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Correlations between mineral composition and mechanical properties of granite using digital image processing and discrete element method

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International Journal of Mining Science and Technology 2023年第8期33卷 949-962页

作者： Changdi He Brijes Mishra Qingwen Shi Yun Zhao Dajun Lin Xiao Wang Department of Mining Engineering University of UtahSalt Lake City 84112USA College of Mine Safety North China Institute of Science and TechnologyLangfang 065201China Department of Mining Engineering West Virginia UniversityMorgantown 26506USA Department of Electrical and Computer Engineering University of UtahSalt Lake City 84112USA College of Energy and Mining Engineering Shandong University of Science and TechnologyQingdao 266590China

This study investigated the correlations between mechanical properties and mineralogy of granite using the digital image processing(DIP) and discrete element method(DEM). The results showed that the X-ray diffraction(XRD)-based DIP method effectively analyzed the mineral composition contents and spatial distributions of granite. During the particle flow code(PFC2D) model calibration phase, the numerical simulation exhibited that the uniaxial compressive strength(UCS) value, elastic modulus(E), and failure pattern of the granite specimen in the UCS test were comparable to the experiment. By establishing 351 sets of numerical models and exploring the impacts of mineral composition on the mechanical properties of granite, it indicated that there was no negative correlation between quartz and feldspar for UCS, tensile strength(σ_(t)), and E. In contrast, mica had a significant negative correlation for UCS, σ_(t), and E. The presence of quartz increased the brittleness of granite, whereas the presence of mica and feldspar increased its ductility in UCS and direct tensile strength(DTS) tests. Varying contents of major mineral compositions in granite showed minor influence on the number of cracks in both UCS and DTS tests.

关键词： Granite digital image processing Discrete element method Mineral composition Mechanical properties

Analysis of morphological characteristics of gravels based on digital image processing technology and self-organizing map

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Journal of Arid Land 2023年第3期15卷 310-326页

作者： XU Tao YU Huan QIU Xia KONG Bo XIANG Qing XU Xiaoyu FU Hao College of Earth Science Chengdu University of TechnologyChengdu 610059China Beijing SuperMap Software Co. Ltd.Beijing 100015China Sichuan Real Estate Registration Center Chengdu 610014China Chengdu Institute of Mountain Land and Disasters Chinese Academy of SciencesChengdu 610041China School of Earth Systems and Sustainability Southern Illinois University CarbondaleCarbondaleIL 62901United States of America Environmental Resources and Policy Southern Illinois University CarbondaleCarbondaleIL 62901United States of America Sichuan Institute of Land and Space Ecological Restoration and Geohazard Prevention Chengdu 610081China

A comprehensive understanding of spatial distribution and clustering patterns of gravels is of great significance for ecological restoration and ***,traditional methods for studying gravels are low-efficiency and have many *** study researched the spatial distribution and cluster characteristics of gravels based on digital image processing technology combined with a self-organizing map(SOM)and multivariate statistical methods in the grassland of northern Tibetan ***,the correlation of morphological parameters of gravels between different cluster groups and the environmental factors affecting gravel distribution were *** results showed that the morphological characteristics of gravels in northern region(cluster C)and southern region(cluster B)of the Tibetan Plateau were similar,with a low gravel coverage,small gravel diameter,and elongated *** regions were mainly distributed in high mountainous areas with large topographic *** central region(cluster A)has high coverage of gravels with a larger diameter,mainly distributed in high-altitude plains with smaller *** component analysis(PCA)results showed that the gravel distribution of cluster A may be mainly affected by vegetation,while those in clusters B and C could be mainly affected by topography,climate,and *** study confirmed that the combination of digital image processing technology and SOM could effectively analyzed the spatial distribution characteristics of gravels,providing a new mode for gravel research.

关键词： self-organizing map digital image processing morphological characteristics multivariate statistical method environmental monitoring

Simulation of Fracture Process of Lightweight Aggregate Concrete Based on digital image processing Technology

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Computers, Materials & Continua 2024年第6期79卷 4169-4195页

作者： Safwan Al-sayed Xi Wang Yijiang Peng Key Laboratory of Urban Security and Disaster Engineering Ministry of EducationBeijing University of TechnologyBeijing100124China

The mechanical properties and failure mechanism of lightweight aggregate concrete(LWAC)is a hot topic in the engineering field,and the relationship between its microstructure and macroscopic mechanical properties is also a frontier research topic in the academic *** this study,the image processing technology is used to establish a micro-structure model of lightweight aggregate *** the information extraction and processing of the section image of actual light aggregate concrete specimens,the mesostructural model of light aggregate concrete with real aggregate characteristics is *** numerical simulation of uniaxial tensile test,uniaxial compression test and three-point bending test of lightweight aggregate concrete are carried out using a new finite element method-the base force element method ***,the image processing technology is used to produce beam specimens,uniaxial compression specimens and uniaxial tensile specimens of light aggregate concrete,which can better simulate the aggregate shape and random distribution of real light aggregate ***,the three-point bending test is numerically ***,the uniaxial compression specimen generated by image processing technology is numerically ***,the uniaxial tensile specimen generated by image processing technology is numerically *** mechanical behavior and damage mode of the specimen during loading were *** results of numerical simulation are compared and analyzed with those of relevant *** feasibility and correctness of the micromodel established in this study for analyzing the micromechanics of lightweight aggregate concrete materials are *** processing technology has a broad application prospect in the field of concrete mesoscopic damage analysis.

关键词： digital image processing lightweight aggregate concrete mesoscopic model numerical simulation fracture analysis bending beams

Numerical simulation of direct shear tests on mechanical properties of talus deposits based on self-adaptive PCNN digital image processing

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Journal of Central South University 2014年第7期21卷 2904-2914页

作者：王盛年徐卫亚石崇张强 Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering(Hohai University) Institute of Geotechnical Research Hohai University

The macro mechanical properties of materials with characteristics of large scale and complicated structural composition can be analyzed through its reconstructed *** this work,the meso-structures of talus deposits that widely exist in the hydro-power engineering in the southwest of China were first reconstructed by small particles according to the in-situ photographs based on the self-adaptive PCNN digital image processing,and then numerical direct shear tests were carried out for studying the mechanical properties of talus *** indicate that the reconstructed meso-structures of talus deposits are more consistent with the actual situation because the self-adaptive PCNN digital image processing has a higher discrimination in the details of soil-rock *** existence and random distribution of rock blocks make the initial shear stiffness,the peak strength and the residual strength higher than those of the "pure soil" with particle size less than 1.25 cm apparently,but reduce the displacements required for the talus deposits reaching its peak shear *** increase of rock proportion causes a significant improvement in the internal friction angle of talus deposit,which to a certain degree leads to the characteristics of shear stress-displacement curves having a changing trend from the plastic strain softening deformation to the nonlinear strain hardening deformation,while an unconspicuous increase in *** uncertainty and heterogeneity of rock distributions cause the differences of rock proportion within shear zone,leading to a relatively strong fluctuation in peak strengths during the shear process,while movement features of rock blocks,such as translation,rotation and crossing,expand the scope of shear zone,increase the required shear force,and also directly lead to the misjudgment that the lower shear strength is obtained from the samples with high rock ***,however,just explains the reason why the shear st

关键词： talus deposits digital image processing pulse coupled neural networks(PCNN) direct shear test mechanical property granular discrete element method

3D reconstruction of single rising bubble in water using digital image processing and characteristic matrix

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Particuology 2013年第2期11卷 170-183页

作者： Yuchen Bian Feng Dong Weida Zhang Hongyi Wang Chao Tan Zhiqiang Zhang Tianjin Key Laboratory of Process Measurement and Control School of Electrical Engineering and AutomationTianjin University School of Electrical Engineering and Automation Tianjin Polytechnic University

Reconstructing the shape of a bubble will lay a firm foundation for further description of the dynamic characteristics of bubbly flow, especially for a single rising bubble or separate bubbles whose interaction could be neglected. In this case, the rising bubble is usually simulated as an ellipsoid consisting of two semi-eUipsoids up and down. Thus the projected image of a bubble consists of two semi-ellipses. In this paper, a method for reconstructing the ellipsoid bubble model is described following digital image processing, using the Hough transform in 2D ellipse parameter extraction which could cover most of the bubble edge points in the image. Then a method based on characteristic symmetric matrix is described to detect 3D bubble ellipsoid model parameters from 2D ellipse parameters of projection planes. This method can be applied to bubbles rising with low-velocity in static flow field much in conformity with the projection theory and the shape variation of the rising bubble. This method does not need to solve nonlinear equation sets and provides an easy way to calculate the characteristic matrix of a space ellipsoid model for deformed bubble. For bubble application, two assumed conditions and a calibration factor are proposed to simplify calculation and detection. Errors of ellipsoid center and three axes are minor. Errors of the three rotation angles have no negative effect on further study on bubbly flow.

关键词： Bubble digital image processing Parameter extraction Ellipsoid model Reconstruction Characteristic matrix

Measuring Structural Parameters of Knitted Fabrics by digital image processing Techniques

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Journal of Donghua University(English Edition) 2005年第4期22卷 58-62页

作者：宋广礼陈莉 School of textile and clothing TianJin Polytechnic University TianJin 300160

In the knitting industry the measurements of the stitch density and the stitch length are usually done manually, which may lead to lower efficiency and less definition and also bring subjective ideas into the test results. In order to improve the effect we can measure with digital image processing Techniques. A piece of sample is scanned into computer and changed into a digital image, which is processed with media filtering. To acquire the power spectrum, the image in the spatial domain is converted into the frequency domain. Picking up the characteristic points describing the stitch density and the stitch length separately in the power spectra and reconstructing them, the values of the stitch density and the stitch length could be calculated. When measuring the stitch length, we should establish a geometric model of the stitch based en the digital image processing, which provides a method to transform the stitch length in the two-dimensien space into the three-dimensien space and to measure the value of the stitch length more accurately. This method also provides a new way to measure the stitch length without damaging the fabric.

关键词： Weft knitted fabrics stitch density stitch length digital image processing two-dimension Fourier transformation geometric model of the stitch.

Shape characterization of sand particles based on digital image processing technology

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Journal of Southeast University(English Edition) 2020年第3期36卷 313-321页

作者： Zhou Xinwen Liu Jianzhong Zhu Jiang Mao Yonglin Liu Jiaping School of Materials Science and Engineering Southeast UniversityNanjing 211189China State Key Laboratory of High Performance Civil Engineering Materials Jiangsu Research Institute of Building ScienceNanjing 210008China College of Materials Science and Engineering Chongqing UniversityChongqing 400044China Sobute New Materials Co. Ltd.Nanjing 211103China

To characterize the shape of sand particles for concrete,a new method is proposed based on digital image processing(known as the DIP method).By analyzing sand particles projection,the length,width and thickness of sand were measured to characterize particle *** area and perimeter were measured to characterize particle *** results of the DIP method and Vernier caliper were compared to examine the accuracy of the DIP *** sample size test was conducted to show the statistical significance of shape results measured by the DIP *** practicality of the DIP method was verified by instance *** results show that aspect ratios and roundness measured by the DIP method are equal to ones by the Vernier *** by DIP are dependent on the sand particle number,and at least 350 particles should be measured to represent the overall shape property of *** results show that the DIP method is able to distinguish the differences in the shape of sand *** achieves the direct measurement of sand particle thickness,and the characterization results of sand aspect ratios and roundness are accurate,statistically significant and ***,the DIP method is suitable for sand particle shape characterization.

关键词： particle shape sand form angularity digital image processing

New Optical Triangulation and digital image processing in Measurement

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Semiconductor Photonics and Technology 1996年第2期2卷 103-107页

作者： ZHOU Jian ZHAO Hong CHEN Wenyi TIAN Feng TAN Yushan(Xi’an Jiaotong University,Xi’an 710049 CHN)

In this paper,a new direct optical triangulation(DOT) for measuring theout-of-plane displacement is *** order to state its principle,DOT is used to measure a micro-displacement of a rigid body,and at the same time,the... 详细信息

关键词： Optical Triangulation Displacement Measurement Sensor digital image processing

Application of digital image processing technology in the data restoring process of multi-level digital holographic storage

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Application of digital image processing technology in the da...