基于拓扑优化的压电分流阻尼抑振实验研究

将结构拓扑优化引入压电分流振动抑制中,以压电元件的分布面积为设计变量,压电元件产生的电荷最大化为优化目标,对压电元件的拓扑进行了优化以获得最佳抑振效果。针对悬臂梁结构,得到了对不同的结构模态进行抑制时的压电元件最优拓扑构型。建立了带有压电分流阻尼系统的悬臂梁振动控制实验模型,将压电元件拓扑优化后的压电分流阻尼系统应用于悬臂梁多阶弯曲模态的振动响应抑制实验,并对比分析了带最优拓扑和非优拓扑压电元件的悬臂梁压电分流阻尼抑振效果。结果表明,对压电元件进行拓扑优化可以明显提高压电分流阻尼系统的抑振效果。     

点式压电智能柔性板的振动主动控制的建模与仿真

基于有压电电层的层合板结构的二维传动方程与二维传感方程,导出了粘贴有点压电传感器与执行器的智能板结构的有限元模型的模态振动控制方程与传感方程。由此模态－状态方程,利用线性二次优化方法得到了智能板结构的最优控制输入。     

复合材料层合板智能结构主动振动控制的边界元法

利用边界元法模拟智能结构的振动控制，推导出具有压电传感器及致动器的复合材料层合板的边界积分方程，应用负速度反馈控制律，研究了复合材料层合板智能结构主动振动控制问题，算例分析证明该方程的正确性。     

压电智能结构振动的一致性PID(CPID)控制EI北大核心CSCD

将一致性控制方法和PID控制方法的基本思想相结合,提出了一种适用于压电智能结构振动控制的一致性PID(Consensus-PID,CPID)控制方法。该方法将系统输出偏差作为PID控制器的输入,PID控制器的输出及其在采样周期内的变化量作为一致性控制器的输入,致动器的输入电压为一致性控制器的输出。推导压电智能结构振动控制方程,以两边简支的压电智能梁为数值算例,建立动力学有限元模型,数值结果表明CPID控制方法能够有效控制压电智能结构的振动,当某些传感器失效时,对比集中式PID控制,系统在CPID控制下仍然能保持较好的控制效果。     

智能梁压电致动器位置布置探讨

本文针对智能梁振动主动控制中,目前压电驱动器输出功率不足的缺点,通过振动模态理论和应变理论及观点,分析推导了智能梁中压电驱动器的最佳贴片位置,弥补了上述压电致动器的出力不足,提高了抑制控制效果,并通过实验验证了上述结论。     

压电智能结构的一种模态控制新方法

提出了一个用于压电智能结构振动控制的模态控制方法。就智能梁给出了压电模态传感器与压电模态致动器的新设计方法以及相应的模态控制方法，并对相应的观测溢出与控制溢出问题进行了分析，给出了抑制这些溢出的措施。     

基于可控性柱面网壳结构主动控制作动器布置的优化研究

利用磁致伸缩材料的磁控特性制作的作动器可以对结构进行主动控制。首先分析了这种作动器的工作原理和设计方法,并通过实验对其进行了输出性能测试。接着在对作动器进行动力学建模的基础上,推导出整个柱面网壳结构的作动控制方程,同时基于作动效率,提出了不依赖于控制方法的位置优化准则,并且在综合考虑控制效果系数、硬件成本和系统复杂性等因素的基础上,初步确定了作动器的数量,然后采用遗传算法,对作动器的布置位置进行了优化。最后利用LQR主动控制算法,对一柱面网壳模型结构进行了主动控制分析。结果表明,通过优化布置的作动器能够有效地减小结构的动力反应,是一种较好的主动控制方法。此外,主动控制模拟结果也验证了应用遗传算法优化此类问题的优越性和可靠性。     

点式压电智能柔性板振动主动控制的建模与仿真

基于有压电层的层合板结构的二维传动方程与二维传感方程,导出了粘贴有点压电传感器与执行器的智能板结构的有限元模型的模态振动控制方程与传感方程。由此模态-状态方程,利用线性二次优化方法得到了智能板结构的最优控制输入。对在冲击与随机激励下的悬壁智能板的计算机仿真结果,证明了本有限元模型的可行性与有效性。     

简支板振动无线主动控制及驱动器优化布置研究

推导光电层合简支板结构动力学方程及模态控制方程,以规格化后模态控制力指数作为遗传算法的适应度函数,基于二进制编码的遗传算法对用于简支板振动控制的单对、双对光致伸缩驱动器布局进行优化,计算机仿真结果表明优化后的驱动器布局方案可有效提高板结构振动控制的有效性。在此基础上进一步对板结构多模态振动控制进行探讨,提出适用于板结构多模态振动控制的驱动器布局优化方法及振动控制方案,仿真算例表明该方法可有效地对简支板前二阶模态进行振动无线控制。     

压电层合板高阶计算模型

压电复合(层合)结构可应用于结构振动控制、形状保持、健康监测等,建立压电层合结构精确的机电耦合计算模型成为了研究的焦点.针对表面粘贴或内部嵌入压电片的压电层合板结构,基于高阶位移场和高阶电势模型,根据Hamilton原理建立了机电耦合高阶有限元模型.该模型适用于薄板和中厚板,并且能够捕捉压电层内沿厚度方向呈抛物线型分布的诱导电势.以压电双晶片简支板为例,进行了作动器构型和开环、闭环状态传感器构型的数值分析.结果指出,诱导电势对压电传感器有重要影响,而压电作动器可忽略这种电势.     

Active vibration control of an arbitrary thick smart cylindrical panel with optimally placed piezoelectric sensor/actuator pairs

Active vibration suppression of a simply supported, arbitrarily thick, transversely isotropic circular cylindrical host panel, integrated with spatially distributed piezoelectric actuator and sensor layers, is investigated based on the linear three dimensional exact piezo-elasticity theory. To assist control system design, system identification is conducted by applying a frequency domain subspace approximation method based on N4SID algorithm using the first few structural modes of the system. The state space model is constructed from system identification and used for state estimation and development of control algorithm. The optimal electrode configuration for the collocated piezoelectric actuator–sensor pair is found by applying a genetic optimization procedure based on maximization of a quantifiable objective function considering the controllability, observability and spillover prevention of the identified system. A linear quadratic Gaussian (LQG) optimal controller is subsequently designed and simulated based on the identified model of optimally configured smart structure in order to actively control the system response in both frequency and time domains. The dynamic performance and effectiveness of the optimized vibration control system is demonstrated for two different types of external mechanical excitations (i.e., impulsive load and white noise disturbance). The accuracy of dynamic analysis is established with the aid of a commercial finite element package and the data available in the literature.     

Active vibration control of composite plate with optimal placement of piezoelectric patches

The active vibration control of a composite plate using discrete piezoelectric patches has been investigated. Based on first order shear deformation theory, a finite element model with the contributions of piezoelectric sensor and actuator patches to the mass and stiffness of the plate was used to derive the state space equation. A global optimization based on LQR performance is developed to find the optimal location of the piezoelectric patches. Genetic algorithm is adopted and implemented to evaluate the optimal configuration. The piezoelectric actuator provides a damping effect on the composite plate by means of LQR control algorithm. A correlation between the patches number and the closed loop damping coefficient is established.     

自适应桁架结构局部力反馈振动控制及其主动构件的配置研究

本文主要研究利用自适应桁架结构自身的主动构件实现控制结构动态特性的理论和有效性以及主动构件的最优配置问题。首先，基于自适应桁架结构的有限元模型，将主动构件的弹性内力直接用于实现反馈控制桁架结构的振动特性；然后，引用模态耗散能因子和模态应变能因子的概念，研究了主动构件的优化配置问题。通过一平面自适应桁架结构的优化配置计算和数值仿真，说明了文中提出的控制方法和主动构件优化配置的有效性。     

Optimal design in vibration control of adaptive structures using a simulated annealing algorithm

Advanced reinforced composite structures incorporating piezoelectric sensors and actuators are increasingly becoming important due to the development of smart structures. These structures offer potential benefits in a wide range of engineering applications such as vibration and noise suppression, shape control and precision positioning. This paper presents a finite element formulation based on the classical laminated plate theory for laminated structures with integrated piezoelectric layers or patches, acting as sensors and actuators. The finite element model is a single layer triangular nonconforming plate/shell element with 18 degrees of freedom for the generalized displacements, and one additional electrical potential degree of freedom for each surface bonded piezoelectric element layer or patch. The control is initialized through a previous optimization of the core of the laminated structure, in order to minimize the vibration amplitude and maximize the first natural frequency. Also the optimization of the patches position is performed to maximize the piezoelectric actuators efficiency. The simulated annealing algorithm is used for these purposes. To achieve a mechanism of active control of the structure dynamic response, a feedback control algorithm is used, coupling the sensor and active piezoelectric layers or patches, and to calculate the dynamic response of the laminated structures the Newmark method is considered. The model is applied in the optimization of an illustrative adaptive laminated plate case. The influence of the position and number of piezoelectric patches, as well as the control gain, are investigated and the results are presented and discussed.     

考虑静水压力的压电弹性层合圆柱壳动力响应的控制模型

基于经典的层合板理论和Navier解法,对静水压作用下压电弹性层合圆柱壳的动力问题的主动控制进行了研究。首先由Hamilton原理导出压电弹性层合壳的非线性动力基本方程。利用压电材料的正、逆压电效应,通过闭环方式,采用速度反馈控制方法得到了任意形式动载作用下带压电感测层/激励层的简支层合圆柱壳动力响应的主动控制模型。数值算例中对于三种不同的外载条件下该控制模型对圆柱壳的动力响应的控制效果进行了研究。结果表明本文中提出的控制模型能够有效抑制动载作用下结构的振动。     

Active control of functionally graded laminated cylindrical shells

An analytical method on active vibration control of smart FG laminated cylindrical shells with thin piezoelectric layers is presented based on Hamilton’s principle. The thin piezoelectric layers embedded on inner and outer surfaces of the smart FG laminated cylindrical shell act as distributed sensor and actuator, which are used to control vibration of the smart FG laminated cylindrical shell under thermal and mechanical loads. Here, the modal analysis technique and Newmark’s integration method are used to calculate the dynamic response of the smart FG laminated cylindrical shell with thin piezoelectric layers. Constant-gain negative velocity feedback approach is used for active vibration control with the structures subjected to impact, step and harmonic excitations. The influences of different piezoelectric materials (PZT-4, BaTiO₃ and PZT-5A) and various loading forms on the active vibration control are described in the numerical results.     

Active aeroelastic flutter analysis and vibration control of supersonic composite laminated plate

The active aeroelastic flutter analysis and vibration control at the flutter bounds of the supersonic composite laminated plates with the piezoelectric patches are studied. The piezoelectric patches are bonded on the top and bottom surfaces of the composite laminated plate to act as the sensor and actuator so that the active aeroelastic flutter suppression and vibration control for the supersonic laminated plate can be conducted. The unsteady aerodynamic pressure in supersonic flow is computed by using the supersonic piston theory. Hamilton’s principle with the assumed mode method is used to develop the governing equation of the structural system. The controller is designed by the velocity feedback and proportional feedback control algorithm, and the active damping and stiffness are obtained. The solutions for the complex eigenvalue problem are obtained by using the generalized eigenvalue methodology. The natural frequencies and damping ratios are also gotten. The aeroelastic flutter bounds of the supersonic composite laminated plate are calculated to investigate the characteristics of the aeroelastic flutter. The impulse responses of the structural system are calculated by using the Houbolt numerical algorithm to study the active aeroelastic vibration control. The influences of ply angle of the laminated plate and the control method on the characteristic of flutter and active vibration control are analyzed. From the numerical results it is observed that the aeroelastic flutter characteristics of the supersonic composite laminated plate can be improved and that the aeroelastic vibration response amplitudes can be reduced, especially at the flutter points, by the proportional feedback or the velocity feedback control algorithm using the piezoelectric actuator/sensor pairs. The effectiveness of the flutter control by the two control algorithms is also compared. The results of this study are of great significance to the flutter analysis and aeroelastic design of the aircraft.     

Design of laminated piezocomposite shell transducers with arbitrary fiber orientation using topology optimization approach

Sensor and actuator based on laminated piezocomposite shells have shown increasing demand in the field of smart structures. The distribution of piezoelectric material within material layers affects the performance of these structures; therefore, its amount, shape, size, placement, and polarization should be simultaneously considered in an optimization problem. In addition, previous works suggest the concept of laminated piezocomposite structure that includes fiber‐reinforced composite layer can increase the performance of these piezoelectric transducers; however, the design optimization of these devices has not been fully explored yet. Thus, this work aims the development of a methodology using topology optimization techniques for static design of laminated piezocomposite shell structures by considering the optimization of piezoelectric material and polarization distributions together with the optimization of the fiber angle of the composite orthotropic layers, which is free to assume different values along the same composite layer. The finite element model is based on the laminated piezoelectric shell theory, using the degenerate three‐dimensional solid approach and first‐order shell theory kinematics that accounts for the transverse shear deformation and rotary inertia effects. The topology optimization formulation is implemented by combining the piezoelectric material with penalization and polarization model and the discrete material optimization, where the design variables describe the amount of piezoelectric material and polarization sign at each finite element, with the fiber angles, respectively. Three different objective functions are formulated for the design of actuators, sensors, and energy harvesters. Results of laminated piezocomposite shell transducers are presented to illustrate the method. Copyright © 2012 John Wiley & Sons, Ltd.     

Response and control of functionally graded laminated piezoelectric shells under thermal shock and moving loadings

Based on the first-order shear deformation theory (FSDT), approximate solution for FG (functionally graded) laminated piezoelectric cylindrical shells under thermal shock and moving mechanical loads is given utilizing Hamilton’s principle. The thin piezoelectric layers embedded on inner and outer surfaces of the functionally graded layer are acted as distributed sensor and actuator to control dynamic characteristics of the FG laminated cylindrical shells. Here, the modal analysis technique and Newmark’s integration method are used to calculate the dynamic response of FG laminated cylindrical shells. Constant-gain negative velocity feedback approach is used for active vibration control. The active vibration control to a single moving concentrated loading, thermal shock loading and a continuous stream of moving concentrated loadings is, respectively, investigated. Results indicate that the control gain and velocity of moving loadings have significant effects on the dynamic response and resonance of the system.