压电分流阻尼控制悬臂梁振动的参数优化分析

采用阻抗分析技术,根据压电材料的机电耦合特性和RLC电路的电学阻抗特性,详细推导了RLC串联压电分流阻尼系统的机械阻抗特性,研究了作单模态振动的悬臂梁在粘贴压电片后形成的压电悬臂梁系统的位移传递函数特性。借助于调谐质量阻尼减振理论,进行了压电分流阻尼系统的参数优化分析,并通过算例验证了参数优化前后压电分流阻尼系统对悬臂梁振动的被动控制效果。     

通过压电分流阻尼技术抑制结构振动的实验研究

以一四边固定矩形板为例,通过实验方法对三种不同的压电分流阻尼技术（RL串联压电分流电路、RL并联压电分流电路以及RL-C并联压电分流电路）的振动控制效果进行分析和比较。实验结果表明,当压电分流电路的参数调节到最优值时,能够有效降低结构振动;RL串联压电分流电路和RL并联压电分流电路的控制效果基本相等;RL—C并联压电分流电路能够降低分流电路中的最优电感值,但是控制效果也随之变差。实验结果还表明压电分流电路对电感值相当敏感,如果电感值偏离最优值,有可能会使得控制效果大幅下降。     

基于模拟退火算法的旋转梁压电分流电路优化

采用压电分流控制方法对旋转柔性梁进行振动抑制,在分析旋转梁压电分流控制方程的基础上采用模拟退火算法对电路中的电阻、电感原件进行了优化。首先,使用Hamilton原理建立了绕x轴旋转柔性梁的压电分流阻尼控制方程,推导了基于压电分流控制的压电分流系统传递函数;然后,基于模拟退火优化算法思想,建立传递函数的优化模型,并对目标函数进行优化;最后,针对旋转梁压电分流电路优化进行数值计算与分析。仿真结果表明:压电分流阻尼可以很好地抑制柔性旋转梁振动;与遗传算法相比,模拟退火优化算法不仅可以取得很好的优化效果,且优化效率得到极大的提高。     

基于压电分流阻尼技术的弹性环式隔振器阻尼研究

针对某发动机推力轴承弹性环式隔振器阻尼效果不太理想、阻尼不可调等问题,引入压电分流阻尼技术用于弹性环式隔振器减振特性研究。采用压电片代替弹性环式隔振器中的阻尼材料,设计了弹性环式压电分流阻尼隔振器,并设计了基于回转器的共振压电分流电路,建立压电分流阻尼系统机电耦合模型,研究分流电路参数的优化方法,确定了分流电路最优参数。最后建立弹性环式压电分流阻尼隔振器测试系统,实验测试了压电分流阻尼系统的减振性能,结果表明压电分流阻尼使得结构共振响应幅值降低了9 d B,明显改善了弹性环式隔振器的阻尼特性。     

采用压电开关分流电路技术的半主动振动控制

利用压电材料的正压电效应,设计出一种新型的状态开关型压电分流电路.由压电换能器将结构振动变形的应变能转化为电介能,当压电换能器极化表面的电荷积聚达到最大值时,闭合分流电路中的状态开关,分流电路短路,压电换能器上下表面的正负电荷中和抵消,以焦耳热的形式耗散掉电介能,达到抑制结构振动的目的.将这种振动控制技术应用于柔性悬臂梁的振动抑制,研究状态开关闭合持续时间对抑振效果的影响.实验结果表明,开关的闭合持续时间约为结构振动周期的1/10时,抑振效果最佳,悬臂梁第一阶稳态响应幅值降低量约为55%.     

负电容压电阻尼振动控制系统稳定性研究

实验中发现,当负电容值选取较小时,基于负电容压电分流阻尼控制系统将不稳定。针对这个问题,利用反馈控制理论推导了负电容压电阻尼振动控制系统模型,并对其进行了稳定性分析,最后,基于d SPACE实时仿真系统,利用模拟电路和压电元件,设计并建立了四边固支的压电合金板的振动控制实验平台,进行了基于负电容压电分流阻尼的振动控制方法的稳定性实验研究,理论分析和实验结果表明:当负电容值大于且接近于或小于压电片的容抗值时,系统将不稳定,负电容压电阻尼振动系统稳定性的研究将会对负电容在振动和噪声控制系统中的应用具有重要指导意义。     

单晶压电悬臂梁等效黏性阻尼建模与实验

为了完善压电悬臂梁非耦合集总参数模型,进而优化设计压电振子,本文根据机械振动理论以及阻尼理论,建立了单晶压电振子等效阻尼系数的理论模型。理论分析并实验验证了基板材料性能,结构尺寸以及截面形状等不同因素对等效机械阻尼及电阻尼的影响规律。最后,制备了3组不同形状尺寸的压电振子样品,并进行了冲击振动试验来验证理论分析结果。研究表明,压电材料层对整体阻尼的影响主要取决于基板与压电材料的弹性模量比;压电材料每个振动周期的电能损耗与悬臂梁长度的三次方成正比,与宽度成反比;而决定振幅放大因子的阻尼比并非随结构尺寸单调变化。实验结果与理论模型的误差为2.5%~14.7%,证明了理论模型的可靠性。分析表明,在可承受极限载荷相同的情况下,静态特性最优的变曲面悬臂梁动态特性并非最佳,得到的结果对于压电振子的优化设计具有现实意义。     

悬臂梁振动自适应模糊控制及DSP实现

以粘贴压电自感作动器的悬臂梁为研究对象,推导了悬臂梁振动主动控制的压电元传感方程和作动方程的传递函数,给出了压电自感作动器位置配置优化方法,设计了硬件电路以及软件流程.试验结果表明,利用压电自感作动器和模糊自适应控制器可有效地抑制悬臂梁振动.     

悬臂梁式压电振动能采集器的建模及实验验证

为了根据环境振动和电学负载的特点对悬臂梁式微型压电振动能采集器进行优化,本文考虑质量块质心与悬臂梁末端的位置差异,建立了在基础激励作用下采集器的运动微分方程和边界条件.通过引入常数,建立了对单压电层、双压电层并联和双压电层串联的3个悬臂梁式微型压电振动能采集器均适用的耦合电路方程,得到了采集器固有频率和振型的表达式,推...     

基于TMS320F2812的悬臂梁振动半主动控制

基于压电元件的主动振动控制不仅需要复杂的信号处理系统,而且需要庞大的能量供给系统,被动控制方法中电感和电阻参数对环境变化适应能力差,而且在低频控制时需要很大的电感,不容易实现。为了克服主被动控制中存在的缺点,本文采用一种基于同步开关阻尼技术的半主动振动控制的新方法。利用TMS320F2812处理器,通过合适的开关控制算法,使埋入复合材料悬臂梁约束端的压电元件上的电压极性在合适的时候进行翻转,使其电压始终与应变反相,从而达到振动控制的效果。实验结果表明该方法可以使悬臂梁一阶振动模态减小3.1641dB。     

Multiple-mode structural vibration control using negative capacitive shunt damping

This paper deals with a novel shunt circuit, which is capable of suppressing multimode vibration amplitudes by using a pair of piezoceramic patches. In order to describe the characteristic behaviors of a piezoelectric damper connected with a series and a parallel resistor-negative capacitor branch circuit, the stiffness ratio and loss factor with respect to the non-dimensional frequency are considered. The mechanism of the shunt damper is also described by considering a shunt voltage constrained by shunt impedance. To obtain a guideline model of the piezo/beam system with a negative capacitive shunting, the governing equations of motion are derived through the Hamilton’ s principle and a piezo sensor equation as well as a shunt-damping matrix is developed. The theoretical analysis shows that the piezo/beam system combined with a series and a parallel resistor-negative capacitor branch circuit developed in this study can significantly reduce the multiple-mode vibration amplitudes over the whole structural frequency range.     

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.     

Passive suppression of nonlinear panel flutter using piezoelectric materials with resonant circuit

In this study, a passive suppression scheme for nonlinear flutter problem of composite panel, which is believed to be more reliable than the active control methods in practical operations, is proposed. This scheme utilizes a piezoelectric inductor-resistor series shunt circuit. The finite element equations of motion for an electromechanically coupled system is derived by applying the Hamilton’s principle. The aerodynamic theory adopted for the present study is based on the quasi-steady piston theory, and von-Karrnan nonlinear strain-displacement relation is also applied. The passive suppression results for nonlinear panel flutter are obtained in the time domain using the Newmark-β method. To achieve the best damping effect, optimal share and location of the piezoceramic (PZT) patches are determined by using genetic algorithms. The effects of passive suppression are investigated by employing in turn one shunt circuit and two independent shunt circuits. Feasibility studies show that two independent inductor-resistor shunt circuits suppresses flutter more effectively than a single shunt circuit. The results clearly demonstrate that the passive damping scheme that uses piezoelectric shunt circuit can effectively attenuate the flutter.     

Vibration control efficiency of piezoelectric shunt damping system

The piezoelectric shunt damping technique based on the direct piezoelectric effect has been known as a simple, low-lost, lightweight, and easy to implement method for passive damping control of structural vibration. In this technique, a piezoelectric material is used to transform mechanical energy to electrical energy. When applying the piezoelectric shunt damping technique to passively control structural vibration, the piezoelectric materials must be bonded on or embedded in host structure where large strain is induced during vibration, thus to ensure vibrational mechanical energy to be transformed into electrical energy as much as possible. In this paper, the concept of vibration control efficiency of a piezoelectric shunt damping system is proposed and studied theoretically and experimentally. In the study, PZT patches are used as energy converter, and the vibration control efficiency is expressed by the vibration reduction rate per area of the PZT patches. Emphasis is laid on the effect of the generalized electromechanical coupling coefficient K₃₁ on the vibration control efficiency. Four PZT patches with different sizes are bonded on the geometrical central area of four similar clamped aluminum plates, respectively, and vibration control experiments are conducted for these plates using the R-L shunt circuit. The results indicate that the bigger the coupling coefficient K₃₁, the larger the rate of vibration reduction, and hence, the higher the vibration control efficiency. It also shows that the vibration responses of the first mode of the plates bonded with different PZT patches can be reduced by about 30.5%，48.58%，85.47%, and 89.91%, respectively. It comes to a conclusion that the vibration control efficiency of the piezoelectric shunt damping system decreases with the increase of the area of the PZT patch, whereas the vibration reduction of the plate increases with the area of the PZT patch. Therefore, it is necessary to make topology optimization for the PZT patch in the vibration control utilizing the piezoelectric shunt damping technique.     

Vibration control efficiency of piezoelectric shunt damping system

The piezoelectric shunt damping technique based on the direct piezoelectric effect has been known as a simple, low-lost, lightweight, and easy to implement method for passive damping control of structural vibration. In this technique, a piezoelectric material is used to transform mechanical energy to electrical energy. When applying the piezoelectric shunt damping technique to passively control structural vibration, the piezoelectric materials must be bonded on or embedded in host structure where large strain is induced during vibration, thus to ensure vibrational mechanical energy to be transformed into electrical energy as much as possible. In this paper, the concept of vibration control efficiency of a piezoelectric shunt damping system is proposed and studied theoretically and experimentally. In the study, PZT patches are used as energy converter, and the vibration control efficiency is expressed by the vibration reduction rate per area of the PZT patches. Emphasis is laid on the effect of the generalized electromechanical coupling coefficient K ₃₁ on the vibration control efficiency. Four PZT patches with different sizes are bonded on the geometrical central area of four similar clamped aluminum plates, respectively, and vibration control experiments are conducted for these plates using the R-L shunt circuit. The results indicate that the bigger the coupling coefficient K ₃₁, the larger the rate of vibration reduction, and hence, the higher the vibration control efficiency. It also shows that the vibration responses of the first mode of the plates bonded with different PZT patches can be reduced by about 30.5%, 48.58%, 85.47%, and 89.91%, respectively. It comes to a conclusion that the vibration control efficiency of the piezoelectric shunt damping system decreases with the increase of the area of the PZT patch, whereas the vibration reduction of the plate increases with the area of the PZT patch. Therefore, it is necessary to make topology optimization for the PZT patch in the vibration control utilizing the piezoelectric shunt damping technique.     

非对称智能减振板优化设计

通过分析非对称智能板的导纳值,实现了智能板压电片的优化设计。由于压电分流阻尼电路中能量的消耗是导纳值的函数,因此用导纳值来评价智能板的减振效果。用模态分析得到智能板的振型和固有频率,再通过谐响应分析求得智能板的导纳值。针对3个非对称模态,采用子问题的优化方法,优化设计压电片的位置,使其减振效果达到最佳。     

Vibration Control of a Composite Beam Using Self-sensing Semi-active Approach

Structural vibration control was an active research area for the past twenty years because of their potential applications in aerospace structures,civil structures,naval structures,etc.Semi-active vibration control methods based on piezoelectric actuators and synchronized switch damping on inductance(SSDI) techniques attract the attention of many researchers recently due to their advantages over passive and active methods.In the SSDI method,a switch shunt circuit is connected to the piezoelectric patch to shift the phase and amplify the magnitude of the voltage on the piezoelectric patch.The most important issue in SSDI method is to control the switching actions synchronously with the maximum vibration displacement or maximum strain.Hence,usually a displacement sensor is used to measure the vibration displacement or a collocated piezoelectric sensor is needed to measure the strain of the structure near the piezoelectric actuator.A self-sensing SSDI approach is proposed and applied to the vibration control of a composite beam,which avoids using a separate sensor.In the self-sensing technique,the same piezoelectric element functions as both a sensor and an actuator so that the total number of required piezoelectric elements can be reduced.One problem in the self-sensing actuator,which is the same as that in the traditional collocated piezoelectric sensors,is the noise generated in the sensor signal by the impact of voltage inversion,which may cause extra switching actions and deteriorate control performance.In order to prevent the shunt circuit from over-frequent on-and-off actions,a simple switch control algorithm is proposed.The results of control experiments show that the self-sensing SSDI approach combined with the improved switch control algorithm can effectively suppress over-frequent switching actions and gives good control performance by reducing the vibration amplitude by 45%,about 50% improvement from the traditional SSDI with a separate piezoelectric element and a classical switch.     

Beam vibration control using cellulose-based Electro-Active Paper sensor

Cellulose based Electro-Active Paper (EAPap) has recently shown a great potential as an environment-friendly smart material due to its biodegradability, biocompatibility and flexibility. Lots of studies have been conducted to investigate the basic smart characteristics of EAPap, but its application has not yet developed well. In this paper, the possibility of cellulose-based Electro-Active Paper (EAPap) as a piezoelectric sensor was investigated by the vibration control of the cantilevered beam. The EAPap sample was attached at the root of the cantilevered beam and used as a vibration sensor. The piezoceramic patch was also attached at the root of the beam and played as an actuator. The voltage output of EAPap showed exact dynamic characteristics of the cantilevered beam. The frequency bandwidth and quality factor of EAPap were similar to those of piezoceramic patch, which results EAPap has similar sensing capability of piezoceramic patch. To find the application of EAPap sensor, beam vibration control was performed. EAPap sensor output was considered as a position error of the cantilevered beam and a simple PID controller was designed to suppress the vibration of the beam. The EAPap sensor output provided clear time response of the beam. The controlled system showed good vibration control performance of the beam. The results provided that the piezoelectric characteristic of EAPap has a great potential as a sensor and also as a new smart material.