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Acta Mechanica Solida Sinica 2023年第5期36卷 710-723页

作者： Lan Jin demin zhao Jianlin Liu College of Pipeline and Civil Engineering China University of Petroleum(East China)Qingdao 266580China

The rubber cylinder is a key component for maintaining the sealing pressure of the packer,particularly in deep underground *** stress relaxation of materials,as a typical feature of viscoelasticity,has become one of the main factors causing the failure of rubber cylinders in *** the present study,a visco-hyperelastic model for the sealing rubber considering different strain levels is proposed based on the Prony ***,the uniaxial compression stress relaxation experiments are conducted on the sealing rubber under different temperatures and strain levels,and the model parameters are thereby *** a case study,the proposed model is incorporated into the ABAQUS software via the UM AT subroutine,and the finite element simulation of the sealing packer is carried *** results show that the sealing performance of the packer improves with a decrease in temperature or an increase in strain *** is also noted that a large strain level can lead to the protrusion of the shoulder of the rubber cylinder.

关键词： Visco-hyperelastic model Temperature Strain level Rubber cylinder Sealing performance

Nonlinear dynamic analysis of dielectric elastomer membrane with electrostriction

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Applied Mathematics and Mechanics(English Edition) 2022年第6期43卷 793-812页

作者： Yaode YIN demin zhao Jianlin LIU Zengyao XU College of Pipeline and Civil Engineering China University of Petroleum(East China)Qingdao 266580Shandong ProvinceChina

The dielectric elastomer(DE)is an important intelligent soft material widely used in soft actuators,and the dynamic response of the DE is highly nonlinear due to the material *** the DE,electrostriction denotes the deformation-dependent *** the present study,we formulate the nonlinear dynamic governing equations of the DE membrane considering the electrostriction *** free vibration and parametric excitation of the DE membrane with different geometric sizes are *** free vibration bifurcations induced by the initial location and the voltage are both discussed according to an energy-based *** amplitude-frequency characteristics and bifurcation diagrams of parametric excitation are also *** results show that electrostriction decreases the free vibration amplitude and increases the frequency,but it has less influence on the parametric excitation oscillation frequency and decreases the parametric excitation amplitude except when the membrane *** initial location and the applied voltage can induce the snap-through instability of the free vibration.A large geometric size will lead to a much lower resonance *** resonance amplitudes increase while the resonance frequencies decrease with the increase in the applied *** critical voltage of snap-through instability for the parametric excitation is larger than that for the free vibration one.

关键词： dielectric elastomer(DE) nonlinear dynamics electrostriction bifurcation electroelasticity

Effect of temperature on tensile and vibration properties of bilayer boron nitride

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International Journal of Mechanical System Dynamics 2023年第4期3卷 397-405页

作者： demin zhao Kexin Fang College of Pipeline and Civil Engineering China University of Petroleum(East China)QingdaoChina

Hexagonal boron nitride(h‐BN)is a semiconductor material with a wide band gap,holding promising potential for applications in thermal conductivity devices and nanoresonators in the field of ***,molecular dynamics is simulated to investigate the tensile and vibrational behaviors of bilayer h‐BN under five different stacking modes across varying *** mechanical properties of five different stacking modes of h‐BN at various temperatures are focused on,including Young's modulus,the ultimate stress,and the ultimate *** indicate that bilayer h‐BN nanosheets exhibit anisotropic characteristics,with their tensile properties decreasing as temperature ***,we explore the influence of temperature on the natural frequency of bilayer h‐BN under five different stacking *** results establish a fundamental understanding of the mechanical and vibrational characteristics of bilayer h‐BN nanosheets under different stacking modes,contributing to their potential applications in advanced nanodevices operating in extremely high‐temperature environments.

关键词： bilayer hexagonal boron nitride five stacking mode temperature natural frequency molecular dynamics simulation

Stability and local bifurcation of parameter-excited vibration of pipes conveying pulsating fluid under thermal loading

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Applied Mathematics and Mechanics(English Edition) 2015年第8期36卷 1017-1032页

作者： demin zhao Jianlin LIU C.Q.WU Department of Mechanics College of Pipeline and Civil Engineering China University of Petroleum Department of Mechanical and Manufacturing Engineering University of Manitoba

The parametric excited vibration of a pipe under thermal loading may occur because the fluid is often transported heatedly. The effects of thermal loading on the pipe stability and local bifurcations have rarely been studied. The stability and the local bifurcations of the lateral parametric resonance of the pipe induced by the pulsating fluid velocity and the thermal loading are studied. A mathematical model for a simply supported pipe is developed according to the Hamilton principle. Two partial differential equations describing the lateral and longitudinal vibration are obtained. The singularity theory is utilized to anMyze the stability and the bifurcation of the system solutions. The transition sets and the bifurcation diagrams are obtained both in the unfolding parameter space and the physical parameter space, which can reveal the relationship between the thermal field parameter and the dynamic behaviors of the pipe. The frequency response and the relationship between the critical thermal rate and the pulsating fluid velocity are obtained. The numerical results demonstrate the accuracy of the single-mode expansion of the solution and the stability and local bifurcation analyses. It also confirms the existence of the chaos. The presented work can provide valuable information for the design of the pipeline and the controllers to prevent the structural instability.

关键词： thermal load parameter excited local bifurcation,unfolding parameterspace physical parameter space

Surface Effect on Vibration of Timoshenko Nanobeam Based on Generalized Differential Quadrature Method and Molecular Dynamics Simulation

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Nanomanufacturing and Metrology 2021年第4期4卷 298-313页

作者： demin zhao Jiangwei Wang Zengyao Xu Department of Engineering Mechanics College of Pipeline and Civil EngineeringChina University of Petroleum(East China).Qingdao 266580.People's Republic of China

Nanobeams have promising applications in areas such as sensors,actuators,and resonators in nanoelectromechanical systems(NEMS).Considering the effects of gyration inertia,surface layer mass,surface residual stress,and surface Young's modulus,this study develops the vibration equations of the Timoshenko *** generalized differential quadrature(GDQ)method and molecular dynamics(MD)simulation are used to study the surface effect on *** a rectangular cross section,surface residual stress and surface Young's modulus are all affected by the height of the cross section rather than by the length-height *** surface layer mass is considered,then the first three natural frequencies all decrease relative to their counterparts in the case in which surface layer mass is *** show that the effect of gyration inertia on resonance frequency is *** vibration does not easily occur relative to the bending and rotation vibrations of *** addition,the results obtained by the GDQ method fit those obtained by MD simulation for beams with length-height ratios of *** study provides insights into the mechanism of the vibration of short and deep nanobeams and sheds light on the quantitative design of the elements in NEMSs.

关键词： Timoshenko nanobeams Surface effect Vibration Generalized differential quadrature(GDQ)method Molecular dynamics(MD)simulation

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柔性货车端墙机器人焊接生产线研制

焊接 2024年第8期 75-80页

作者：赵德民杨泽坤田成军唐麒龙白德斌肖安中国机械总院集团哈尔滨焊接研究所有限公司武汉科迈机械制造有限责任公司

【目的】根据国家能源货运输送干线主体建设与自动化/智能化焊接装备转型升级的切实需求，依据多年板梁式端墙自动化焊接装备设计制造经验，构建铁路货车端墙全工序柔性制造机器人焊装生产模式，研制出多信息传感交互、多机器人智慧协... 详细信息

【目的】根据国家能源货运输送干线主体建设与自动化/智能化焊接装备转型升级的切实需求，依据多年板梁式端墙自动化焊接装备设计制造经验，构建铁路货车端墙全工序柔性制造机器人焊装生产模式，研制出多信息传感交互、多机器人智慧协同的端墙柔性制造生产线。【方法】应用了基于点激光三角定位与机器人系统的柔性控制方法，【结果】实现了多轴重载机器人系统焊接中整体空间轨迹的人机交互共生，解决端墙框架结构下的焊缝位置确定与焊接盲区作业的技术难题。【结论】经生产应用表明，柔性端墙机器人焊接生产线满足端墙的焊接工艺要求，大幅提高了生产效率，实现多规格端墙的柔性生产制造。

关键词：端墙弧焊机器人焊接工作站柔性生产线

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考虑表面效应的纳米圆形薄板振动

中国石油大学学报（自然科学版） 2017年第5期41卷 153-158页

作者：赵德敏龚宇龙中国石油大学储运与建筑工程学院山东青岛266580

基于Gurtin的表面弹性理论考虑表面弹性和残余表面应力,建立周边固支的轴对称纳米圆板的振动微分方程。研究残余表面应力对纳米板振动频率和主振型的影响。结果表明:前四阶固有频率分别随着残余表面应力参数的增大而减小;但残余表面应... 详细信息

基于Gurtin的表面弹性理论考虑表面弹性和残余表面应力,建立周边固支的轴对称纳米圆板的振动微分方程。研究残余表面应力对纳米板振动频率和主振型的影响。结果表明:前四阶固有频率分别随着残余表面应力参数的增大而减小;但残余表面应力对一阶固有频率和主振型影响最大,随着振动阶数的增大,残余表面应力对固有频率和主振型的影响逐渐减小;同时对于一阶固有频率,板的厚度越薄或者板的半径越大,受残余表面应力的影响越大。

关键词：纳米圆板振动表面弹性残余表面应力固有频率主振型

高速铣削颤振系统稳定性及分岔的Chebyshev多项式数值分析(英文)

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机床与液压 2013年第6期41卷 22-27,41页

作者：赵德敏张琪昌中国石油大学(华东)储运与建筑工程学院工程力学系山东青岛266580 天津大学机械工程学院力学系天津300072

采用Chebyshev多项式法和Floquet理论相结合来预测铣床运行中的颤振和分岔。得到了稳定性极限形图,可以准确地预示机床的稳定性。通过系统的特征值分析得到此系统发生了倍周期分岔和Hopf分岔。系统由稳定的平衡点通过倍周期分岔收敛到... 详细信息

采用Chebyshev多项式法和Floquet理论相结合来预测铣床运行中的颤振和分岔。得到了稳定性极限形图,可以准确地预示机床的稳定性。通过系统的特征值分析得到此系统发生了倍周期分岔和Hopf分岔。系统由稳定的平衡点通过倍周期分岔收敛到稳定的极限环运动,由Hopf分岔转化到概周期运动。庞加莱截面的数值结果也证实了概周期运动的发生。

关键词：铣削颤振稳定性 Chebyshev多项式法分岔