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Finite element simulation of stress intensity factors in elastic-plastic crack growth

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2006年第8期7卷 1336-1342页

作者： ALSHOAIBI Abdulnaser m ARIFFIN Ahmad Kamal Computational mechanics Research Group Department of Mechanical and Materials Engineering Faculty of Engineering Universiiy Kebangsaan Malaysia Bangi 43600 Malaysia

A finite element program developed elastic-plastic crack propagation simulation using Fortran language. At each propagation step, the adaptive mesh is automatically refined based on a posteriori h-type refinement using norm stress error estimator. A rosette of quarter-point elements is then constructed around the crack tip to facilitate the prediction of crack growth based on the maximum normal stress criterion and to calculate stress intensity factors under plane stress and plane strain conditions. Crack was modelled to propagate through the inter-element in the mesh. Some examples are presented to show the results of the implementation.

关键词： Crack propagation Nodal displacement Stress intensity factor Adaptive mesh Finite element method (FEm)

Efficient Data Augmentation Techniques for Improved Classification in Limited Data Set of Oral Squamous Cell Carcinoma

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Computer modeling in Engineering & Sciences 2022年第6期131卷 1387-1401页

作者： Wael Alosaimi m.Irfan Uddin Department of Information Technology College of Computers and Information TechnologyTaif UniversityTaif21944Saudi Arabia Institute of Computing Kohat University of Science and TechnologyKohat26000Pakistan

Deep Learning(DL)techniques as a subfield of data science are getting overwhelming attention mainly because of their ability to understand the underlying pattern of data in making *** techniques require a considerable amount of data to efficiently train the DL ***,when the data size is larger,the DL models perform ***,it is not possible to have a considerable amount of data in different domains such as *** healthcare,it is impossible to have a substantial amount of data to solve medical problems using Artificial Intelligence,mainly due to ethical issues and the privacy of *** solve this problem of small dataset,different techniques of data augmentation are used that can increase the size of the training ***,these techniques only change the shape of the image and hence the classification model does not increase *** Adversarial Networks(GANs)are very powerful techniques to augment training data as new samples are *** technique helps the classification models to increase their *** this paper,we have investigated augmentation techniques in healthcare image *** objective of this research paper is to develop a novel augmentation technique that can increase the size of the training set,to enable deep learning techniques to achieve higher *** have compared the performance of the image classifiers using the standard augmentation technique and *** results demonstrate that GANs increase the training data,and eventually,the classifier achieves an accuracy of 90%compared to standard data augmentation techniques,which achieve an accuracy of up to 70%.Other advanced CNN models are also tested and have demonstrated that more deep architectures can achieve more than 98%accuracy for making classification on Oral Squamous Cell Carcinoma.

关键词： Data science deep learning data augmentation classification data manipulation

Dynamic analysis of dam-reservoir-foundation interaction using finite difference technique

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Journal of Central South University 2012年第5期19卷 1399-1410页

作者： m.Abdollahi R.Attarnejad School of Civil Engineering University of TehranTehranIran

Time domain dynamic analysis of inclined dam-reservoir-foundation interaction was conducted using finite difference method （FDm）. The Timoshenko beam theory and the Euler-Bemoulli beam theory were implemented to draw out governing equation of beam. The interactions between the dam and the soil were modeled by using a translational spring and a rotational spring. A Sommerfeld＇s radiation condition at the infinity boundary of the fluid domain was adopted. The effects of the reservoir bottom absorption and surface waves on the dam-reservoir-foundation interaction due to the earthquake were studied. To avoid the instability of solution, a semi-implicit scheme was used for the discretization of the governing equation of dam and an explicit scheme was used for the discretization of the governing equation of fluid. The results show that as the slope of upstream dam increases, the hydrodynamic pressure on the dam is reduced. moreover, when the Timoshenko beam theory is used, the system response increases.

关键词： dam-reservoir-foundation interaction inclined dam explicit method semi-implicit method reservoir bottomabsorption free surface waves

Error bounds of a quadrature formula with multiple nodes for the Fourier-Chebyshev coefficients for analytic functions

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Science China mathematics 2019年第9期62卷 1657-1668页

作者： Aleksandar V.■ miodrag m.■ Department of mathematics Faculty of Mechanical Engineering University of Beograd

Three kinds of effective error bounds of the quadrature formulas with multiple nodes that are generalizations of the well-known micchelli-Rivlin quadrature formula, when the integrand is a function analytic in the regions bounded by confocal ellipses, are given. A numerical example which illustrates the calculation of these error bounds is included.

关键词： error bound quadrature formula with multiple nodes analytic function

Study on the Effect of Surface modification on the mechanical and Thermal Behaviour of Flax,Sisal and Glass Fiber

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Journal of Renewable materials 2019年第2期7卷 153-169页

作者： C.m.meenakshi A.Krishnamoorthy Department of mechanical Engineering Sathyabama Institute of Science and TechnologyChennaiTamil NaduIndia

Natural fiber-reinforced hybrid composites can be a better replacement for plastic composites since these plastic composites pose a serious threat to the *** aim of this study is to analyze the effect of surface modification of the natural fibers on the mechanical,thermal,hygrothermal,and water absorption behaviors of flax,sisal,and glass fiber-reinforced epoxy hybrid *** mechanical properties of alkaline treated sisal and flax fibers were found to increase ***,flexural and impact strength of glass/flax-fiber-reinforced hybrid samples improved by 58%,36%,and 51%,respectively,after surface alkaline *** addition,the hygrothermal analysis and water absorption capacity are studied and also the Interfacial bonding properties were analyzed using Scanning Electron microscopic *** thermal analysis using thermogravimetric analyzer reveals that the decomposition temperature for hybrid fiber reinforced composites are between 306 and 312℃.In conclusion,surface treatment improves the performance of natural fiber in hybrid fiber-reinforced composites,particularly flax fiber.

关键词： Hybrid composite surface treatments mechanical testing thermal analysis hygrothermal testing water absorption SEm analysiss

Investigation of Even-Even Ru Isotopes in Interacting Boson model-2

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Communications in Theoretical Physics 2006年第4X期46卷 697-703页

作者： A.H. Yilmaz m. Kuruoglu Department of Physics Karadeniz Technical University Trabzon 61080 ~hrkey

The interacting boson model of Arima, Iachello, and co-workers is applied to the even ruthenium isotopes, ^96 Ru -116Ru. Excitation energies, electromagnetic transition strengths, quadrupole and magnetic dipole moments, and △（E2/m1） mixing ratios have been described systematically. mixed symmetry states are investigated. It is seen that the properties of low-lying levels in these isotopes, for which the comparison between experiment and theory is possible, can be satisfactorily characterized by the Interacting Boson model-2.

关键词： nuclear structure ^96Ru- ^116Ru energy levels interacting boson model-2

Evaluation of zirconia–porcelain interface using X-ray diffraction

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International Journal of Oral Science 2015年第3期7卷 187-195页

作者： Tariq F Alghazzawi Gregg m Janowski Department of materials Science and Engineering School of Engineering The University of Alabama at Birmingham Department of Prosthetic Dental Sciences College of Dentistry Taibah University

The aim of this study was to determine if accelerated aging of porcelain veneering had an effect on the surface properties specific to a tetragonal-to-monoclinic transformation（TmT） of zirconia restorations. Thirty-six zirconia samples were milled and sintered to simulate core fabrication followed by exposure to various combinations of surface treatments including as-received（control）,hydrofluoric acid（HF）, application of liner plus firings, application of porcelain by manual layering and pressing with firing, plus accelerated aging. The quantity of transformed tetragonal to monoclinic phases was analyzed utilized an X-ray diffractometer and one-way analysis of variance was used to analyze data. The control samples as provided from the dental laboratory after milling and sintering process had no TmT（X m5 0）. There was an effect on zirconia samples of HF application with TmT（X m5 0.8%） and liner plus HF application with TmT（X m5 8.7%）. There was an effect of aging on zirconia samples（no veneering） with significant TmT（X m5 70.25%）. Both manual and pressing techniques of porcelain applications reduced the TmT（manual, X m5 4.41%, pressing,X m5 11.57%）, although there was no statistical difference between them. It can be concluded that simulated applications of porcelain demonstrated the ability to protect zirconia from TmT after aging with no effect of a liner between different porcelain *** HF treatment also caused TmT.

关键词： aging hydrofluoric acid monoclinic pressing tetragonal X-ray diffraction

Evaluating droplet distribution of spray-nozzles for dust reduction in livestock buildings using machine vision

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International Journal of Agricultural and Biological Engineering 2015年第5期8卷 58-64页

作者： Saman Abdanan mehdizadeh Thomas m Banhazi National Centre for Engineering in Agriculture(NCEA) University of Southern Queensland(USQ)Toowoomba QLD 4350 Australia Department of mechanics of Biosystems Engineering College of Agricultural Engineering and Rural DevelopmentRamin University of Agriculture and Natural Resources of KhuzestanMollasaniAhvazKhuzestan 118/7 Iran

Previous studies have demonstrated the negative effects of sub-optimal air quality on profitability,production efficiency,environmental sustainability and animal *** were conducted to assess potential environmental improvement techniques such as installing oil-spraying systems in piggery *** developed spray system worked very well and it was easy to assemble and ***,before selecting the most suitable spray heads,their capacity to uniformly distribute the oily mixture and the area covered by the spray heads had to be *** vision techniques were used to evaluate the ability of different spray heads to evenly distribute the oil/water *** results indicated that the best coverage was achieved by spray head No.4 and spray head No.1 which covered 79%and 67%of the target area,*** distribution uniformity(variance)value was the lowest for spray head No.4(0.015).Spray head No.3 had the highest variance value(0.064).As the lowest variance means higher uniformity,nozzle No.4 was identified as the most suitable spray head for dust reduction in livestock buildings.

关键词： spray head livestock buildings dust reduction machine vision spray distribution uniformity animal welfare

mRI Brain Tumor Segmentation with Intuitionist Possibilistic Fuzzy Clustering and morphological Operations

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Computer Systems Science & Engineering 2022年第10期43卷 363-379页

作者： J.Anitha m.Kalaiarasu Department of Information Technology Sri Ramakrishna Engineering CollegeCoimbatore641022India

Digital Image Processing(DIP)is a well-developed field in the biological sciences which involves classification and detection of *** medical science,automatic brain tumor diagnosis is an important *** tumor detection is performed by Computer-Aided Diagnosis(CAD)*** human image creation is greatly achieved by an approach namely medical imaging which is exploited for medical and research *** Automatic brain tumor detection from mRI images has become the emerging research area of medical *** tumor diagnosis mainly performed for obtaining exact location,orientation and area of abnormal *** and edema regions inference from brain magnetic resonance imaging(mRI)information is considered to be great challenge due to brain tumors complex structure,blurred borders,besides exterior features like *** noise compassion is mainly reduced along with segmentation stability by suggesting efficient hybrid clustering method merged with morphological process for brain cancer *** form of median modified Wiener filter(CmmWF)is chiefly deployed for denoising,and morphological operations which in turn eliminate nonbrain tissue,efficiently dropping technique’s sensitivity to *** proposed system contains the main phases such as preprocessing,brain tumor extraction and post *** segmentation is greatly achieved by presenting Intuitionist Possibilistic Fuzzy Clustering(IPFC)*** algorithm’s stability is greatly enhanced by this clustering along with clustering parameters sensitivity ***,the post processing of images are done through morphological operations along with Hybrid median filtering(HmF)for attaining exact tumors ***,suggested algorithm is substantiated by comparing with other existing segmentation *** outcomes reveal that suggested algorithm achieves improved outcomes pertaining to accuracy,sensitivity,specificity,and recall.

关键词： morphological Image Processing(mIP) magnetic Resonance Imaging(mRI) brain tumor clustering K-means clustering image segmentation Fuzzy-Cmeans(FCm)