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1.
We study the bending of a two-layer piezoelectric semiconductor plate (bimorph). The macroscopic theory of piezoelectric semiconductors is employed. A set of two-dimensional plate equations is derived from the three-dimensional equations. The plate equations exhibit direct couplings among bending, electric polarization along the plate thickness, and mobile charges. In the case of pure bending, a combination of physical and geometric parameters is identified which characterizes the strength of the interaction between the mechanical load and the distribution of mobile charges. In the bending of a rectangular plate under a distributed transverse mechanical load, it is shown that mobile charge distributions and potential barriers/wells develop in the plate. When the mechanical load is local and self-balanced, the induced carrier distributions and potential barriers/wells are also localized near the loading area. The results are fundamentally useful for mechanically manipulating mobile charges in piezoelectric semiconductor devices. 相似文献
2.
非线性压电效应下压电弯曲执行器的动力分析 总被引:4,自引:1,他引:3
研究压电弯曲执行器在强电场作用下的非线性动力行为.考虑电致伸缩和电致弹性的非线性压电效应,导出了压电悬臂执行器变刚度的弯曲振动控制方程.利用非定常振动的渐近理论,讨论了弯曲压电执行器的动力特征.根据目前的非线性模型可以计算压电悬臂执行器的固有共振频率与电场的变化关系.结果表明压电执行器端头挠度谐振幅度随作用电场振幅的增大而增大,以及力学品质因数随电场振幅的增大而减少,并且与实验结果非常吻合.通过数值比较得到在电场频率随时间变化非常缓慢的情况下非定常振动问题可以近似地用定常振动来处理. 相似文献
3.
给出了一个对复合材料压电层合梁进行数值分析的高精度压电层合梁单元。基于Shi三阶剪切变形板理论的位移场和Layer-wise理论的电势场,用力-电耦合的变分原理及Hamilton原理推导了压电层合梁单元列式。采用拟协调元方法推导了一个可显式给出单元刚度矩阵的两节点压电层合梁单元,并应用于压电层合梁的力-电耦合弯曲和自由振动分析。计算结果表明,该梁单元给出的梁挠度和固有频率与解析解吻合良好,并优于其它梁单元的计算结果,说明了本文所给压电层合梁单元的可靠性和准确性。研究结果可为力-电耦合作用下压电层合梁的力学分析提供一个简单、精确且高效的压电层合梁单元。 相似文献
4.
P.S. Yang J.Y. Liou J.C. Sung 《International Journal of Solids and Structures》2007,44(25-26):8556-8578
In this paper, the problem of a crack embedded in a half-plane piezoelectric solid with traction-induction free boundary is analyzed. A system of singular integral equations is formulated for the materials with general anisotropic piezoelectric properties and for the crack with arbitrary orientation. The kernel functions developed are in complex form for general anisotropic piezoelectric materials and are then specialized to the case of transversely isotropic piezoelectric materials which are in real form. The obtained coupled mechanical and electric real kernel functions may be reduced to those kernel functions for purely elastic problems when the electric effects disappear. The system of singular integral equations is solved numerically and the coupling effects of the mechanical and electric phenomena are presented by the generalized stress intensity factors for transversely isotropic piezoelectric materials. 相似文献
5.
压电介质损伤、断裂力学研究的现状 总被引:10,自引:1,他引:9
压电介质的损伤与断裂力学是现代固体力学的重要课题.本文简要地综述了压电介质损伤与断裂力学研究的现状,集中讨论了:(1)裂纹面电边界条件的不同模型及其求解的结果;(2)宏观连续力学与细观力学用于压电介质的损伤与断裂的静力学分析;(3)压电介质动态断裂分析的某些新结果.文末,指出了今后在压电介质损伤与断裂研究的某些有吸引力的研究方向 相似文献
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The fracture behavior of a cracked strip under antiplane mechanical and inplane electrical loading is studied. A functionally graded piezoelectric strip with exponential material gradation is under consideration. The mechanical and electrical loading is combined via loading coupling factor. The problem of a graded piezoelectric strip containing a screw dislocation is solved. This solution results in stress and electric displacement components with Cauchy singularity. Based on the solution achieved for the dislocation, the distributed dislocation technique (DDT) is utilized to form any geometry of multiple cracks and analyze the behavior of a cracked strip under antiplane mechanical and inplane electrical loading. This technique is capable of the analysis of a strip with a system of interacting cracks. Several examples including strips with single crack, two straight cracks and two curved cracks are presented. 相似文献
8.
本构造了正交异性压电复合材料(OPCM)应变传感元件。从理论上推导了OPCM传感元件检测平面应变场中任意方向应变的力-电耦合方程,用实验手段对OPCM元件的压电正交异性效应进行了验证。实验证明仅当压电相的极化方向与元件的受力面平行时,OPCM元件具备压电正交异性之特性。 相似文献
9.
Zuguang Ying Xinqun Zhu 《Acta Mechanica Solida Sinica》2009,22(2):152-160
The random response of a piezoelectric thick shell in plane strain state under boundary random excitations is studied and illustrated with a piezoelectric cylindrical shell. The differential equation for electric potential is integrated radially to obtain the electric potential as a function of displacement. The random stress boundary conditions are converted into homogeneous ones by transformation,which yields the electrical and mechanical coupling differential equation for displacement under random excitations. Then this partial differential equation is converted into ordinary differential equations using the Galerkin method and the Legendre polynomials,which represent a random multi-degree-of-freedom system with asymmetric stiffness matrix due to the electrical and mechanical coupling and the transformed boundary conditions. The frequency-response function matrix and response power spectral density matrix of the system are derived based on the theory of random vibration. The mean-square displacement and electric potential of the piezoelectric shell are finally obtained,and the frequency-response characteristics and the electrical and mechanical coupling properties are explored. 相似文献
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IntroductionDuetotheextensiveapplicationsofpiezoelectricmaterialsinsmartstructures,itisveryimportanttoprobeintotheirmechanismasactuatorsandsensors[1].Oneofthefirstimportantstudiesinvolvingthemodelingoftheperformanceofpiezoelectricactuatorswhicharesurfa… 相似文献
13.
Piezoelectric generator based on torsional modes for power harvesting from angular vibrations 总被引:1,自引:0,他引:1
Torsional vibration of a circular piezoelectric shell of polarized ceramics mounted on a rotationally vibrating base is analyzed. The shell is properly electroded and connected to a circuit such that an electric output is generated. The structure analyzed represents a piezoelectric generator for converting mechanical energy from angular vibrations to electrical energy. Analytical expressions and numerical results for the output voltage, current, power, efficiency and power density are given. 相似文献
14.
本文在经典层合板理论和三维压电材料本构方程的基础上,依据压电材料与纤维复合材料之间的相互作用、位移连续条件,建立了压电—纤维复合材料旋转耦合驱动器力学模型,并推导出电耦合方程。计算和初步实验说明,这种新型结构的压电伸缩变形—离轴纤维复合层扭转变形耦合旋转驱动器比同类型驱动器能量密度高、转矩大,且这种旋转电机结构简单紧凑、工作稳定、寿命长、预计随着研究的进一步深入,可望成为一种新型的微致驱动器而广泛应用于微型机械、精密测量和自动控制等领域。 相似文献
15.
Ivan Giorgio Antonio Culla Dionisio Del Vescovo 《Archive of Applied Mechanics (Ingenieur Archiv)》2009,79(9):859-879
In this paper a new approach is presented to reduce vibrations for one- and two-dimensional mechanical structures, as beam
or thin plates, by means of several piezoelectric transducers shunted with a proper electric network system. The governing
equations of the whole system are coupled to each other through the direct and converse piezoelectric effect. More in detail,
the mechanical equations are expressed in accordance with the modal theory considering n vibration modes and the electrical equations reduce to the one-dimensional charge equation of electrostatics for each of
n considered piezoelectric transducers. In this electromechanical system, a shunting electric device forms an electric subsystem
working as multi degrees of freedom (dof’s) damped vibration absorber for the mechanical subsystem. Herein, it is introduced
a proper transformation of the electric coordinates in order to approximate the governing equations for the whole shunted
system with n uncoupled, single mode piezoelectric shunting systems that can be readily damped by the methods reported in literature. A
further numerical optimisation problem on the spatial distribution of the piezoelectric elements allows to achieve a better
performance. Numerical case studies of two relevant systems, a double clamped beam and a fully clamped plate, allow to take
into account issues relative to the proposed approach. Laboratory experiments carried out in real time on a beam clamped at
both ends consent to validate the proposed technique. 相似文献
16.
Bao-Lin Wang Naotake Noda Jie-Cai Han Shan-Yi Du 《European Journal of Mechanics - A/Solids》2001,20(6):377
In this paper, we develop a model to treat penny-shaped crack configuration in a piezoelectric layer of finite thickness. The piezoelectric layer is subjected to axially symmetric mechanical and electrical loads. Hankel transform technique is used to reduce the problem to the solution of a system of integral equations. A numerical solution for the crack tip fields is obtained for different crack radius and crack position. 相似文献
17.
P.S. Yang J.Y. Liou J.C. Sung 《International Journal of Solids and Structures》2008,45(18-19):4990-5014
In this paper, the problem of a subinterface crack in an anisotropic piezoelectric bimaterial is analyzed. A system of singular integral equations is formulated for general anisotropic piezoelectric bimaterial with kernel functions expressed in complex form. For commonly used transversely isotropic piezoelectric materials, the kernel functions are given in real forms. By considering special properties of one of the bimaterial, various real kernel functions for half-plane problems with mechanical traction-free or displacement-fixed boundary conditions combined with different electric boundary conditions are obtained. Investigations of half-plane piezoelectric solids show that, particularly for the mechanical traction-free problem, the evaluations of the mechanical stress intensity factors (electric displacement intensity factor) under mechanical loadings (electric displacement loading) for coupled mechanical and electric problems may be evaluated directly by considering the corresponding decoupled elastic (electric) problem irrespective of what electric boundary condition is applied on the boundary. However, for the piezoelectric bimaterial problem, purely elastic bimaterial analysis or purely electric bimaterial analysis is inadequate for the determination of the generalized stress intensity factors. Instead, both elastic and electric properties of the bimaterial’s constants should be simultaneously taken into account for better accuracy of the generalized stress intensity factors. 相似文献
18.
本文研究简支,固支和悬臂压电层合梁在强电场和机械荷载联合作用下的非线性变形。考虑材料的电致伸缩和电致弹性压电效应以及几何非线性导出压电层合梁的数学模型。并求得在电场和均布力联合作用下各种边界条件梁的挠度和位移解析表达式。通过对双压电晶片梁和单压电晶片梁的数值计算及分析得到线性与非线性模型之间的差别和适用范围。 相似文献
19.
The forced monoharmonic bending vibrations and dissipative heating of a piezoelectric circular sandwich plate under monoharmonic
mechanical and electrical loading are studied. The core layer is passive and viscoelastic. The face layers (actuators) are
piezoelectric and oppositely polarized over the thickness. The plate is subjected to harmonic pressure and electrical potential.
The viscoelastic behavior of the materials is described by complex moduli dependent on the temperature of heating. The coupled
nonlinear problem is solved numerically. A numerical analysis demonstrates that the natural frequency, amplitude of vibrations,
mechanical stresses, and temperature of dissipative heating can be controlled by changing the area and thickness of the actuator.
It is shown that the temperature dependence of the complex moduli do not affect the electric potential applied to the actuator
to compensate for the mechanical stress
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Translated from Prikladnaya Mekhanika, Vol. 44, No. 1, pp. 79–89, January 2008. 相似文献
20.
I.IntroductionPiezoelectricmedia,asa"ex\'typeoffullctionalmaterial.arex'idel}'appliedtomanytechnologicalfieldsduetoitselectronlechallicalcouplillgeffect.Defects.likethatofothermaterials.arenotlimitedtocracks.x'oidsandinclusionsillpiezoelectricmaterialsorelements.Yet,stressconcentrationsornoll-ullitbrllldistl-ibutionsofelectricfieldillducedbythosedefectsareoneofthehe}l'filctorswllicllwouldleadpiezoelectricstructurestonon-normalfailure.Therel'ore.itisofgrealimportancetostudythepropertiesofthos… 相似文献