检索结果-内蒙古大学图书馆

Dynamic Topology Multi Force Particle Swarm Optimization Algorithm and Its Application

Chinese Journal of Mechanical Engineering 2016年第1期29卷 124-135页

作者： CHEN Dongning ZHANG Ruixing YAO Chengyu ZHAO Zheyu Hebei Provincial Key Laboratory of Heavy Machinery Fluid Power Transmission and Control Yanshan University Qinhuangdao 066004 China Key Laboratory of Advanced Forging & Stamping Technology and Science (Yanshan University) Ministry of Education of China Qinhuangdao 066004 China Hebei Provincial Key Laboratory of Industrial Computer Control Engineering Yanshan University Qinhuangdao 066004 China

Particle swarm optimization （PSO） algorithm is an effective bio-inspired algorithm but it has shortage of premature convergence. Researchers have made some improvements especially in force rules and population topologies. However, the current algorithms only consider a single kind of force rules and lack consideration of comprehensive improvement in both multi force rules and population topologies. In this paper, a dynamic topology multi force particle swarm optimization （DTMFPSO） algorithm is proposed in order to get better search performance. First of all, the principle of the presented multi force particle swarm optimization （MFPSO） algorithm is that different force rules are used in different search stages, which can balance the ability of global and local search. Secondly, a fitness-driven edge-changing （FE） topology based on the probability selection mechanism of roulette method is designed to cut and add edges between the particles, and the DTMFPSO algorithm is proposed by combining the FE topology with the MFPSO algorithm through concurrent evolution of both algorithm and structure in order to further improve the search accuracy. Thirdly, Benchmark functions are employed to evaluate the performance of the DTMFPSO algorithm, and test results show that the proposed algorithm is better than the well-known PSO algorithms, such as gPSO, MPSO, and EPSO algorithms. Finally, the proposed algorithm is applied to optimize the process parameters for ultrasonic vibration cutting on SiC wafer, and the surface quality of the SiC wafer is improved by 12.8% compared with the PSO algorithm in Ref. [25]. This research proposes a DTMFPSO algorithm with multi force rules and dynamic population topologies evolved simultaneously, and it has better search performance.

关键词： force rule MFPSO algorithm FE topology DTMFPSO algorithm parameter optimization

来源：评论

学校读者我要写书评

暂无评论

Dynamic Characteristics Analysis Of Axial Piston Pump Slipper Pair With Wear Fault

Dynamic Characteristics Analysis Of Axial Piston Pump Slippe...

引用

第六届工程机械与车辆工程新进展国际学术会议

作者： Zhang Geng-xin Zhang Jian-jiao Wang Chuang Liu Si-yuan Hebei Provincial Key Laboratory of Heavy Machinery Fluid Power Transmission and Control Yanshan University Key Laboratory of Advanced Forging & Stamping Technology and Science Ministry of Education of ChinaYanshan University CRRC Nanjing Puzhen Co. Ltd.

Considering development mechanism of slipper pair wear fault,the mathematical description equation of slipper wear loss and wear profile was presented,and was used to be wear correction quantity to es

关键词：

来源：评论

学校读者我要写书评

暂无评论

Stress-strain analysis on AA7075 cylindrical parts during hot granule medium pressure forming

引用

Journal of Central South University 2016年第11期23卷 2845-2857页

作者：董国疆杨卓云赵建培赵长财曹秒艳 College of Vehicles and Energy Yanshan University Qinhuangdao 066004 China Key Laboratory of Advanced Forging & Stamping Technology and Science of Ministry of Education of China (Yanshan University) Qinhuangdao 066004 China National Engineering Research Center for Equipment and Technology of Cold Strip Rolling Yanshan University Qinhuangdao 066004 China

Hot granule medium pressure forming(HGMF) is a technology in which heat-resistant granules are used to replace liquids or gases in existing flexible-die forming technology as pressure-transfer medium. Considering the characteristic of granule medium that seals and loads easily, the technology provides a new method to realize the hot deep-drawing forming on high strength aluminum alloy sheet. Based on the pressure-transfer performance test of granule medium and the material performance test of AA7075-T6 sheet, plastic mechanics analysis is conducted for the areas, such as the flange area, force-transfer area and free deforming area, of cylindrical parts deep-drawn by HGMF technology, and the function relation of forming pressure is obtained under the condition of nonuniform distribution of internal pressure. The comparison between theoretical result and experimental data shows that larger deviation occurs in the middle and later period of forming process, and the maximum theoretical forming force is less than the experimental value by 24.6%. The variation tendency of the theoretical thickness curve is close to the practical situation, and the theoretical value basically agrees well with experimental value in the flange area and the top area of spherical cap which is in the free deforming area.

关键词： granule medium aluminum alloy sheet deep-drawing hot forming limit drawing ratio

来源：评论

学校读者我要写书评

暂无评论

Frictional characteristics of granular system under high pressure

引用

Journal of Central South University 2016年第5期23卷 1132-1141页

作者：曹秒艳彭雅新赵长财董国疆杜冰 national engineering research center for equipment and technology of cold strip rolling(yanshan university) Qinhuangdao 066004China Key Laboratory of Advanced Forging&Stamping Technology and Science of Ministry of Education of China(Yanshan University) Qinhuangdao 066004China College of Vehicles and Energy Yanshan UniversityQinhuangdao 066004China

In order to reveal the force transmission features of the granules in the solid granule medium forming(SGMF) technology,the frictional characteristics of the non-metallic granule medium(NGM) under high pressure were investigated by tests and *** the relevant changing curves of the internal friction coefficient of the granular system under different normal pressures were obtained by self-designed shear *** the granule volume compression test,the accurate discrete element simulation parameters were obtained,based on this,the discrete element method(DEM) was adopted to reveal the evolution law of the NGM granules movement in the sample shear process from the microscopic *** on the DEM,the influence of granule diameter,surface friction coefficient,normal pressure and shear velocity on the internal friction coefficient of the granular system were *** the parameters were conducted to be dimensionless by introducing the inertia ***,the expression showing power-law relationship of inertia coefficient,surface friction coefficient and internal friction coefficient is obtained.

关键词： granule friction coefficient discrete element method inertia coefficient

来源：评论

学校读者我要写书评

暂无评论

Effect of Rolling Reduction Rate on the Microstructure of Hot Rolling Stainless Steel Clad Plate

引用

IOP Conference Series: Materials science and Engineering 2018年第3期394卷

作者： Herong Jin Lei Zhang Yali Yi Key Laboratory of Advanced Forging & Stamping Technology and Science of Ministry of National Education Yanshan University Qinhuangdao 066004 China Parallel Robot and Mechatronic System Laboratory of Hebei Province Yanshan University Qinhuangdao 066004 China School of Mechanical Engineering Yanshan University Qinhuangdao 066004 China

The macro-scale and meso-scale simulation models of stainless steel clad plate were established by DEFORM-3D. The multi-scale coupling simulations of clad plate with different rolling parameters were carried out. The seven pass hot rolling process of stainless steel clad plate was simulated by numerical simulation. By contrasting the vertical stress and the deformation resistance of cladding layer, the rolling reduction rate satisfying interface bonding was obtained. The grain distribution at the center of the substrate layer was analyzed and reasonable hot rolling reduction rates were selected considering their effects on the recrystallization volume percent and the grain size. The results show that the grain size decreases with the increase of reduction rate. However, too much reduction rate will decrease the rate of recrystallization volume percent and the refining effect of grain is not obvious. To ensure uniform grain size distribution, it is most reasonable to set the rolling temperature to 1150°C and the reduction rate to 50%.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Hot Granules Medium pressure forming Process of AA7075 Conical Parts

引用

Chinese Journal of Mechanical Engineering 2015年第3期28卷 580-591页

作者： DONG Guojiang ZHAO Changcai PENG Yaxin LI Ying College of Vehicles and Energy Yanshan University Key Laboratory of Advanced Forging & Stamping Technology and Science of Ministry of Education Yanshan University

High strength aluminum alloy plate has a low elongation at room temperature, which leads to the forming of its components need a high temperature. Liquid or gas is used as the pressure-transfer medium in the existing flexible mould forming process, the heat resistance of the medium and pressurizing device makes the application of aluminum alloy plate thermoforming restricted. To solve this problem, the existing medium is replaced by the heat-resisting solid granules and the general pressure equipments are applied. Based on the pressure-transfer performance test of the solid granules medium, the feasibility that the assumption of the extended Drucker-Prager linear model can be used in the finite element analysis is proved. The constitutive equation, the yield function and the theoretical forming limit diagram（FLD） of AA7075 sheet are established. Through the finite element numerical simulation of hot granules medium pressure forming（HGMF） process, not only the influence laws of the process parameters, such as forming temperature, the blank-holder gap and the diameter of the slab, on sheet metal forming performance are discussed, but also the broken area of the forming process is analyzed and predicted, which are coincided with the technological test. The conical part whose half cone angle is 15° and relative height H/d0 is 0.57, is formed in one process at 250℃. The HGMF process solves the problems of loading and seal in the existing flexible mould forming process and provides a novel technology for thermoforming of light alloy plate, such as magnesium alloy, aluminium alloy and titanium alloy.

关键词： granules medium aluminum alloy sheet drawing hot forming forming limit diagram

来源：评论

学校读者我要写书评

暂无评论

Deployable unit 3R-3URU and its application in deployable truss antenna

引用

Hangkong Xuebao/Acta Aeronautica et Astronautica Sinica 2017年第11期38卷 421285页

作者： Liu, Wenlan Xu, Yundou Yao, Jiantao Chen, Liangliang Wang, Hui Zhao, Yongsheng Parallel Robot and Mechatronic System Laboratory of Hebei Province Yanshan University Qinhuangdao066004 China Key Laboratory of Advanced Forging & Stamping Technology and Science of Ministry of Education Yanshan University Qinhuangdao066004 China Xi'an710100 China

A spatial deployable unit 3R-3URU with one Degree of Freedom (DoF) is proposed. The DoF of the single closed-loop mechanism RURUR is analyzed, based on the screw theory and the modified G-K formula. The analytical expression for the velocities of active joints and passive joints of the mechanism RURUR are then established. According to the velocity expression and the structural characteristic that three RURUR mechanisms share their first and last revolute joints, the DoF of the 3R-3URU mechanism is derived. The geometrical relationship among the positions and directions of all joints is also obtained when the 3R-3URU mechanism has one DoF. Novel deployable mechanisms are obtained by applying the 3R-3URU mechanism to the 3RR-3RRR tetrahedral unit and a deployable truss antenna composed of the tetrahedral units, and the novel mechanisms have two types of DoFs: movement and orientation adjustment. DoF analysis and application of the 3R-3URU deployable unit are verified by the Adams software. The proposed deployable unit 3R-3URU has the advantages of one DoF, simple structure, and single type of joints, and can be applied to the supporting mechanism of deployable truss antennas with a curved surface to achieve a large folding ratio. © 2017, press of Chinese Journal of Aeronautics. All right reserved.

关键词： Degrees of freedom (mechanics)

来源：评论

学校读者我要写书评

暂无评论

Instability analysis of free deformation zone of cylindrical parts based on hot-granule medium-pressure forming technology

引用

Transactions of Nonferrous Metals Society of China 2016年第8期26卷 2188-2196页

作者： Miao-yan CAO Chang-cai ZHAO Guo-jiang DONG Sheng-fu YANG College of Mechanical Engineering Yanshan University Qinhuangdao 066004 China Key Laboratory of Advanced Forging & Stamping Technology and Science Ministry of Education Yanshan University Qinhuangdao 066004 China College of Vehicles and Energy Yanshan University Qinhuangdao 066004 China

The cylindrical part of sheet metal based on hot-granule medium-pressure forming (HGMF) technology was *** stress functions of the free deformation zone and the fracture instability theory were combined to establish the analytical expression of the critical pressure of punch. The results show that the active friction between the granule medium and the sheet metal, as well as the non-uniform internal pressure presented by the solid granule medium, can obviously improve the forming performance of the sheet metal. The critical pressure of punch increases with the increment of the friction coefficient between the granule medium and sheet metal, as well as the plastic strain ratio, whereas it decreases with the increase of the material-hardening exponent. Furthermore, the impact on the critical pressure from high to low order is the plastic strain ratio, the friction coefficient,and material-hardening exponent. The deep-drawing experiment with HGMF technology on AZ31B magnesium alloy sheet verified the instability *** words: hot-granule

关键词： hot-granule medium-pressure forming deep-drawing instability cylindrical part

来源：评论

学校读者我要写书评

暂无评论

Mobility analysis of a deployable truss-antenna mechanism-Method based on link-demolishing and equivalent idea

引用

Hangkong Xuebao/Acta Aeronautica et Astronautica Sinica 2017年第9期38卷 421188页

作者： Xu, Yundou Liu, Wenlan Chen, Liangliang Yao, Jiantao Zhao, Yongsheng Zhu, Jialong Parallel Robot and Mechatronic System Laboratory of Hebei Province Yanshan University Qinhuangdao066004 China Key Laboratory of Advanced Forging & Stamping Technology and Science of Ministry of National Education Yanshan University Qinhuangdao066004 China Xi'an710100 China

A method for Degree Of Freedom (DOF) analysis of spatial mechanisms with multiple coupled-loops is proposed based on the link-demolishing and equivalent idea, in view of the multi-loop coupling characteristic of a deployable truss antenna assembled by tetrahedral elements. The coupling constraint chain of the deployable tetrahedral element is removed, and the remainder is regarded as a parallel mechanism. The number and characteristic of the DOF of each output node are then analyzed using the screw theory, and the equivalent serial kinematic chain between the output nodes and the fixed node are then established. The equivalent mechanism of the deployable tetrahedral element is obtained by reconstructing the coupling constrained chain. The number and characteristic of the DOF of the equivalent mechanism are got using the modified G-K formula and the reciprocal screw theory, respectively. As a result, the kinematic characteristics of the tetrahedral element are known. The structure of the minimum composite unit and the large-scale truss deployable antenna are simplified, according to the equivalent mechanism and the combination of the tetrahedral elements. The numbers of the DOF of the minimum composite unit and the large-scale truss deployable antenna are derived on the basis of the geometric constraint equations. The simulation model for a deployable truss antenna assembled by 27 tetrahedral elements is built, and its DOF is verified. The result shows that the DOF of the antenna analyzed by the proposed method is correct. The method lays a foundation for further analysis of the kinematics and dynamics of similar type of antennas, providing a new idea for DOF analysis of other multi-loop coupling mechanisms. © 2017, press of Chinese Journal of Aeronautics. All right reserved.

关键词： Antennas

来源：评论

学校读者我要写书评

暂无评论

Kinematics and Dynamics Hessian Matrices of Manipulators Based on Screw Theory

引用

Chinese Journal of Mechanical Engineering 2015年第2期28卷 226-235页

作者： ZHAO Tieshi GENG Mingchao CHEN Yuhang LI Erwei YANG Jiantao Hebei Provincial Key Laboratory of Parallel Robot and Mechatronic System Yanshan University Key Laboratory of Advanced Forging & Stamping Technology and Science of Ministry of Education Yanshan University

The complexity of the kinematics and dynamics of a manipulator makes it necessary to simplify the modeling ***,the traditional representations cannot achieve this because of the absence of coordinate ***,the coordinate invariant method is an important research ***,the rigid-body acceleration,the time derivative of the twist,is proved to be a screw,and its physical meaning is *** on the twist and the rigid-body acceleration,the acceleration of the end-effector is expressed as a linear-bilinear form,and the kinematics Hessian matrix of the manipulator（represented by Lie bracket）is ***,Newton-Euler＇s equation is rewritten as a linear-bilinear form,from which the dynamics Hessian matrix of a rigid body is *** formulae and the dynamics Hessian matrix are proved to be coordinate *** to the principle of virtual work,the dynamics Hessian matrix of the parallel manipulator is gotten and the detailed dynamic model is *** index of dynamical coupling based on dynamics Hessian matrix is *** the end,a foldable parallel manipulator is taken as an example to validate the deduced kinematics and dynamics *** screw theory based method can simplify the kinematics and dynamics of a manipulator,also the corresponding dynamics Hessian matrix can be used to evaluate the dynamical coupling of a manipulator.

关键词： kinematics dynamics Hessian matrix parallel manipulator screw theory

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：