Motion and stress analysis of direct-driven compliant mechanisms with general-purpose finite element software

Compliant mechanisms with embedded direct-driven actuators are gaining a wide interest in manufacturing systems as well as structural systems. In this paper, we present a procedure for motion analysis of a compliant mechanism which is driven by three embedded piezoelectric actuators with a general-purpose finite element system, in particular, ANSYS. This includes finite element modeling of the piezoelectric actuator and finite element modeling of the compliant mechanism. An experimental validation was conducted, which shows that the model is highly accurate. The contribution of this paper is a novel application of finite element methods with multidisciplinary elements to motion and stress analysis of compliant mechanisms with embedded piezoelectric actuators. In the current literature, for a complaint mechanism, either the piezoelectric actuator is modeled with absence of piezoelectric effects or a pseudo rigid body approach is applied with poor accuracy. Another contribution lies in the use of a general-purpose finite element software system, which will greatly increase the generalization of finite element modeling applications.     

Single discharge thermo-electrical modeling of micromachining mechanism in electric discharge machining

In this study, single discharge thermo-electrical model of workpiece material removal in electrical discharge machining (EDM) was developed. Developed model includes generation of energy in liquid media, variation of plasma channel radius and transfer of heat from the channel by the electrical discharge. Effect of generated energy in plasma channel on workpiece removal was theoretically investigated by using different experimental parameters used in literature. The developed model finds the temperature distribution in the workpiece material using finite element solver ANSYS Workbench (v.11) software. It’s assumed that the workpiece material reaches the melting point of workpiece material was removed from the surface. Electrical discharge process was simulated by using transient thermal analysis. The developed model has also been validated by comparing the theoretically obtained material removal values with the experimental ones.     

自适应调频声衬及其控制系统设计

为克服现有声衬结构固定、敏感频率无法调节的弊端,提出了一种逆压电效应的调频式声衬结构。该声衬由颈部、共振腔以及压电膜片组成亥姆霍兹共振器。采用有限元法对声衬结构的固有频率、声场分布进行了计算,研究了压电膜片变形与共振频率偏移的关系。在阻抗管内对压电声衬致动前后系统的传递损失进行了对比,系统传递损失峰值频率与驱动电压呈线性关系,灵敏度为0.1Hz/V。在建立控制电压-驱动电压-噪声频率的对应关系的基础上,提出了一种基于光敏电阻的直流升压电路,采用LabVIEW软件编制了压电声衬的自适应控制程序,当噪声频率从746变化至788Hz时,驱动电压由110V自动升高至420V,声衬始终工作于共振状态,实现了宽频噪声的自适应控制。     

基于APDL的柔性铰链位移放大机构

针对压电陶瓷微位移驱动器输出位移范围小的局限性,应用柔性铰链位移放大原理,设计了一种柔性铰链微位移放大机构,提出了柔性铰链杠杆放大机构的参数化数学建模方法,并采用ANSYS参数化程序设计语言（APDL）编写了柔性铰链杠杆放大机构的建模和仿真分析程序。仿真试验表明,所设计的柔性铰链杠杆放大机构的输入位移与输出位移线性度高,实际放大位移与理论值相差5％,完全可以满足机构的微位移放大要求。     

基于VB和ANSYS的塔式起重机臂架参数化设计

用ANSYS软件提供的参数化设计语言(APDL)建立的智能分析方法,为零件参数化有限元分析提供了有力的工具.介绍了基于VB与ANSYS的参数化有限元分析方法,并以塔式起重机吊臂有限元分析为例,说明了其实现方法,根据输入参数自动生成APDL代码文本,然后在ANSYS中运行该APDL代码文本,分析结果可直接在程序中查看.     

永磁直线进给系统多柔性体机电耦合动力学特性分析

针对高精度数控机床直接驱动进给系统动力学特性易受机械部件弹性变形、电气系统控制参数影响的特点,从机电耦合角度出发,用有限元法将永磁直线进给工作台进行柔性化,应用拉格朗日-麦克斯韦方程建立直线进给系统多柔性体的机电耦合模型。结合有限元分析软件ANSYS、动力学仿真软件ADAMS建立直线进给系统多柔性体的机电耦合仿真模型,并对系统进行动力学仿真分析和实验验证。结果表明,工作台柔性化更接近真实的工作情况;电气控制参数对系统动力学特性有显著影响。直线进给系统多柔性体机电耦合模型的建立可为直接驱动系统结构优化设计提供依据。     

基于VB的水轮机温度场分析可视化界面设计

水轮发电机结构复杂性、参数多样性、温度场分析方法的专业性增加了水轮机温度场分析的难度,为了开发一个便于实现水轮机温度场研究的平台,结合ANSYS有限元分析的优点与VB界面开发的优势,通过混合编程设计人机界面软件,实现了“在前端界面输入参数,在后台调用ANSYS运算,最后在界面输出”等功能,完成了大型水轮发电机转子温度场...     

球罐接管结构有限元分析的ANSYS二次开发

运用Visual Basic的控件开发技术,通过修改ANSYS的启动文件,实现了Visual Basic 6.0和ANSYS的无缝连接。基于该技术,以ANSYS 8.1为开发平台,以Visual Basic 6.0和APDL语言为开发工具,开发了专用于球罐接管结构的有限元分析接口程序,旨在帮助用户快速地实现球罐接管结构的有限元应力分析,缩短球罐分析设计的周期。     

超声切割用压电换能器理论设计及有限元仿真

基于波动方程和频率方程,建立了电镀金刚石线锯超声切割用压电换能器的解析模型,得到了压电换能器各组成部分的结构尺寸。借助有限元分析软件ANSYS对理论设计的压电换能器进行了动力学分析和优化设计,得到了压电换能器的优化模型。分析结果表明,有限元法对压电换能器的设计和分析具有很好的指导作用。这种换能器具有良好的性能,对下一步的应用研究有重要意义。     

管结构摩托车有限元建模与实测

针对在UG中建立的管式摩托车结构模型,研发了适用于空间复杂管式车架有限元建模自动前处理软件和后处理软件,先将车架空间模型、车架板件等结构件自动导入ANSYS软件中,并在此基础上建立摩托车整车有限元模型。ANSYS计算分析完成后,经过后处理可为用户提供单元数据列表、各单元和截面内力,以及最大应力截面和最大应力方位。在应用中,某跨骑式125摩托车采用传统方法建立有限元模型需要6个工作日,使用该方法只需1.5小时,并通过实测验证了摩托车有限元模型的合理性。为工程技术人员提供了一套简易、实用的建立整车有限元模型和求解的通用方法。     

Simulation and Finite Element Analysis of Porous Piezoceramic Disk-Shaped Transducer with Plano-Concave Surface

The paper investigates a disk-shaped piezoelectric transducer with plano-concave surface. Special form of the construction enhances the flexibility of the transducer and improves its effectiveness similar to the known transducers of Cymbal and Moonie types. The analysis of the transducer was performed using the finite element technologies and ANSYS finite element software. The influence of the porosity of the piezoceramic material of the transducer on its performance was studied both in static analysis and steady-state oscillations mode. The porosity of the piezoceramic material was taken into account by the effective properties of porous piezoceramic as a composite structure, which were calculated in numerical experiments on solving the homogenization problems by the effective moduli method and the finite element method.     

基于ANSYS和iSIGHT的磁悬浮轴承结构优化设计

以8极径向主动磁悬浮轴承为例,提出了一种使用多学科优化软件iSIGHT与通用有限元软件ANSYS集成的分析方法。首先应用ANSYS建立相应的模型并对其进行仿真,得出该轴承的一些参数,在此基础上将参数及模型集成到多学科优化软件iSIGHT中,采用NLPQL算法对该模型进行多目标优化设计,在指定的约束条件下得出了磁悬浮轴承结构的最优尺寸。     

基于ANSYS的电气柜体强度与模态分析

采用大型通用有限元软件ANSYS建立了某机车电气柜体及其过渡梁的有限元模型,根据有限元法对其进行了静强度分析,得到了整体结构的变形及应力分布.然后采用Block Lanczos法对该电气柜体及其过渡梁进行了模态分析,得到了其低阶固有频率及其相应的振型和振型动画,找出了结构振动薄弱部位,并对其进行了优化.这为结构优化设计以及深入的动力学分析和疲劳分析提供了依据.     

Passive vibration damping enhancement of piezoelectric shunt damping system using optimization approach

Piezoelectric materials can be used for structural damping because of their ability to efficiently transform mechanical energy to electrical energy and vice versa. The electrical energy may be dissipated through a connected load resistance. In this paper, a new optimization technique for the optimal piezoelectric shunt damping system is investigated in order to search for the optimal shunt electrical components of the shunt damping circuit connected to the piezoelectric patch on a vibrating structure for the structural vibration suppression of several modes. The vibration suppression optimization technique is based on the idea of using the piezoelectric shunt damping system, the integrated p-version finite element method (p-version FEM), and the particle swarm optimization algorithm (PSOA). The optimal shunt electrical components for the piezoelectric shunt damping system are then determined by wholly minimizing the objective function, which is defined as the sum of the average vibration velocity over a frequency range of interest. Moreover, the optimization technique is performed by also taking into account the inherent mechanical damping of the controlled structure with the piezoelectric patch. To numerically evaluate the multiple-mode damping capability by the optimal shunting damper, an integrated p-version FEM for the beam with the shunt damping system is modeled and developed by MATLAB. Finally, the structural damping performance of the optimal shunt damping system is demonstrated numerically and experimentally with respect to the beam. The simulated result shows a good agreement with that of the experimental result. This paper was recommended for publication in revised form by Associate Editor Eung-Soo Shin Jin-Young Jeon received his Ph.D. degree in Mechanical and Aerospace Engineering from Tokyo Institute of Technology in 2005. Dr. Jeon is currently a senior engineer at Digital Printing Division, Digital Media & Communications Business at Samsung Electronics Co., Ltd., Korea. His research interests are the areas of structural-acoustic optimization, sound quality, motion quality, and vibration control.     

一种新型盘式行波型压电钻

设计了一种基于逆压电效应的新型盘式行波型压电钻.该压电钻利用压电陶瓷的逆压电效应,使定子基体产生两相面外的弯振,利用存在相位差的两相弯振的合成使钻杆端部产生摇头运动,从而为切削和钻孔提供动力.利用有限元软件ANSYS对压电钻进行了结构仿真,分析并确定了压电钻的工作模态.根据仿真结果试制了一台样机,对该样机进行了激光扫频试验,结果显示样机工作频率为40 kHz,切削频率可达240万次/min,切削幅度可以控制在微米级.试验表明,该样机配上普通牙钻,可以在打印纸、硬纸板、铝板和钢板上进行切削、钻孔等操作.     

双质量硅微陀螺仪驱动模态测试

考虑双线振动双质量硅微陀螺仪环境适应性强且两个质量块的差动输出能够有效消除共模干扰的影响,提出了一种新型双质量陀螺仪。依据双质量硅微陀螺的结构和工作原理,对该陀螺的驱动模态进行了理论分析,并提出了简化的动力学方程。利用ANSYS有限元软件对陀螺的驱动模态进行了数值仿真,并对陀螺仪样品进行了电路测试。通过几种不同的加载方式,分别得到了相应的仿真和测试的幅频曲线,结果表明,仿真和实验结果与理论分析完全一致,且双边驱动方式要优于单边驱动方式,反向驱动方式可以使陀螺仪在工作模态运动。仿真和实验结果验证了双质量硅微陀螺的驱动模态特性。     

悬臂梁双压电晶片振子发电性能研究

以双压电晶片振子为研究对象,对悬臂梁式双压电晶片振子在正压电效应下电压输出特性进行了有限元分析与试验研究,给出了压电晶片在悬臂梁上的最佳粘贴位置,并且利用有限元分析软件建立了悬臂梁双压电晶片振子的有限元模型,进行了结构尺寸参数对悬臂梁双压电晶片振子输出电压影响规律的仿真分析;利用压电陶瓷发电能力测试系统进行了试验测试,通过仿真和试验结果对比分析,得出了结构尺寸参数对悬臂梁双压电晶片振子发电的输出电压影响规律。     

液压纠偏机构强度分析及结构优化

以初步设计的液压纠偏机构为研究对象,建立了基于ANSYS/APDL的参数化有限元模型,对其进行强度分析;建立了液压纠偏机构的结构优化模型,采用零阶优化方法求解得到最优设计参数,在满足结构强度的同时实现了轻量化;以优化结果为依据重新设计了液压纠偏机构并进行制作,目前使用效果良好。     

固定式刚度测试仪有限元分析及结构优化

固定式刚度测试仪是针对大型汽车覆盖件刚度测量的高精度测量仪器.通过确定相关参数、建立机架有限元模型,运用有限元软件ANSYS对固定式刚度测试仪初定方案进行了结构分析,并通过查看锡青铜衬套应力云图,找出初定方案所存在的问题;在此基础上对结构进行优化并进行有限元分析,通过对比分析结果,确定了固定式刚度测试仪优化后结构的合理性.优化方案解决了初定方案所存在的问题,减小了两边立导柱和衬套之间的摩擦力,改善了摩擦力的不均衡性,使横梁的升降更加平稳.     

采用ANSYS对片弹簧式触点开关受力状况的研究

片弹簧是电气接触装置中的关键部件.通过Pro/E三维建模对传统的片弹簧结构进行相应的设计改进,使其加工工艺更简化.利用ANSYS有限元软件对片弹簧在加载预紧力工况下进行工作挠度和静力分析研究,生成载荷-变形的仿真结果,得出片弹簧在受力作用时的位移量.模拟过程准确、迅速,对同类型产品的设计、计算具有一定的借鉴意义.