电场作用下复合材料压电层合板的有限元分析

以压电结构的变分原理为基础，依据经典线性层合板理论和压电弹性体的本构方程，采用DKQ薄板弯曲单元和薄膜单元的位移插值函数，建立了电场作用下纤维增强型复合材料压电层合板的有限元分析模型，数值算例表明，此方法具有良好的计算精度。     

梯度压电悬臂梁的解析解及其逆问题

在平面应变状态下，考虑材料压电参数的梯度特性，采用逆解法求解了悬臂梁受力偶和外加电压作用时的解析解，并通过与基于BaTiO3陶瓷所得实验值的对比发现，其结果与N层压电板组成的悬臂梁当N趋于∞时其端部弯曲位移值十分接近，且悬臂梁内部应力场逐渐减少为零的结论在此得到了验证．基于所得到的解析解，提出了梯度相物性参数识别的方法．     

复合压电材料尖劈端部奇性问题有限元分析

从应力平衡方程、电场Maxwell方程和尖劈边界条件构成的控制方程出发,导出一个基于位移场、电势的弱式方程．采用一维有限元分析技术,沿着尖劈端部领域进行单元离散,建立求解压电复合材料尖劈附近奇性场问题的有限元特征分析方法,对于压电材料非常重要的电学边界问题,本文也有所涉及,并给出了平面导电裂纹和绝缘裂纹的算例。     

基于PCI-7464采集卡的多通道压电陶瓷驱动电源的研制

利用PCI-7464数据采集卡提供的DLL动态连接库函数及VB中的Timer控件,实现了8路0～10 V的压电陶瓷驱动电源模拟控制信号的可编程输出,通过后续的放大电路,实现了0～300 V控制电压的输出.所设计电源具有低纹波、多通道、高精度等特点,满足压电陶瓷的驱动要求.     

外加磁场对氩等离子体鞘层尘埃粒子密度分布的影响

采用流体模型数值模拟了含有尘埃粒子的氩等离子体鞘层结构,研究了外加磁场对鞘层内尘埃粒子密度分布的影响.模拟结果显示外加磁场能够改变鞘层电势分布,使尘埃粒子受到的电场力随之改变.同时,外加磁场对尘埃粒子的密度分布有明显的影响.随着磁场平行基板分量增大,尘埃粒子在鞘层内聚集区域将远离鞘层.如果尘埃粒子较小或磁场较强,尘埃粒子可以离开鞘层,不打到基板上.因此可以利用外加磁场调控鞘层内尘埃粒子的运动方向.     

智能悬臂梁的振动控制

从压电材料的驱动原理出发，将压电驱动器对梁的作用，在压电片两端点处的梁截面中点，等效为一对平衡力和一对平衡车偶，然后采用频响应函数进行驱动器位置优化，并采用模态空间方法对智能悬臂梁的振动进行了主动控制，并用实验验证了该智能悬壁梁振动控制理论的有效性。     

精化一阶剪切变形理论和三角形层合板单元

基于L i和L iu的整体-局部高阶理论思想(1997),推导了精化一阶剪切变形理论.这种理论满足位移和横向剪切应力层间连续条件并且未知数个数独立于层合板的层数,同时不需要任何剪切校正系数.基于此理论建立了满足C1连续条件的三节点三角形单元.结果表明:当前理论能准确计算层合板的自然频率.     

半平面压电复合介质中的螺位错

研究了半平面压电复合介质中螺位错的性能。使用复变函数理论和虚拟镜像原理，得到了螺位错产生的电弹场和作用在位错上像力的解析表达式。作为特例，计算了由横观各向同性压电材料和非压电材料组成的半平面复合介质中螺位错的像力，结果表明，位错总是被自由边界所吸引，而位错被界面吸引还是排斥依赖于非压电材料的弹性常数与压电变硬的材料常数的相对值。     

精化一阶剪切变形理论和三角形层合板单元

基于Li和 Liu的整体-局部高阶理论思想(1997),推导了精化一阶剪切变形理论.这种理论满足位移和横向剪切应力层间连续条件并且未知数个数独立于层合板的层数,同时不需要任何剪切校正系数.基于此理论建立了满足C1连续条件的三节点三角形单元.结果表明:当前理论能准确计算层合板的自然频率.     

刀具磨损补偿用压电陶瓷微位移器的特性分析与实现方案

通过对所选择压电陶瓷微位移器的电压一位移关系进行实验分析,提出了针对刀具磨损补偿系统的有效方法来消除压电陶瓷非线性、迟滞和蠕变所带来的影响.采用基于平均曲线模型的方法建立补偿系统的数学模型,提出了可消除蠕变影响的针对进给系统的驱动方式.阐明了适用于实际生产的刀具磨损补偿控制系统的原理,为控制系统的设计提供了科学的依据.     

Analytical Solution for Thermo-Electro-Elastic Problems of an Orthotropic Piezoelectric Hollow Cylinder Subjected to Various Loading

An interpolation method was used to solve the Volterra integral equation of the second kind caused by interaction among thermal, electric and mechanical fields. The exact expressions for the transient responses of stresses, electric displacement and electric potential in an orthotropic piezoelectric hollow cylinder were obtained by means of the finite integral transforms. From the sample numerical calculations, it is seen that the present method is suitable for an orthotropic piezoelectric hollow cylinder subjected to arbitrary thermal shock, mechanical load and transient electric excitation. The result can be used as a reference to solve other transient coupled problems of thermo-electro-elasticit y.     

压电板的主动控制实验研究

研究了压电板模型的主动控制。建立了主动控制方程,进行了实验研究。结果表明,采用压电片作为传感器和制动器的压电板的振动可以得到较好的抑制。说明了控制策略的可行性。为压电智能结构的进一步应用提供了实验基础。     

盘式压电变压器与Rosen型的特性比较

基于压电变压器的经典集总参数等效电路模型,给出了由双口网络导纳矩阵Y参数描述的压电变压器电气特性表达式,采用盘式降压压电变压器和Rosen型反接的模型参数进行了仿真分析和比较.结果表明,Rosen型压电变压器反接后的电气特性在一定负载范围内与降压压电变压器的特性相吻合.     

Development of the large increment method in analysis for thin and moderately thick plates

Many displacement-based quadrilateral plate elements based on Mindlin-Reissner plate theory have been proposed to analyze the thin and moderately thick plate problems. However, numerical inaccuracies of some elements appear since the presence of shear locking and spurious zero energy modes for thin plate problems. To overcome these shortcomings, we employ the large increment method （LIM） for the analyses of the plate bending problems, and propose a force-based 8-node quadrilateral plate （8NQP） element which is based on Mindlin- Reissner plate theory and has no extra spurious zero energy mode. Several benchmark plate bending problems are presented to illustrate the accuracy and convergence of the plate element by comparing with the analytical solutions and displacement-based plate elements. The results show that the 8-node plate element produces fast convergence and accurate stress distributions in both the moderately thick and thin plate bending problems. The plate element is insensitive to mesh distortion and it can avoid the shear locking for thin plate analysis.     

压电陶瓷非线性断裂的有限元分析

提出了一个简单的包含有极化反转及电饱和影响的压电材料的本构模型。在此基础上实施了非线性有限元分析,并以局部Ｊ积分作为断裂准则,导出了作用电场与断裂载荷的关系曲线,其趋势与Ｐａｒｋ和Ｓｕｎ的实验观察现象相一致。     

Numerical Investigation of Ultrasonic Guided Wave Dynamics in Piezoelectric Composite Plates for Establishing Structural Self-Sensing

This article presents a numerical investigation of guided wave generation, propagation, interaction with damage, and reception in piezoelectric composite plates for the purpose of establishing structural self-awareness.This approach employs piezoelectric composite materials as both load bearing structure and sensing elements.Finite element modal analysis of a plate cell with Bloch-Floquet boundary condition(BFBC) is performed to understand the wave propagation characteristics in piezoelectric composite plates. A comparative study is carried out between a standard composite plate and a piezoelectric composite plate to highlight the influence of piezoelectricity on guided wave dispersion relations. Subsequently, a transient dynamic coupled-field finite element model is constructed to simulate the procedure of guided wave generation, propagation, interaction with damage, and reception in a piezoelectric composite plate. Active sensing array is designed to capture the structural response containing the damage information. Three engineering scenarios, including a pristine case, a one-damage-location case and a two-damage-location case, are considered to demonstrate the ultrasonic sensing capability of the piezoelectric composite system. Finally, time-reversal method is utilized to locate and image the damage zones. This research shows that piezoelectric composite material possesses great potential to establish structural self-awareness, if it serves both as the load bearing and structural sensing components.     

关于厚梁横向振动的研究

本文应用哈密顿变分原理较简捷地建立了厚梁横向振动的微分方程.同时得到梁的边界条件和运动的初始条件,进而导出了简支厚梁的频率方程.由计算数据可知剪切变形和转动惯量对厚梁振动(以及薄梁的高阶振型)的影响至关重要.不容忽略.     

Dynamic investigation on composite flexible multi-body system considering thermal effect

The dynamic performance of composite flexible multi-body system under the simultaneous action of thermal fields and driving constraint is analyzed. Based on strain-displacement relation of the Mindlin plate theory which includes transverse shear deformation, and considering thermal effect, variation equations of laminated plate are derived by the principle of virtual work. The finite element method is used for discretization. According to kinematics constraint relation, dynamic equations for spatial slider-crank system are established. Simulation results show that spatial deformation (torsion deformation) appears in the multi-layered composite slider-crank mechanism which is simulated with planar motions. Furthermore, the influence of coupling between thermal expansion and flexible deformations of non-symmetrical composite plates on the large overall motion under the uniform temperature field is investigated. Finally, significant change in constraint force due to the spatial deformation is shown.     

压电双晶片谐响应有限元模拟分析

利用ANSYS软件对压电双晶片进行谐响应模拟分析,得到压电双晶片的谐振频率为36000Hz,谐振振幅为0.512×10-5m.通过正交实验,分析比较出影响压电双晶片谐振频率及振幅的主要因素,得出了压电双晶片尺寸的优化组合,压电片尺寸参数为:20mm×6mm ×0.4mnm,基片尺寸为20mm×6mm×4mm.     

径向层状压电复合介质中的螺位错

研究了径向层状压电复合介质中的螺位错与界面的相互作用，基于扰动的概念和级数展开的方法，推导了基体和压电环的弹性场和电场，并在此基础上给出了像力的表达式，分析了几何尺寸和材料的相对刚度对像力和界面应力的影响。