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Design method and magnetic field analysis of axial-magnetized permanent magnet micromotor

YANG Jiewei, WU Yihui, JIA Hongguang, ZHANG Ping, WANG Shurong

《机械工程前沿（英文）》 2007年 第2卷 第3期   页码 318-322 doi: 10.1007/s11465-007-0056-0

摘要： To investigate the impact of size on its performance in designing an axial-magnetized permanent magnet micro motor, the finite element method is adopted to simulate the magnetic field of the dual rotor motor, and the flux density wave form distributed in the airgap is obtained. The influence of the external dimensions, pole numbers and magnet thicknesses of the rotor, and the airgap distances on the flux density, are analyzed and analytical results are given. With the increase of the airgap distance, the flux density under more poles reduces more quickly than under fewer poles. With the increase of the magnet thickness, the flux density is a rising curve, and after the magnet thickness attains a certain point, the flux density is almost a constant. While reducing the diameter of the rotor, the decrease of the flux density slows down as magnet thickness is reduced. To avoid having a seriously distorted waveform, the distance between inner and outer radii of the rotor must be larger than 1.5 millimeter. Results of the magnetic field analysis can guide a microminiaturization of the motor. Moreover, the results are analyzed theoretically and the simulated values are almost consistent with the experimental values.

关键词： axial-magnetized permanent     diameter     constant     certain     magnetic    

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基于新型拓扑Halbach阵列的PCB定子无铁心轴向磁通电机设计 Regular Papers

Xiao-yuan WANG, Xiang LI, Chun-peng LI, Si-jia XU, Le-tao LING

《信息与电子工程前沿（英文）》 2019年 第20卷 第3期   页码 414-424 doi: 10.1631/FITEE.1700345

摘要： 针对印刷电路板（PCB）定子轴向磁通永磁电机特点，提出一种新型拓扑Halbach永磁体阵列，设计并分析应用该永磁体阵列的PCB定子轴向磁通永磁电机。与传统无铁心轴向磁通永磁电机相比，在相同尺寸、同等永磁体用量下，该新型拓扑Halbach永磁体阵列PCB定子轴向磁通永磁电机具有更高气隙磁密及每极磁通，可获得更高空载反电势，同时有效降低漏磁，使气隙磁密更接近正弦波，提升了电机整体性能。有限元分析结果和样机对比实验验证了该新型拓扑Halbach永磁体阵列PCB定子电机的合理性和有效性，为PCB定子轴向磁通永磁电机设计提供了参考依据和工程应用价值。

关键词： 轴向磁通电机；印制电路板；Halbach永磁体阵列；有限元法    

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Influence of steel corrosion on axial and eccentric compression behavior of coral aggregate concrete

《结构与土木工程前沿（英文）》 2021年 第15卷 第6期   页码 1415-1425 doi: 10.1007/s11709-021-0786-9

摘要： To study the behavior of coral aggregate concrete (CAC) column under axial and eccentric compression, the compression behavior of CAC column with different types of steel and initial eccentricity (ei) were tested, and the deformation behavior and ultimate bearing capacity (Nu) were studied. The results showed that as the ei increases, the Nu of CAC column decreases nonlinearly. Besides, the steel corrosion in CAC column is severe, which reduces the steel section and steel strength, and decreases the Nu of CAC column. The durability of CAC structures can be improved by using new organic coated steel. Considering the influence of steel corrosion and interfacial bond deterioration, the calculation models of Nu under axial and eccentric compression were presented.

关键词： coral aggregate concrete column     axial compression     eccentric compression     steel corrosion     calculation model    

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Fast scaling approach based on cavitation conditions to estimate the speed limitation for axial piston

Qun CHAO, Jianfeng TAO, Junbo LEI, Xiaoliang WEI, Chengliang LIU, Yuanhang WANG, Linghui MENG

《机械工程前沿（英文）》 2021年 第16卷 第1期   页码 176-185 doi: 10.1007/s11465-020-0616-0

摘要： The power density of axial piston pumps can benefit greatly from increased rotational speeds. However, the maximum rotational speed of axial piston machines is limited by the cavitation phenomenon for a given volumetric displacement. This paper presents a scaling law derived from an analytical cavitation model to estimate the speed limitations for the same series of axial piston pumps. The cavitation model is experimentally verified using a high-speed axial piston pump, and the scaling law is validated with open specification data in product brochures. Results show that the speed limitation is approximately proportional to the square root of the inlet pressure and inversely proportional to the cube root of volumetric displacement. Furthermore, a characteristic constant is defined based on the presented scaling law. This constant can represent the comprehensive capacity of axial piston pumps free from cavitation.

关键词： axial piston pump     cavitation     speed limitation     scaling law    

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Integrated slipper retainer mechanism to eliminate slipper wear in high-speed axial piston pumps

《机械工程前沿（英文）》 doi: 10.1007/s11465-021-0657-z

摘要： The power density of axial piston pumps can greatly benefit from increasing the speed level. However, traditional slippers in axial piston pumps are exposed to continuous sliding on the swash plate, suffering from serious wear at high rotational speeds. Therefore, this paper presents a new integrated slipper retainer mechanism for high-speed axial piston pumps, which can avoid direct contact between the slippers and the swash plate and thereby eliminate slipper wear under severe operating conditions. A lubrication model was developed for this specific slipper retainer mechanism, and experiments were carried out on a pump prototype operating at high rotational speed up to 10000 r/min. Experimental results qualitatively validated the theoretical model and confirmed the effectiveness of the new slipper design.

关键词： axial piston pump     high speed     slipper wear     slipper design     retainer     lubrication model    

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New response surface model and its applications in aerodynamic optimization of axial compressor blade

LIU Xiaojia, NING Fangfei

《能源前沿（英文）》 2008年 第2卷 第4期   页码 541-549 doi: 10.1007/s11708-008-0077-3

摘要： A parametric method for the axial compressor 2D blade profiles is proposed in which the blade geometries are defined with the parameters commonly used for blade definition, which ensures that the geometric significance is clear and an unreasonable blade profile is not generated. Several illustrations are presented to show the fitting precision of the method. A novel response surface model is proposed which regards the objective distribution function in the vicinity of a sample as normal school, and then generates the response surface function in the whole design space by a linear combination of distribution functions of all the samples. Based on this model, a numerical aerodynamic optimization platform for the axial compressor 2D blade profiles is developed, by which aerodynamic optimization of two compressor blade profiles are presented.

关键词： definition     objective distribution     fitting precision     combination     numerical aerodynamic    

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Three-dimensional electromagnetic analysis and design of permanent magnet retarder

Lezhi YE, Desheng LI, Bingfeng JIAO

《机械工程前沿（英文）》 2010年 第5卷 第4期   页码 438-441 doi: 10.1007/s11465-010-0111-0

摘要： An eddy current retarder for vehicles generates much heat when it works continuously, which leads to serious decline in braking torque. This paper proposes a novel permanent magnet retarder (PMR) for vehicles, whose cooling system connects with engine cooling-water. A three-dimensional finite element model is developed to model the electromagnetic behavior of a permanent magnet retarder under a constant speed. The magnetic field and eddy current field in PMR are numerically solved by a finite element method. By accounting for the nonlinear permeability of the rotor and the weakened effect in the magnetic field that is generated by the eddy current magnetic field, the calculation accuracy of air-gap magnetic field is enhanced. Experiment shows that the temperature of the retarder is less than 150°C, and the braking torque keeps the hard characteristics curve. The calculated air-gap magnetic flux density is fairly good agreement with the measured one.

关键词： auxiliary brake     permanent magnet retarder     water-cooling     finite element method    

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Characteristics of force acting on adjustable axial flow pump blade

WEI Peiru, CHEN Hongxun, LU Wei

《能源前沿（英文）》 2008年 第2卷 第4期   页码 508-513 doi: 10.1007/s11708-008-0054-x

摘要： The internal three-dimensional turbulent flow of adjustable axial-flow pump arrangement was simulated, and the force acting on the blade surface was calculated under different operating conditions. Based on the calculated results, finite element method (FEM) was adopted to analyze stress and strain distributions of the adjustment blade in different operations. Hydraulic moment, centrifugal moment and friction moment which must be conquered by adjusting the blades were also calculated.

关键词： three-dimensional     adjustable axial-flow     calculated     FEM     centrifugal    

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Structure optimization for magnetic equipment of permanent magnet retarder

Bingfeng JIAO, Desheng LI, Yunkang SUI, Lezhi YE

《机械工程前沿（英文）》 2010年 第5卷 第4期   页码 442-445 doi: 10.1007/s11465-010-0112-z

摘要： The main purpose of this research is to perform a magnetic analysis on the magnetic equipment of permanent magnet retarder (PMR) and optimize the structure of magnetic equipment with the commercial FEM software ANSYS and its design optimization module. The FEM model is built as an axisymmetric model according to the characteristics of the structure of magnetic equipment. Using this model, the magnetic field distribution and magnetic force are calculated by ANSYS. The mathematical model of structure optimization is also built. The design variables are structural parameters including the dimensions of permanent magnets and magnetic yoke, and the objective function is the magnetic force. The unconstrained optimization model takes the maximum value of magnetic force as the objective. A first-order optimization method is used to determine the optimum design of this problem. The optimization process works entirely with the ANSYS parametric design language (APDL). The design tools are used to understand design space and the behavior of the dependent variables. It is shown that designing a structure with the ANSYS optimization module and its design tools is an effective means to improve the structure.

关键词： optimization     ANSYS     permanent magnet retarder     numerical simulation    

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三峡永久船闸高边坡工程的实践及验证

张超然

《中国工程科学》 2001年 第3卷 第5期   页码 22-27

摘要：

三峡工程永久船闸高边坡工程系从左岸山体内开挖形成，两侧高边坡最大开挖深度达170 m，其下部为68 m高的直立墙，是三峡工程建设的重大技术难题。文章对三峡永久船闸高边坡设计原则和轮廓，施工程序，防渗及排水系统，高边坡加固支护措施，高边坡稳定分析以及永久船闸高边坡变形预测和高边坡监测资料验证等的研究结论和工程的重大科技成就做了介绍。

关键词： 三峡     永久船闸     高边坡    

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Effect of axial load and transverse reinforcements on the seismic performance of reinforced concrete

Mounir Ait BELKACEM, Hakim BECHTOULA, Nouredine BOURAHLA, Adel Ait BELKACEM

《结构与土木工程前沿（英文）》 2019年 第13卷 第4期   页码 831-851 doi: 10.1007/s11709-018-0513-3

摘要： The aim of this research is to assess the seismic performance of reinforced concrete columns under different axial load and transverse reinforcement ratios. These two parameters are very important as for the ductility, strength, stiffness, and energy dissipation capacity for a given reinforced concrete column. Effects of variable axial load ratio and transverse reinforcement ratio on the seismic performance of reinforced concrete columns are thoroughly analyzed. The finite element computer program Seismo-Structure was used to perform the analysis of series of reinforced concrete columns tested by the second author and other researchers. In order to reflect the reality and grasp the actual behavior of the specimens, special attention was paid to select the models for concrete, confined concrete, and steel components. Good agreements were obtained between the experimental and the analytical results either for the lateral force-drift relationships or for the damage progress prediction at different stages of the loading.

关键词： reinforced concrete columns     axial load     transverse reinforcement     ductility    

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Bending and vibration of a discontinuous beam with a curvic coupling under different axial forces

Heng LIU, Jie HONG, Dayi ZHANG

《机械工程前沿（英文）》 2020年 第15卷 第3期   页码 417-429 doi: 10.1007/s11465-019-0584-4

摘要： The transverse stiffness and vibration characteristics of discontinuous beams can significantly differ from those of continuous beams given that an abrupt change in stiffness may occur at the interface of the former. In this study, the equations for the deflection curve and vibration frequencies of a simply supported discontinuous beam under axial loads are derived analytically on the basis of boundary, continuity, and deformation compatibility conditions by using equivalent spring models. The equation for the deflection curve is solved using undetermined coefficient methods. The normal function of the transverse vibration equation is obtained by separating variables. The differential equations for the beam that consider moments of inertia, shearing effects, and gyroscopic moments are investigated using the transfer matrix method. The deflection and vibration frequencies of the discontinuous beam are studied under different axial loads and connection spring stiffness. Results show that deflection decreases and vibration frequencies increase exponentially with increasing connection spring stiffness. Moreover, both variables remain steady when connection spring stiffness reaches a considerable value. Lastly, an experimental study is conducted to investigate the vibration characteristics of a discontinuous beam with a curvic coupling, and the results exhibit a good match with the proposed model.

关键词： discontinuous beam     bending stiffness     transverse vibration     axial loads     gyroscopic moments    

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Damage-constitutive model for seawater coral concrete using different stirrup confinements subjected to axial

《结构与土木工程前沿（英文）》 2023年 第17卷 第3期   页码 429-447 doi: 10.1007/s11709-022-0913-2

摘要： Recently, the application of detrital coral as an alternative to natural aggregates in marine structures has attracted increased attention. In this study, research on the compressive performance of coral aggregate concrete (CAC) confined using steel stirrups with anti-rust treatment was experimentally conducted. A total of 45 specimens were cast, including 9 specimens without stirrups and under different strength grades (C20, C30, and C40) and 36 specimens under different strength grades (C20, C30, and C40). Moreover, three stirrup levels (rectangular, diamond-shaped compound, and spiral stirrups) and different stirrup spacings (40, 50, 60, and 70 mm) were used. Subsequently, the stress−strain curves of specimens subjected to axial loading were measured. The effects of the stirrup spacing and stirrup configurations on the stress and strain were investigated, respectively, and the lateral effective stress of the different stirrups was calculated based on the cohesive-elastic ring model and modified elastic beam theory. Moreover, a damage-constitutive model of CAC considering the lateral stress was set up based on damage mechanics theory. The results indicated an increase in the stress and strain with a decrease in the stirrup spacing, and the adopted stirrup ratio had a better strengthening effect than the different concrete grades, and the variation in the deformation was restricted by the performance of coral coarse aggregate (CA). However, an increment in the lateral strain was observed with an increase in the axial strain. The lateral stress model showed a good agreement with the experimental data, and the proposed damage-constitutive model had a good correlation with the measured stress−strain curves.

关键词： coral aggregate concrete     stress−strain curves     lateral effective stress     peak stress     axial−lateral curves     damage-constitutive model.    

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Development of an analytical model to estimate the churning losses in high-speed axial piston pumps

《机械工程前沿（英文）》 2022年 第17卷 第2期 doi: 10.1007/s11465-021-0671-1

摘要： The axial piston pumps in aerospace applications are often characterized by high-speed rotation to achieve great power density. However, their internal rotating parts are fully immersed in the casing oil during operation, leading to considerable churning losses (more than 10% of total power losses) at high rotational speeds. The churning losses deserve much attention at the design stage of high-speed axial piston pumps, but accurate analytical models are not available to estimate the drag torque associated with the churning losses. In this paper, we derive the analytical expressions of the drag torque acting on the key rotating parts immersed in oil, including the cylinder block and the multiple pistons in a circular array. The calculated drag torque agrees well with the experimental data over a wide range of rotational speeds from 1500 to 12000 r/min. The presented analytical model provides practical guidelines for reducing the churning losses in high-speed axial piston pumps or motors.

关键词： axial piston pump     rotating parts     high rotational speed     churning losses     drag torque    

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Experimental study on flexural behavior of ECC/RC composite beams with U-shaped ECC permanent formwork

Zhi QIAO, Zuanfeng PAN, Weichen XUE, Shaoping MENG

《结构与土木工程前沿（英文）》 2019年 第13卷 第5期   页码 1271-1287 doi: 10.1007/s11709-019-0556-0

摘要： To enhance the durability of a reinforced concrete structure, engineered cementitious composite (ECC), which exhibits high tensile ductility and good crack control ability, is considered a promising alternative to conventional concrete. However, broad application of ECC is hindered by its high cost. This paper presents a new means to address this issue by introducing a composite beam with a U-shaped ECC permanent formwork and infill concrete. The flexural performance of the ECC/RC composite beam has been investigated experimentally with eight specimens. According to the test results, the failure of a composite beam with a U-shaped ECC formwork is initiated by the crushing of compressive concrete rather than debonding, even if the surface between the ECC and the concrete is smooth as-finished. Under the same reinforcement configurations, ECC/RC composite beams exhibit increases in flexural performance in terms of ductility, load-carrying capacity, and damage tolerance compared with the counterpart ordinary RC beam. Furthermore, a theoretical model based on the strip method is proposed to predict the moment-curvature responses of ECC/RC composite beams, and a simplified method based on the equivalent rectangular stress distribution approach has also evolved. The theoretical results are found to be in good agreement with the test data.

关键词： engineered cementitious composite (ECC)     durability     ECC/RC composite beam     permanent formwork     flexural performance     theoretical method    

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标题 作者 时间 类型 操作

Design method and magnetic field analysis of axial-magnetized permanent magnet micromotor

YANG Jiewei, WU Yihui, JIA Hongguang, ZHANG Ping, WANG Shurong

期刊论文

基于新型拓扑Halbach阵列的PCB定子无铁心轴向磁通电机设计

Xiao-yuan WANG, Xiang LI, Chun-peng LI, Si-jia XU, Le-tao LING

期刊论文

Influence of steel corrosion on axial and eccentric compression behavior of coral aggregate concrete

期刊论文

Fast scaling approach based on cavitation conditions to estimate the speed limitation for axial piston

Qun CHAO, Jianfeng TAO, Junbo LEI, Xiaoliang WEI, Chengliang LIU, Yuanhang WANG, Linghui MENG

期刊论文

Integrated slipper retainer mechanism to eliminate slipper wear in high-speed axial piston pumps

期刊论文

New response surface model and its applications in aerodynamic optimization of axial compressor blade

LIU Xiaojia, NING Fangfei

期刊论文

Three-dimensional electromagnetic analysis and design of permanent magnet retarder

Lezhi YE, Desheng LI, Bingfeng JIAO

期刊论文

Characteristics of force acting on adjustable axial flow pump blade

WEI Peiru, CHEN Hongxun, LU Wei

期刊论文

Structure optimization for magnetic equipment of permanent magnet retarder

Bingfeng JIAO, Desheng LI, Yunkang SUI, Lezhi YE

期刊论文

三峡永久船闸高边坡工程的实践及验证

张超然

期刊论文

Effect of axial load and transverse reinforcements on the seismic performance of reinforced concrete

Mounir Ait BELKACEM, Hakim BECHTOULA, Nouredine BOURAHLA, Adel Ait BELKACEM

期刊论文

Bending and vibration of a discontinuous beam with a curvic coupling under different axial forces

Heng LIU, Jie HONG, Dayi ZHANG

期刊论文

Damage-constitutive model for seawater coral concrete using different stirrup confinements subjected to axial

期刊论文

Development of an analytical model to estimate the churning losses in high-speed axial piston pumps

期刊论文

Experimental study on flexural behavior of ECC/RC composite beams with U-shaped ECC permanent formwork

Zhi QIAO, Zuanfeng PAN, Weichen XUE, Shaoping MENG

期刊论文