scholarly journals Surface roughness in relation to altitude of hornbeam wood

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. 

Estimating Roughness Parameters Resulting From Various Machining Techniques for Fluid Flow Applications

2007 ◽  
Author(s):  
Perry L. Young ◽  
Timothy P. Brackbill ◽  
Satish G. Kandlikar
Keyword(s):  
Surface Roughness ◽  
Fluid Flow ◽  
Smooth Surface ◽  
Roughness Parameter ◽  
Practical Interest ◽  
Roughness Parameters ◽  
Machining Processes ◽  
Average Roughness ◽  
Digital Microscope ◽  
Microfabrication Techniques

Recently, a set of new roughness parameters was proposed by Kandlikar et al. [1] and Taylor et al. [2] for reporting surface roughness as related to fluid flow. The average roughness Ra parameter is often used in microfluidic applications, but this parameter alone is insufficient for describing surface roughness; a specimen with deep grooves and sharp obstructions can share the same average roughness value as a relatively smooth surface with low uniform surface roughness. Since the average roughness parameter is broad, it is difficult to access the surface topography features that result from different machining processes or etches. A profilometer and a digital microscope are used to examine the surface roughness profiles of various materials submitted to different machining techniques. The materials studied will be similar to those used for microchannels including aluminum, stainless steel, copper, and silicon. Depending on the material, these samples are submitted to several machining processes including milling, grinding, fly cutting, and microfabrication techniques. These machining processes and microfabrication techniques are of practical interest in microfluidics applications. After studying the surface roughness patterns exhibited in these samples, the roughness parameters employed in some of the recent roughness models are evaluated. This study is expected to provide more understanding of assorted surface roughness.

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.

Measuring and Quantifying the Surface-Roughness Anisotropy of Modeled and Industrially Produced Surfaces

2005 ◽  
Vol 6-8 ◽  
pp. 573-582 ◽  
Author(s):  
C.M. Wichern ◽  
W. Rasp
Keyword(s):  
Surface Roughness ◽  
Rolling Direction ◽  
Three Dimensional ◽  
Roughness Parameter ◽  
Orientation Angle ◽  
Textured Surface ◽  
Angular Orientation ◽  
Textured Surfaces ◽  
Average Roughness ◽  
Dimensional Surface

‘Three-dimensional surface profilometry’ when used for analysis and product specification reports roughness parameters that provide an average surface description over a relatively large area. Many commercial sheet steels are produced with special textured surfaces for tribological benefits or appearance benefits. These surfaces, as well as others, may demonstrate high levels of roughness anisotropy that is not quantifiable by simple three dimensional surface parameters. This anisotropy can play an important role in the surface appearance of the finished product and in the tribological behaviour during forming. The current work presents a method for quantifying surface-roughness features as a function of angular orientation with respect to rolling direction. The measurement methodology was applied to several model surfaces and one industrially produced electron-beam textured-surface (EBT). This methodology extracts multiple surface-height profiles of the same angular orientation from a single surface and calculates an average roughness parameter for the orientation angle based on the multiple profiles. Particularly interesting results were the large number of profiles necessary to obtain repeatable values for the roughness variation with respect to direction and the strong influence of surface feature size on the repeatability of said results. These results indicate that care must be taken when using a single extracted profile to represent a ‘three-dimensional’ surface.

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

Measurements and Evaluation of Internal Wall Surface Roughness of Small Diameter Pipes for High Pressure Natural Gas Systems

2014 ◽  
Author(s):  
C. Hartloper ◽  
K. K. Botros ◽  
J. Geerligs ◽  
H. Golshan ◽  
K. Jensen
Keyword(s):  
Surface Roughness ◽  
Pipe Wall ◽  
Large Diameter ◽  
Roughness Parameter ◽  
Small Diameter ◽  
Wall Roughness ◽  
Roughness Parameters ◽  
Internal Wall ◽  
Effective Roughness ◽  
Pipe Size

The default roughness parameter values used in industry to determine the pressure loss through small diameter pipeline systems are much higher than the values employed in typical large diameter gas transmission and lateral systems. It is uncertain whether these higher roughness values are due to higher topological roughness of the internal wall of the small diameter pipes or if they are a result of other factors. Measurements were taken on 17 small diameter pipe samples in order to evaluate the pipe-wall roughness parameter. A model to calculate the effective roughness parameter, which takes into account pressure losses due to the measured roughness as well as internal welds and scaling, has been developed. The effective roughness parameter of these samples is found to range from 20.4μm to 62.9μm, an increase of 11.0μm to 23.3μm over the measured pipe-wall roughness parameter. This range of effective roughness parameters agrees well with the default range of 35μm to 65μm used in industry, as well as the literature quoted range for clean pipe of 40μm to 100μm. The measured roughness parameter on average increases with increasing nominal pipe size, a result that may be a characteristic of the extrusion or hot-rolling processes used to manufacture small diameter pipes. Additionally, there is a large variation in the measured roughness parameters of pipe samples of the same nominal pipe size, indicating that surface roughness can vary depending on the manufacturing source of these pipes.

scholarly journals The influence of technological parameters on surface roughness during turning and roughness prediction using artificial neutral networks

Mechanik ◽  
2018 ◽  
Vol 91 (10) ◽  
pp. 898-900 ◽  
Author(s):  
Ireneusz Zagórski ◽  
Monika Kulisz ◽  
Tomasz Warda
Keyword(s):  
Neural Network ◽  
Surface Roughness ◽  
Artificial Neural Network ◽  
Aluminum Alloy ◽  
Roughness Parameter ◽  
Cutting Speed ◽  
Roughness Parameters ◽  
Technological Parameters ◽  
Surface Roughness Parameters ◽  
Roughness Prediction

The purpose of this investigation was to determine whether and to what extent the technological parameters of turning (feed, cutting speed) affect selected surface roughness parameters of aluminum alloy EN-AW 7075 (AlZn5.5MgCu). The principal findings indicate a significant impact of feed and show on the surface roughness and simultaneously show that cutting speed has no effect on the value of surface roughness parameters under investigation. An artificial neural network was employed to evaluate the prediction of surface roughness parameter Rz in turning.

Performance study of a back-depression mechanical dry gas seal

1998 ◽  
Vol 212 (4) ◽  
pp. 279-290 ◽  
Author(s):  
T. A. Stolarski ◽  
Y Xue
Keyword(s):  
Finite Element Analysis ◽  
Surface Roughness ◽  
Finite Element ◽  
Roughness Parameter ◽  
Design Procedure ◽  
Control Parameters ◽  
Roughness Parameters ◽  
Performance Study ◽  
Element Analysis ◽  
Dry Gas Seal

An aerostatic mechanical dry gas seal is described in this paper. The seal has shallow depression grooves (compensators) on the back and annular grooves on one of the working faces. With the help of the back depression grooves, a hydrostatic pressure and thereby a separating force with satisfactory stiffness are produced within the sealing gap. A model which takes surface roughness into account was used to predict the performance of the seal. Relationships between the control parameters (the recess position, rG, the nominal film thickness, h0, the depth, hv, of depression grooves and the surface roughness parameter, a) are investigated against various pressure ratios, pe/ pi. The analysis provides a simple optimum design procedure. A finite element analysis was carried out to account for the effect of face deformation during operation of the seal. Experiments for various speeds, pressures and roughness parameters were carried out and the results from the experiments were used to validate the analysis performed. Analysis and experiment revealed the importance of the surface roughness and deformation of the faces for the creation and retention of the gap.

scholarly journals Roughness parameters as the elements of surface condition and deformation assessment based on the results of TLS scanning

2017 ◽  
Vol 49 (1) ◽  
pp. 29-41
Author(s):  
Maria E. Kowalska ◽  
Janina Zaczek-Peplinska
Keyword(s):  
Surface Roughness ◽  
Laser Scanning ◽  
Surface Condition ◽  
Roughness Parameter ◽  
Terrestrial Laser Scanning ◽  
Point Clouds ◽  
Arithmetic Mean ◽  
Roughness Parameters ◽  
Small Surface ◽  
Alternative Approach

Abstract Roughness parameters as the elements of surface condition and deformation assessment based on the results of TLS scanning. Roughness is the attribute of a surface that can be defined as a collection of small surface unevennesses that can be identified optically or detected mechanically which do not result from the surface’s shape and their size depends on a material type as well as on undergone processing. The most often utilised roughness parameters are: Ra - mean distance value of the points on the observed profile from the average line on the sampling length, and Rz - difference between arithmetic mean height of the five highest peaks and arithmetic mean depth of the five deepest valleys regarding to the average line on the length of the measured fragment. In practice, roughness parameters are most often defined for surface elements that require relevant manufacturing or processing through grinding, founding or polishing in order to provide the expected surface roughness. To measure those parameters for the produced elements profilometers are used. In this paper the authors present an alternative approach of determining and utilising such parameters. Instead of the utilising methods based on sampling length measurement, roughness parameters are determined on the basis of point clouds, that represent a surface of rough concrete, obtained through terrestrial laser scanning. The authors suggest using the surface roughness parameter data acquired in this way as a supplementary data in the condition assessment (erosion rate) of surfaces being a part of engineering constructions made of concrete.

scholarly journals Tribological Properties of PVD Ti/C-N Nanocoatnigs

2017 ◽  
Vol 54 (2) ◽  
pp. 64-71
Author(s):  
A. Leitans ◽  
J. Lungevics ◽  
J. Rudzitis ◽  
A. Filipovs
Keyword(s):  
Surface Roughness ◽  
Wear Resistance ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Tribological Properties ◽  
Roughness Parameter ◽  
Surface Wear ◽  
Roughness Parameters ◽  
Coating Deposition ◽  
2D And 3D

Abstract The present paper discusses and analyses tribological properties of various coatings that increase surface wear resistance. Four Ti/C-N nanocoatings with different coating deposition settings are analysed. Tribological and metrological tests on the samples are performed: 2D and 3D parameters of the surface roughness are measured with modern profilometer, and friction coefficient is measured with CSM Instruments equipment. Roughness parameters Ra, Sa, Sz, Str, Sds, Vmp, Vmc and friction coefficient at 6N load are determined during the experiment. The examined samples have many pores, which is the main reason for relatively large values of roughness parameter. A slight wear is identified in all four samples as well; its friction coefficient values range from 0,.21 to 0.29. Wear rate values are not calculated for the investigated coatings, as no expressed tribotracks are detected on the coating surface.

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