Effect of Sampling Interval and Anisotropy on Laser Scanning Accuracy in Rock Material Surface Roughness Measurements

2019 ◽  
Vol 51 (4) ◽  
pp. 678-687
Author(s):  
S. M. Hu ◽  
L. Huang ◽  
Z. J. Chen ◽  
Z. M. Ji ◽  
Z. Liu
Keyword(s):  
Surface Roughness ◽  
Laser Scanning ◽  
Sampling Interval ◽  
Rock Material ◽  
Material Surface ◽  
Roughness Measurements

scholarly journals A Method for Estimating the Surface Roughness of Rock Discontinuities

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Yi Cai ◽  
Hui-ming Tang ◽  
Ding-jian Wang ◽  
Tao Wen
Keyword(s):  
Surface Roughness ◽  
Shear Strength ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Back Analysis ◽  
Sampling Interval ◽  
Primary Objective ◽  
Roughness Coefficient ◽  
Rock Discontinuities ◽  
Estimation Formula

The primary objective of this study is to develop a parameter with a clear physical meaning to estimate the surface roughness of rock discontinuities. This parameter must be closely related to the shear strength of rock discontinuities. The first part of this study focuses on defining and computing this parameter. The estimation formula for the shear strength of a triangle within a discontinuity surface is derived based on Patton’s model. The parameter, namely, the index of roughness (IR), is then proposed to quantitatively estimate discontinuity roughness. Based on laser scanning techniques, digital models of discontinuities and discontinuity profiles are constructed, and then their corresponding IR values are computed. In the second part of this study, the computational processes and estimated effects of the two-dimensional (2D) and three-dimensional (3D) IR values of the discontinuities are illustrated through several applications. Results show that the 2D and 3D IR values of these discontinuities indicate anisotropy and sampling interval effects. In addition, a strong linear correlation is detected between IR and the joint roughness coefficient (JRC) for seventy-four profiles and eleven discontinuity specimens, respectively. Finally, the proposed method, back analysis method, root mean square (Z2) method, and Grasselli’s method are compared to study the use of the parameter IR.

Surface roughness measurements of vanadium-contaminated fluidized cracking catalysts by atomic force microscopy

1996 ◽  
Vol 54 ◽  
pp. 866-867
Author(s):  
H. Kinney ◽  
M.L. Occelli ◽  
S.A.C. Gould
Keyword(s):  
Surface Roughness ◽  
Zeolite Y ◽  
Atomic Level ◽  
Microporous Structure ◽  
Contact Mode ◽  
Force Microscopy ◽  
Atomic Force ◽  
Before And After ◽  
Roughness Measurements ◽  
Cracking Catalysts

For this study we have used a contact mode atomic force microscope (AFM) to study to topography of fluidized cracking catalysts (FCC), before and after contamination with 5% vanadium. We selected the AFM because of its ability to well characterize the surface roughness of materials down to the atomic level. It is believed that the cracking in the FCCs occurs mainly on the catalysts top 10-15 μm suggesting that the surface corrugation could play a key role in the FCCs microactivity properties. To test this hypothesis, we chose vanadium as a contaminate because this metal is capable of irreversibly destroying the FCC crystallinity as well as it microporous structure. In addition, we wanted to examine the extent to which steaming affects the vanadium contaminated FCC. Using the AFM, we measured the surface roughness of FCCs, before and after contamination and after steaming.We obtained our FCC (GRZ-1) from Davison. The FCC is generated so that it contains and estimated 35% rare earth exchaged zeolite Y, 50% kaolin and 15% binder.

Application of Taguchi and Response Surface Methodologies for Surface Roughness in Rotary Tool Polishing Hardness Mould Steels

2011 ◽  
Vol 87 ◽  
pp. 82-89
Author(s):  
Potejanasak Potejana ◽  
Chakthong Thongchattu
Keyword(s):  
Surface Roughness ◽  
Response Surface ◽  
Laser Scanning ◽  
Cutting Speed ◽  
Optimal Level ◽  
Confocal Laser ◽  
Milling Machine ◽  
Cnc Milling ◽  
Polishing Process ◽  
Cnc Milling Machine

This research proposes a new application of 3-axis CNC milling machine for polishing the 60 HRC hardness steels. The rotary polishing tools are designed by refer to the end-mill ball nose’s design. The diamond powder are coated in rotary polishing tools by resinoid bonding method and concentrated in 4.4 karat/cm2. The Zig-milling tool paths are used to polish the hardness steel. After polishing, the confocal laser scanning microscope is used to analyze the arithmetic mean surface roughness of the hardness steels. The L12 orthogonal array of the Taguchi’s method is selected to conduct the matrix experiment to determine the optimal polishing process parameters. The diamond grit size and cutting speed of the rotary polishing tools, feed rate and step over of the tool path, the depth of polishing process penetration, and polishing time are used to study. The combination of the optimal level for each factor of the hardness steel polishing process are used to study again in the confirmation experiment. The predicted signal to noise ratio of smaller - the better under optimal condition are calculated by using the data from the experiment. The combination of the optimal level for each factor are used to study again in the confirmation experiment and the result show that polishing time was a dominant parameter for the surface roughness and the next was depth of penetration. The response surface design is then used to build the relationship between the input parameters and output responses. The experimental results show that the integrated approach does indeed find the optimal parameters that result in very good output responses in the rotary polishing tools polished hardness mould steel using CNC milling machine. The mean surface roughness of hardness steel polishing process is improved by the diamond rotary tools with the 3-axis CNC milling machine.

scholarly journals Atomic force microscopy comparative analysis of the surface roughness of two posterior chamber phakic intraocular lens models: ICL versus IPCL

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Juan Gros-Otero ◽  
Samira Ketabi ◽  
Rafael Cañones-Zafra ◽  
Montserrat Garcia-Gonzalez ◽  
Cesar Villa-Collar ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Atomic Force Microscopy ◽  
Intraocular Lenses ◽  
Posterior Chamber ◽  
Anterior Surface ◽  
Contact Mode ◽  
Force Microscopy ◽  
Atomic Force ◽  
Phakic Intraocular Lenses ◽  
Roughness Measurements

Abstract Background To compare the anterior surface roughness of two commercially available posterior chamber phakic intraocular lenses (IOLs) using atomic force microscopy (AFM). Methods Four phakic IOLs were used for this prospective, experimental study: two Visian ICL EVO+ V5 lenses and two iPCL 2.0 lenses. All of them were brand new, were not previously implanted in humans, were monofocal and had a dioptric power of − 12 diopters (D). The anterior surface roughness was assessed using a JPK NanoWizard II® atomic force microscope in contact mode immersed in liquid. Olympus OMCL-RC800PSA commercial silicon nitride cantilever tips were used. Anterior surface roughness measurements were made in 7 areas of 10 × 10 μm at 512 × 512 point resolution. The roughness was measured using the root-mean-square (RMS) value within the given regions. Results The mean of all anterior surface roughness measurements was 6.09 ± 1.33 nm (nm) in the Visian ICL EVO+ V5 and 3.49 ± 0.41 nm in the iPCL 2.0 (p = 0.001). Conclusion In the current study, we found a statistically significant smoother anterior surface in the iPCL 2.0 phakic intraocular lenses compared with the VISIAN ICL EVO+ V5 lenses when studied with atomic force microscopy.

The effect of a footprint on perceived surface roughness

1986 ◽  
Vol 405 (1829) ◽  
pp. 303-327 ◽  
Keyword(s):  
Surface Roughness ◽  
Weighting Function ◽  
Sampling Interval ◽  
Asymptotic Convergence ◽  
Reference Surface ◽  
Two Dimensional ◽  
Random Surface ◽  
Spectral Density Functions ◽  
Continuous Theory ◽  
Discrete Theory

A two-dimensional homogeneous random surface { y ( X )} is generated from another such surface { z ( X )} by a process of smoothing represented by y ( X ) = ∫ ∞ d u w ( u – X ) z ( u ), where w ( X ) is a deterministic weighting function satisfying certain conditions. The two-dimensional autocorrelation and spectral density functions of the smoothed surface { y ( X )} are calculated in terms of the corresponding functions of the reference surface { z ( X )} and the properties of the ‘footprint’ of the contact w ( X ). When the surfaces are Gaussian, the statistical properties of their peaks and summits are given by the continuous theory of surface roughness. If only sampled values of the surface height are available, there is a corresponding discrete theory. Provided that the discrete sampling interval is small enough, profile statistics calculated by the discrete theory should approach asymptotically those calculated by the continuous theory, but it is known that such asymptotic convergence may not occur in practice. For a smoothed surface { y ( X )} which is generated from a reference surface { z ( X )} by a ‘good’ footprint of finite area, it is shown in this paper that the expected asymptotic convergence does occur always, even if the reference surface is ideally white. For a footprint to be a good footprint, w ( X ) must be continuous and smooth enough that it can be differentiated twice everywhere, including at its edges. Sample calculations for three footprints, two of which are good footprints, illustrate the theory.

Testing the Accuracy of Surface Roughness Measurements Carried out with a Portable Profilometer

2015 ◽  
Vol 637 ◽  
pp. 69-73 ◽  
Author(s):  
Krzysztof Stępień
Keyword(s):  
Surface Roughness ◽  
Measurement Accuracy ◽  
Environmental Changes ◽  
Experimental Tests ◽  
Evaluation Procedure ◽  
Human Errors ◽  
Modern Manufacturing ◽  
Machine Parts ◽  
Roughness Measurements

Surface roughness is a factor that has a vital influence on overall quality of machine parts. This is the reason why proper measurements of surface roughness are a matter of great importance in modern manufacturing technology. Nowadays portable profilometers are common instruments to be used under industrial conditions. Measurements with such instruments can be affected by numerous factors, for example environmental changes, human errors of an operator, etc. This paper discusses problem of an evaluation of measurement accuracy of portable profilometers. It also describes the evaluation procedure and presents results experimental tests.

Influence of surface roughness on the wetting angle

1995 ◽  
Vol 10 (8) ◽  
pp. 1984-1992 ◽  
Author(s):  
X.B. Zhou ◽  
J.Th.M. De Hosson
Keyword(s):  
Surface Roughness ◽  
Gaussian Distribution ◽  
Rough Surfaces ◽  
Contact Angles ◽  
Wetting Angle ◽  
Experimental Results ◽  
Solid Surfaces ◽  
Roughness Measurements

A this paper the influence of surface roughness on contact angles in the system of liquid Al wetting solid surfaces of Al2O3 has been studied. It was observed that contact angles of liquid Al vary significantly on different rough surfaces of Al2O3. A model is proposed to correlate contact angles with conventional roughness measurements and wavelengths by assuming a cosine profile of rough grooves with a Gaussian distribution of amplitudes. In comparison with the experimental results, the model provides a good estimate for describing the influence of surface roughness on contact angles of liquid Al on Al2O3.

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