On the Multiphysics Modeling of the Sliding Wear Between Deformable Heat Conducting Bodies

2018 ◽  
Author(s):  
John G. Michopoulos ◽  
Athanasios P. Iliopoulos ◽  
John C. Steuben ◽  
Andrew J. Birnbaum
Keyword(s):  
Dissimilar Materials ◽  
Mass Conservation ◽  
Sliding Contact ◽  
Contact Pair ◽  
Heat Conducting ◽  
Arbitrary Lagrangian Eulerian ◽  
Efficient Manner ◽  
Conservation Of Energy ◽  
Tightly Coupled ◽  
Conducting Bodies

An approach exploiting the relevant conservation laws associated with the wear due to sliding between deformable heat conducting bodies is presented in this work. The proposed methodology considers a pair of wearing objects in contact where their wear behaviors are encapsulated by semantically reduced one-dimensional, time-dependent ordinary differential equations (ODEs) as a replacement to the full mass conservation PDEs governing mass loss due to the various mechanisms present at the interface. At the same time, the conservation of energy and momentum are still expressed by the full form of the PDEs representing them. To assess the feasibility of this approach a reciprocating sliding contact pair of dissimilar materials is considered. The high dimensional thermo-mechanical problem is solved simultaneously and tightly coupled with the two ODE wear models for each of the wear pair bodies, thus enabling predictions of wear for both of them. Furthermore, an Arbitrary-Lagrangian-Eulerian (ALE) approach has been used to produce the evolution of the wear fronts on both elements of the sliding contact pair through physics-informed mesh deformation consistent with the results computed in the previous step. The main advantage of this approach enables the usage of any low dimensional wear model (i.e, mechanical failure, phase transformation-based, etc.) in a computationally detailed and efficient manner.

Evolution of Sliding Contact Wear Between Deformable Conducting Bodies via a Multiphysics Framework

2020 ◽  
Vol 20 (5) ◽  
Author(s):  
John G. Michopoulos ◽  
Athanasios P. Iliopoulos ◽  
Nicole A. Apetre ◽  
John C. Steuben ◽  
Andrew J. Birnbaum
Keyword(s):  
Differential Equations ◽  
Wear Behavior ◽  
Sliding Contact ◽  
Thin Strip ◽  
Soda Lime Glass ◽  
Glass Layer ◽  
Heat Conducting ◽  
Arbitrary Lagrangian Eulerian ◽  
Conservation Of Energy ◽  
Conducting Bodies

Abstract A multiphysics computational framework is introduced and exercised to predict the wear behavior of two deformable, heat-conducting bodies under conditions of sliding contact. This framework enables the solution of a coupled system of partial differential equations (PDEs) expressing the conservation of energy and momentum along with two ordinary differential equations (ODEs) expressing mass conservation. This system is intended to capture wear evolution for each of the bodies forming a wear pair, in a self-consistent manner. Furthermore, an arbitrary-Lagrangian-Eulerian approach has been integrated to enable tracking the evolution of the wear fronts on both elements of the sliding contact pair through physics-informed mesh deformation. A theorem and a corollary are proved to indicate that most existing models describing wear that are expressed in the form of an ODE are actually manifestations of the law of conservation of mass. The framework is applied for two distinct slider-base pairs. The first involves an aluminum alloy slider and a copper alloy base. The second pair is identical to the first except it contains a thin strip of soda-lime glass embedded in the surface of the base. The effects of this glass layer on the wear of all participating bodies in comparison to the pair that does not contain this layer are presented. They indicate that while the glass layer has a wear mitigation effect for the stationary base it slightly increases the wear of the slider when compared with the respective bodies when the glass is not present.

On the Effect of Glassy Coatings on the Wear of a Sliding Contact via Multiphysics Modeling

2019 ◽  
Author(s):  
John G. Michopoulos ◽  
Athanasios P. Iliopoulos ◽  
John C. Steuben ◽  
Andrew J. Birnbaum ◽  
Nicole A. Apetre
Keyword(s):  
Wear Behavior ◽  
Soda Lime ◽  
Sliding Contact ◽  
Thin Strip ◽  
Soda Lime Glass ◽  
Glass Layer ◽  
Heat Conducting ◽  
Alloy Base ◽  
Tightly Coupled ◽  
Conducting Bodies

Abstract A recently developed multiphysics computational framework is exercised to predict the wear behavior of two deformable and heat conducting bodies under conditions of sliding contact. This framework enables the solution of a high dimensional thermo-mechanical problem simultaneously and tightly coupled with the associated wear evolution models for each of the wear pair bodies, thus enabling predictions of wear for both of them. Two distinct slider-base pairs are modeled. The first involves an aluminum alloy slider and a copper alloy base. The second is a pair identical to the first except it contains a thin strip of soda lime glass embedded in the surface of the base. The objective of this effort is to establish the effects of this glass layer on the wear of all participating bodies in comparison to the pair that does not contain this layer. The results indicate that while the glass layer has a wear mitigation effect for the stationary base it slightly increases the wear of the slider when compared with the respective bodies when the glass is not present.

scholarly journals Fundamental laws of nature confirmed by free fall

2021 ◽  
Author(s):  
Grit kalies
Keyword(s):  
Laws Of Nature ◽  
Free Fall ◽  
Mass Conservation ◽  
History Of Physics ◽  
Conservation Of Energy ◽  
History Of ◽  
Real Mass ◽  
Level I ◽  
First Time ◽  
Mass Increase

Abstract The principle of conservation of energy is often demonstrated by means of free fall. In mechanics, states of a body with potential and kinetic energy are energetically compared. Based on the mass concept of relativistic mechanics, energy conservation is considered to be linked with mass conservation. We show that the process of free fall can be interpreted more thoroughly, if the cause-effect principle and the mass concept of thermodynamics are applied. For the first time in the history of physics, the mechanism of energy conversion in free fall can be shown, which is valid for any object, whether body or elementary particle. The phenomenon of falling confirms the following facts to be valid of on a fundamental level: i) The principle of conservation of energy, ii) The equivalence of inertial and gravitational mass, iii) The real mass increase of any object with its velocity, and iv) The continuousness of space and time. At the end of the article we explain why the theory of general relativity is unsuitable to demonstrate the conservation of energy during free fall.

Thermal Effects Due to Surface Films in Sliding Contact

1994 ◽  
Vol 116 (2) ◽  
pp. 238-245 ◽  
Author(s):  
Brian Vick ◽  
L. P. Golan ◽  
M. J. Furey
Keyword(s):  
Thermal Properties ◽  
Temperature Rise ◽  
Thermal Effects ◽  
Three Dimensional ◽  
Sliding Contact ◽  
Frictional Heat ◽  
Solution Technique ◽  
Surface Films ◽  
Thermal Coupling ◽  
Efficient Manner

The present work examines theoretically the influence of surface coatings on the temperatures produced by friction due to sliding contact. A generalized thermal model is developed which incorporates three-dimensional, transient heat transfer between layered media with thermal coupling at multiple, interacting contact patches. A solution technique based on a variation of the boundary element method is developed and utilized. The method allows for the solution of the distribution of frictional heat and the resulting temperature rise in an accurate yet numerically efficient manner. Results are presented showing the influence of film thickness, thermal properties, velocity, and contact area on the division of heat and surface temperature rise. The results show that a film with thermal properties different than those of the substrate can have a pronounced effect on the predicted temperature rise.

scholarly journals Progressive Wave Simulation Using Stabilized Edge-Based Finite Element Methods

2009 ◽  
Author(s):  
Renato N. Elias ◽  
Milton A. Gonc¸alves ◽  
Alvaro L. G. A. Coutinho ◽  
Paulo T. T. Esperanc¸a ◽  
Marcos A. D. Martins ◽  
...  
Keyword(s):  
Finite Element ◽  
Mass Conservation ◽  
Element Formulation ◽  
Normal Velocity ◽  
Offshore Platforms ◽  
Arbitrary Lagrangian Eulerian ◽  
Progressive Wave ◽  
Parallel Edge ◽  
Two Fluids ◽  
Edge Based

Flows involving waves and free-surfaces occur in several problems in hydrodynamics, such as sloshing in tanks, waves breaking in ships and motions of offshore platforms. The computation of such wave problems is challenging since the water/air interface (or free-surface) commonly present merging, fragmentation and cusps, leading to the use of interface capturing Arbitrary Lagrangian-Eulerian (ALE) approaches. In such methods the interface between the two fluids is captured by the use of a marking function which is transported in a flow field. In this work we simulate these problems with a 3D incompressible SUPG/PSPG parallel edge-based finite element flow solver associated to the Volume-of-Fluid (VOF) method [1]. The hyperbolic equation for the transport of the marking function is also solved by a fully implicit parallel edge-based SUPG finite element formulation. Global mass conservation is enforced adding or removing mass proportionally to the absolute value of the normal velocity at the interface. The performance and accuracy of the proposed solution method is tested in the simulation of progressive waves and the interaction of a fixed cylinder with a progressive wave.

scholarly journals Analysis of solar energy technology in leading countries

2019 ◽  
Vol 10 (4) ◽  
pp. 1995
Author(s):  
Kannan Kaliappan ◽  
M Sankar ◽  
B Karthikeyan ◽  
Budamkayala Vineeth ◽  
V. Chetan Raju
Keyword(s):  
Solar Energy ◽  
Energy Demand ◽  
Human Life ◽  
Cost Effective ◽  
Vital Role ◽  
Photovoltaic Systems ◽  
Efficient Manner ◽  
Conservation Of Energy ◽  
Demand And Supply ◽  
Present Generation

In the present generation energy plays a vital role in our world and for human life it´s very important factor. There is a methodical meeting taking place regarding the conservation of energy and every time there is a review in the agenda. Energy demand and supply were endeavored by these countries. To rectify these problems, there should be more research in the generation of energy with the greater efficiency and try to use energy in more efficient manner. Solar energy remains as the most prominent source of energy as it is cost effective and environmentally friendly. Reviews convey that solar energy systems will play a major role in the power generations. As per present scenario there is a great importance to the solar energy using photovoltaic systems. Photovoltaic systems exhibit an important role for solar energy production.

An Integrative Behavioral-Based Physics-Inspired Approach to Traffic Congestion Control

2020 ◽  
Author(s):  
Hossein Rastgoftar ◽  
Jean-Baptiste Jeannin ◽  
Ella Atkins
Keyword(s):  
Traffic Congestion ◽  
Mass Conservation ◽  
Flow Density ◽  
Fundamental Diagram ◽  
Efficient Manner ◽  
Steady State Condition ◽  
Control Approach ◽  
Traffic Congestion Control ◽  
And Control ◽  
Control Traffic

Abstract This paper offers an integrative behavioral-based physics-inspired approach to model and control traffic congestion in an efficient manner While existing physics-based approaches commonly assign density and traffic flow states with the Fundamental Diagram, this paper specifies the flow-density relation using past traffic behavior (intent) recorded over a time sliding window with constant horizon length. With this approach, traffic coordination trends can be consistently learned and incorporated into traffic planning. This is integrated with mass conservation law (continuity) to model traffic coordination as a probabilistic process and obtain traffic feasibility conditions using linear temporal logic. By spatial discretization of a network of inter-connected roads (NOIR), the NOIR is represented by a graph with inlet boundary nodes, outlet boundary nodes, and interior nodes. The paper offers a boundary control approach to manage congestion through the inlet boundary nodes. More specifically, model predictive control (MPC) is applied to control traffic congestion through the boundary of the traffic network. Therefore, the optimal boundary in flow is assigned as the solution of a constrained quadratic programming problem with equality and inequality constrained. The simulation results shows that the proposed MPC boundary controller can successfully control the traffic through the inlet boundary nodes where traffic reaches the steady state condition.

Sign in / Sign up

Export Citation Format

Share Document