Incipient Slip and Frictional Creep of Tyred Systems

2008 ◽  
Author(s):  
Saverio Reina ◽  
Daniele Dini
Keyword(s):  
Systematic Study ◽  
Rolling Contact ◽  
Two Dimensional ◽  
Elastic Strip ◽  
Moving Loads ◽  
Load Case ◽  
Contact Conditions ◽  
Substrate Interface ◽  
Interfacial Behaviour ◽  
Local Slip

This research presents a systematic study of the interfacial behaviour of tyred systems. A simplified two-dimensional contact model of an elastic strip, shrink-fitted onto a wheel, and subjected to different rolling contact conditions, has been developed. This model enables us to characterise the behaviour at the strip/substrate interface caused by a quasi-static application of moving loads on the surface of the layer. The solution is compared to the stationary load case and regimes of local slip, full stick, separation and frictional creep are identified and mapped for a variety of loading conditions, materials and geometries.

Creep and Wear Due to Microslip in Conforming Rolling Contacts

1969 ◽  
Vol 11 (6) ◽  
pp. 611-614
Author(s):  
J. Hailing ◽  
M. A. Al-Qishtaini
Keyword(s):  
Slip Velocity ◽  
Rolling Contact ◽  
Local Pressure ◽  
Contact Conditions ◽  
Strip Theory ◽  
Rolling Contacts ◽  
Tangential Traction ◽  
Local Slip ◽  
Wear Law ◽  
Minimum Wear

The paper presents experimental results for the creep and wear due to microslip under dry rolling contact conditions. Creep results show good correlation with the strip theory predictions for conforming geometric contacts. The wear effects of increasing the tangential traction on plane rolling contacts are explained using an incremental wear law related to the square of both the local pressure and the local slip velocity. Various degrees of geometric conformity are examined and support the theoretical arguments for the minimum wear conditions associated with any particular loading in terms of a prescribed geometric conformity.

Elasto-Plastic Coupled Temperature-Displacement Finite Element Analysis of Two-Dimensional Rolling-Sliding Contact With a Translating Heat Source

1991 ◽  
Vol 113 (1) ◽  
pp. 93-101 ◽  
Author(s):  
S. M. Kulkarni ◽  
C. A. Rubin ◽  
G. T. Hahn
Keyword(s):  
Finite Element ◽  
Half Space ◽  
Plastic Material ◽  
Element Model ◽  
Rolling Contact ◽  
Two Dimensional ◽  
Element Analysis ◽  
Element Mesh ◽  
Perfectly Plastic ◽  
Elastic Perfectly Plastic

The present paper, describes a transient translating elasto-plastic thermo-mechanical finite element model to study 2-D frictional rolling contact. Frictional two-dimensional contact is simulated by repeatedly translating a non-uniform thermo-mechanical distribution across the surface of an elasto-plastic half space. The half space is represented by a two dimensional finite element mesh with appropriate boundaries. Calculations are for an elastic-perfectly plastic material and the selected thermo-physical properties are assumed to be temperature independent. The paper presents temperature variations, stress and plastic strain distributions and deformations. Residual tensile stresses are observed. The magnitude and depth of these stresses depends on 1) the temperature gradients and 2) the magnitudes of the normal and tangential tractions.

Investigation of Contact Conditions During Stamping of a Thin Plate

2020 ◽  
Author(s):  
Harshal Y. Shahare ◽  
Rohan Rajput ◽  
Puneet Tandon
Keyword(s):  
Wave Propagation ◽  
Material Properties ◽  
High Speed ◽  
Fdtd Method ◽  
Propagation Model ◽  
Transmitted Wave ◽  
Two Dimensional ◽  
Contact Conditions ◽  
Simulation Based ◽  
Difference Time

Abstract Stamping is one of the most used manufacturing processes, where real-time monitoring is quite difficult due to high speed of the mechanical press, which leads to deterioration of the accuracy of the products In the present work, a method is developed to model elastic waves propagation in solids to measure contact conditions between die and workpiece during stamping. A two-dimensional model is developed that reduces the wave propagation equations to two-dimensional equations. To simulate the wave propagation inside the die-workpiece model, the finite difference time domain (FDTD) method and modified Yee algorithm has been employed. The numerical stability of the wave propagation model is achieved through courant stability condition, i.e., Courant-Friedrichs-Lewy (CFL) number. Two cases, i.e., flat die-workpiece interface and inclined die-workpiece interface, are investigated in the present work. The elastic wave propagation is simulated with a two-dimension (2D) model of the die and workpiece using reflecting boundary conditions for different material properties. The experimental and simulation-based results of reflected and transmitted wave characteristics are compared for different materials in terms of reflected and transmitted wave height ratio and material properties such as acoustic impedance. It is found that the numerical simulation results are in good agreement with the experimental results.

scholarly journals An evaluation of ultrasonic arrays for the static and dynamic measurement of wheel–rail contact pressure and area

2020 ◽  
Vol 234 (10) ◽  
pp. 1580-1593
Author(s):  
Henry Brunskill ◽  
Andy Hunter ◽  
Lu Zhou ◽  
Rob Dwyer Joyce ◽  
Roger Lewis
Keyword(s):  
Contact Pressure ◽  
Ultrasonic Transducer ◽  
Dynamic Contact ◽  
Pressure Profile ◽  
Calibration Procedure ◽  
Railway Vehicle ◽  
Profile Measurement ◽  
Two Dimensional ◽  
Cross Sectional ◽  
Contact Conditions

The interfacial contact conditions between a railway vehicle wheel and the rail are paramount to the lifespan, safety and smooth operation of any rail network. The wheel–rail interface contact pressure and area conditions have been estimated, calculated and simulated by industry and academia for many years, but a method of accurately measuring dynamic contact conditions has yet to be realised. Methods using pressure-sensitive films and controlled air flow have been employed, but both are limited. Ultrasonic reflectometry is the term given to active ultrasonics in which an ultrasonic transducer is mounted on the outer surface of a component and a sound wave is generated. This ultrasonic wave packet propagates through the host medium and reflects off the contacting interface of interest. The reflected waveform is then detected and contact area and interfacial stiffness information can be extracted from the signal using the quasi-static spring model. Stiffness can be related to contact pressure by performing a simple calibration procedure. Previous contact pressure measurement work has relied on using a focusing transducer and a two-dimensional scanning arrangement which results in a high-resolution image of the wheel–rail contact, but is limited to static loading of a specimen cut from a wheel and rail. The work described in this paper has assessed the feasibility of measuring a dynamic wheel–rail contact patch using an array of 64 ultrasonic elements mounted in the rail. Each element is individually pulsed in sequence to build up a linear cross-sectional pressure profile measurement of the interface. These cross-sectional, line measurements are then processed and collated resulting in a two-dimensional contact pressure profile. Measurements have been taken at different speeds and loads.

A Direct Analysis of Two-Dimensional Elastic-Plastic Rolling Contact

1993 ◽  
Vol 115 (2) ◽  
pp. 227-236 ◽  
Author(s):  
M. Yu ◽  
B. Moran ◽  
L. M. Keer
Keyword(s):  
Finite Element ◽  
Direct Analysis ◽  
Rolling Contact ◽  
Direct Approach ◽  
Two Dimensional ◽  
Elastic Plastic ◽  
Finite Element Calculations ◽  
Plastic Analysis ◽  
Plastic Shakedown ◽  
Residual Problem

A direct approach for elastic-plastic analysis and shakedown is presented and its application to a two-dimensional rolling contact problem is demonstrated. The direct approach consists of an operator split technique, which transforms the elastic-plastic problem into a purely elastic problem and a residual problem with prescribed eigenstrains. The eigenstrains are determined using an incremental projection method which is valid for nonproportional loading and both elastic and plastic shakedown. The residual problem is solved analytically and also by using a finite element procedure which can be readily generalized to more difficult problems such as three-dimensional rolling point contact. The direct analysis employs linear-kinematic-hardening plastic behavior and thus either elastic or plastic shakedown is assured, however, the phenomenon of ratchetting which can lead to incremental collapse, cannot be treated within the present framework. Results are compared with full elastic-plastic finite element calculations and a step-by-step numerical scheme for elastic-plastic analysis. Good agreement between the methods is observed. Furthermore, the direct method results in substantial savings in computational effort over full elastic-plastic finite element calculations and is shown to be a straightforward and efficient method for obtaining the steady state (shakedown) solution in the analysis of rolling and/or sliding contact.

The Effects of Prediction, Quickening, Frequency Separation, and Percent of Pursuit in Perspective Displays for Low-Visibility Landing

1978 ◽  
Vol 22 (1) ◽  
pp. 208-212 ◽  
Author(s):  
Richard S. Jensen
Keyword(s):  
Systematic Study ◽  
High Potential ◽  
Frequency Separation ◽  
Two Dimensional ◽  
Display System ◽  
Aircraft Landing ◽  
Cockpit Displays ◽  
Low Visibility ◽  
Effective Use ◽  
Unique Context

Pictorial realism has long been considered necessary in aircraft landing displays because it makes effective use of man's superior perceptual capabilities. A serious limitation to pictorially realistic two-dimensional displays is that they must be magnified to provide distance cues equivalent to those provided in scenes viewed directly. This paper presents a rationale for applying some well known concepts including prediction, quickening, frequency separation, and percent of pursuit, to the development of forward-looking cockpit displays for low-visibility curved approach and landing tasks that may permit a compromise of the magnification principle. The development of such a display system provides a unique context for the systematic study of the interrelationships among these display concepts with a high potential for scientific and applied payoffs.

Sign in / Sign up

Export Citation Format

Share Document