Evaluating Surface Roughness From Contact Vibrations

This paper examines the relationship between the contact dynamics and the composite surface roughness of two bodies in planar contact. Measurements of the natural contact frequency are obtained for a range of surface roughness levels and normal loads from an apparatus which isolates the contact dynamics of two steel blocks from all other system dynamics. The normal contact dynamics of the contacting components are modeled with a single-degree-of-freedom system which incorporates the Greenwood and Williamson surface roughness model. Analytical and empirical expressions relating the normal natural contact frequency and roughness parameters, such as the standard deviation of asperity heights and the average roughness value, are developed. Both theory and experiments show that the contact frequency increases with a decrease in the composite roughness and vice versa; a power law relation between the contact frequency and the roughness parameters is found in most cases. The results of this work indicate that it may be possible to use contact vibration as a means for assessing or monitoring composite roughness parameters of surfaces in contact.

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Sensitivity of C-Band SAR Polarimetric Variables to the Directionality of Surface Roughness Parameters

Remote Sensing ◽

10.3390/rs13112210 ◽

2021 ◽

Vol 13 (11) ◽

pp. 2210

Author(s):

Zohreh Alijani ◽

John Lindsay ◽

Melanie Chabot ◽

Tracy Rowlandson ◽

Aaron Berg

Keyword(s):

Surface Roughness ◽

Soil Moisture ◽

Laser Scanner ◽

Careful Attention ◽

Roughness Parameters ◽

Retrieval Models ◽

Surface Roughness Parameters ◽

The Look ◽

The Relationship ◽

Roughness Measurements

Surface roughness is an important factor in many soil moisture retrieval models. Therefore, any mischaracterization of surface roughness parameters (root mean square height, RMSH, and correlation length, ʅ) may result in unreliable predictions and soil moisture estimations. In many environments, but particularly in agricultural settings, surface roughness parameters may show different behaviours with respect to the orientation or azimuth. Consequently, the relationship between SAR polarimetric variables and surface roughness parameters may vary depending on measurement orientation. Generally, roughness obtained for many SAR-based studies is estimated using pin profilers that may, or may not, be collected with careful attention to orientation to the satellite look angle. In this study, we characterized surface roughness parameters in multi-azimuth mode using a terrestrial laser scanner (TLS). We characterized the surface roughness parameters in different orientations and then examined the sensitivity between polarimetric variables and surface roughness parameters; further, we compared these results to roughness profiles obtained using traditional pin profilers. The results showed that the polarimetric variables were more sensitive to the surface roughness parameters at higher incidence angles (θ). Moreover, when surface roughness measurements were conducted at the look angle of RADARSAT-2, more significant correlations were observed between polarimetric variables and surface roughness parameters. Our results also indicated that TLS can represent more reliable results than pin profiler in the measurement of the surface roughness parameters.

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The influence of titanium alloys phase composition on the surface roughness parameters obtained in the process of wire EDM

Omsk Scientific Bulletin ◽

10.25206/1813-8225-2021-178-18-24 ◽

2021 ◽

pp. 18-24

Author(s):

A. A. Fedorov ◽

◽

Yu. E. Zhdanova ◽

A. V. Linovsky ◽

N. V. Bobkov ◽

...

Keyword(s):

Surface Roughness ◽

Phase Composition ◽

Titanium Alloys ◽

Electrical Discharge ◽

Electrical Discharge Machining ◽

Wire Edm ◽

Roughness Parameters ◽

Electrical Parameters ◽

Electrode Tool ◽

The Relationship

The paper investigates a roughness of titanium α, α+β and β alloys, obtained by wire electrical discharge machining (EDM) with a brass electrode-tool in distilled water. The purpose of the article is to establish the relationship between the electrical parameters of wire EDM with the surface roughness α, α+β and β of titanium alloys, in particular with the group of parameters Rk. It was established by the method of contact profilometry that the phase composition of titanium alloys significantly affects the height parameters of the roughness of the treated surfaces. It was shown experimentally that the phase composition has a significant effect on the roughness parameters of the Rk group obtained in the process of EDM

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Stability of a Rigid Rotor Supported on Rough Oil Journal Bearings

Journal of Tribology ◽

10.1115/1.2920233 ◽

1990 ◽

Vol 112 (1) ◽

pp. 73-77 ◽

Cited By ~ 12

Author(s):

B. C. Majumdar ◽

M. K. Ghosh

Keyword(s):

Surface Roughness ◽

Journal Bearings ◽

Variance Ratio ◽

Rigid Rotor ◽

Roughness Parameters ◽

Roughness Effect ◽

Composite Surface ◽

The Stability ◽

Orientation Pattern ◽

Rigid Rotors

This investigation deals with the stability of rigid rotors supported on finite rough oil journal bearings using perturbation method. The effect of various surface roughness parameters, viz., composite surface roughness, roughness orientation pattern and variance ratio on the stability has been studied. In general, surface roughness effect when incorporated into the analysis does not show a significant change in the stability for surfaces having same roughness structure. However, the effect of variance ratio (i.e., surfaces having different roughness structure) on stability is quite marked.

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The Relationship between Roughness of Finished Wood Floors and Slip Resistance

Drvna industrija ◽

10.5552/drvind.2021.2009 ◽

2021 ◽

Vol 72 (1) ◽

pp. 49-56

Author(s):

Josip Miklečić ◽

Vlatka Jirouš-Rajković

Keyword(s):

Surface Roughness ◽

Beech Wood ◽

Roughness Parameters ◽

Strong Negative Correlation ◽

Slip Resistance ◽

Wood Flooring ◽

Dry Conditions ◽

Dry Water ◽

The Relationship ◽

Roughness Measurements

The present study investigates the relationship between the roughness of beech wood and oak wood surfaces treated with oil and polyurethane coating and the slip resistance in dry, water-wet and oily conditions. Pendulum tests were conducted for slip resistance assessment, and roughness measurements were performed by stylus instrument using Ra, Rt, Rp, Rz and Rsm parameters for surface roughness evaluation. Slip potential in dry conditions was low for all finished wood floors studied. Contamination of the surface with water and oil reduced the slip resistance of finished oak and beech flooring. The strong negative correlation was found between slip resistance on dry finished flooring and roughness parameters Ra, Rz, Rt and Rp, and positive correlation between slip resistance on water-wet finished flooring and roughness parameters Ra, Rz, Rt and Rp. Moreover, the correlations between roughness parameters Ra, Rt, Rp and Rz and slip resistance were very similar, and the roughness parameters correlated more strongly with the slip resistance on dry and water-wet surfaces than with the slip resistance on oil-wet surface. Comparison of the slip potential classifications of finished wood floors based on pendulum data and based on Rz surface roughness parameters showed that in some cases the Rz parameter appeared to overestimate the slip potential of the floors in wet conditions. The results confirm previous research that roughness measurements should only be used as a guide and should not be used as the only indicator of the slip potential of wood flooring materials.

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Optimization of Surface Roughness in Turning Operation using Al- 6063 and Effect of Dry Machining

International Journal for Research in Applied Science and Engineering Technology ◽

10.22214/ijraset.2021.35993 ◽

2021 ◽

Vol 9 (VI) ◽

pp. 4210-4215

Author(s):

Md Jafar Khan

Keyword(s):

Surface Roughness ◽

Root Mean Square Roughness ◽

Depth Of Cut ◽

Work Piece ◽

Machining Parameters ◽

Dry Machining ◽

Roughness Parameters ◽

Average Roughness ◽

Alloy Material ◽

Good Agreement

ALUMINIUM-6063 is a widely used alloy material in the production of aerospace, aircraft, gas turbine components. This investigation focuses on the influence of machining parameters, viz., spindle speed, depth of cut and feed rate on the surface roughness obtained in Lathe operation of Al 6063 alloy. In the present study, experiments are conducted for nine different Al 6063 work piece materials to see the effect of work piece material variation in this respect. This roughness parameters, viz., Centre line average roughness, root mean square roughness. The roughness models as well as the significance of the machining parameters have been validated with analysis of variance. In addition, a good agreement between the predicted and measured surface roughness was observed. Therefore, the developed model can be effectively used to predict the surface roughness on the machining of Al6063 within 95% confidence intervals ranges of parameters studied.

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Roughness-Induced Adhesive Hysteresis in Self-Affine Fractal Surfaces

Lubricants ◽

10.3390/lubricants9010007 ◽

2021 ◽

Vol 9 (1) ◽

pp. 7

Author(s):

Guido Violano ◽

Luciano Afferrante

Keyword(s):

Surface Roughness ◽

Fractal Dimension ◽

Applied Load ◽

Roughness Parameters ◽

Normal Contact ◽

Fractal Surfaces ◽

Elastic Bodies ◽

Roughness Amplitude ◽

Loading And Unloading ◽

Hysteretic Loss

It is known that in the presence of surface roughness, adhesion can lead to distinct paths of loading and unloading for the area–load and penetration–load relationships, thus causing hysteretic loss. Here, we investigate the effects that the surface roughness parameters have on such adhesive hysteresis loss. We focus on the frictionless normal contact between soft elastic bodies and, for this reason, we model adhesion according to Johnson, Kendall, and Roberts (JKR) theory. Hysteretic energy loss is found to increase linearly with the true area of contact, while the detachment force is negligibly influenced by the maximum applied load reached at the end of the loading phase. Moreover, for the micrometric roughness amplitude hrms considered in the present work, adhesion hysteresis is found to be affected by the shorter wavelengths of roughness. Specifically, hysteresis losses decrease with increasing fractal dimension and cut-off frequency of the roughness spectrum. However, we stress that a different behavior could occur in other ranges of roughness amplitude.

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Stability of Rough Journal Bearings Using Nonlinear Transient Method

Journal of Tribology ◽

10.1115/1.2831538 ◽

1995 ◽

Vol 117 (4) ◽

pp. 691-695 ◽

Cited By ~ 10

Author(s):

J. Ramesh ◽

B. C. Majumdar

Keyword(s):

Surface Roughness ◽

Journal Bearings ◽

Variance Ratio ◽

Transient Method ◽

Roughness Parameters ◽

Composite Surface ◽

Nonlinear Transient ◽

The Stability ◽

Orientation Pattern ◽

Rigid Rotors

The stability of rigid rotors supported on finite oil rough journal bearings has been investigated using nonlinear transient method. The effect of various surface roughness parameters, viz., composite surface roughness, roughness orientation pattern, variance ratio on the stability is presented in the form of journal center trajectories. Although the stability is affected marginally with the increase in composite roughness, the variation is quite significant when the shear flow factor comes into the picture.

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ESTIMATING THE EFFECT OF MACHINING PARAMETERS ON SURFACE ROUGHNESS DURING MACHINING OF HARDENED EN24 STEEL USING COATED CARBIDE INSERTS

International Journal of Mechanical and Industrial Engineering ◽

10.47893/ijmie.2014.1197 ◽

2014 ◽

pp. 123-128

Author(s):

Sudhansu Ranjan Das ◽

Amaresh Kumar ◽

Debabrata Dhupal ◽

Kali Charan Rath

Keyword(s):

Surface Roughness ◽

Cutting Speed ◽

Depth Of Cut ◽

Machining Parameters ◽

Roughness Parameters ◽

Surface Roughness Parameters ◽

Hardened En24 ◽

Coated Carbide ◽

The Relationship ◽

Carbide Inserts

In the present study, an attempt has been made to evaluate the performance of multilayer coated carbide inserts during dry turning of hardened EN24 steel (47 HRC). The effect of machining parameters (depth of cut, feed and cutting speed) on surface roughness parameters (Ra and Rz) were investigated by applying ANOVA. The experiments were planned based on Taguchi’s L27 Orthogonal array design. Results showed that surface roughness parameters (Ra and Rz) are mainly influenced by feed and cutting speed, whereas depth of cut exhibits minimum influence on surface roughness (Rz) and neglegible influence in case of surface roughness (Ra). The experimental data were further anlyzed to predict the optimal range of surface roughness parameters (Ra and Rz). Finally, second order regression models were carried out to find out the relationship between the machining parameters and surface roughness parameters.

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Surface roughness in relation to altitude of hornbeam wood

Madera y Bosques ◽

10.21829/myb.2018.241964 ◽

2018 ◽

Vol 24 (1) ◽

Author(s):

Majid Kiaei ◽

Rasoul Mosavi Paloj

Keyword(s):

Surface Roughness ◽

Native Species ◽

Roughness Parameter ◽

Surface Characteristics ◽

Peak Height ◽

Solid Wood ◽

Wood Products ◽

Roughness Parameters ◽

Average Roughness ◽

Test Pieces

Hornbeam wood (Carpinus betulus) is a native species from Iran and covers 33% of the commercial volume of Iranian woods. Surface quality of solid wood products is one of the most important properties influencing further manufacturing processes such as finishing or strength of adhesive joint. Wood surface roughness is affected by growth condition. The objective of this study was to evaluate effect of altitude index (400 m, 800 m and 1200 m) on the surface roughness of sanded hornbeam wood (C. Betulus). Surface characteristics of sanded specimens of hornbeam wood were made employing a stylus profilmeter. Average roughness (Ra), mean peak-to-valley height (Rz), root-mean square deviation of the profile (Rq), core roughness depth (Rk), reduced peak height (Rpk), and reduced valley depth (Rvk) roughness parameters were used to determine surface characteristics of the test pieces. Significant statistical differences were found among altitude indexes in reduced valley depth parameter and wood oven-dried density, but not for the other variables. This variable did not have significantly effect on other surface roughness parameters in hornbeam wood. The low altitude had a rougher surface than intermediate and high altitudes. There is no relationship between surface roughness parameter and wood oven-dried density.

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