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Chinese Journal of Aeronautics 2020年第2期33卷 721-729页

作者： Xunzhong GUO Xuan CHENG Yong XU Jie TAO Ali ABD EL-ATY Hai LIU College of Material Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 211100China Jiangsu Key Laboratory of Nuclear Energy Equipment Materials Engineering Nanjing University of Aeronautics and AstronauticsNanjing 211100China Institute of Metal Research Chinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering Nanjing University of Science and TechnologyNanjing 210094China Department of Precision Manufacturing Engineering Suzhou Vocational Institute of Industrial TechnologySuzhou 215104China

3D free bending process,an advanced metal forming technology,has attracted much attention due to its unique geometrical flexibility and *** tubes with materials may effectively reduce the distortion in the cross-section area and restrain wrinkling and collapse of tube *** the present study,the impacts of filling different materials on the copper tubes during 3D free bending process were *** have found that copper tubes filled with low melting point alloys could induce the most uniform stress distribution,which result in better formability and moderate thickness changing rates when compared to SS304 steel balls and PU *** lowest ellipticity reached to 1.467%.

关键词： 3D free bending Ellipticity Filling bending finite element modelling Force model Thickness

finite element simulation of elastoplastic fieldnear crack tips and results for a central crackedplate of le-lhp material under tension

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Acta Mechanica Sinica 2019年第4期35卷 828-838页

作者： X. Ji F. Zhu School of Aerospace Engineering and Applied Mechanics Tongji University Shanghai 200092 China

The elastoplastic field near crack tips is investigated through finite element simulation.A refined mesh model near the crack tip is proposed. In the mesh refining area, element size continuously varies from the nanometer scale to themicrometer scale and the millimeter scale. Graphics of the plastic zone, the crack tip blunting, and the deformed crack tip elements are given in the *** on the curves of stress and plastic strain, closely near the crack tip, the stresssingularity index and the stress intensity factor,as well as the plastic strain singularity index and the plastic strain intensity factor are *** and plastic strainsingular index vary with the load, while the dimensions of the stress and the plastic strain intensity factorsdependon the stress and the plastic strain singularity index, respectively. The singular field near the elastoplastic crack tip is characterized by the stress singularity index and the stress intensity factor, or alternativelythe plastic strain singularity index and the plastic strain *** the end of the paper, following Irwin’s concept of fracture mechanics,σδKσδKcriterion andεδQεδQcriterion are ***, crack tip angle criterion is also presented.

关键词： Crack Fracture mechanics Elastoplasticity finite element method Geometry Nonlinearity

finite ELEMENT ANALYSES OF THE EXTRUSION FLOWS OF BOGER FLUIDS WITH END-DRAWING AND GRAVITY-DRAWING

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Chinese Journal of Chemical Engineering 1995年第2期3卷 50-59页

作者：范毓润范西俊路甬祥浙江大学力学系浙江杭州

The spinning flow of Boger fluids and the gravity-drawing extrusion flow of a Newtonianas well as a Boger fluid have been simulated by using the stream-line finite element method and thetechnique of matching the finite element solutions with those of one-dimensional spinning *** recoverable shear strain is proved not to be a basic parameter in characterising thespinning flow of Boger *** Newtonian fluids this technique predicts the experimental jetshape *** Boger fluids,the numerical simulation agrees with the experimental data of spin-ning flow reported by Sridhar et al.,but seems to give an insufficient swelling and over contractionof the jets when drawn by its own weight,compared with the experimental results of Trang *** implies that the Oldroyd-B model fitting the viscometric-flow data fails to describeaccurately the elasticity and extensional viscosity in the extrusion flow of Boger fluids with gravi-ty-drawing.

关键词： finite element method spinning flow extrusion flow end drawing gravity drawing

A finite-ELEMENT ANALYSIS OF ELECTROMAGNETIC SHEET METAL-EXPANSION PROCESS

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中国有色金属学会会刊：英文版 1998年第3期8卷 135-140页

作者： Huang, SY Chang, ZH Wang, ZR Wang, LF Yang, M Wuhan Automot Polytech Univ Sch Mat Engn Wuhan 430070 Peoples R China Harbin Inst Technol Sch Mat Sci & Engn Harbin 150006 Peoples R China

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关键词： finite element analysis electromagnetic forming magnetic pressure

finite element analysis of controlled low strength materials

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Frontiers of Structural and Civil Engineering 2019年第5期13卷 1243-1250页

作者： Vahid ALIZADEH Gildart Haase School of Computer Sciences & Engineering Fairleigh Dickinson UniversityTeaneckNJ 07666USA

Controlled low strength materials (CLSM) are flowable and self-compacting construction materials that have been used in a wide variety of applications. This paper describes the numerical modeling of CLSM fills with finite element method under compression loading and the bond performance of CLSM and steel rebar under pullout loading. The study was conducted using a plastic-damage model which captures the material behavior using both classical theory of elasto-plasticity and continuum damage mechanics. The capability of the finite element approach for the analysis of CLSM fills was assessed by a comparison with the experimental results from a laboratory compression test on CLSM cylinders and pullout tests. The analysis show's that the behavior of a CLSM fill w'hile subject to a failure compression load or pullout tension load can be simulated in a reasonably accurate manner.

关键词： CLSM finite element method compressive strength pullout numerical modeling plastic damage model

finite element analysis of the effect of interlayer on interfacial stress transfer in layered graphene nanocomposites

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Journal of Materials Science & Technology 2019年第6期35卷 1147-1152页

作者： C.C.Roach Y.C.Lu Department of Mechanical Engineering University of Kentucky

Understanding the roles of interlayers in reinforcement efficiencies by layered graphene is very important in order to produce strong and light graphene based nanocomposites. The present paper uses the finite element method to evaluate the interfacial strain transfers and reinforcement efficiencies in layered graphene-polymer composites. Results indicate that the presence of compliant interlayers in layered graphene plays significant roles in the transfers of strain/stress from matrix to graphene and subsequently the reinforcement effectiveness of layered graphene. In general, the magnitude of shear strain transferred onto the rigid graphene decreases as the thickness of the interlayer increases. This trend becomes insignificant as the graphene becomes sufficiently large(s>25,000). The shear strain at the interface of graphene-matrix is also greatly influenced by the interlayer modulus. A stiffer interlayer would result in a higher shear strain transferred on the graphene. The performance of the interlayers is further affected by the property of the composite and the architecture of the layered graphene stack. If a composite contains more graphene phase, the efficiency of reinforcement by a layered graphene becomes improved. If a graphene stack contains more interlayers, the effectiveness of reinforcement at the edges of the graphene becomes negatively affected.

关键词： Interlayer Layered graphene Nanocomposites Interfacial stress transfer finite element method

finite Element Analysis of the Steel Reinforced Plastic Pipe

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Journal of Materials Science & Technology 2003年第z1期19卷 43-45页

作者： Hongyi SUN Wenqi MA Dachang KANG Keding ZHAO Harbin University of Science and Technology Harbin 150080 China Daqing Oilfields Postdoctoral Workstation Daqing 163453 China Harbin Institute of Technology Harbin 150001 China Daqing Oilfields Postdoctoral Workstation Daqing 163453 China Harbin Institute of Technology Harbin 150001 China Harbin Institute of Technology Harbin 150001 China

The steel reinforced plastic pipe is a kind of green environmental protection pipelines with double-sides corrosionresisting and better withstanding to medium working pressure. The structure and technical process of this pipe are described briefly in this paper, and the finite element analysis has been done for the sake of understanding the distributions of stress and displacement inside this pipe under hydrostatic pressure. The analysis results are very important for safety application of the steel reinforced plastic pipe.

关键词： Steel reinforced plastic pipe, finite element analysis

finite Eement Facture Aalysis of the Main Arm of Tower Cranes with the 3-D Cracks

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上海交通大学学报 2004年第z2期38卷 171-175页

作者： Zongjie Cao Zhenbang Kuang Changping Li Department of Engineering Mechanics Shanghai Jiaotong University Shanghai200240 China Department of Mechanical Engineering Aeronautic University of Air ForceChangchun 130022 China Department of Engineering Mechanics Shanghai Jiaotong University Shanghai200240 China Department of Mechanical Engineering Aeronautic University of Air ForceChangchun 130022 China

In this paper the local solutions of displacement fields in front of three-dimensional cracks are introduced and a new singular element of three-dimensional crack problems is constructed, and a new method for calculating stress intensity factors of three-dimensional crack problems is presented. With the present method, the structural strength of with longitudinal closed cracks under axial tensions is analyzed. It is possible for the crack to propagate because there are ring tensile stresses near joints of the main arm in tower cranes under axial press stresses. The stress and the stress intensity factor are calculated at joints on the main arm of tower cranes. Influences of welding residual stress on stress intensity factors and stresses are discussed.

关键词： stress intensity factor residual stress singular finite element crack

finite-time Adaptive Fault-tolerant Control for Nonlinear Systems With Multiple Faults

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IEEE/CAA Journal of Automatica Sinica 2019年第6期6卷 1417-1427页

作者： Huanqing Wang Wen Bai Peter Xiaoping Liu School of Mathematics Bohai UniversityJinzhou 121000China Department of Systems and Computer Engineering Carleton UniversityOttawaON K1S 5B6Canada

This paper focuses on the problem of adaptive finitetime fault-tolerant control for a class of non-lower-triangular nonlinear *** faults encountered in the control system include the actuator faults and the abrupt system *** applying backstepping design and neural networks approximation,an adaptive finite-time fault-tolerant control scheme is *** is shown that the proposed controller ensures that all signals in the closed-loop system are semi-globally practically finite-time stable and the track-ing error converges to a small neighborhood around the origin within finite *** simulation is carried out to explain the validity of the developed strategy.

关键词： Adaptive control backstepping faults finite time

finite-Element Simulation and Experimental Research of the Hot-Press Sintering of Nano-Sized Ceramic Powders

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Journal of Materials Science & Technology 2003年第z1期19卷 40-42页

作者： Guoqing CHEN Kaifeng ZHANG Guofeng WANG Yandong YU Department of Materials Engineering Harbin Institute of Technology Harbin 150001 China Department of Materials Engineering Harbin Institute of Technology Harbin 150001 China Department of Materials Engineering Harbin Institute of Technology Harbin 150001 China Department of Materials Engineering Harbin Institute of Technology Harbin 150001 China

Numerical simulation of hot-press sintering of nano-sized ceramic powders was introduced by the commercial finite element code ***. The powder plastic model and the thermo-mechanical coupled quadrilateral element were developed and adopted in the simulation. The mechanical and thermal properties of the nano-sized alumina based powders were *** addition, the experimental research and numerical simulation of the sintering process of different initial densities were carried out. The stress state in sintering of green compacts with different initial densities was analyzed by the densification *** reason for the density fluctuations of as-sintered ceramic bulks was found out.

关键词： Sintering, finite element method, Green compacts, Stress