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Applied Mathematics and Mechanics(English Edition) 2018年第2期39卷 219-240页

作者： M.MOHAMMADIMEHR R.ROSTAMI Department of Solid Mechanics Faculty of Mechanical Engineering University of Kashan

The bending and free vibration of a rotating sandwich cylindrical shell are analyzed with the consideration of the nanocomposite core and piezoelectric layers subjected to thermal and magnetic fields by use of the first-order shear deformation theory （FSDT） of shells. The governing equations of motion and the corresponding boundary conditions are established through the variational method and the Maxwell equation. The closed-form solutions of the rotating sandwich cylindrical shell are obtained. The effects of geometrical parameters, volume fractions of carbon nanotubes, applied voltages on the inner and outer piezoelectric layers, and magnetic and thermal fields on the natural frequency, critical angular velocity, and deflection of the sandwich cylindrical shell are investigated. The critical angular velocity of the nanocomposite sandwich cylindrical shell is obtained. The results show that the mechanical properties, e.g., Young＇s modulus and thermal expansion coefficient, for the carbon nanotube and matrix are functions of temperature, and the magnitude of the critical angular velocity can be adjusted by changing the applied voltage.

关键词： free vibration bending rotating sandwich cylindrical shell nanocompositecore piezoelectric layer

bending of a Flexoelectric Semiconductor Plate

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Acta Mechanica Solida Sinica 2022年第3期35卷 434-445页

作者： Yilin Qu Feng Jin Jiashi Yang State Key Laboratory for Strength and Vibration of Mechanical Structures XVan Jiaotong UniversityXi’an 710049China Department of Mechanical and Materials Engineering University of Nebraska-LincolnLincolnNE 68588-0526USA

We study electromechanical responses of a flexoelectric semiconductor plate in bending under mechanical loads.A two-dimensional theory for classical bending without shear deformation is derived from the three-dimensional macroscopic theory of flexoelectric semiconductors.A simple solution is obtained for pure bending.A combination of physical and geometric parameters is introduced as a measure of the strength of the coupling between the mechanical load and the redistribution of charge carriers.A trigonometric series solution is obtained for a simply supported rectangular plate under a local normal mechanical load,which shows concentration of mobile charges and the formation of electric potential barriers near the loading *** results are fundamental to the mechanical manipulation of charge carriers in these *** also analyze the buckling of a simply supported rectangular plate under in-plane compressive forces.A series of buckling loads and modes are *** results show that flexoelectric coupling exhibits a stiffening effect and increases the buckling load,while semiconduction weakens the flexoelectric *** distributions of mobile charges in the first few buckling modes are presented.

关键词： Flexoelectric Plate bending Buckling Flexotronic

bending behavior of as-cast and annealed ZrCuNiAl bulk metallic glass

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Journal of Materials Science & Technology 2017年第10期33卷 1153-1158页

作者： Yongjiang Huang Zhiliang Ning Zhe Shen Weizhong Liang Haicao Sun Jianfei Sun School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001 China National Key Laboratory of Precision Hot Processing of Metals Harbin Institute of Technology Harbin 150001 China Shenyang Engine Research Institute Aero Engine Corporation of China Shenyang 110000 China School of Materials Science and Engineering Heilongjiang University of Science and Technology Harbin 150027 China

Here ZrCuNiAl bulk metallic glass samples were annealed below its glass transition temperature. The bending behaviors and thermal properties of the as-cast and the annealed samples were studied. The increase of annealing time leads to the transition from ductile to more brittle behavior during bending tests. Meanwhile, prolonging the annealing causes a gradual decrease in the free volume content. Based on free volume theory, the change in the microstructure and mechanical properties induced by annealing treatment has been interpreted in detail.

关键词： Bulk metallic glasses Annealing bending Fracture Free volume

bending of orthotropic plates resting on Pasternak's foundations using mixed shear deformation theory

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Acta Mechanica Sinica 2011年第6期27卷 956-962页

作者： A.M.Zenkour Department of Mathematics Faculty of Science King AbdulAziz University Department of Mathematics Faculty of Science Kafrelsheikh University

The mixed first-order shear deformation plate theory（MFPT） is employed to study the bending response of simply-supported orthotropic *** present plate is subjected to a mechanical load and resting on Pasternak＇s model or Winkler＇s model of elastic foundation or without any elastic *** examples are presented to verify the accuracy of the present *** results for deflection and stresses are *** proposed MFPT is shown simplely to implement and capable of giving satisfactory results for shear deformable plates under static loads and resting on two-parameter elastic *** results presented here show that the characteristics of deflection and stresses are significantly influenced by the elastic foundation stiffness,plate aspect ratio and side-to-thickness ratio.

关键词： Mixed theory bending Rectangular plates Pasternak's model

bending fracture behavior of freestanding (Gd0.9Yb0.1)2Zr2O7 coatings by using digital image correlation and FEM simulation with 3D geometrical reconstruction

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Journal of Advanced Ceramics 2019年第4期8卷 564-575页

作者： Weiguo MAO Yujie WANG Jun SHI Huiyu HUANG Yuncheng WANG Liang LV Haoyong YANG Chen ZOU Cuiying DAI Xiaolei ZHU Daining FANG School of Materials Science and Engineering Xiangtan UniversityXiangtan 411105China Department of Science and Technology Engineering AECC South Industry Co.Ltd.Xiangtan 412002China School of Mechanical and Power Engineering Nanjing Tech UniversityNanjing 210009China Institute of Advanced Structure Technology Beijing Institute of TechnologyBeijing 100081China

It is important to investigate the mechanical performances of (Gd0.9Yb0.1)2Zr2O7 (GYbZ) materials deposited on irregular substrates for improving new thermal barrier coatings. Three-point bending fracture characteristics of freestanding GYbZ coating prepared by supersonic plasma sprayed(SPS) technique were investigated with the help of digital image correlation technique. The cracking time, crack propagation path, and mechanical properties of GYbZ coating were obtained. Meanwhile, the X-ray computed tomography technique was introduced to scan the microstructure of freestanding GYbZ coatings, which are used to establish three-dimensional(3D) finite element model by using the Avizo software. The brittle cracking criterion was applied to describe the bending fracture process of GYbZ coatings. The critical cracking strain was estimated as 0.36%±0.03% by repeatedly comparing the difference between the experimental and simulated curves. The results would be extended to predict the dangerous region and failure mechanisms of GYbZ coatings deposited on irregular substrate during finite element simulations.

关键词： thermal barrier coating X-ray computed tomography bending fracture geometrical reconstruction cracking strain

bending-induced phase transition in monolayer black phosphorus

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Chinese Physics B 2015年第8期24卷 474-479页

作者：潘斗兴王自强郭万林 State Key Laboratory of Nonlinear Mechanics Institute of Mechanics Chinese Academy of Sciences University of Chinese Academy of Sciences State Key Laboratory of Mechanics and Control for Mechanical Structures and Key Laboratory for Intelligent Nano Materials and Devices (MOE) Nanjing University of Aeronautics and Astronautics

bending-induced phase transition in monolayer black phosphorus is investigated through first principles *** wrapping the layer into nanotubes along armchair and zigzag directions with different curvatures, it is found that phase transitions of the tubes occur when radius of curvature is smaller than 5 in bending along the zigzag direction, while the tubes remain stable along the armchair direction. Small zigzag tubes with odd numbered monolayer unit cells tend to transfer toward armchair-like phases, but the tubes with even numbered monolayer unit cells transfer into new complex bonding structures. The mechanism for the bending-induced phase transition is revealed by the comprehensive analyses of the bending strain energies, electron density distributions, and band structures. The results show significant anisotropic bending stability of black phosphorus and should be helpful for its mechanical cleavage fabrication in large size.

关键词： bending monolayer black phosphorus phase transition

bending and vibration of two-dimensional decagonal quasicrystal nanoplates via modified couple-stress theory

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Applied Mathematics and Mechanics(English Edition) 2022年第3期43卷 371-388页

作者： Miao ZHANG Junhong GUO Yansong LI Department of Mechanics Inner Mongolia University of TechnologyHohhot 010051China School of Aeronautics Inner Mongolia University of TechnologyHohhot 010051China College of Architecture and Civil Engineering Guangdong University of Petrochemical TechnologyMaoming 525000Guangdong ProvinceChina

Based on the modified couple-stress theory,the three-dimensional(3D)bending deformation and vibration responses of simply-supported and multilayered twodimensional(2D)decagonal quasicrystal(QC)nanoplates are *** surface loading is assumed to be applied on the top surface in the bending analysis,the tractionfree boundary conditions on both the top and bottom surfaces of the nanoplates are used in the free vibration analysis,and a harmonic concentrated point loading is applied on the top surfaces of the nanoplates in the harmonic response *** general solutions of the extended displacement and traction vectors for the homogeneous QC nanoplates are derived by solving the eigenvalue problem reduced from the final governing equations of motion with the modified couple-stress *** utilizing the propagator matrix method,the analytical solutions of the displacements of bending deformation for the phonon and phason fields,the natural frequency of free vibration,and the displacements of the harmonic responses of the phonon and phason fields are *** examples are illustrated to show the effects of the quasiperiodic direction,the material length scale parameter,and the the stacking sequence of the nanoplates on the bending deformation and vibration responses of two sandwich nanoplates made of QC and crystal materials.

关键词： quasicrystal(QC) bending vibration layered nanoplate

bending performance of composite bridge deck with T-shaped ribs

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Frontiers of Structural and Civil Engineering 2019年第4期13卷 990-997页

作者： Qingtian SU Changyuan DAI Xu JIANG Department of Bridge Engineering Tongji University Shanghai 200092 China

This paper proposes a new type of steel-concrete composite deck, which is composed of orthotropic steel deck (OSD) with T-shaped ribs, concrete plate and studs connecting OSD and concrete plate. The OSD can act as framework for concrete plate and contribute to load bearing capacity at the same time, which could save construction time. Compared with conventional OSD system, this new type of composite bridge deck can also improve fatigue performance.?Considering that this type of composite deck is not yet applied in practical engineering and its mechanical performance is not revealed in previous literatures, two full-scale specimens were designed and manufactured in this research. The mechanical performance, particularly, bending capacity in positive and negative region was carefully tested and analyzed. The load-deflection curve, load-slip relation, strain distribution in concrete and steel were obtained. The test results showed that the plastic performance of this kind of composite bridge deck was satisfying and the bending capacity was high.

关键词： bending performance composite bridge deck T-shaped steel ribs

bending properties of extruded AZ91–0.9Ca–0.6Y alloy and their improvement through precompression and annealing

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Journal of Magnesium and Alloys 2022年第8期10卷 2238-2251页

作者： Jong Un Lee Gyo Myeong Lee Sung Hyuk Park School of Materials Science and Engineering Kyungpook National UniversityDaegu 41566Republic of Korea

In this study,an extruded Mg–9Al–1Zn–0.3Mn–0.9Ca–0.6Y(AZXW9110)alloy is subjected to precompression and subsequent annealing(PCA)treatment for improving its bending formability,and the three-point bending properties of the as-extruded material and the precompressed and subsequently annealed(PCAed)material at room temperature are *** bending,microcracks formed in undissolved Al2Ca,Al2Y,and Al8Mn4Y particles propagate along the grain boundaries or twin boundaries and consequently form a macrocrack in the tension zones of the bending samples of both the ***,the bending formability of the PCAed material is 75%higher than that of the as-extruded material owing to the promoted twinning and slip behaviors in the *** as-extruded material has a strong normal direction(ND)texture and a weak transverse direction(TD)texture,and the ND-and TD-oriented grains are unfavorable for both{10–12}twinning and basal slip in the tension zone of the bending sample of this material,which eventually results in its low bending *** PCAed material has a strong extrusion direction(ED)texture,weak TD texture,and spread ND *** bending,{10–12}twins are fully formed in the ED-oriented grains,and this{10–12}twinning effectively accommodates the plastic strain in the tension *** addition,the activation of basal slip in the ND-oriented grains of the PCAed material is promoted owing to the spread ND texture of this ***,this material exhibits substantially superior bending formability because of the vigorous{10–12}twinning in its ED-oriented grains and promoted basal slip in its ND-oriented grains.

关键词： Magnesium bending Formability Twinning Texture

bending Solutions of FGM Reddy-Bickford Beams in Terms of Those of the Homogenous Euler-Bernoulli Beams

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Acta Mechanica Solida Sinica 2019年第4期32卷 499-516页

作者： You-Ming Xia Shi-Rong Li Ze-Qing Wan School of Civil Science and Engineering Yangzhou UniversityYangzhou 225127 China

In this paper, correspondence relations between the solutions of the static bending of functionally graded material (FGM) Reddy-Bickford beams (RBBs) and those of the corresponding homogenous Euler-Bernoulli beams are presented. The effective material properties of the FGM beams are assumed to vary continuously in the thickness direction. Governing equations for the titled problem are formulated via the principle of virtual displacements based on the third-order shear deformation beam theory, in which the higher-order shear force and bending moment are included. General solutions of the displacements and the stress resultants of the FGM RBBs are derived analytically in terms of the deflection of the reference homogenous Euler- Bernoulli beam with the same geometry, loadings and end conditions, which realize a classical and homogenized expression of the bending response of the shear deformable non-homogeneous FGM beams. Particular solutions for the FGM RBBs under specified end constraints and load conditions are given to validate the theory and methodology. The key merit of this work is to be capable of obtaining the high-accuracy solutions of thick FGM beams in terms of the classical beam theory solutions without dealing with the solution of the complicated coupling differential equations with boundary conditions of the problem.

关键词： Functionally graded material beams Reddy-Bickford beam theory Euler- Bernoulli beam theory bending solution Shear deformation