检索结果-内蒙古大学图书馆

A theoretical and deep learning hybrid model for predicting surface roughness of diamond-turned polycrystalline materials

引用

International Journal of Extreme Manufacturing 2023年第3期5卷 620-644页

作者： Chunlei He Jiwang Yan Shuqi Wang Shuo Zhang Guang Chen Chengzu Ren Tianjin Key Laboratory of Equipment Design and Manufacturing Technology Department of Mechanical EngineeringTianjin UniversityTianjin 30054People’s Republic of China Department of Mechanical Engineering Keio UniversityYokohama 223-8522Japan Tianjin Key Laboratory of the Design and Intelligent Control of the Advanced Mechatronical System School of Mechanical EngineeringTianjin University of TechnologyTianjin 300384People’s Republic of China School of Mechanical Engineering Yanshan UniversityQinhuangdao 066004People’s Republic of China

Polycrystalline materials are extensively employed in *** surface roughness significantly affects the working *** defects,particularly grain boundaries,have a great impact on the achieved surface roughness of polycrystalline ***,it is difficult to establish a purely theoretical model for surface roughness with consideration of the grain boundary effect using conventional analytical *** this work,a theoretical and deep learning hybrid model for predicting the surface roughness of diamond-turned polycrystalline materials is *** kinematic–dynamic roughness component in relation to the tool profile duplication effect,work material plastic side flow,relative vibration between the diamond tool and workpiece,etc,is theoretically *** material-defect roughness component is modeled with a cascade forward neural *** the neural network,the ratio of maximum undeformed chip thickness to cutting edge radius RT S,work material properties(misorientation angle θ_(g) and grain size d_(g)),and spindle rotation speed n s are configured as input *** material-defect roughness component is set as the output *** validate the developed model,polycrystalline copper with a gradient distribution of grains prepared by friction stir processing is machined with various processing parameters and different diamond *** with the previously developed model,obvious improvement in the prediction accuracy is observed with this hybrid prediction *** on this model,the influences of different factors on the surface roughness of polycrystalline materials are *** influencing mechanism of the misorientation angle and grain size is quantitatively *** fracture modes,including transcrystalline and intercrystalline fractures at different RTS values,are ***,optimal processing parameters are obtained with a simulated annealing *** experiments are performed with

关键词： diamond turning material-defect roughness component polycrystalline copper neural network simulated annealing algorithm

来源：评论

学校读者我要写书评

暂无评论

Kinematic Modeling and Error Analysis of the Six Pole Parallel Robot

Kinematic Modeling and Error Analysis of the Six Pole Parall...

引用

2016 IEEE advanced Information Management,Communicates,Electronic and Automation control Conference(IMCEC 2016)

作者： ZHAO Xin-hua LUAN Qian-qian ZHAO Lei WANG Shou-jun GE Wei-min FAN Meng-ran Tianjin Key Laboratory of the Design and Intelligent Control of the Advanced Mechatronic System Tianjin University of Technology School of Mechanic Engineering

ISBN: (纸本)9781509001668

The parallel manipulator has some advantages of high accuracy,high speed and high stiffness *** makes up for the shortcomings of serial *** the parallel mechanism becomes a potential motion platform with high speed and high *** poles parallel robot improves these defects of more singularity,poor load capacity and low stiffness which exist in workspace of the classic plane five poles parallel *** and forward kinematic models are established based on the structure of the *** influence of foundation beds' location error,driving angle error and rod processing error on control accuracy is systematically *** theoretical foundation has been provided for realizing the optimal design of the robot and control in high accuracy.

关键词： high speed parallel robot kinematics error analysis

来源：评论

学校读者我要写书评

暂无评论

Multi-objective Dimensional Optimization of a 3-DOF Translational PKM Considering Transmission Properties

引用

International Journal of Automation and computing 2019年第6期16卷 748-760页

作者： Song Lu Yang-Min Li Bing-Xiao Ding Department of Electromechanical Engineering University of MacaoTaipaMacao 853China Department of Industrial and Systems Engineering The Hong Kong Polytechnic UniversityKowloonHong Kong 852China Tianjin Key Laboratory of the Design and Intelligent Control of the Advanced Mechatronical System Tianjin University of TechnologyTianjin 300384China

Multi-objective dimensional optimization of parallel kinematic manipulators(PKMs) remains a challenging and worthwhile research endeavor. This paper presents a straightforward and systematic methodology for implementing the structure optimization analysis of a 3-prismatic-universal-universal(PUU) PKM when simultaneously considering motion transmission, velocity transmission and acceleration transmission. Firstly, inspired by a planar four-bar linkage mechanism, the motion transmission index of the spatial parallel manipulator is based on transmission angle which is defined as the pressure angle amongst limbs. Then, the velocity transmission index and acceleration transmission index are derived through the corresponding kinematics model. The multi-objective dimensional optimization under specific constraints is carried out by the improved non-dominated sorting genetic algorithm(NSGA Ⅱ), resulting in a set of Pareto optimal solutions. The final chosen solution shows that the manipulator with the optimized structure parameters can provide excellent motion, velocity and acceleration transmission properties.

关键词： Multi-objective optimization parallel kinematic manipulator transmission property non-dominated sorting genetic algorithm(NSGA Ⅱ)

来源：评论

学校读者我要写书评

暂无评论

Investigation of the Conjugate Heat Transfer and Flow Field for a Flat Plate with Combined Film and Impingement Cooling

引用

Journal of Thermal Science 2020年第4期29卷 955-971页

作者： FU Jinglun CAO Ying ZHANG Chao ZHU Junqiang Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control Tianjin 300384China

Film cooling combined with internal impingement cooling is one of the most effective technologies to protect the gas turbine vanes and blades from the hot gas. In this study, conjugate heat transfer CFD study was undertaken for a flat plate with combined film cooling and impingement cooling. An experiment on conjugate heat transfer of a flat plate with combined film and impingement cooling was performed to validate the code. Then the effects of several parameters including Biot number, blowing ratio, film hole shape and impingement hole diameter on the overall cooling effectiveness were numerically studied. The results show that for a specific combined cooling scheme and a given blowing ratio, the coolant potential can be reasonably allocated to the internal and the external cooling to achieve the overall cooling effectiveness. As the blowing ratio increases, the overall cooling effectiveness trends to reach a maximum value. For different film hole geometrical, the maximum values of the overall cooling effectiveness at high blowing ratio approximate to the same value. At a given mass flow rate of coolant, the increase of the impingement hole diameter leads to the reduction of the overall cooling effectiveness.

关键词： conjugate heat transfer combined film and impingement cooling overall cooling effectiveness Biot number blowing ratio

来源：评论

学校读者我要写书评

暂无评论

Vibration Absorption Efficiency and Higher Branches Elimination of Variable-Stiffness Nonlinear Energy Sink

引用

Journal of Harbin Institute of Technology(New Series) 2020年第1期27卷 76-84页

作者： Rui Zhong Jian’en Chen Weimin Ge Jun Liu Xiaofeng Wang Tianjin Key Laboratory of the Design and Intelligent Control of the Advanced Mechatronical System Tianjin University of TechnologyTianjin 300384China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of TechnologyTianjin 300384China

Vibration absorption efficiency of a variable⁃stiffness nonlinear energy sink(NES)was investigated when the main oscillator was subjected to harmonic and impulse *** slow flow equations of the coupled system were derived by using the complexification⁃averaging method,and the nonlinear equations which describe the steady⁃state response were *** the harmonic excitation force increased,the system which comprises constant⁃stiffness NES generated higher branch responses,greatly reducing the vibration absorption *** influence of nonlinear stiffness on the responses of the system was *** show that,with the increase of harmonic exciting force,a reduction of NES stiffness can eliminate the higher branch responses and even the frequency band of strongly modulated *** vibration absorption efficiency of variable⁃stiffness NES attached to the linear oscillator for different amplitudes of impulse excitation was *** show that the proper reduction of nonlinear stiffness under increasing impulse excitation can greatly increase the vibration absorption efficiency of NES,and the variable⁃stiffness design can effectively mitigate the negative influences of the increase of the excitation amplitude on the efficiency of constant⁃stiffness NES.

关键词： nonlinear energy sink efficiency variable⁃stiffness vibration suppression higher branch

来源：评论

学校读者我要写书评

暂无评论

Dynamic modeling and simulation of flexible load system operated by reconfigurable manipulators under different constraints 15

Dynamic modeling and simulation of flexible load system oper...

引用

15th IEEE International Conference on Mechatronics and Automation, ICMA 2018

作者： Ma, Huidong Guo, Jinjin Ge, Weimin Wang, Xiaofeng School of Mechanical Engineering Tianjin University of Technology China Tianjin Key Laboratory of the Design and Intelligent Control of the Advanced Mechatronical System Binshui Xidao 391 Xiqing District Tianjin300384 China

ISBN: (纸本)9781538660720

This paper aims at solving the problems that the manipulator will be constrained by the flexible load, and the caused constraint force is difficult to control. Based on the deflection screw theory, the dynamic model of the manipulator system is established by using the Lagrange equation. Firstly, according to the interaction of the end effector, the flexible load and the environmental constraints of the manipulator, the equation of motion of the entire system is built. Secondly, the dynamic model of the manipulator system is set up, that the system including the flexible load and the manipulator. Finally, Under the certain known environmental constraints, the dynamic modeling of a manipulator is performed. The effectiveness of the proposed method is verified by the simulation of a flexible beam operated by a 3-DOF manipulator. © 2018 IEEE.

关键词： Screws

来源：评论

学校读者我要写书评

暂无评论

Non-reciprocity of energy transfer derived from cubic stiffness-induced nonlinear phenomena

引用

Results in Physics 2025年 73卷

作者： Kong, Na Sun, Min Chen, Jianen Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin 300384 China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology Tianjin 300384 China School of Science Tianjin Chengjian University Tianjin 300384 China

Introducing purely nonlinear elastic elements can induce rich dynamic behaviors, such as bifurcations, jumps and isolated resonance curves, to linear systems. Therefore, these elements are suitable for constructing strong non-reciprocity of vibration energy transfer. First, the energy transfer along reciprocal directions in a three-degree-of-freedom system is investigated, where three oscillators are connected by cubic springs. The semi-analytical solutions of the system are obtained using the complexification-averaging method and the least squares method. The results are compared against numerical solutions obtained by the Runge-Kutta method. The excitation amplitude range that produces strong non-reciprocity of vibration energy is analyzed. The jump phenomenon under combined excitation is investigated, and a trigger method for constructing non-reciprocity using an impulse is proposed. Then, an oscillator chain with cubic stiffness and scaling parameters is embedded into a multi-degree-of-freedom linear oscillator system to further explore the effect of cubic stiffness. Energy transfer along two directions is compared by exciting the leftmost oscillator and the rightmost oscillator. Moreover, the trigger effect of the impulse on non-reciprocity is demonstrated. The results show significant differences in vibration energy transfer within three distinct frequency bands. The critical points between reciprocal and non-reciprocal states are obtained, and the three stages of reciprocity related to excitation amplitude are analyzed. Lastly, the modulation effect of the cubic stiffness on non-reciprocity is conducted by comparing the energy of the output oscillator. © 2025 The Authors

关键词： Cubic stiffness Energy transfer Jump phenomenon Non-reciprocity

来源：评论

学校读者我要写书评

暂无评论

Research on Crack Detection of Nonlinear Rotor Based on Energy Tracks 17

Research on Crack Detection of Nonlinear Rotor Based on Ener...

引用

17th IEEE International Conference on Mechatronics and Automation, ICMA 2020

作者： Zhang, Yu Liu, Jun Han, Zhu Tianjin University of Technology Tianjin Key Laboratory for Advanced Mechanical System Design and Intelligent Control Tianjin300384 China

ISBN: (纸本)9781728164151

In rotating machinery, because of high-speed working characteristics and terrible working conditions with variable cycles and variable loads, it is easy for rotors to cause a crack initiation and propagation, which may cause serious harm or even the life-threatening. The super harmonic component is an important role of the crack detection. But it is difficult to reflect the super harmonic component in the high-speed region after super harmonic resonances. In this paper, the dynamic equation of a nonlinear rotor system with a crack is considered, the potential energy expression of the cracked rotor is derived, and the concept of energy tracks is proposed. In the distortion of energy tracks, the effects of different crack parameters and nonlinear parameters on the vibration characteristics of the rotor system are compared. The results show that the energy trajectory distortion can diagnose the crack fault. It provides a new research method for vibration response analyses and fault diagnoses of cracked rotor system. © 2020 IEEE.

关键词： Crack detection

来源：评论

学校读者我要写书评

暂无评论

design and Practice of Blended Teaching Model of Engineering Professional Courses based on Outcome-based Education 3

Design and Practice of Blended Teaching Model of Engineering...

引用

3rd International Conference on Educational Technology, ICET 2023

作者： Xu, Jinyou Zhang, Lei Rui, Chengjie Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin China

ISBN: (纸本)9798350302332

In the context of engineering education, to improve the practical engineering skills of engineering students, the teaching ideas and implementation methods of the curriculum are designed based on Outcome-based Education. A blended teaching approach was used to design the implementation process to achieve the curriculum objectives. In this paper, we explain the process of blended teaching from the two aspects of basic knowledge and competency training. Active learning of basic knowledge is implemented based on a three-step blended teaching model before, after, and during classes. It adopts the project-driven learning approach of the flipped classroom model and cultivates students' ability to solve complex engineering problems through collaborative group and intra-group mutual assessment. Based on the original objective assessment of the curriculum and under the current teaching model, we design a diversified evaluation approach to comprehensively assess the effectiveness of student competence achievement. Practice has shown that project-based inquiry-based teaching methods based on the flipped classroom model can promote learning outcomes for students and increase their interest in learning. It avoids the blind and aimless theoretical learning process of the student and improves the practical ability of the student. The methods and means of instruction of teachers have been further extended, and the ability of students to learn independently has been improved. © 2023 IEEE.

关键词： Students

来源：评论

学校读者我要写书评

暂无评论

Research on Asymmetrical Dual-rotor system Based on the Energy Orbit 17

Research on Asymmetrical Dual-rotor System Based on the Ener...

引用

17th IEEE International Conference on Mechatronics and Automation, ICMA 2020

作者： Han, Zhu Liu, Jun Zhang, Yu Tianjin University of Technology Tianjin Key Laboratory for Advanced Mechanical System Design and Intelligent Control Tianjin300384 China

ISBN: (纸本)9781728164151

Studying the vibration of asymmetrical dual-rotor is very important for aero engines. In this paper, based on the vibration characteristics of an aero-engine, a different novel coupled dynamic model is proposed based on the spring recovery characteristics of rotor. The model dynamic equations of asymmetrical dual-rotor are obtained by the Lagrange equation, and vibration resonance curves of high pressure and low pressure rotors are numerically simulated and theoretically analyzed by using the Runge-Kutta algorithm. The research show that the system occurs combined vibration, harmonic vibration and superharmonic vibration. In addition, the vibration occurring mechanism was investigated and verified in detail through numerical simulation. For the first time, the concept of energy orbit was introduced into the dual-rotor model system. The energy orbit represents the vibration characteristics and energy exchange process of the model system. Energy orbit is a new energy orbit method for analyzing vibration characteristics of rotor system. The new researches of this paper will show a different research direction for complex dual-rotor systems. © 2020 IEEE.

关键词： Equations of motion

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：