scholarly journals Class Ratio Transform with an Application to Describing the Roughness Anisotropy of Natural Rock Joints

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Rui Yong ◽  
Lei Huang ◽  
Qinkuan Hou ◽  
Shigui Du
Keyword(s):  
Roughness Parameter ◽  
Rock Joints ◽  
Anisotropic Model ◽  
Roughness Parameters ◽  
Transform Method ◽  
Smooth Coefficient ◽  
Natural Rock ◽  
Smoothing Process ◽  
Regular Roughness ◽  
Parameter Values

In this study, we explore the potential of class ratio transform with an application to describing the roughness anisotropy of natural rock joints. Roughness smooth coefficient, used for suitably smoothing the roughness parameter values to realize an anisotropic model, is proposed to represent the apparent anisotropy of surface roughness. The geometric irregularities of roughness parameters in polar plots allow transforming to a regular roughness asperity pattern, which can be readily approximated by the ellipse function. The joint roughness coefficients in different orientations of natural rock joints were measured and revealed to be identical after applying the smoothing process using the class ratio transform method. The results show that the roughness smooth coefficient increases with sample size but decreases as azimuthal interval narrows. This method demonstrates the ability in describing the roughness anisotropy and inferring the roughness parameters Z2, Rp, and θmax∗/C+12 D.

scholarly journals Method of test blanks in assurance of surface roughness parameters of machine parts

2018 ◽  
pp. 9-14
Author(s):  
Олег Горленко ◽  
Oleg Gorlenko
Keyword(s):  
Rough Surface ◽  
Statistical Approach ◽  
Roughness Parameter ◽  
Surface Profile ◽  
Roughness Parameters ◽  
Measuring Systems ◽  
Technological Support ◽  
Machine Parts ◽  
Definition Of ◽  
Parameter Values

A method for technological support of roughness parameters for machine parts based on an experimental statistical approach is considered. The essence of the method consists in the processing of test blanks (or their test surfaces) according to a pre-planned scheme, in the roughness parameter assessment of test blanks, in the development of mathematical statistical model of the connection of roughness parameters with technological factors and on the basis of the model given a definition of their levels ensuring obtaining the roughness parameter values specified at machining a basic batch blanks. The peculiarities in technological support of relative supporting lengths of a rough surface profile and also a method for the formation of complex functional parameters of a rough surface are touched upon. The necessity for the creation of portable control measuring systems allowing the realization in practice this method is emphasized.

scholarly journals Differential Transform Method as an Effective Tool for Investigating Fractional Dynamical Systems

2021 ◽  
Vol 11 (15) ◽  
pp. 6955
Author(s):  
Andrzej Rysak ◽  
Magdalena Gregorczyk
Keyword(s):  
Optimal Parameter ◽  
Differential Transform Method ◽  
Bifurcation Diagrams ◽  
Transform Method ◽  
Rossler System ◽  
Differential Transform ◽  
Rössler System ◽  
Fractional System ◽  
Parameter Values

This study investigates the use of the differential transform method (DTM) for integrating the Rössler system of the fractional order. Preliminary studies of the integer-order Rössler system, with reference to other well-established integration methods, made it possible to assess the quality of the method and to determine optimal parameter values that should be used when integrating a system with different dynamic characteristics. Bifurcation diagrams obtained for the Rössler fractional system show that, compared to the RK4 scheme-based integration, the DTM results are more resistant to changes in the fractionality of the system.

Correlation between the surfaces of natural rock joints

1986 ◽  
Vol 13 (13) ◽  
pp. 1430-1433 ◽  
Author(s):  
Stephen R. Brown ◽  
Robert L. Kranz ◽  
Brian P. Bonner
Keyword(s):  
Rock Joints ◽  
Natural Rock

A multiscale topography analysis of ground stainless steel and titanium alloys

2007 ◽  
Vol 221 (9) ◽  
pp. 1407-1420 ◽  
Author(s):  
S Giljean ◽  
M Bigerelle ◽  
K Anselme
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Titanium Alloys ◽  
Roughness Parameter ◽  
Roughness Parameters ◽  
Observation Scale ◽  
316L Austenitic Stainless Steel ◽  
The Mean ◽  
Best Parameter

This study aims to perform a multiscale analysis of abraded surfaces of 316L austenitic stainless steel and titanium alloys (TiAl6V4) grinded at different paper grades. The authors propose to answer the following question: For a given distribution of silicon carbide grains of the paper, what is the best roughness parameter and at which scale must it be evaluated better to discriminate the effect of the mechanical properties of the materials? Paper grades from 80 to 4000 were used under identical pressure and erosion time. It can be concluded that the values of the amplitude roughness parameters depend on the observation scale. It is outlined that the abrasion process is very reproducible. A statistical analysis is then proposed, first, to define a classification of the relevance of the roughness parameters for each grain size distribution, and second, to determine at which scale the mechanical properties of the bulk are more influenced for all paper grades. Finally, at relevant scales, the Abbott amplitude parameters roughness kernel (RK) is the best parameter to discriminate the paper grade effect. The mean distance between asperities (SM) is the preferred method for determining the wear effect on materials and the linear mean normalizing autocorrelation (AMNLN) is the preferred method for determining the interaction between paper grade and materials.

scholarly journals Differences in Roughness Parameter Values from Skid and Skidless Contact Stylus Profilometers

2021 ◽  
Vol 15 (1) ◽  
pp. 58-70
Author(s):  
Karol Grochalski ◽  
Michał Mendak ◽  
Michał Jakubowicz ◽  
Bartosz Gapiński ◽  
Natalia Swojak ◽  
...  
Keyword(s):  
Roughness Parameter ◽  
Parameter Values

Calculation of Roughness Parameters during Ultrasonic Hobbing from the Viewpoint of the Theory of Elastic-Plastic Contact

2019 ◽  
Vol 973 ◽  
pp. 170-173
Author(s):  
Sergey I. Agapov ◽  
Yuriy I. Sidyakin ◽  
Oleg F. Korpelyanskiy
Keyword(s):  
Surface Roughness ◽  
Analytical Solutions ◽  
Roughness Parameter ◽  
Regression Equations ◽  
Ultrasonic Machining ◽  
Roughness Parameters ◽  
Elastic Plastic ◽  
Fine Pitch

This article analyses the process of occurrence of the surface roughness during the ultrasonic hobbing of the fine pitch gears from the viewpoint of the theory of elastic-plastic contact, and suggests analytical solutions and regression equations to estimate the roughness parameter Ra in both conventional and ultrasonic machining.

scholarly journals Predictability of Microbial Adhesion to Dental Materials by Roughness Parameters

Coatings ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 456 ◽  
Author(s):  
Andrea Schubert ◽  
Torsten Wassmann ◽  
Mareike Holtappels ◽  
Oliver Kurbad ◽  
Sebastian Krohn ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Titanium Alloy ◽  
Biofilm Formation ◽  
Dental Materials ◽  
Roughness Parameter ◽  
In Vitro Study ◽  
Mean Deviation ◽  
Roughness Parameters ◽  
Microbial Adhesion

Microbial adhesion to intraoral biomaterials is associated with surface roughness. For the prevention of oral pathologies, smooth surfaces with little biofilm formation are required. Ideally, appropriate roughness parameters make microbial adhesion predictable. Although a multitude of parameters are available, surface roughness is commonly described by the arithmetical mean roughness value (Ra). The present study investigates whether Ra is the most appropriate roughness parameter in terms of prediction for microbial adhesion to dental biomaterials. After four surface roughness modifications using standardized polishing protocols, zirconia, polymethylmethacrylate, polyetheretherketone, and titanium alloy specimens were characterized by Ra as well as 17 other parameters using confocal microscopy. Specimens of the tested materials were colonized by C. albicans or S. sanguinis for 2 h; the adhesion was measured via luminescence assays and correlated with the roughness parameters. The adhesion of C. albicans showed a tendency to increase with increasing the surface roughness—the adhesion of S. sanguinis showed no such tendency. Although Sa, that is, the arithmetical mean deviation of surface roughness, and Rdc, that is, the profile section height between two material ratios, showed higher correlations with the microbial adhesion than Ra, these differences were not significant. Within the limitations of this in-vitro study, we conclude that Ra is a sufficient roughness parameter in terms of prediction for initial microbial adhesion to dental biomaterials with polished surfaces.

Considerations Regarding Some Surface State Parameters Characterized by a more Restricted Use

2015 ◽  
Vol 809-810 ◽  
pp. 93-98
Author(s):  
Ionuţ Urzică ◽  
Ciprian Râznic ◽  
Mihai Apostol ◽  
Corina Mihaela Pavăl ◽  
Mihai Boca ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Roughness Parameter ◽  
Cutting Speed ◽  
Roughness Parameters ◽  
Turning Process ◽  
Nose Radius ◽  
Machined Surface ◽  
Surface Roughness Parameter ◽  
Surface Roughness Parameters ◽  
Restricted Use

Frequently, on the drawings of mechanical parts, only indications concerning the surface roughness parameter Ra and, relatively rarely, the surface roughness parameter Rz are included. However, the study of the machined surface roughness highlights the necessity to use yet other surface roughness parameters, in order to have a clearer image on the state of the machined surface. Some other surface roughness parameters possible to be used and presenting importance, without the parameters Ra and Rz, were highlighted. One took into consideration the possibility of measuring parameters Rsk and Rmr by means of the available surface roughness testers. Experimental researches of turning by applying the method of full factorial experiment were developed. As input factors in turning process, the cutting speed, the feed rate and the tool nose radius were used. The experimental results were mathematically processed, being determined empirical mathematical models that highlight the influence of certain input factors of turning process on the values of some surface roughness parameters characterized by a more restricted use

scholarly journals Scale Dependence of Waviness and Unevenness of Natural Rock Joints through Fractal Analysis

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-18
Author(s):  
Yingchun Li ◽  
Shengyue Sun ◽  
Hongwei Yang
Keyword(s):  
Surface Roughness ◽  
Rock Joint ◽  
Fractal Dimensions ◽  
Window Size ◽  
Scale Dependence ◽  
Rock Joints ◽  
Joint Surface ◽  
Triangular Prism ◽  
Natural Rock ◽  
Waviness And Unevenness

The scale dependence of surface roughness is critical in characterising the hydromechanical properties of field-scale rock joints but is still not well understood, particularly when different orders of roughness are considered. We experimentally reveal the scale dependence of two-order roughness, i.e., waviness and unevenness through fractal parameters using the triangular prism surface area method (TPM). The surfaces of three natural joints of granite with the same dimension of 1000 mm×1000 mm are digitised using a 3D laser scanner at three different measurement resolutions. Waviness and unevenness are quantitatively separated by considering the area variation of joint surface as grid size changes. The corresponding fractal dimensions of waviness and unevenness in sampling window sizes ranging from 100 mm×100 mm to 1000 mm×1000 mm at an interval of 100 mm×100 mm are determined. We find that both the fractal dimensions of waviness and unevenness vary as the window size increases. No obvious stationarity threshold has been found for the three rock joint samples, indicating the surface roughness of natural rock joints should be quantified at the scale of the rock mass in the field.

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