共查询到18条相似文献,搜索用时 140 毫秒
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含压电片层合板的静变形控制 总被引:3,自引:0,他引:3
借助阶梯函数,建立了含有任意分布的用作执行器的的压电片的层合板弯曲方程,然后利用该方程,进行了层合板静变形控制的研究,最后给实例,用“遗传+配点”法对压电片的位置和尺寸进行了优化。结果表明,用压电片作执行器,用“遗传+配点”法进行优化是对板进行静力变形控制的一条有效途径。 相似文献
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基于压电导率特性识别结构裂纹方法的研究 总被引:6,自引:0,他引:6
基于粘贴于外部主体裂纹在压电陶瓷片导率的变化,实验提取出梁系统的变民模态频率。建立了考虑压电陶瓷片影响的裂纹梁的特性方程,根据裂纹梁的固有频率的变化,采用剪切弹簧模拟裂纹的方法,进行了裂纹的识别,结果表明满足一定的识别精度。 相似文献
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文章利用重心有理插值迭代配点法分析计算非线性MEMS微梁问题。通过处理MEMS微梁的几何通过假设初始函数,将微梁非线性控制方程转换为线性化微分方程,建立逼近非线性微分方程的线性化迭代格式。采用重心有理插值配点法求解线性化微分方程,提出了数值分析MEMS微梁非线性弯曲问题的重心插值迭代配点法。给出了非线性微分方程的直接线性化和Newton线性化计算公式,详细讨论了非线性积分项的计算方法和公式。利用重心有理插值微分矩阵,建立了矩阵-向量化的重心插值迭代配点法的计算公式。数值算例结果表明,重心插值迭代配点法求解微梁非线性弯曲问题,具有计算公式简单、程序实施方便和计算精度高的特点。 相似文献
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摘要:挠曲电效应是由应变梯度引起的,与尺度相关的力电耦合效应。基于Kirchhoff板假设和挠曲电理论,本文推导了温度和电压作用下的压电薄板力-电-热耦合微分控制方程,定量分析了微分控制方程中非线性项的影响,并针对四周固支压电薄板采用Ritz法求解,数值计算了压电薄板的弯曲和振动行为。在研究温度和挠曲电效应对薄板耦合特性和力学行为的影响时,本文分别考虑了材料系数不随温度变化和随温度线性变化两种情况。以PZT-5H为例,我们讨论了挠曲电和温度对压电薄板的横向位移和固有频率的影响。研究结果表明挠曲电效应对压电纳米薄板的力学行为影响很大,且具有明显的尺寸效应。此外,薄板对温度变化非常敏感。因此,可通过挠曲电效应和温度来调控压电纳米薄板的多场耦合特性和力学行为,进而优化基于压电薄板的NEMS/MEMS中传感器、作动器等电子器件的性能。 相似文献
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基于压电层合结构的有限元方程,运用ANSYS/APDL语言,编制了力-电耦合有限元分析程序(MPFEMP).以该程序为计算基础,采用遗传算法和一阶梯度优化算法,以压电片尺寸为设计变量,以压电层合梁和板的预期位移或最小重量为目标函数,给定初始变量和适应度函数,通过循环迭代MPFEMP计算程序,研究了多点控制的压电层合梁板结构的形状最优控制.结论对比分析证明了两种优化方法分析压电层合结构的有效性,同时,对复杂多层智能结构的最优形状控制和主动控制研究具有一定的参考价值. 相似文献
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挠曲电效应是由应变梯度引起的,与尺度相关的力电耦合效应.基于Kirchhoff板假设和挠曲电理论,论文推导了温度和电压作用下的压电薄板力-电-热耦合微分控制方程,定量分析了微分控制方程中非线性项的影响,并针对四周固支压电薄板采用Ritz法求解,数值计算了压电薄板的弯曲和振动行为.在研究温度和挠曲电效应对薄板耦合特性和力学行为的影响时,论文分别考虑了材料系数不随温度变化和随温度线性变化两种情况.以PZT-5H为例,作者讨论了挠曲电和温度对压电薄板的横向位移和固有频率的影响.研究结果表明挠曲电效应对压电纳米薄板的力学行为影响很大,且具有明显的尺寸效应.此外,薄板对温度变化非常敏感.因此,可通过挠曲电效应和温度来调控压电纳米薄板的多场耦合特性和力学行为,进而优化基于压电薄板的NEMS/MEMS中传感器、作动器等电子器件的性能. 相似文献
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为了解决旋转悬臂梁的挠曲线函数的计算问题,本文联合应用d'Alembert原理和Bernoulli-Euler方程建立了重力场中旋转悬臂梁的挠曲线微积分方程;在此基础上,采用Rayleigh-Ritz法求得了这类梁的挠曲线解析函数。最后,应用该函数具体计算了一悬臂梁以不同角速度旋转时的挠曲线形状,从中归纳出旋转悬臂梁的弯曲变形随着其角速度的增大而减小的结论。 相似文献
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By applying the Heaviside function, the equations governing laminated plates possessing spatially distributed piezoelectric
patches have been established. Based on these equations, static shape control of laminated plates is discussed. By using a
genetic and collocation algorithm, the optimal locations and scales of these piezoelectric patches have been selected. Numerical
examples are presented to illustrate the efficiency of the algorithm and the piezoelectric actuators. 相似文献
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含压电片层合壳的有限元分析与控制仿真 总被引:5,自引:0,他引:5
本文首先针对含压电材料的一般结构,推导了按位移和电位移求解时的混合变分原理,在此基础上,通过对面电荷取变分,直接得到了含按电压驱动压电片层合壳的有限元方程,最后给出了利用压电片进行静变形和振动控制的仿真算例,并进行了分析。结果表明,本文建立的有限元方程准确、可靠。 相似文献
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由于具有良好的结构、力学性能,复合材料层合板在现代飞行器上大量应用;而压电复合材料,作为一种新兴的智能材料,由于其独特的力电耦合性能得到了人们更多的关注。本文研究含有压电片的复合材料梁和板在电场作用下的变形控制问题。基于经典的梁理论和层合板理论,分别研究了下列问题:(1)双压电片布置的悬臂梁的变形;(2)含有压电层的层合板变形控制问题;(3)含有一对压电片的层合板的变形控制问题。针对上述问题,分别给出了理论解和数值解,并进行了相关讨论分析。结果表明压电材料可对结构进行精确控制,因此本文的结果可对复合材料梁和板在电场作用下的变形控制问题提供工程参考。 相似文献
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A new continuum model is developed to study the influence of surface stress on the behaviors of piezoelectric nanobeams. Different from existing piezoelectric surface models which only consider the surface properties, the proposed model takes surfaceinduced initial fields into consideration. Due to the fact that the surface-induced initial fields are totally different under various boundary conditions, two kinds of beams, the doubly-clamped beam and the cantilever beam, are analyzed. Furthermore, boundary conditions can affect not only the initial state of the piezoelectric nanobeam but also the forms of the governing equations. Based on the Euler-Bernoulli beam theory, the nonlinear Green-Lagrangian strain-displacement relationship is applied. In addition, the surface area change is also considered in the proposed model. The governing equations of the doubly-clamped and cantilever beams are derived by the energy variation principle. Compared with existing Young-Laplace models, the proposed model for the doubly-clamped beam is similar to the Young-Laplace models. However, the governing equation of the cantilever beam derived by the proposed model is very different from that derived by the Young-Laplace models. The behaviors of piezoelectric nanobeams predicted by these two models also have significant discrepancies, which is owing to the surface-induced initial fields in the bulk beam. 相似文献
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In this work, bifurcation control using a piezoelectric actuator isimplemented to stabilize the parametric resonance induced in acantilever beam. The piezoelectric actuator is attached to the surfaceof the beam to produce a bending moment in the beam. The dimensionlessequation of motion for the beam with the piezoelectric actuator on itssurface is derived and the modulation equations for the complexamplitude of an approximate solution are obtained using the method ofmultiple scales. We then acquire the bifurcation set that expresses theboundary of the stable and unstable regions. The bifurcation set ischaracterized by the modulation equations. Next, we determine the orderof feedback gains to modify these modulation equations. By actuating thepiezoelectric actuator under the appropriate feedback, bifurcationcontrol is carried out resulting in the shift of the bifurcation set andthe expansion of the stable region. The main characteristic of thestabilization method introduced above is that the work done by thepiezoelectric actuator is zero in the state where the parametricresonance is stabilized. Thus zero power control is realized in such astate. Experimental results show the validity of the proposedstabilization method for the parametric resonance induced in thecantilever beam. 相似文献
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In this work, variation of piezoelectric strain coe?cient and permittivity with change in electric field is included in constitutive equations of piezoelectricity and used for developing finite element model of a plate instrumented with piezoelectric patches. Simulation results show that nodal displacement response and sensor voltage is less controlled if variation of piezoelectric strain coe?cient and permittivity with change in electric field is not included in finite element modelling as compared to the case in which these variations are included in finite element modeling. An experiment is performed so as to validate simulation results. 相似文献
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采用压电机敏元件进行结构振动控制Ⅲ:控制系统设计与实验研究 总被引:5,自引:0,他引:5
采用作者在上篇导出的压电耦合体动力学模型,给出了压电主动阻尼控制系统的设计方法;导出了压电耦合梁系统的作动方程和检测方程的显式表达式。以此为基础,以简单梁为对象,对压电检测器和作动器的性能、粘结层的影响、压电主动阻尼控制及压电主、被动阻尼双控制进行了实验研究 相似文献