Intelligent Modeling of Contact Mechanics and Friction Dynamics

2005 ◽  
Author(s):  
R. Marumo
Keyword(s):  
Contact Mechanics ◽  
Dynamic Models ◽  
Sliding Friction ◽  
Dynamic Modelling ◽  
Contact Friction ◽  
Friction Forces ◽  
Intelligent Modeling ◽  
Adhesion Contact ◽  
Frictional Forces ◽  
Friction Dynamics

This paper considers the investigations into adhesion, contact mechanics metal erosion effects, wear and tare as a result of the effects of frictional forces. Mechanical components rely on friction for the transformation and delivery of energy from point A to point B. This requires the knowledge of combined energies as well as their associated dynamic models and ancillary parameters. Adhesion, contact, friction and wear are major problems limiting both the fabrication yield and lifetime of any devices. Since it is the area of real contact, which determines the sliding friction, adhesion interaction may strongly affect the friction force even when no adhesion can be detected in a pull-off experiment. Therefore a good scientific dynamic modelling of friction forces is a prerequisite for the understanding and monitoring of friction adverse effect on mechanical systems for good maintenance purposes.

Dynamical Modeling of Gear Transmission Considering Gearbox Casing

2018 ◽  
Author(s):  
Yang Luo ◽  
Natalie Baddour ◽  
Ming Liang
Keyword(s):  
Dynamic Models ◽  
Signal Propagation ◽  
Gear Transmission ◽  
Gear System ◽  
Dynamical Model ◽  
Contact Friction ◽  
Dynamical Response ◽  
Dynamic Simulations ◽  
Friction Forces ◽  
Frequency Domains

Much research has been carried out to investigate the dynamical response of a gear system because of its importance on vibration feature analysis. It is well known that the gearbox casing is one of the most important components of the gear system and plays an important role in signal propagation. However, its effects have widely been neglected within the dynamic simulations and few dynamic models have considered the gearbox casing when modeling a gear transmission. This paper proposes a gear transmission dynamical model with the consideration of the effects of gearbox casing. The proposed dynamical model incorporates TVMS, a time-varying load sharing ratio, as well as dynamic tooth contact friction forces, friction moments and dynamic mesh damping coefficients. The proposed gear dynamical model is validated by comparison with responses obtained from experimental test rigs under different speed conditions. Comparisons indicate that the responses of the proposed dynamical model are consistent with experimental results, in both time and frequency domains under different rotation speeds.

Construction of Semianalytical Solutions to Spur Gear Dynamics Given Periodic Mesh Stiffness and Sliding Friction Functions

2008 ◽  
Vol 130 (12) ◽  
Author(s):  
Song He ◽  
Todd Rook ◽  
Rajendra Singh
Keyword(s):  
Dynamic Models ◽  
Sliding Friction ◽  
Linear Time ◽  
Transmission Error ◽  
Spur Gear ◽  
Degree Of Freedom ◽  
System Model ◽  
Time Varying ◽  
Mesh Stiffness ◽  
Friction Forces

Gear dynamic models with time-varying mesh stiffness, viscous mesh damping, and sliding friction forces and moments lead to complex periodic differential equations. For example, the multiplicative effect generates higher mesh harmonics. In prior studies, time-domain integration and fast Fourier transform analysis have been utilized, but these methods are computationally sensitive. Therefore, semianalytical single- and multiterm harmonic balance methods are developed for an efficient construction of the frequency responses. First, an analytical single-degree-of-freedom, linear time-varying system model is developed for a spur gear pair in terms of the dynamic transmission error. Harmonic solutions are then derived and validated by comparing with numerical integration results. Next, harmonic solutions are extended to a six-degree-of-freedom system model for the prediction of (normal) mesh loads, friction forces, and pinion/gear displacements (in both line-of-action and off-line-of-action directions). Semianalytical predictions compare well with numerical simulations under nonresonant conditions and provide insights into the interaction between sliding friction and mesh stiffness.

Development and Verification of a Dynamic TKR Model

2002 ◽  
Author(s):  
Jason P. Halloran ◽  
Anthony J. Petrella ◽  
Paul J. Rullkoetter
Keyword(s):  
Finite Element ◽  
Contact Mechanics ◽  
Dynamic Loading ◽  
Soft Tissues ◽  
Dynamic Models ◽  
Total Joint Replacement ◽  
Fe Model ◽  
Loading Conditions ◽  
Dynamic Loading Conditions

The success of current total knee replacement (TKR) devices is contingent on the kinematics and contact mechanics during in vivo activity. Indicators of potential clinical performance of total joint replacement devices include contact stress and area due to articulations, and tibio-femoral and patello-femoral kinematics. An effective way of evaluating these parameters during the design phase or before clinical use is via computationally efficient computer models. Previous finite element (FE) knee models have generally been used to determine contact stresses and/or areas during static or quasi-static loading conditions. The majority of knee models intended to predict relative kinematics have not been able to determine contact mechanics simultaneously. Recently, however, explicit dynamic finite element methods have been used to develop dynamic models of TKR able to efficiently determine joint and contact mechanics during dynamic loading conditions [1,2]. The objective of this research was to develop and validate an explicit FE model of a TKR which includes tibio-femoral and patello-femoral articulations and surrounding soft tissues. The six degree-of-freedom kinematics, kinetics and polyethylene contact mechanics during dynamic loading conditions were then predicted during gait simulation.

scholarly journals Analytical substantiation of constructive parameters of rotating field board of plow’s body

2019 ◽  
Vol 126 ◽  
pp. 00038
Author(s):  
Vladimir Konovalov ◽  
Sergey Konovalov ◽  
Victoria Igumnova
Keyword(s):  
Sliding Friction ◽  
Rolling Friction ◽  
High Energy ◽  
Cultivated Plants ◽  
Friction Forces ◽  
Technical Parameters ◽  
Cutting Resistance ◽  
Different Depths ◽  
Analytical Relations ◽  
Rotating Field

The article shows importance of use of dump plowing for formation and maintenance of soil structure and pest control and diseases of cultivated plants. A significant drawback of plowing process is indicated, which is its high energy intensity. To reduce energy consumption, it is proposed to use rotating field boards, which allow replacing sliding friction forces with rolling friction forces. The article presents a description of design of plow’s body with rotating field board and notes that without a preliminary analytical study and justification of initial parameters, their use may not be effective. Analytical relations connecting value of radius of rotating field of board, rate of collapse of soil, allowable value of indentation of field board into soil and specific force of cutting resistance of soil that ability to use it for baseline technical parameters. To analyze obtained dependence, the article presents its graphical solution. The authors obtained an expression for determining the value of arm’s force of reference reaction from soil to balance a plow’s body, in addition, this indicator can be used to adjust a body when working on soils with different physical and mechanical parameters and at different depths.

scholarly journals Single-asperity sliding friction across the superconducting phase transition

2020 ◽  
Vol 6 (12) ◽  
pp. eaay0165 ◽  
Author(s):  
Wen Wang ◽  
Dirk Dietzel ◽  
André Schirmeisen
Keyword(s):  
Energy Dissipation ◽  
Sliding Friction ◽  
Point Contact ◽  
Electronic Energy ◽  
Contact Friction ◽  
Electron Systems ◽  
Single Asperity ◽  
Large Peak ◽  
Friction Models ◽  
Current Point

In sliding friction, different energy dissipation channels have been proposed, including phonon and electron systems, plastic deformation, and crack formation. However, how energy is coupled into these channels is debated, and especially, the relevance of electronic dissipation remains elusive. Here, we present friction experiments of a single-asperity sliding on a high-Tc superconductor from 40 to 300 kelvin. Overall, friction decreases with temperature as generally expected for nanoscale energy dissipation. However, we also find a large peak around Tc. We model these results by a superposition of phononic and electronic friction, where the electronic energy dissipation vanishes below Tc. In particular, we find that the electronic friction constitutes a constant offset above Tc, which vanishes below Tc with a power law in agreement with Bardeen-Cooper-Schrieffer theory. While current point contact friction models usually neglect such friction contributions, our study shows that electronic and phononic friction contributions can be of equal size.

Experimental Study of Friction in a Pneumatic Actuator at Constant Velocity

1993 ◽  
Vol 115 (3) ◽  
pp. 575-577 ◽  
Author(s):  
Lee E. Schroeder ◽  
Rajendra Singh
Keyword(s):  
Experimental Study ◽  
Experimental Method ◽  
Friction Force ◽  
Constant Velocity ◽  
Sliding Friction ◽  
Pneumatic Actuator ◽  
Friction Forces ◽  
Friction Models ◽  
Semi Empirical ◽  
Force Data

This paper describes an experimental method of determining sliding friction forces in a pneumatic actuator. Several empirical and semi-empirical friction models are evaluated using measured friction force data. A repeatability study is also performed to qualitatively assess friction randomness and a change in friction regimes.

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