检索结果-南通市图书馆

Theoretical, Numerical and Experimental Study on Synchronization of Three Identical Exciters in a Vibrating System

Chinese Journal of Mechanical Engineering 2013年第4期26卷 746-757页

作者： ZHANG Xueliang wen bangchun ZHAO Chunyu School of Mechanical Engineering and Automation Northeastern University

The theory on synchronization of two exciters is more widely used in engineering, while that of more than two exciters is less considered. So it is of great significant to investigate synchronization of three exciters. Firstly by introducing the average method of modified small parameters, the dimensionless coupling equations(DCE) of three exciters are derived, which convert the problem of synchronization into that of existence and stability of zero solutions for the DCE and lead to the construction on criterions of synchronization and stability in the simplified form for three exciters. Then the synchronization criterion is discussed numerically, as well as the abilities of synchronization and stability, some results thereof indicate that the synchronization ability increases with the increase of the coupling moment among three exciters, but decreases with that of their phase differences. Finally, an experiment on synchronization with three exciters is carried out. Through the comparison and analysis of experimental data on phase differences among three exciters, responses of system, and phases of three exciters recorded by high-speed camera, the parameters of system satisfying the above two criterions can ensure the synchronous and stable operation of three exciters. As a result, the average method of modified small parameters can be used as a theoretical apparatus studying reasonably the synchronization mechanism of three exciters, it is also proved to be useful and feasible by numeric and experiment. The present research lays the foundation and guidance for the establishment of synchronization theory system with multi-exciter and engineering design.

关键词： synchronization vibrating system stability coupling dynamic double-equilibrium

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Nonlinear Dynamic Analysis of Coupled Gear-Rotor-Bearing System with the Effect of Internal and External Excitations

引用

Chinese Journal of Mechanical Engineering 2016年第2期29卷 281-292页

作者： ZHOU Shihua SONG Guiqiu REN Zhaohui wen bangchun School of Mechanical Engineering and Automation Northeastern University

Extensive studies on nonlinear dynamics of gear systems with internal excitation or external excitation respectively have been carried out. However, the nonlinear characteristics of gear systems under combined internal and external excitations are scarcely investigated. An eight-degree-of-freedom（8-DOF） nonlinear spur gear-rotor-bearing model, which contains backlash, transmission error, eccentricity, gravity and input/output torque, is established, and the coupled lateral-torsional vibration characteristics are studied. Based on the equations of motion, the coupled spur gear-rotor-bearing system（SGRBS） is investigated using the Runge-Kutta numerical method, and the effects of rotational speed, error fluctuation and load fluctuation on the dynamic responses are explored. The results show that a diverse range of nonlinear dynamic characteristics such as periodic motion, quasi-periodic motion, chaotic behaviors and impacts exhibited in the system are strongly attributed to the interaction between internal and external excitations. Significantly, the changing rotational speed could effectively control the vibration of the system. Vibration level increases with the increasing error fluctuation. Whereas the load fluctuation has an influence on the nonlinear dynamic characteristics and the increasing excitation force amplitude makes the vibration amplitude increase, the chaotic motion may be restricted. The proposed model and numerical results can be used for diagnosis of faults and vibration control of practical SGRBS.

关键词： spur gear-rotor-bearing system（SGRBS） backlash eccentricity internal and external excitations coupled lateral-torsional vibration

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Simulations and Experimental Investigation on Motion Stability of a Flexible Rotor-bearing System with a Transverse Crack

引用

Chinese Journal of Mechanical Engineering 2013年第6期26卷 1194-1203页

作者： LI Chaofeng YU Hexing ZHOU Shihua wen bangchun School of Mechanical Engineering & Automation Northeastern University

In the classical process for stability studies on the rotor-bearing system with crack faults, the simple discrete model is adopted for research on such problems, which neglect some needful dynamical influence factor, such as the material damping, shearing effect and gyroscopic effects, etc. Therefore, it is necessary to find a precise calculation model for simulation of the rotor-bearing system with cracks faults. In this paper, instead of the traditional simple discrete model, finite element （FE） model is adopted to investigate the motion stability of a nonlinear rotor system with crack fault. According to finite element theory, the FE model of the cracked rotor system is established firstly. It should be pointed out that the element where the crack occurs is modeled by a particular crack element and the supports at both ends are simulated by two nonlinear loads. Then, based on dimensionless and dimensionality reduction, the Newmark-[3 method and the shooting method are employed to study the effect of eccentricity and the depth of crack on instability speed and bifurcation feature. Furthermore, the simulation results are verified by some corresponding experiments. The simulation and experimental results show that instability speed does not change monotonically, but decreases firstly and then increases when the amount of eccentricity increases. Moreover, as the type of instability changes, the instability speed jumps concomitantly. Additionally, the presence of crack fault can disturb the oil whirl, as a result, instability speed tends to increase slightly, but it does not affect the type of instability and jumping phenomenon. This research presents an effective and convenient method which uses the finite element method （FEM） to research the motion stability of the nonlinear rotor-bearing system with cracked faults and other nonlinear force, and the proposed method can provide a theoretical reference for stability analysis and vibration control in more complex relevant rotor-bearing system.

关键词： rotor-bearing system crack faults finite element model instability

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Dynamic Characteristics of Multi-degrees of Freedom System Rotor-bearing System with Coupling Faults of Rub-impact and Crack

引用

Chinese Journal of Mechanical Engineering 2014年第4期27卷 785-792页

作者： REN Zhaohui ZHOU Shihua LI Chaofeng wen bangchun School of Mechanical Engineering and Automation Northeastern University

Extensive studies on rotor systems with single or coupled multiple faults have been carried out. However these studies are limited to single-span rotor systems. A finite element model for a complex rotor-bearing system with coupled faults is presented. The dynamic responses of the rotor-bearing system are obtained by using the rotor dynamics theory and the modern nonlinear dynamics theory in connection with the continuation-shooting algorithm（commonly used for obtaining a periodic solution for a nonlinear system） for a range of rub-impact clearances and crack depths. The stability and Hopf instability of the periodic motion of the rotor-bearing system with coupled faults are analyzed by using the procedure described. The results indicate that the finite element method is an effective way for determining the dynamic responses of such complex rotor-bearing systems. Further for a rotor system with rub-impact and crack faults, the influences of the clearances are significantly different for different rub-impact stiffness. On the contrary, the influence of crack depths is rather small. The instability speeds of the rotor-bearing system increase due to the presence of the crack fault. The results obtained using the new finite element model, presented for computation and analysis of dynamic responses of the rotor-bearing systems with coupled faults, are in accordance with measurements in experiment. The formulations given can be used for diagnosis of faults, vibration control, and safe and stable operations of real rotor-bearing systems.

关键词： rotor-bearing system rub-impact crack dynamic characteristic instability

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Investigation on meshing and dynamic characteristics of spur gears with tip relief under wear fault

引用

Science China(Technological Sciences) 2019年第11期62卷 1948-1960页

作者： HUANGFU YiFan CHEN KangKang MA Hui LI Xu YU Xi ZHAO BaiShun wen bangchun School of Mechanical Engineering and Automation Northeastern UniversityShenyang 110819China Key Laboratory of Vibration and Control of A ero~Propulsion Systems Ministry of Education of ChinaNortheastern UniversityShenyang 110819China Sate Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819China

Combining the loaded tooth contact analysis(LTCA)method and the gear dynamic model,a wear prediction model for spur gears with tip relief is established.The simulated wear depth is verified by the experimental results in a published reference.Based on the wear profile,the mesh stiffness and the tooth root stress obtained from the proposed model are compared with those obtained from the finite element model.Relative to the finite element method,the proposed method can greatly reduce the computation time.The effects of the tip relief and surface wear on the meshing and the dynamic characteristics are discussed.The tip relief can greatly decelerate the surface wear.Appropriate tip relief and slight wear can decrease the tooth interference and reduce the system vibration.Furthermore,the effects of the rotational speed on the wear depth are also studied and it is found that the quasi-static model is applicable to wear prediction when the rotational speed is away from the harmonic resonance peak.

关键词： spur gears tip relief surface wear mesh stiffness dynamic characteristics

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

System reliability analysis for kinematic performance of planar mechanisms

引用

Chinese Science Bulletin 2009年第14期54卷 2464-2469页

作者： ZHANG YiMin HUANG XianZhen ZHANG XuFang HE XiangDong wen bangchun School of Mechanical Engineering and Automation Northeastern University Shenyang 110004 China School of Mechanical Engineering and Automation Dalian Polytechnic University Dalian 116034 China

Based on the reliability and mechanism kinematic accuracy theories, we propose a general methodology for system reliability analysis of kinematic performance of planar mechanisms. The loop closure equations are used to estimate the kinematic performance errors of planar mechanisms. Reliability and system reliability theories are introduced to develop the limit state functions (LSF) for failure of kinematic performance qualities. The statistical fourth moment method and the Edgeworth series technique are used on system reliability analysis for kinematic performance of planar mechanisms, which relax the restrictions of probability distribution of design variables. Finally, the practicality, efficiency and accuracy of the proposed method are demonstrated by numerical examples.

关键词：系统可靠性分析运动性能机制平面运动学性能可靠性理论运动精度极限状态

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

基于多层次迭代修正的纤维增强复合薄壁截顶圆锥壳振动响应分析

引用

复合材料学报 2024年第3期41卷 1601-1610页

作者：许卓许沛尧初晨姚楠李晖顾大卫李鹤闻邦椿东北电力大学机械工程学院吉林132011 东北大学机械工程与自动化学院沈阳110819 东北大学航空动力装备振动及控制教育部重点实验室沈阳110819 浙江工业大学机械工程学院杭州310014

提出了一种纤维增强复合薄壁截锥壳的振动响应分析模型。针对纤维增强复合薄壁截锥壳的结构特点,考虑基础激励载荷方向与母线的夹角、纤维铺层方向与x轴的夹角,利用板壳振动理论、复弹性模量等方法对所研究结构进行了理论建模。利用双... 详细信息

提出了一种纤维增强复合薄壁截锥壳的振动响应分析模型。针对纤维增强复合薄壁截锥壳的结构特点,考虑基础激励载荷方向与母线的夹角、纤维铺层方向与x轴的夹角,利用板壳振动理论、复弹性模量等方法对所研究结构进行了理论建模。利用双向梁函数法表示振型函数,并通过能量法和模态叠加法对其固有特性和振动响应进行求解。为了验证模型的正确性,基于自行搭建的振动测试平台,以TC300/环氧树脂基纤维增强复合薄壁截锥壳为对象,进行了振动特性测试。为减小因样件加工时产生的材料参数误差影响,开发了二分粒子群迭代法对材料参数进行修正。研究发现,测试结果与理论计算获得的共振响应误差最大不超过3.0%,验证了所提出的理论模型与计算方法的正确性和有效性。

关键词：纤维增强圆锥壳基础激励多层次迭代修正振动响应

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Influence of Non-uniform Parameter of Bolt Joint on Complexity of Frequency Characteristics of Cylindrical Shell

引用

Chinese Journal of Mechanical Engineering 2023年第2期36卷 206-219页

作者： Qiansheng Tang Houxin She Chaofeng Li bangchun wen School of Engineering Anhui Agricultural UniversityHefei 230036China School of Mechanical Engineering and Automation Northeastern UniversityShenyang 110819China Key Laboratory of Vibration and Control of Aero‑Propulsion System Ministry of EducationNortheastern UniversityShenyang 110819China

Bolt connection is one of the main fixing methods of cylindrical shell structures.A typical bolted connection model is considered as a tuned system.However,in the actual working conditions,due to the manufacturing error,installation error and uneven materials of bolts,there are always random errors between different bolts.To investigate the influence of non-uniform parameters of bolt joint,including the stiffness and the distribution position,on frequency complexity characteristics of cylindrical shell through a statistical method is the main aim of this paper.The bolted joints considered here were simplified as a series of springs with random features.The vibration equation of the bolted joined cylindrical shell was derived based on Sanders’thin shell theory.The Monte Carlo simulation and statistical theory were applied to the statistical analysis of mode characteristics of the system.First,the frequency and mode shape of the tuned system were investigated and compared with FEM.Then,the effect of the random distribution and the random constraint stiffness of the bolts on the frequency and mode shape were studied.And the statistical analysis on the natural frequencies was evaluated for different mistuned levels.And some special cases were presented to help understand the effect of random mistuning.This research introduces random theory into the modeling of bolted joints and proposes a reference result to interpret the complexity of the modal characteristics of cylindrical shells with non-uniform parameters of bolt joints.

关键词： Bolted joint Random mistuning Shell vibration Mode shape Statistical analysis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Synchronization and Stability of a Nonlinear Vibrating Mechanical System Characterized by Asymmetrical Piecewise Linearity

引用

Chinese Journal of Mechanical Engineering 2022年第6期35卷 298-311页

作者： Xueliang Zhang Zhenmin Li wenchao Hu bangchun wen School of Mechanical Engineering and Automation Northeastern UniversityShenyang 110819China Key Laboratory of Vibration and Control of Aero‑Propulsion Systems Ministry of Education of China Northeastern UniversityShenyang 110819China

In previous studies about the synchronization of vibrators,the restoring forces of springs are mainly treated as linear directly,whereas the nonlinear features are rarely considered in vibrating systems.To make up this drawback,a dynamical model of a nonlinear vibrating mechanical system with double rigid frames(RFs),driven by two vibrators,is proposed to explore the synchronization and stability of the system.In this paper,the nonlinearity is reflected in nonlinear restoring forces of springs characterized by asymmetrical piecewise linear,where the nonlinear stiffness of springs is linearized equivalently using the asymptotic method.Based on the average method and Hamilton’s principle,the theory conditions to achieve synchronization and stability of two vibrators are deduced.After the theory analyses,some numerical qualitative analyses are given to reveal the coupling dynamical characteristics of the system and the relative motion properties between two RFs.Besides,some experiments are carried out to examine the validity of the theoretical results and the correctness of the numerical analyses results.Based on the comparisons of the theory,numeric and experiment,the ideal working regions of the system are suggested.Based on the present work,some new types of vibrating equipment,such as vibrating discharging centrifugal dehydrators/conveyers/screens,can be designed.

关键词： Synchronization Stability Nonlinear vibrating system Vibrators Asymmetrical piecewise linearity

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Rotation Angle Control Strategy for Telescopic Flexible Manipulator Based on a Combination of Fuzzy Adjustment and RBF Neural Network

引用

Chinese Journal of Mechanical Engineering 2022年第4期35卷 203-226页

作者： Dongyang Shang Xiaopeng Li Meng Yin Fanjie Li bangchun wen School of Mechanical Engineering and Automation Northeastern UniversityShenyang 110819China Shenzhen Institutes of Advanced Technology Chinese Academy of SciencesShenzhen 518055China

The length of fexible manipulators with a telescopic arm alters during movement.The dynamic parameters of telescopic fexible manipulators exhibit signifcant time-varying characteristics owing to variations in length.With an increase in the manipulators’length,the nonlinear terms caused by fexibility in the manipulators’dynamic equations cannot be ignored.The time-varying characteristics and nonlinear terms of telescopic fexible manipulators cause fuctuations in rotation angles,which afect the operation accuracy of end-efectors.In this study,a control strategy based on a combination of fuzzy adjustment and an RBF neural network is utilized to improve the control accuracy of fexible telescopic manipulators.First,the dynamic equation of the manipulators is established using the assumed mode method and Lagrange’s principle,and the infuence of nonlinear terms is analyzed.Subsequently,a combined control strategy is proposed to suppress the fuctuation of the rotation angle in telescopic fexible manipulators.The variation ranges of the feedforward PD controller parameters are determined by the pole placement strategy and length of the manipulators.Fuzzy rules are utilized to adjust the controller parameters in real-time.The RBF neural network is utilized to identify and compensate the uncertain part of the dynamic model of the fexible manipulators.The uncertain part comprises time-varying parameters and nonlinear terms.Finally,numerical simulations and prototype experiments prove the efectiveness of the combined control strategy.The results prove that the proposed control strategy has a smaller standard deviation of errors.Therefore,the combined control strategy is more suitable for telescopic fexible manipulators,which can efectively improve the control accuracy of rotation angles.

关键词： Flexible manipulator RBF neural network Fuzzy control Dynamic uncertainty

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

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

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

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

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

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：