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Application of Nonlinear Lamb Wave Mixing Method for Residual Stress Measurement in Metal Plate

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Chinese Journal of Mechanical Engineering 2023年第1期36卷 211-223页

作者： Jingpin Jiao Li Li Xiang Gao Quan Cheng Cunfu He Bin Wu faculty of Materials and Manufacturing Beijing University of TechnologyBeijing 100124China

Harmonic nonlinear ultrasound can offer high sensitivity for residual stress measurements;however,it cannot be used for local stress measurements at a point in space and exhibits nonlinear distortions in the experimental *** paper presents a feasibility study on the measurement of residual stress in a metal plate using a nonlinear Lamb wave-mixing *** resonant conditions for two Lamb waves to generate a mixing frequency wave are obtained via theoretical *** element simulations are performed to investigate the nonlinear interactions between the two Lamb *** show that two incident A0 waves interact in regions of material nonlinearity and generate a rightward S0 wave at the sum *** stress measurement experiments are conducted on steel plate specimens using the collinear Lamb wave-mixing *** setting different delays for two transmitters,the generated sum-frequency component at different spatial locations is *** results show that the spatial distribution of the amplitude of the sum-frequency component agrees well with the spatial distribution of the residual stress measured using *** proposed collinear Lamb wave-mixing method is effective for measuring the distribution of residual stress in metal plates.

关键词： Residual stress Lamb wave Collinear wave mixing Nondestructive testing Resonant conditions

Lattice Boltzmann simulation of the effects of cavity structures and heater thermal conductivity on nucleate boiling heat transfer

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Applied Mathematics and Mechanics(English Edition) 2023年第6期44卷 981-996页

作者： Fanming CAI Zhaomiao LIU Nan ZHENG Yanlin REN Yan PANG faculty of Materials and Manufacturing Beijing University of TechnologyBeijing 100124China

The boiling heat transfer technology with cavity surfaces can provide higher heat flux under lower wall superheat,which is of great significance for the cooling of electronic chips and microelectromechanical *** this paper,the boiling characteristics of the cavity surfaces are investigated based on the lattice Boltzmann(LB)method,focusing on the effects of cavity shapes,sizes,and heater thermal conductivity on the heat transfer *** results show that the triangular cavity has the best boiling performance since it has less residual vapor and higher bubble departure frequency than those of the trapezoidal and rectangular *** the cavity size increases,the enhancement of heat transfer by the cavity mouth is suppressed by the heat accumulation effect at the heater *** liquid rewetting process during bubble departure is the reason for the fluctuation of the space-averaged heat flux,and the heater thermal conductivity determines the fluctuation *** evaporation of liquid in the cavity with high thermal conductivity walls is more intense,resulting in shorter waiting time and higher bubble departure frequency.

关键词： lattice Boltzmann(LB)method boiling cavity conjugate heat transfer

Cosmological applications in Kaluza-Klein theory

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Chinese Physics B 2012年第4期21卷 631-637页

作者： M. I. Wanas Gamal G. L. Nashed A. A. Nowaya Astronomy Department Faculty of Science Cairo University Giza Egypt Mathematics Department Faculty of Science Ain Shams University Cairo 11566 Egypt Center for Theoretical Physics British University of Egypt Sherouk City 11837 P.O. Box 43 Egypt Mathematics Department Faculty of Science King Faisal University P.O. Box 380 Al-Ahsaa 31982 the Kingdom of Saudi Arabia Egyptian Relativity Group (ERG) Physics Department Faculty of Science Monofia University Monofia Egypt

The field equations of Kaluz-Klein （KK） theory have been applied in the domain of cosmology. These equations are solved for a fiat universe by taking the gravitational and the cosmological constants as a function of time t. We use Taylor＇s expansion of cosmological function, A（t）, up to the first order of the time t. The cosmological parameters are calculated and some cosmological problems are discussed.

关键词： Kaluz-Klein theory cosmology Taylor's expansion of cosmological function

Resonance response of fluid-conveying pipe with asymmetric elastic supports coupled to lever-type nonlinear energy sink

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Applied Mathematics and Mechanics(English Edition) 2022年第12期43卷 1873-1886页

作者： Runqing CAO Zhijian WANG Jian ZANG Yewei ZHANG faculty of Aerospace Engineering Shenyang Aerospace UniversityShenyang 110136China

This paper studies the vibration absorber for a fluid-conveying pipe,where the lever-type nonlinear energy sink(LNES)and spring supports are coupled to the asymmetric ends of the *** pseudo-arc-length method integrated with the harmonic balance method is used to investigate the steady-state responses ***,the numerical solution of the fluid-conveying pipe is calculated with the Runge-Kutta ***,a special response,called the collapsible closed detached response(CCDR),is first observed when the vibration response of mechanical structures is ***,the relationship between the CCDR and the main structure primary response(PR)is *** addition,the closed detached response(CDR)is also observed to research the resonance response of the fluid-conveying *** appearance of either the CCDR or the CDR does affect the resonance ***,the mentioned two phenomena underline that the trend of vibration responses under external excitation goes continuous and ***,the main advantage of the LNES is presented by contrasting the LNES with the nonlinear energy sink(NES)coupled to the same pipe *** is found that the LNES can reduce the resonance response amplitude by 91.33%.

关键词： fluid-conveying pipe vibration attenuation collapsible closed detached response(CCDR) lever-type nonlinear energy sink(LNES) elastic support

Index of microcirculatory resistance: state-of-the-art and potential applications in computational simulation of coronary artery disease

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Journal of Zhejiang University-science B(Biomedicine & Biotechnology) 2022年第2期23卷 123-140页

作者： Yingyi GENG Xintong WU Haipeng LIU Dingchang ZHENG Ling XIA Key Laboratory for Biomedical Engineering of Ministry of Education Institute of Biomedical EngineeringZhejiang UniversityHangzhou 310027China Research Centre of Intelligent Healthcare Faculty of Health and Life ScienceCoventry UniversityCoventry CV15FBUK

The dysfunction of coronary microcirculation is an important cause of coronary artery disease(CAD).The index of microcirculatory resistance(IMR)is a quantitative evaluation of coronary microcirculatory function,which provides a significant reference for the prediction,diagnosis,treatment,and prognosis of *** also plays a key role in investigating the interaction between epicardial and microcirculatory dysfunctions,and is closely associated with coronary hemodynamic parameters such as flow rate,distal coronary pressure,and aortic pressure,which have been widely applied in computational studies of ***,there is currently a lack of consensus across studies on the normal and pathological ranges of *** relationships between IMR and coronary hemodynamic parameters have not been accurately quantified,which limits the application of IMR in computational CAD *** this paper,we discuss the research gaps between IMR and its potential applications in the computational simulation of *** simulation based on the combination of IMR and other hemodynamic parameters is a promising technology to improve the diagnosis and guide clinical trials of CAD.

关键词： Index of microcirculatory resistance(IMR) Coronary artery disease(CAD) Computational simulation

Content Based Automated File Organization Using Machine Learning Approaches

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Computers, Materials & Continua 2022年第10期73卷 1927-1942页

作者： Syed Ali Raza Sagheer Abbas Taher M.Ghazal Muhammad Adnan Khan Munir Ahmad Hussam Al Hamadi School of Computer science National College of Business Administration&EconomicsLahore54000Pakistan Department of Computer science GC University LahorePakistan Center for Cyber Security Faculty of Information Science and TechnologyUniversiti Kebangsaan MalaysiaBangiSelangorMalaysia School of Information Technology Skyline University CollegeUniversity City SharjahSharjah1797UAE Riphah School of Computing&Innovation Faculty of ComputingRiphah International University Lahore CampusLahore54000Pakistan Department of Software Pattern Recognition and Machine Learning LabGachon UniversitySeongnam13120GyeonggidoKorea Cyber-Physical Systems Khalifa UniversityAbu Dhabi127788UAE

In the world of big data,it’s quite a task to organize different files based on their *** with heterogeneous data and keeping a record of every single file stored in any folder is one of the biggest problems encountered by almost every computer *** of file management related tasks will be solved if the files on any operating system are somehow categorized according to their ***,the browsing process can be performed quickly and *** research aims to design a system to automatically organize files based on their similarities in terms of *** proposed methodology is based on a novel strategy that employs the charactaristics of both supervised and unsupervised machine learning approaches for learning categories of digital files stored on any computer *** results demonstrate that the proposed architecture can effectively and efficiently address the file organization challenges using real-world user *** results suggest that the proposed system has great potential to automatically categorize almost all of the user files based on their *** proposed system is completely automated and does not require any human effort in managing the files and the task of file organization become more efficient as the number of files grows.

关键词： File organization natural language processing machine learning

New solitary waves and exact solutions for the fifth-order nonlinear wave equation using two integration techniques

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Journal of Ocean Engineering and science 2023年第5期8卷 475-480页

作者： Ahmed H.Arnous Mohammad Mirzazadeh Lanre Akinyemi Arzu Akbulut Department of Physics and Engineering Mathematics Higher Institute of EngineeringEl Shorouk AcademyCairoEgypt Department of Engineering sciences Faculty of Technology and EngineeringEast of GuilanUniversity of GuilanRudsar-VajargahIran Department of Mathematics Lafayette CollegeEastonPennsylvaniaUSA Department of Mathematics Computer Faculty of Art ScienceEskisehir Osmangazi UniversityEskisehirTurkey

In this paper,we discussed the enhanced Kudryashov’s and general projective Riccati equations tech-niques for obtaining exact solutions to the fifth-order nonlinear water wave(FONLWWE)*** the enhanced Kudryashov’s method,we were able to achieve solitary wave and singular soliton ***-shock hybrid wave,singular soliton,and periodic wave solutions were discovered when we em-ployed the general projective Riccati equations *** can say the given methods are effective and powerful for obtaining exact *** findings in this paper are critical for explaining a wide range of scientific and oceanographic applications involving ocean gravity waves and other related phenomena.

关键词： Enhanced Kudryashov method Riccati equation Water waves Fifth-order nonlinear model Solitons

Research on semi-solid slurry of a hypoeutectic Al-Si alloy prepared by low superheat pouring and weak electromagnetic stirring

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Rare Metals 2006年第2期25卷 177-183页

作者： LIU Zheng MAO Weiming ZHAO Zhengduo Material of science and Engineering School University of Science and Technology Beijing Beijing 100083 China faculty of Material and Chemical Engineering Jiangxi University of Science and Technology Ganzhou 341000 China

The semi-solid slurry of a hypoeutectic Al-Si alloy was manufactured by low superheat pouring and weak electromagnetic stirring. The effects of pouting temperature and stirring power on the semi-solid slurry were investigated. The results indicated that the semi-solid slurry to satisfy rheocasting can be manufactured by low superheat pouring and weak electromagnetic stirring. The pouring temperature （or superheat） and the stirring power remarkably affected the morphology of primary α-Al and the size of primary α-Al, and there is no obvious effect of stirring time on primary α-Al. Compared with the samples made by low superheat pouring with no stirring, the nucleation rate, particle morphology and grain size of primary α-Al in A356 were markedly improved by low superheat pouring and weak electromagnetic stirring. On the condition of weak electromagnetic stirring, the pouring temperature with low superheat can be suitably raised to reach the effectiveness obtained from the lower pouring temperature without stirring.

关键词： semi-solid low superheat pouring weak electromagnetic stirring hypoeutectic Al-Si alloy A356 Al alloy

Effect of Interface Area on Nonlinear Magnetoelectric Resonance Response of Layered Multiferroic Composite Ring

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Acta Mechanica Solida Sinica 2022年第5期35卷 765-774页

作者： Jingyi Liu Lianchun Long Wei Li faculty of Materials and Manufacturing Beijing University of TechnologyBeijing100124China

Multiferroic composite structures are widely used in sensing,driving and *** study of their magnetoelectric(ME)behavior under various excitations is *** study investigates the nonlinear ME influence of a multilayer composite ring structure consisting of Terfenol-D(TD)magnetostrictive and lead zirconate titanate(PZT)piezoelectric rings utilizing a multiphysics field modeling framework based on the fully coupled finite element *** ME coupling coefficient of the PZT/TD concentric composite ring is predicted using the linear piezoelectric constitutive model and the nonlinear magnetostrictive constitutive model,which is congruent to the experimental *** effect of the interface area of a trilayered structure on the coupling performance at the resonant frequency is investigated,considering the magnitude and frequency of the magnetic field and keeping the material ratio *** ME coupling coefficient of a trilayered structure is larger than that of a bilayered structure with the same material ratio,and the maximum ME coupling coefficient of a trilayered structure increases nonlinearly with the increase in the interface *** the resonant frequency,the structure's ME coupling performance is considerably *** optimization technique based on structural geometric design and magnetic field control is presented to optimize the ME coupling coefficient.

关键词： Composite multiferroics Magnetoelectric coupling Finite element simulation Interface area Frequency