scholarly journals Wavelet Analysis-Based Texture Analysis of Ceramic Surface Images

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Yanbing Liu ◽  
Bei Zhou ◽  
Xinghua Yang
Keyword(s):  
Fractal Dimension ◽  
Wavelet Analysis ◽  
Light Source ◽  
Detection System ◽  
Fractal Theory ◽  
Three Dimensional ◽  
Surface Profile ◽  
Ceramic Surface ◽  
Fractal Method ◽  
Main Research

This paper is conducted to explore a new characterization method as a supplement to the traditional roughness characterization. The main research includes the extraction and evaluation of damage features of ceramic surface morphology by applying wavelet methods, the extraction of damage features in surface contours by using wavelet analysis, and the quantitative evaluation of damage degree by using damage rate and damage mean spacing. By comparing various fractal dimension calculation methods, a fractal dimension method suitable for calculating the ceramic surface was selected, and the fractal method was used to describe the ceramic surface topography as a whole. By comparing different methods of calculating the fractal dimension and further verifying them with the measured three-dimensional morphology, it is found that the vibrational method is more suitable for calculating the fractal dimension of ceramic surface, and its calculation accuracy is investigated, and the results show that the method is a reliable one. Based on the fractal theory, a mathematical model of surface wear and surface sealing was established. Further study of the model shows that the surface with a large fractal dimension has a good sealing effect; the surface corresponding to the best fractal dimension is the most resistant to wear. The fractal method can characterize the complexity of the surface profile as a whole. The wavelet method can describe the ceramic surface profile from a local perspective, and the combination of the two methods can characterize the ceramic surface well. Finally, the experimental device of the ceramic surface defect detection system is constructed, and the joint debugging of hardware and software is completed. Under different light source intensities, ceramic image samples are collected, and the accuracy detection experiments of sample defective edges are conducted, and the results show that the light source has a small impact on the accuracy of ceramic defective edge detection. The results show that the light source has more influence on the accuracy of scratch detection. The results show that the system constructed in this thesis has good applicability for different ceramic sample detection.

EFFECT OF FRACTAL FRACTURES ON PERMEABILITY IN THREE-DIMENSIONAL DIGITAL ROCKS

Fractals ◽  
2019 ◽  
Vol 27 (01) ◽  
pp. 1940015 ◽  
Author(s):  
WEIFENG LV ◽  
GUOLIANG YAN ◽  
YONGDONG LIU ◽  
XUEFENG LIU ◽  
DONGXING DU ◽  
...  
Keyword(s):  
Fractal Dimension ◽  
Fractal Theory ◽  
Fractured Reservoirs ◽  
Three Dimensional ◽  
Absolute Permeability ◽  
Fracture Aperture ◽  
Fracture Networks ◽  
Discrete Fracture Networks ◽  
Discrete Fracture ◽  
The Relationship

The fracture has great impact on the flow behavior in fractured reservoirs. Fracture traces are usually self-similar and scale-independent, which makes the fractal theory become a powerful tool to characterize fracture. To obtain three-dimensional (3D) digital rocks reflecting the properties of fractured reservoirs, we first generate discrete fracture networks by stochastic modeling based on the fractal theory. These fracture networks are then added to the existing digital rocks of rock matrixes. We combine two low-permeable cores as rock matrixes with a group of discrete fracture networks with fractal characteristics. Various types of fractured digital rocks are obtained by adjusting different fracture parameters. Pore network models are extracted from the 3D fractured digital rock. Then the permeability is predicted by Darcy law to investigate the impacts of fracture properties to the absolute permeability. The permeability of fractured rock is subject to exponential increases with fracture aperture. The relationship between the permeability and the fractal dimension of fracture centers is exponential, as well as the relationship between permeability and the fractal dimension of fracture lengths.

Quantitative Analysis for Micro Geometrical Characteristic of Rough Surface Profile Based on Fractal Theory

2010 ◽  
Vol 154-155 ◽  
pp. 19-22
Author(s):  
Xiu Juan Yang ◽  
Zhi Qian Xu ◽  
Xiang Zhen Yan
Keyword(s):  
Surface Roughness ◽  
Fractal Dimension ◽  
Quantitative Analysis ◽  
Rough Surface ◽  
Vertical Section ◽  
Fractal Theory ◽  
Surface Profile ◽  
Fractal Dimensions ◽  
Geometrical Characteristic ◽  
Accuracy Requirement

In this paper, a quantitative analysis for the micro geometrical characteristic of rough surface profile is researched with the fractal theory. Firstly, the fractal dimensions of profile curves under different surface roughness are obtained by using the vertical section method, and then the theoretical relationship between the surface roughness and the fractal dimension is built. Secondly, according to the surface profile curve composed of many triangle peaks, the angles and heights of them are calculated to study the micro geometrical size. Through their variation laws changing with the fractal parameters, the calculation formulas of their average values related to fractal dimension are obtained by using mathematics regression tools. Finally, combing three theoretical relationships built above, the geometrical characteristic of the rough surface profile can be calculated with the surface roughness and accuracy requirement known.

Erosion Characteristics Based on GIS and Fractal Dimensions

2011 ◽  
Vol 271-273 ◽  
pp. 1142-1145
Author(s):  
Chun Xia Yang ◽  
Bin Zhen ◽  
Li Li ◽  
Jing Huang ◽  
Peng Jiao
Keyword(s):  
Fractal Dimension ◽  
Soil Erosion ◽  
Rainfall Intensity ◽  
Fractal Theory ◽  
Three Dimensional ◽  
Laser Scanner ◽  
Fractal Dimensions ◽  
Rill Erosion ◽  
Pattern Complexity ◽  
Erosion Processes

Soil erosion processes and erosion distribution was research focus to establish distributed mathematical equation in the soil erosion areas, GIS techniques and fractal theory provide a means to advance these studies.Slope erosion patterns of bare slope was studied under rainfall intensities of 45、90 and 130mm/h with 20°slope gradient using simulated rainfall experiment. The results showed that the time of rill appeared of lower rainfall intensity was later than that of high rainfall intensity；Within the rainfall time，the rill scale expanded increased with the increasing of rainfall intensity; The erosion distribution was studied by the three-dimensional laser scanner，The trend of rill erosion deep kept roughly consistent with that of sediment; The characteristics was analyzed of slope erosion by GIS, the fractal dimension and sediment were both increased with rainfall intensity, The fractal dimension was increasing with erosion pattern complexity. So the fractal dimension is the representative of erosion complexity.

scholarly journals Research on the Three Dimensional Detection Technology for Magnetic Sheet in Industrial Production

2015 ◽  
Vol 9 (1) ◽  
pp. 585-593
Author(s):  
Wenbo Zhang ◽  
Chuo Yang ◽  
Yongxin Feng ◽  
Deyu Zhang
Keyword(s):  
Edge Detection ◽  
Detection System ◽  
Three Dimensional ◽  
Measurement Data ◽  
Surface Profile ◽  
Noise Interference ◽  
Image Edge Detection ◽  
Detection Technology ◽  
Measurement Function ◽  
Image Edge

This study proposes a three-dimensional size detection system for inerratic magnetic sheets according to specific size parameter requirements, such as the volume of the industrial micro magnetic sheet. Based on the noise interference generated by the corresponding detection environment of the magnetic sheet, a hybrid filtering method for the inerratic magnetic sheet is also proposed here, which effectively implements denoising filtering. In the image edge detection module, the edge detection operator most suitable for detecting image edge extraction is selected, and in order to realize the inerratic shape detection in Hough transform, the measurement function of size parameters (including the top surface radius, tilt angle of the profile and top surface, profile thickness, and volume) for the micro cylinder magnetic sheet are designed and implemented. Measurement data, gathered through repeated experiments, builds a more effective detection system for magnetic sheet size than traditional methods at the millimeter level.

scholarly journals Numerical Simulation and Accuracy Verification of Surface Morphology of Metal Materials Based on Fractal Theory

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4158
Author(s):  
Xiaokai Mu ◽  
Wei Sun ◽  
Chong Liu ◽  
Bo Yuan ◽  
Yunlong Wang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Fractal Dimension ◽  
Surface Morphology ◽  
Fractal Theory ◽  
Surface Profile ◽  
Reference Value ◽  
Fractal Dimensions ◽  
Current Method ◽  
Simulation Method ◽  
Surface Morphologies

This paper presents a numerical simulation method to determine the surface morphology characteristics of metallic materials. First, a surface profiler (NV5000 5022s) was used to measure the surface, and the morphology data thereof were characterized. Second, fractal theory was used to simulate the surface profile for different fractal dimensions D and scale coefficients G, and statistical analyses of different surface morphologies were carried out. Finally, the fractal dimension D of the simulated morphology and the actual morphology were compared. The analysis showed that the error of fractal dimension D between the two morphologies was less than 10%; meanwhile, the comparison values of the characterization parameters of the simulated morphology and the actual morphology were approximately equal, and the errors were below 6%. Therefore, the current method used to evaluate the surface morphologies of parts processed by the grinding/milling method can be replaced by the simulated method using the corresponding parameters. This method makes it possible to theorize about the surface morphologies of machined parts, and provides a theoretical basis and reference value for the surface morphology design of materials, with the potential to improve the assembly quality of products.

Fractal Analysis of Self-Sharpening Phenomenon in cBN Grinding

2008 ◽  
Vol 389-390 ◽  
pp. 42-47 ◽  
Author(s):  
Yoshio Ichida ◽  
Ryunosuke Sato ◽  
Masakazu Fujimoto ◽  
Nabil Ben Fredj
Keyword(s):  
Fractal Dimension ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Fractal Analysis ◽  
Three Dimensional ◽  
Surface Profile ◽  
Cutting Edge ◽  
The Self ◽  
Grinding Process ◽  
Scanning Electron

This paper presents a fractal analysis of the self-sharpening phenomenon of the grain cutting edges in cBN grinding. To clarify the self-sharpening mechanism due to the micro fracture of the cutting edges, the changes in three-dimensional profile of the cutting edges in the grinding process have been measured using a scanning electron microscope with four electron probes and evaluated on the basis of the fractal analysis. The fractal dimension for surface profile of the cutting edge formed by the micro fracture is higher than that of the cutting edge formed by the ductile attritious wear. Therefore, the complicated changes in shape of the cutting edge due to the self-sharpening can be evaluated quantitatively using the fractal dimension.

scholarly journals Dynamic characteristics and fractal representations of crack propagation of rock with different fissures under multiple impact loadings

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bing Sun ◽  
Shun Liu ◽  
Sheng Zeng ◽  
Shanyong Wang ◽  
Shaoping Wang
Keyword(s):  
Fractal Dimension ◽  
Crack Propagation ◽  
Crack Growth ◽  
Impact Test ◽  
Fractal Theory ◽  
Dynamic Change ◽  
Fractal Dimensions ◽  
Peak Stress ◽  
Dynamic Mechanical Properties ◽  
Gravitational Potential Energy

AbstractTo investigate the influence of the fissure morphology on the dynamic mechanical properties of the rock and the crack propagation, a drop hammer impact test device was used to conduct impact failure tests on sandstones with different fissure numbers and fissure dips, simultaneously recorded the crack growth after each impact. The box fractal dimension is used to quantitatively analyze the dynamic change in the sandstone cracks and a fractal model of crack growth over time is established based on fractal theory. The results demonstrate that under impact test conditions of the same mass and different heights, the energy absorbed by sandstone accounts for about 26.7% of the gravitational potential energy. But at the same height and different mass, the energy absorbed by the sandstone accounts for about 68.6% of the total energy. As the fissure dip increases and the number of fissures increases, the dynamic peak stress and dynamic elastic modulus of the fractured sandstone gradually decrease. The fractal dimensions of crack evolution tend to increase with time as a whole and assume as a parabolic. Except for one fissure, 60° and 90° specimens, with the extension of time, the increase rate of fractal dimension is decreasing correspondingly.

scholarly journals Effect of Hydrophobic Silica Nanochannel Structure on the Running Speed of a Colloidal Damper

2021 ◽  
Vol 11 (15) ◽  
pp. 6808
Author(s):  
Gengbiao Chen ◽  
Zhiwen Liu
Keyword(s):  
Fractal Dimension ◽  
Silica Gel ◽  
Fractal Theory ◽  
Percolation Model ◽  
Silica Gels ◽  
Practical Significance ◽  
Running Speed ◽  
Fractal Percolation ◽  
Micropore Structure ◽  
Hydrophobic Silica

A colloidal damper (CD) can dissipate a significant amount of vibrations and impact energy owing to the interface power that is generated when it is used. It is of great practical significance to study the influence of the nanochannel structure of hydrophobic silica gel in the CD damping medium on the running speed of the CD. The fractal theory was applied to observe the characteristics of the micropore structure of the hydrophobic silica gel by scanning electron microscopy (SEM), the primary particles were selected to carry out fractal analysis, and the two-dimensional fractal dimension of the pore area and the tortuous fractal dimension of the hydrophobic silica gel pore structure were calculated. The fractal percolation model of water in hydrophobic silica nanochannels based on the slip theory could thus be obtained. This model revealed the relationship between the micropore structure parameters of the silica gel and the running speed of the CD. The CD running speed increases with the addition of grafted molecules and the reduction in pore size of the silica gel particles. Continuous loading velocity testing of the CD loaded with hydrophobic silica gels with different pore structures was conducted. By comparing the experimental results with the calculation results of the fractal percolation model, it was determined that the fractal percolation model can better characterize the change trend of the CD running velocity for the first loading, but the fractal dimension was changed from the second loading, caused by the small amount of water retained in the nanochannel, leading to the failure of fractal characterization.

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