ◽  
M. I. Chebakov ◽  
S. A. Danilchenko
Keyword(s):  
Contact Problem ◽  
Friction Surface ◽  
Reinforcing Layer

A Thermal, Thermoelastic, and Wear Simulation of a High-Energy Sliding Contact Problem

1974 ◽  
Vol 96 (3) ◽  
pp. 497-505 ◽  
Author(s):  
F. E. Kennedy ◽  
F. F. Ling
Keyword(s):  
Contact Problem ◽  
Friction Surface ◽  
Thermomechanical Analysis ◽  
High Energy ◽  
Sliding Contact ◽  
Transient Temperature ◽  
Wear Rates ◽  
Disk Brake ◽  
Transient Temperature Distribution ◽  
Disk Brakes

This paper describes an investigation of the sliding contact problem encountered in high-energy disk brakes. The analysis includes a simulation modeling, using the finite element method, of the thermoelastic instabilities that cause transient changes in contact to occur on the friction surface. In order to include the effect of wear of the concentrated contacts on the friction surface, a wear criterion is proposed that results in prediction of wear rates for disk brakes that are quite close to experimentally determined wear rates. The thermal analysis shows that the transient temperature distribution in a disk brake can be determined more accurately by use of this thermomechanical analysis than by a more conventional analysis that assumes constant contact conditions. It is also shown that lower, more desirable, temperatures in disk brakes can be attained by increasing the volume, the thermal conductivity, and especially, the heat capacity of the brake components.

To the issue of application of thermoplastic reinforced pipes for the construction of oil and gas pipelines in the Arctic

2020 ◽  
pp. 88-99
Author(s):  
A. A. Tolmachev ◽  
V. A. Ivanov ◽  
T. G. Ponomareva
Keyword(s):  
Oil And Gas ◽  
The Arctic ◽  
Labor Costs ◽  
Hydrocarbon Production ◽  
Environmental Disasters ◽  
The North ◽  
Reinforcing Fibers ◽  
Wear And Tear ◽  
Oil And Gas Companies ◽  
Reinforcing Layer

Ensuring the safety of oil and gas facilities and increasing their facility life are today one of the most important tasks. Emergencies related to rupture and damage of steel pipelines because of their wear and tear and external factors are still the most frequent cases of emergencies during the transportation of hydrocarbons. To expand the fuel and energy complex in the north, in the direction of the Arctic, alternative types of pipelines are needed that solve the problems of reducing energy and labor costs in oil and gas companies, reducing the risk of environmental disasters and depressurization of pipelines during hydrocarbon production. Fiber-reinforced thermoplastic pipes can be such an alternative. This article is devoted to a comparative analysis of the materials of a composite system consisting of a thermoplastic pipe (inner layer) and reinforcing fibers (outer layer); we are discussing the design of the structural system consisting of polyethylene (inner layer) and aramid fibers (outer reinforcing layer).

A method for evaluating the edge strength of soil-cutting parts of forestry machines

2020 ◽  
Vol 67 (1) ◽  
pp. 111-115
Author(s):  
Sergey A. Voynash ◽  
Viktoriya A. Sokolova ◽  
Viktor I. Kretinin ◽  
Viktor A. Markov ◽  
Elena A. Alekseeva Alekseeva ◽  
...  
Keyword(s):  
Fatigue Failure ◽  
Research Purpose ◽  
Solid Inclusion ◽  
Hard Alloys ◽  
Blade Edge ◽  
Solid Soil ◽  
Soil Cutting ◽  
Cyclic Impact ◽  
Working Bodies ◽  
Reinforcing Layer

One of the main factors that determine the resistance of blade working bodies against damage under dynamic loads is their resistance to plastic crumpling, brittle or fatigue failure. Hard alloys that strengthen the blades of tillage parts are more brittle materials than steel, so the blunting of their edges is caused by the formation of cracks, their gradual growth or microchipping, even from a possible single impact of a solid inclusion in the soil. In addition to the usual brittle fracture of hard alloys, fatigue failure occurs under cyclic impact conditions. (Research purpose) The research purpose is in identifying the pattern of destruction of the blade edge of soil-cutting parts of forestry machines and theoretically justifying the algorithm for assessing the strength to determine the rational thickness of the wear-resistant coating during hardening. (Materials and methods) The article presents the main regularities of the influence of material properties and geometric parameters of the blade on the radius of rounding. (Results and discussion) The process of breaking the edge of the blade of hardened working bodies of forestry machines has been studied. The claim that the blunting of the blades is mainly due to its destruction and not to wear has been proved. The article presents a method for evaluating the strength of bimetallic blades of soil-cutting parts of forestry machines. It was found that the blunting of the blade occurs as a result of edge destruction in the process of multiple impacts of solid soil inclusions along the edge of the blade. (Conclusions) The article shows that the destruction of the edge of the blade leads to blunting of soil-cutting parts, which affects their performance. It was found that the sharpness of a self-sharpening hardened blade is determined by the thickness of the reinforcing layer and its ability to resist destruction under impact.

scholarly journals The Indentation Rolling Resistance in Belt Conveyors: A Model for the Viscoelastic Friction

Lubricants ◽  
2019 ◽  
Vol 7 (7) ◽  
pp. 58 ◽  
Author(s):  
Nicola Menga ◽  
Francesco Bottiglione ◽  
Giuseppe Carbone
Keyword(s):  
Contact Problem ◽  
Finite Thickness ◽  
Numerical Procedure ◽  
Contact Problems ◽  
Accurate Solution ◽  
Rolling Contact ◽  
Viscoelastic Layer ◽  
Force Coefficient ◽  
Belt Conveyors ◽  
Energy Dissipated

In this paper, we study the steady-state rolling contact of a linear viscoelastic layer of finite thickness and a rigid indenter made of a periodic array of equally spaced rigid cylinders. The viscoelastic contact model is derived by means of Green’s function approach, which allows solving the contact problem with the sliding velocity as a control parameter. The contact problem is solved by means of an accurate numerical procedure developed for general two-dimensional contact geometries. The effect of geometrical quantities (layer thickness, cylinders radii, and cylinders spacing), material properties (viscoelastic moduli, relaxation time) and operative conditions (load, velocity) are all investigated. Physical quantities typical of contact problems (contact areas, deformed profiles, etc.) are calculated and discussed. Special emphasis is dedicated to the viscoelastic friction force coefficient and to the energy dissipated per unit time. The discussion is focused on the role played by the deformation localized at the contact spots and the one in the bulk of the thin layer, due to layer bending. The model is proposed as an accurate solution for engineering applications such as belt conveyors, in which the energy dissipated on the rolling contact of idle rollers can, in some cases, be by far the most important contribution to their energy consumption.

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