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Mechanical behavior and damage constitutive model of sandstone under hydro-mechanical (H-M) coupling
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作者 Tao Tan Chunyang Zhang +1 位作者 Yanlin Zhao Xiaoshuang Li 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第6期837-853,共17页
Underground engineering often passes through water-rich fractured rock masses, which are prone to fracture and instability under the long-term coupling of in-situ stress field and pore water(P-W) pressure, ultimately ... Underground engineering often passes through water-rich fractured rock masses, which are prone to fracture and instability under the long-term coupling of in-situ stress field and pore water(P-W) pressure, ultimately threatening the stability of underground structures. In order to explore the mechanical properties of rocks under H-M coupling, the corresponding damage constitutive(D-C) model has become the focus of attention. Considering the inadequacy of the current research on rock strength parameters,energy evolution characteristics and D-C model under H-M coupling, the mechanical properties of typical sandstone samples are discussed based on laboratory tests. The results show that the variation of characteristic stresses of sandstone under H-M coupling conforms to the normalized attenuation equation and Mohr-Coulomb(M-C) criterion. The P-W pressure mechanism of sandstone exhibits a dynamic change from softening effect to H-M fracturing effect. The closure stress is mainly provided by cohesive strength, while the initiation stress, damage stress, and peak stress are jointly dominated by cohesive strength and friction strength. In addition, residual stress is attributed to the friction strength formed by the bite of the fracture surface. Subsequently, the energy evolution characteristics of sandstone under H-M coupling were studied, and it was found that P-W pressure weakened the energy storage capacity and energy dissipation capacity of sandstone, and H-M fracturing was an important factor in reducing its energy storage efficiency. Finally, combined with energy dissipation theory and statistical damage theory, two types of D-C models considering P-W pressure are proposed accordingly, and the model parameters can be determined by four methods. The application results indicate that the proposed and modified D-C models have high reliability, and can characterize the mechanical behavior of sandstone under H-M coupling, overcome the inconvenience of existing D-C models due to excessive mechanical parameters,and can be applied to the full-range stress–strain process. The results are conducive to revealing the deformation and damage mechanisms of rocks under H-M coupling, and can provide theoretical guidance for related engineering problems. 展开更多
关键词 H-M coupling Water-saturated sandstone mechanical mechanism Energy evolution D-C model
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Characterization and quantification of multi-field coupling in lithium-ion batteries under mechanical constraints
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作者 Xue Cai Caiping Zhang +3 位作者 Zeping Chen Linjing Zhang Dirk Uwe Sauer Weihan Li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第8期364-379,I0009,共17页
The safety and durability of lithium-ion batteries under mechanical constraints depend significantly on electrochemical,thermal,and mechanical fields in applications.Characterizing and quantifying the multi-field coup... The safety and durability of lithium-ion batteries under mechanical constraints depend significantly on electrochemical,thermal,and mechanical fields in applications.Characterizing and quantifying the multi-field coupling behaviors requires interdisciplinary efforts.Here,we design experiments under mechanical constraints and introduce an in-situ analytical framework to clarify the complex interaction mechanisms and coupling degrees among multi-physics fields.The proposed analytical framework integrates the parameterization of equivalent models,in-situ mechanical analysis,and quantitative assessment of coupling behavior.The results indicate that the significant impact of pressure on impedance at low temperatures results from the diffusion-controlled step,enhancing kinetics when external pressure,like 180 to 240 k Pa at 10℃,is applied.The diversity in control steps for the electrochemical reaction accounts for the varying impact of pressure on battery performance across different temperatures.The thermal expansion rate suggests that the swelling force varies by less than 1.60%per unit of elevated temperature during the lithiation process.By introducing a composite metric,we quantify the coupling correlation and intensity between characteristic parameters and physical fields,uncovering the highest coupling degree in electrochemical-thermal fields.These results underscore the potential of analytical approaches in revealing the mechanisms of interaction among multi-fields,with the goal of enhancing battery performance and advancing battery management. 展开更多
关键词 Lithium-ion battery Muti-field coupling mechanical constraints Interaction mechanisms Quantitative analysis
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Mechanical behaviours of bedded sandstone under hydromechanical coupling
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作者 Junwen Zhang Zhixiang Song +7 位作者 Lichao Zhang Shaokang Wu Shanyong Wang Yang Zhang Xukai Dong Jinxin Wang Yanbo Han Baohua Kan 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第4期1245-1261,共17页
The combination of the dipping effect and hydromechanical(H-M)coupling effect can easily lead to water inrush disasters in water-rich roadways with different dip angles in coal mines.Therefore,H-M coupling tests of be... The combination of the dipping effect and hydromechanical(H-M)coupling effect can easily lead to water inrush disasters in water-rich roadways with different dip angles in coal mines.Therefore,H-M coupling tests of bedded sandstones under identical osmotic pressure and various confining pressures were conducted.Then,the evolution curves of stress-strain,permeability and damage,macro-and mesoscopic failure characteristics were obtained.Subsequently,the mechanical behaviour was characterized,and finally the failure mechanism was revealed.The results showed that:(1)The failure of the sandstone with the bedding angle of 45°or 60°was the structure-dominant type,while that with the bedding angle of 0°,30°or 90°was the force-dominant type.(2)When the bedding angle was in the range of(0°,30°)or(45°,90°),the confining pressure played a dominant role in influencing the peak strength.However,withinβ∈(30°,45°),the bedding effect played a dominant role in the peak strength.(3)With the increase in bedding angle,the cohesion increased first,then decreased and finally increased,while the internal friction angle was the opposite.(4)When the bedding angle was 0°or 30°,the“water wedging”effect and the“bedding buckling”effect would lead to the forking or converging shear failure.When the bedding angle was 45°or 60°,the sliding friction effect would lead to the shear slipping failure.When the bedding angle was 90°,the combination of the“bedding buckling”effect and shear effect would lead to the mixed tension-shear failure.The above conclusions obtained are helpful for the prevention of water inrush disasters in water-rich roadways with different dips in coal mines. 展开更多
关键词 Hydromechanical coupling Bedded sandstones mechanical behaviour Bedding effect Failure mechanism
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Thermal-hydro-mechanical coupling stress intensity factor of brittle rock 被引量:3
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作者 李鹏 饶秋华 +1 位作者 李卓 敬静 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第2期499-508,共10页
A new calculation formula of THM coupling stress intensity factor was derived by the boundary collocation method, in which an additional constant stress function was successfully introduced for the cracked specimen wi... A new calculation formula of THM coupling stress intensity factor was derived by the boundary collocation method, in which an additional constant stress function was successfully introduced for the cracked specimen with hydraulic pressure applied on its crack surface. Based on the newly derived formula, THM coupling fracture modes (including tensile, shear and mixed fracture mode) can be predicted by a new fracture criterion of stress intensity factor ratio, where the maximum axial load was measured by self-designed THM coupling fracture test. SEM analyses of THM coupling fractured surface indicate that the higher the temperature and hydraulic pressure are and the lower the confining pressure is, the more easily the intergranular (tension) fracture occurs. The transgranular (shear) fracture occurs in the opposite case while the mixed-mode fracture occurs in the middle case. The tested THM coupling fracture mechanisms are in good agreement with the predicted THM coupling fracture modes, which can verify correction of the newly-derived THM coupling stress intensity factor formula. 展开更多
关键词 stress intensity factor thermal-hydro-mechanical coupling boundary collocation method fracture mechanism brittle rock
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Research on modeling and self-excited vibration mechanism in magnetic levitation-collision interface coupling system
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作者 Jinghu TANG Chaofeng LI +1 位作者 Jin ZHOU Zhiwei WU 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第5期873-890,共18页
The modeling and self-excited vibration mechanism in the magnetic levitation-collision interface coupling system are investigated.The effects of the control and interface parameters on the system's stability are a... The modeling and self-excited vibration mechanism in the magnetic levitation-collision interface coupling system are investigated.The effects of the control and interface parameters on the system's stability are analyzed.The frequency range of self-excited vibrations is investigated from the energy point of view.The phenomenon of self-excited vibrations is elaborated with the phase trajectory.The corresponding control strategies are briefly analyzed with respect to the vibration mechanism.The results show that when the levitation objects collide with the mechanical interface,the system's vibration frequency becomes larger with the decrease in the collision gap;when the vibration frequency exceeds the critical frequency,the electromagnetic system continues to provide energy to the system,and the collision interface continuously dissipates energy so that the system enters the self-excited vibration state. 展开更多
关键词 magnetic levitation coupling system self-excited vibration mechanical interface vibration frequency
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A mechanically coupled MEMS filter with high-Q width extensional mode resonators
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作者 Wei Wang Wenli Liu +5 位作者 Junyuan Zhao Bo Niu Zeyu Wu Yinfang Zhu Jinling Yang Fuhua Yang 《Journal of Semiconductors》 EI CAS CSCD 2024年第8期41-48,共8页
This work presents a novel radio frequency(RF)narrowband Si micro-electro-mechanical systems(MEMS)filter based on capacitively transduced slotted width extensional mode(WEM)resonators.The flexibility of the plate lead... This work presents a novel radio frequency(RF)narrowband Si micro-electro-mechanical systems(MEMS)filter based on capacitively transduced slotted width extensional mode(WEM)resonators.The flexibility of the plate leads to multiple modes near the target frequency.The high Q-factor resonators of around 100000 enable narrow bandwidth filters with small size and simplified design.The 1-wavelength and 2-wavelength WEMs were first developed as a pair of coupled modes to form a passband.To reduce bandwidth,two plates are coupled with aλ-length coupling beam.The 79.69 MHz coupled plate filter(CPF)achieved a narrow bandwidth of 8.8 kHz,corresponding to a tiny 0.011%.The CPF exhibits an impressive 34.84 dB stopband rejection and 7.82 dB insertion loss with near-zero passband ripple.In summary,the RF MEMS filter presented in this work shows promising potential for application in RF transceiver front-ends. 展开更多
关键词 MEMS narrowband filter mechanically coupling quality factor width extensional mode
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Hardening mechanism and thermal-solid coupling model of laminar plasma surface hardening of 65 Mn steel
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作者 Xiuquan CAO Lin WANG +2 位作者 Haoming XU Guangzhong HU Chao LI 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第12期110-120,共11页
In the present work,the laminar plasma surface hardening method is employed to enhance the service life of metal components fabricated from 65 Mn steel.The mechanical and wear behaviors of the laminar plasma surface h... In the present work,the laminar plasma surface hardening method is employed to enhance the service life of metal components fabricated from 65 Mn steel.The mechanical and wear behaviors of the laminar plasma surface hardened 65 Mn steel were analyzed.The martensite transition transformation of the temperature of the laminar plasma-hardened 65 ferrite Mn steel was determined by a thermal-solid coupling model.Based on the orthogonal experimental results,the optimal hardening parameters were confirmed.The scanning velocity,quenching distance and arc current are 130 mm/min,50 mm and 120 A,respectively.The pearlites and ferrites are transformed into martensites in the hardened zone,while the ratio of martensite in the heataffected zone decreases with the increase in the hardening depth.Compared to the untreated 65Mn steel,the average hardness increases from 220 HV_(0.2)to 920 HV_(0.2)in the hardened zone and the corresponding absorbed power increases from 118.7 J to 175.5 J.At the same time,the average coefficient of friction(COF)decreases from 0.763 to 0.546,and the wear rate decreases from 5.39×10^(-6)mm^(3)/(N·m)to 2.95×10^(-6)mm^(3)/(N·m),indicating that the wear resistance of 65Mn steel could be significantly improved by using laminar surface hardening.With the same hardening parameters,the depth and width of the hardened zone predicted by the thermal-solid coupling model are 1.85 mm and 11.20 mm,respectively,which are in accordance with the experimental results;depth is 1.83 mm and width is 11.15 mm.In addition,the predicted hardness distributions of the simulation model are in accordance with the experimental results.These results indicate that the simulation model could effectively predict the microstructure characteristics of 65 Mn steel. 展开更多
关键词 65 Mn steel laminar plasma surface hardening hardening mechanism microstructure characteristics thermal-solid coupling model
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Effects of Silane Coupling Agent on Microstructure and Mechanical Properties of EPDM/Carbonyl Iron Microwave Absorbing Patch 被引量:3
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作者 冯永宝 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2006年第4期78-82,共5页
The effects of types and amounts of silane coupling agent on mechanical properties of vuleanized rubber microwave absorbing patch (VRMAP) were studied. The mechanisms of silane coupling agent's effects on mechanica... The effects of types and amounts of silane coupling agent on mechanical properties of vuleanized rubber microwave absorbing patch (VRMAP) were studied. The mechanisms of silane coupling agent's effects on mechanical properties of rubber microwave absorbing patch ( RMAP ) and microvave absorbing patch's (MAP's) mierostrueture were also discussed by using SEM and FT-IR. The experimental results show that the tensile strength of RMAP could be increased through adding the filler of carbonyl iron powder (CIP) modified by silane coupling agent. RMAP fiUed with CIP, which was treated by silane coupling agent KH550, possessed a high tensile strength of 11.5 MPa, which was 448% more than that of MAP whose filler wus not modified by any coupling agent. It was found that the optimal amount of KH550 was 1.0 phr to 100.0 phr carbonyl iron powder. The effects of different modifying techniques on RMAP's mechanical properties were also inrestigated. It is indieated that MAP whose filler is modified by the wet process has the highest tensile strength, but it is not the optimal modiifying technique due to complieated wet process. On the contrary, the dry process was very simple, and VRMAP possessed fairly high mechanical properties, therefore, it was the perfect modifying process. 展开更多
关键词 silane coupling ageat carbonyl iron powder microwave absorbing patch mechanical property mierostructure
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Hydro-mechanical coupling mechanism on joint of clay core-wall and concrete cut-off wall 被引量:3
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作者 罗玉龙 詹美礼 +1 位作者 盛金昌 吴强 《Journal of Central South University》 SCIE EI CAS 2013年第9期2578-2585,共8页
The joint of clay core-wall and concrete cut-off wall is one of the weakest parts in high earth and rockftll dams.A kind of highly plastic clay is always fixed on the joint to fit the large shear deformation between c... The joint of clay core-wall and concrete cut-off wall is one of the weakest parts in high earth and rockftll dams.A kind of highly plastic clay is always fixed on the joint to fit the large shear deformation between clay core-wall and concrete cut-offwall,so the hydro-mechanical coupling mechanisms on the joint under high stress,high hydraulic gradient,and large shear deformation are of great importance for the evaluation of dam safety.The hydro-mechanical coupling characteristics of the joint of the highly plastic clay and the concrete cut-off wall in a high earth and rockfill dam in China were studied by using a newly designed soil-structure contact erosion apparatus.The experimental results indicate that:1) Shear failure on the joint is due to the hydro-mechanical coupling effect of stress and seepage failure.The seepage failure will induce the final shear failure when the ratio of deviatoric stress to confining pressure is within 1.0-1.2; 2) A negative exponential permeability empirical model for the joint denoted by a newly defined principal stress function,which considers the coupling effect of confining pressure and axial pressure on the permeability,is established based on hydro-mechanical coupling experiments.3) The variation of the settlement before and after seepage failure is very different.The settlement before seepage failure changes very slowly,while it increases significantly after the seepage failure.4) The stress-strain relationship is of a strain softening type.5) Flow along the joint still follows Darcian flow rule.The results will provide an important theoretical basis for the further evaluation on the safety of the high earth and rockfill dam. 展开更多
关键词 high earth and rockfill dam soil/structure interface hydro-mechanical coupling mechanism seepage failure shear failure
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Crack initiation rate of brittle rock under thermal-hydro-mechanical coupling condition 被引量:2
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作者 Zhuo LI Qiu-hua RAO +1 位作者 Peng LI Wei YI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2018年第10期2107-2113,共7页
A calculation formula of thermal-hydro-mechanical(THM)coupling crack initiation rate for brittle rock was derived based on the energy conservation law.The self-designed THM coupling fracture test with conductive adhe... A calculation formula of thermal-hydro-mechanical(THM)coupling crack initiation rate for brittle rock was derived based on the energy conservation law.The self-designed THM coupling fracture test with conductive adhesive electrical measurement method was applied to measuring the THM coupling crack propagation rate of brittle rock continuously.Research results show that both calculation and test results of crack initiation rate increased with increase of the temperature and the hydraulic pressure.They are almost in good agreement,which can prove validity of the calculation formula of THM coupling crack initiation rate. 展开更多
关键词 crack initiation rate thermal-hydro-mechanical coupling test conductive adhesive electrical method fracture mechanism brittle rock
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Thermal-hydro-mechanical coupling damage model of brittle rock 被引量:1
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作者 李鹏 饶秋华 +2 位作者 李卓 马雯波 马彬 《Journal of Central South University》 SCIE EI CAS 2014年第3期1136-1141,共6页
Based on fluid mechanics, thermodynamics and damage mechanics, thermal-hydro-mechanical (THM) coupling damage model of brittle rock is established by analyzing THM coupling mechanism, where THM coupling damage varia... Based on fluid mechanics, thermodynamics and damage mechanics, thermal-hydro-mechanical (THM) coupling damage model of brittle rock is established by analyzing THM coupling mechanism, where THM coupling damage variable DTHM is dominated by TH coupling damage variable DTH, TM coupling damage variable DTM and HM coupling damage variable DHM, and DTH is firstly expressed in term of dimensionless total thermal conductivity of the water Nu. Permeability test, uni-axial compression test and THM coupling test are conducted to measure the permeability, elastic modulus and THM coupling stress-strain curves of brittle rock. The tested values of THM coupling elastic modulus E'HM are in good agreement with the predicted values of THM coupling elastic modulus ETHM, which can verify the newly established THM coupling damage model. 展开更多
关键词 damage model THM coupling mechanism permeability test THM coupling test brittle rock
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Analysis of the Oscillating Mechanism of an Aerial Work Platform Based on ADAMS Hydraulic-Mechanical Coupling Simulation 被引量:2
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作者 GU De-jun TENG Ru-min +2 位作者 GAO Shun-de BAI Ri GAO Kai-qing 《International Journal of Plant Engineering and Management》 2008年第3期154-158,共5页
Rigid model of the aerial work platform and hydraulic model of the oscillating mechanism were established with ADAMS. The simulation of two parameters, cy-linder force and oil chamber pressure, was carried out. The si... Rigid model of the aerial work platform and hydraulic model of the oscillating mechanism were established with ADAMS. The simulation of two parameters, cy-linder force and oil chamber pressure, was carried out. The simulation result is useful to the design of the oscillating mechanism. 展开更多
关键词 aerial work platform oscillating mechanism hydraulic-mechanical coupling simulation
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MECHANICAL-ELECTRIC COUPLING DYNAMICAL CHARACTERISTICS OF AN ULTRA-HIGH SPEED GRINDING MOTORIZED SPINDLE SYSTEM 被引量:23
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作者 LUE Lang XIONG Wanli GAO Hang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2008年第5期34-40,共7页
On the basis of the traditional mechanical model of a grinding wheel rotor and the mechanical-electric coupling model with ideal sinusoidal supply, taking high-frequency converting current of inverter power switches i... On the basis of the traditional mechanical model of a grinding wheel rotor and the mechanical-electric coupling model with ideal sinusoidal supply, taking high-frequency converting current of inverter power switches into further consideration, a modified mechanical-electric coupling model is created. The created model consists of an inverter, a motorized spindle, a grinding wheel and grinding loads. Some typical non-stationary processes of the grinding system with two different supplies, including the starting, the speed rising and the break in grinding loads, are compared by making use of the created model. One supply is an ideal sinusoidal voltage source, the other is an inverter. The theoretical analysis of the high-order harmonic is also compared with the experimental result. The material strategy of suppressing high-order harmonic mechanical-electric coupling vibration by optimizing inverter operating parameters is proposed. 展开更多
关键词 Ultra-high speed grinding Motorized spindle mechanical-electric coupling Vibration Suppression
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Formation Mechanism in Alloy Steel Rolling Process Using Thermo-mechanical Coupling Method
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作者 杨理诚 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2012年第3期422-426,共5页
Based on the theory of elastic-plastic finite element method, the high-speed hot continuous rolling process of a billet is simulated and analyzed in vertical and horizontal passes. The billet is dragged into the passe... Based on the theory of elastic-plastic finite element method, the high-speed hot continuous rolling process of a billet is simulated and analyzed in vertical and horizontal passes. The billet is dragged into the passes by contact friction force between the billet and rollers. The rollers and billet are represented by respectively rigid and deformable bodies, and three-dimensional models are developed for the billet and rollers. The distribution of deformation field, effective strain, rolling force and temperature field are accurately calculated for the whole rolling process (including unstable and stable stages). In addition, the rolling pressure on the width symmetry center is compared with that in the in-situ experimental measurements. It is revealed that various heat exchange phenomena among the billet, rollers and surroundings can result in unbalanced temperature distribution on the cross section. Rolling force and strain can change significantly when the billet is moved towards or away from the roller gap, and keep almost invariable in the stable stage. It is expected that the simulation results would be useful for practical manufacture and provide the theoretical foundation for improvement of process planning and optimization of process parameters. 展开更多
关键词 thermo-mechanical coupling temperature field deformation mechanism hot rolling process
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Transient thermo-mechanical coupling simulation of wet brake friction disk on tracked vehicle
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作者 李杰 王敏 +1 位作者 王志勇 周广明 《Journal of Beijing Institute of Technology》 EI CAS 2011年第1期71-76,共6页
The transient finite element technique is applied, and a transient heat conduction model of wet brake friction disk is established. For obtaining the accurate heat flow density mathematic model and avoiding possibly i... The transient finite element technique is applied, and a transient heat conduction model of wet brake friction disk is established. For obtaining the accurate heat flow density mathematic model and avoiding possibly instable thermoelastic stress produced by the non uniform contact pressure of friction pair, a test method is applied to collect accurate contact pressure between the dual sheet steel and friction disk in the combining process. And then the heat-flow density and transient ther mo mechanical coupling simulation are analyzed. At the same time all possible boundary conditions are considered, such as the heat generation, heat conduction problem, relation between friction and contact, variation in load and heat change problem etc. The simulation results show that the me chanical model of thermo mechanical coupling can express well the dynamic characteristics of fric tion disk, and gives perfect reference for more study on thermoelastic distortion of brake friction pairs. 展开更多
关键词 friction disk thermo mechanical coupling transient stress finite element heat flowdensity
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Coupling Characteristics and Control of Dual Mechanical Port Machine with Spoke Type Permanent Magnet Arrangement
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作者 ZHUANG Xingming SONG Qiang +2 位作者 WEN Xuhui ZHAO Feng FAN Tao 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2014年第6期1186-1202,共17页
Dual mechanical port machine(DMPM), as a novel electromechanical energy conversion device, has attracted widespread attention. DMPM with spoke type permanent magnet arrangements(STPM-DMPM), which is one of several... Dual mechanical port machine(DMPM), as a novel electromechanical energy conversion device, has attracted widespread attention. DMPM with spoke type permanent magnet arrangements(STPM-DMPM), which is one of several types of DMPM, has been of interest recently. The unique coupling characteristics of STPM-DMPM are beneficial to improving system performance, but these same characteristics increase the difficulties of control. Now there has been little research about the control of STPM-DMPM, and this has hindered its practical application. Based on a mathematical model of STPM-DMPM, the coupling characteristics and the merits and demerits of such devices are analyzed as applied to a hybrid system. The control strategies for improving the disadvantages and for utilizing the advantage of coupling are researched. In order to weaken the interaction effect of torque outputs in the inner motor and the outer motor that results from coupling in STPM-DMPM, a decoupling control method based on equivalent current control is proposed, and independent torque control for the inner motor and outer motor is achieved. In order to solve address the problem of adequately utilization of coupling, minimizing the overall copper loss of the inner motor and the outer motor of STPM-DMPM is taken as the optimization objective for optimal control, and the purpose of utilizing the coupling adequately and reasonably is achieved. The verification tests of the proposed decoupling control and optimal control strategies are carried out on a prototype STPM-DMPM, and the experimental results show that the interaction effect of torque outputs in the inner motor and the outer motor can be markedly weakened through use of the control method. The overall copper loss of the inner motor and the outer motor can be markedly reduced through use of the optimal control method, while the power output remains unchanged. A breakthrough in the control problem of STPM-DMPM is accomplished by combining the control methods. Good performance in the control of STPM-DMPM will enhance its practicality, particularly as applied to hybrid systems. 展开更多
关键词 dual mechanical port machine spoke type permanent magnet arrangement coupling characteristics decoupling control optimal control
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ELECTRO-MECHANICAL COUPLING ANALYSIS OF MEMS STRUCTURES BY BOUNDARY ELEMENT METHOD 被引量:1
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作者 张恺 崔云俊 +2 位作者 熊春阳 王丛舜 方竞 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2004年第2期185-191,共7页
In this paper,we present the applications of Boundary Element Method(BEM) to simulate the electro-mechanical coupling responses of Micro-Electro-Mechanical systems(MEMS). The algorithm is programmed in our research gr... In this paper,we present the applications of Boundary Element Method(BEM) to simulate the electro-mechanical coupling responses of Micro-Electro-Mechanical systems(MEMS). The algorithm is programmed in our research group based on BEM modeling for electrostatics and elastostatics.Good agreement is shown while the simulation results of the pull-in voltages are compared with the theoretical/experimental ones for some examples. 展开更多
关键词 MEMS boundary element method(BEM) electro-mechanical coupling
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Mechanical Behaviors of Silt Rock Subjected to Coupling Static and Impact Loads
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作者 ZHOU Zilong LI Xibing HONG Liang MA Chunde 《Transactions of Tianjin University》 EI CAS 2006年第B09期205-209,共5页
Experiments of silt rock subjected to coupling loads were carried out on tailormade equipment. With a constant dynamic load, the behaviors of eight sets of siltite specimens were investigated with different axial stat... Experiments of silt rock subjected to coupling loads were carried out on tailormade equipment. With a constant dynamic load, the behaviors of eight sets of siltite specimens were investigated with different axial static loads. The experimental results show that the modulus of the specimens under coupling loads increases at first and then decreases with the increase of axial static pressure. The failure model of the specimens also varies. Keeping the dynamic load constant, when the axial static pressure is low, the specimen breaks in two simply. With the increase of axial static pressure, the cone-shaped fragment appeares. When the axial static pressure reaches 90% of the static strength of rock, the specimen smashes into amount of small fragments. 展开更多
关键词 rock mechanics coupling loads EXPERIMENTS
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Numerical simulation of a sheet metal extrusion process by using thermal-mechanical coupling EAS FEM 被引量:2
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作者 ZhanghuaChen T.C.Lee 《Journal of University of Science and Technology Beijing》 CSCD 2002年第5期378-382,共5页
The thermal-mechanical coupling finite element method(FEM)was usedto simulate a non-isothermal sheet metal extrusion process. On thebasis of the finite plasticity consistent with multiplicativedecomposition of the def... The thermal-mechanical coupling finite element method(FEM)was usedto simulate a non-isothermal sheet metal extrusion process. On thebasis of the finite plasticity consistent with multiplicativedecomposition of the deformation gradient, the enhanced as- sumedstrain(EAS)FEM was applied to carry out the numerical simulation. Inorder to make the computation reliable ad avoid hour- glass mode inthe EAS element under large compressive strains, an alterative formof the original enhanced deformation gradient was employed. Inaddition, reduced factors were used in the computation of the elementlocal internal parameters and the enhanced part of elementalstiffness. 展开更多
关键词 enhanced assumed strain element thermal-mechanical coupling process houyrglass mode
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Formulation of thermo-hydro-mechanical coupling behavior of unsaturated soils based on hybrid mixture theory 被引量:2
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作者 Guo-Qing Cai Cheng-Gang Zhao +1 位作者 Dai-Chao Sheng An-Nan Zhou 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2014年第4期559-568,共10页
Thermo-Hydro-Mechanical (THM) coupling pro- cesses in unsaturated soils are very important in both theoretical researches and engineering applications. A coupled formulation based on hybrid mixture theory is derived... Thermo-Hydro-Mechanical (THM) coupling pro- cesses in unsaturated soils are very important in both theoretical researches and engineering applications. A coupled formulation based on hybrid mixture theory is derived to model the THM coupling behavior of unsaturated soils. The free-energy and dissipative functions for different phases are derived from Taylor's series expansions. Constitutive relations for THM coupled behaviors of unsaturated soils, which include deformation, entropy change, fluid flow, heat conduction, and dynamic compatibility conditions on the interfaces, are then established. The number of field equations is shown to be equal to the number of unknown variables; thus, a closure of this coupling problem is established. In addition to modifications of the physical conservation equations with coupling effect terms, the constitutive equations, which consider the coupling between elastoplastic deformation of the soil skeleton, fluid flow, and heat transfer, are also derived. 展开更多
关键词 Thermo-hydro-mechanical coupling Unsatu-rated soils Hybrid mixture theory Constitutive equations ·Elastoplastic deformation
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