Determining the Number of Peaks of Rough Surfaces Necessary for Wear Calculation

2014 ◽  
Vol 604 ◽  
pp. 59-62 ◽  
Author(s):  
Oskars Linins ◽  
Armands Leitans ◽  
Guntis Springis ◽  
Janis Rudzitis
Keyword(s):  
Working Conditions ◽  
Sliding Friction ◽  
Friction Pair ◽  
Calculation Model ◽  
Fatigue Wear ◽  
Wear Model ◽  
Wear Process ◽  
Wear Calculation ◽  
Service Conditions ◽  
Micro Topography

The problem of evaluating the life period of different mechanisms is of great importance nowadays. This could be explained by the fact that the wear process is very complex and very many factors take place simultaneously. During the history a variety of theories that offered different methods of wear calculation models were developed. However still there is no exact wear calculation model that could be applied to all cases of wear processes. The offered method is dealing with the calculation of rough surface peaks that make the contact between two surfaces. Taking into account the number of these peaks and applying fatigue wear model based on 3D surface micro-topography, assessing the materials physical and mechanical characteristic quantities and considering definite service conditions of sliding friction pair it is possible to make the wear calculation of friction pair under definite working conditions.

Wear Problems of Slide-Friction Pair

2015 ◽  
Vol 220-221 ◽  
pp. 361-366
Author(s):  
Guntis Springis ◽  
Janis Rudzitis ◽  
Anita Avišāne ◽  
Maris Kumermanis ◽  
Jevgenijs Semjonovs ◽  
...  
Keyword(s):  
Service Life ◽  
Sliding Friction ◽  
Friction Pair ◽  
Calculation Model ◽  
Surface Geometry ◽  
Wear Process ◽  
Layer Material ◽  
Wear Calculation ◽  
Form Deviation ◽  
Friction Surfaces

A number of different mechanisms and devices may involve sliding-friction surfaces. The issues of service life and its prediction for the details of such surfaces have always been of particular importance. The article determines the most suitable wear calculation model that allows considering the set of parameters necessary for calculating slide-friction pair. The offered model is based on the application of the theories of several branches of sciences. Since the wear process is variable and many-sided, it is influenced by numerous different parameters, for example, surface geometry (roughness, waviness, form deviation, etc.), physical and mechanical conditions of the upper layer, material components, wear regime, wear temperature, etc.

scholarly journals Wear Calculation for Sliding Friction Pairs

2014 ◽  
Vol 51 (2) ◽  
pp. 41-54 ◽  
Author(s):  
G. Springis ◽  
J. Rudzitis ◽  
A. Avisane ◽  
A. Leitans
Keyword(s):  
Service Life ◽  
Sliding Friction ◽  
Theoretical Calculations ◽  
Quality Level ◽  
Wear Process ◽  
Measuring Devices ◽  
Proposed Model ◽  
Wear Calculation ◽  
Production Technologies ◽  
Micro Topography

Abstract One of the principal objectives of modern production process is the improvement of quality level; this means also guaranteeing the required service life of different products and increase in their wear resistance. To perform this task, prediction of service life of fitted components is of crucial value, since with the development of production technologies and measuring devices it is possible to determine with ever increasing precision the data to be used also in analytical calculations. Having studied the prediction theories of wear process that have been developed in the course of time and can be classified into definite groups one can state that each of them has shortcomings that might strongly impair the results thus making unnecessary theoretical calculations. The proposed model for wear calculation is based on the application of theories from several branches of science to the description of 3D surface micro-topography, assessing the material’s physical and mechanical characteristics, substantiating the regularities in creation of the material particles separated during the wear process and taking into consideration definite service conditions of fittings.

scholarly journals Wear Characteristics of Different Groove-Shaped Friction Pairs of a Friction Clutch

2020 ◽  
Vol 11 (1) ◽  
pp. 284
Author(s):  
Heyun Bao ◽  
Chao Zhang ◽  
Xiaonan Hou ◽  
Fengxia Lu
Keyword(s):  
Adhesive Wear ◽  
Friction Pair ◽  
Wear Test ◽  
Calculation Model ◽  
Wear Model ◽  
Wear Performance ◽  
Friction Clutch ◽  
Wear Calculation ◽  
The Mathematical Model ◽  
Sliding Distance

To investigate the influence of the groove shape of friction disks on the wear of a friction clutch friction pair, a wear calculation model that considers the actual sliding distance between the friction clutch friction pair is presented based on the Archard adhesive wear model. The wear of three different groove-shaped friction pairs was calculated and analyzed. The wear test was carried out on the SAE#2 testing rig to obtain the actual wear amount and verify the accuracy and validity of the mathematical model. The results show that, among the three types of grooves, the friction disks with waffle grooves were the most prone to wear, followed by three-way parallel grooves. The wear performance of the two-way parallel grooves was the best, and the wear from one-time engagement can better reflect the change in the dynamic engagement of the friction pair. With the increase in the engagement time, the increase of the wear amount decreases.

A Numerical Simulation of Fretting Wear considering the Dynamic Evolution of Debris for the Coated Contact Surface

2021 ◽  
pp. 1-49
Author(s):  
Li Xiao ◽  
Yingqiang Xu ◽  
Zhiyong Chen
Keyword(s):  
Fretting Wear ◽  
Contact Pair ◽  
Dynamic Evolution ◽  
Wear Depth ◽  
Wear Coefficient ◽  
Wear Model ◽  
Wear Process ◽  
Dlc Coating ◽  
Wear Life ◽  
Wear Calculation

Abstract In this paper, a multi-layer body model in which material properties and wear coefficient change with node coordinates is proposed, so that the wear profile is not restricted by the singularity of the interface of the coated contact pairs. The conversion rate of the adhered particles was obtained to describe the growth and expansion of the debris at the fretting interface based on experiments, and the wear model of coated contact pair considering the dynamic evolution of the debris layer was established. By comparing the previous experimental and computational results, the wear calculation method proposed in this paper is more reasonable to predict the wear profile of the coated contact pair. In addition, the influence of the debris layer on the wear depth, friction width, and contact pressure in the fretting process is analyzed, indicating that the existence of the debris layer can delay the wear process. Finally, the fretting wear life of the SCMV steel contact pair deposited with the W-DLC coating is estimated.

Wear Performance of GCr15 Friction Pairs with Effect of Initial Radial Micro-Grooves

2019 ◽  
Vol 11 (1) ◽  
pp. 56-61
Author(s):  
Wei Yuan ◽  
Shengkai Mei ◽  
Song Li ◽  
Zhiwen Wang ◽  
Jie Yu ◽  
...  
Keyword(s):  
Wear Rate ◽  
Abrasive Wear ◽  
Electrical Discharge Machining ◽  
Friction Pair ◽  
Wear Volume ◽  
Fatigue Wear ◽  
Wear Performance ◽  
Wear Process ◽  
Groove Test ◽  
On Line

Background: Grooves may inevitably occur on the surface of the friction pair caused by severe wear or residual stress, which will play an important role on the reliability of machine parts during operation. Objective: The effect of the micro-grooves perpendicular to sliding direction on the wear performance of the friction pairs should be studied. Method: Micro-grooves can be machined on discs of friction pairs using electrical discharge machining. On-line visual ferrograph method was used to monitor the wear process to research the wear rate changing characteristic. Profilemeter and metallurgical microscope were used to observe the wear scars. Results: Comparing to the non-groove test, i) in one-groove test, wear volume and rate were approximate the same, and the wear scar was smooth, ii) when the grooves more than 4, the test running-in stage will be obviously prolonged, particularly for the test with 8 grooves on the disc, the duration of running-in stage is 4 times than that without grooves on specimen, and the wear rate and volume increase significantly, and then decrease with fluctuation, iii) the abrasive wear can be avoid with the debris stagnating in the groove, however, fatigue wear will significantly emerge. Conclusion: Abrasive wear can be avoided and smooth running-in surfaces can be obtained with proper amount of initial radial micro-grooves.

Theoretical Approach of Wear for Slide-Friction Pairs

2017 ◽  
Vol 260 ◽  
pp. 202-211
Author(s):  
Guntis Springis ◽  
Janis Rudzitis ◽  
Eriks Gerins ◽  
Natalija Bulaha
Keyword(s):  
Mechanical Characteristic ◽  
Theoretical Approach ◽  
Sliding Friction ◽  
Movement Speed ◽  
Kinematic Characteristic ◽  
Surface Geometry ◽  
Mechatronic Systems ◽  
Wear Process ◽  
Proposed Model ◽  
Wear Calculation

A number of different mechanisms and devices in mechatronic systems may involve sliding-friction surfaces. The issues of service life and its prediction for the details of such surfaces have always been of particular importance. Having studied the wear process prediction theories that have been developed in the course of time, which can be classified by dividing them in definite groups based on similar theoretical approach one can state that each of them has different shortcomings, which might affect the result precision, when essential basic parameters have been disregarded, as well as create a need for useless additional practical experiments, as a result of which theoretical calculation becomes unnecessary. [4] The article determines the most suitable wear calculation model that allows considering the set of parameters necessary for calculating slide-friction pair. Wearing usually proceeds in three stages: the running-in stage, the normal wear stage, and the intensive wear stage. The proposed model is provided for normal wear stage calculations. The proposed model for wear calculation is based on the application of theories from several branches of science to the description of 3D surface micro-topography in accordance with random field theory, assessing the material’s physical and mechanical characteristic quantities, substantiating the regularities in creation of material particles separated during the wear process and taking into consideration definite service conditions of fittings. Since the wear process is variable and many-sided, it is influenced by numerous different parameters, for example, surface geometry (roughness, waviness, form deviation, etc.), physical and mechanical conditions of the upper layer, material components, wear regime, wear temperature, etc. Based on the regularities stated in the article one can propose the following wear calculation sequence [4]:1) Initial data should be stated which will be further necessary in calculations: constructive-kinematic characteristic quantities (rated area Aa of wearing component, load P, gliding movement speed v, movement time t), fatigue characteristic of friction component material (friction coefficient f (f≤0,1) and material fatigue destruction parameters (m, σ-1, N0), mechanical characteristic quantities of material (E, μ);2) Parameters should be stated after attachment: surface roughness parameters (Sa, Sm1, Sm2, Sm2a), initial wear Up and corresponding time Tp, tolerated wear Umax.

scholarly journals Analysis of the Screw Flight Wear Model and Wear Regularity of the Bulk Transport in Screw Ship Unloader

2021 ◽  
Author(s):  
Weijie Yang ◽  
Wenjun Meng ◽  
Lingchong Gao ◽  
Yuan Tan ◽  
Johannes Fottner ◽  
...  
Keyword(s):  
Wear Rate ◽  
Working Conditions ◽  
Continuous Medium ◽  
Calculation Model ◽  
Filling Rate ◽  
Wear Model ◽  
Spiral Blade ◽  
Simulation Results ◽  
Wear Law

AbstractThe screw flight, spiral blade welded on the axial cylinder, is the core component of the screw ship unloader and can be seriously worn by the materials during long-term conveying. The damaged screw flight will make the screw ship unloader unable to unload materials or even lead to an accident. However, the existing wear model cannot be directly applied to predict the wear of the screw flight under different working conditions. Hence, we established a new screw flight wear model based on the Archard wear model and Continuous Medium Hypothesis to predict the service life of the screw flight. Three influencing factors, including speed, filling rate, and pitch, were selected to study the wear law of the screw flight, and the wear law was verified by EDEM simulation. Results indicate that the simulation results affected by the changes in various factors were consistent with the calculation model. With the increase of rotation speed and filling rate, the screw flight wear rate increased. Nevertheless, with the increase of pitch, the screw flight wear rate first increased and then decreased. The screw flight wear model can be used to calculate the wear rate under different working conditions for the screw flight life prediction.

Wear Model for Piston Ring and Cylinder Bore System

2005 ◽  
Author(s):  
Yunchao Qiu ◽  
Qian Zou ◽  
Gary C. Barber ◽  
Harold E. McCormick ◽  
Dequan Zou ◽  
...  
Keyword(s):  
Piston Ring ◽  
Thickness Distribution ◽  
Matrix Ring ◽  
Experimental Investigations ◽  
General Tendency ◽  
Wear Model ◽  
Wear Process ◽  
The Matrix ◽  
Surface Profiles ◽  
Cylinder Bore

A new wear model for piston ring and cylinder bore system has been developed to predict wear process with high accuracy and efficiency. It will save time and cost compared with experimental investigations. Surfaces of ring and bore were divided into small domains and assigned to corresponding elements in two-dimensional matrix. Fast Fourier Transform (FFT) and Conjugate Gradient Method (CGM) were applied to obtain pressure distribution on the computing domain. The pressure and film thickness distribution were provided by a previously developed ring/bore lubrication module. By changing the wear coefficients of the ring and bore with accumulated cycles, wear was calculated point by point in the matrix. Ring and bore surface profiles were modified when wear occurred. The results of ring and bore wear after 1 cycle, 10 cycles and 2 hours at 3600 rpm were calculated. They coincided well with the general tendency of wear in a ring and bore system.

Grinding Force Model for Low-Speed Grinding Based on Impact Principle

2013 ◽  
Vol 797 ◽  
pp. 123-128
Author(s):  
Ming He Liu ◽  
Xiu Ming Zhang ◽  
Shi Chao Xiu
Keyword(s):  
Sliding Friction ◽  
Impact Load ◽  
Grinding Force ◽  
Calculation Model ◽  
Force Model ◽  
Grinding Process ◽  
Low Speed ◽  
Impact Area ◽  
Force Mechanism ◽  
The Impact

In the low-speed grinding process, the force generated when the wheel grinding the workpiece is the result of sliding friction, plough and cutting. While in the actual study, the cutting process has attracted extensive attention. Impact effect to the entire grinding process on the contact is ignored so that the error exists between the calculation grinding force and the measured grinding force. Basing on the shock effect to the grinding process, the paper divides the contact area into impact area and cutting area. And the model of impact load generated from single grit is built. Moreover, the grinding force theoretical calculation model and total grinding force mathematical model is also constructed by analyzing the impact load affecting on the grinding force mechanism. Finally experimental study verifies the correctness of theoretical analysis.

Sign in / Sign up

Export Citation Format

Share Document