压电摩擦阻尼器的试验研究

提出了一种新型的压电摩擦阻尼器,并在力学测试与模拟(MTS)电液饲服万能实验机上对其性能进行了测试.介绍了该压电摩擦阻尼器的构造,并测试了不同预压力下压电陶瓷驱动器的出力性能;调整压电摩擦阻尼器的预压力,在不同加载频率和幅值下,测试了该阻尼器的滞回性能及在不同预压力下,对压电陶瓷驱动器施加随时间变化的电压,在不同加载频率和幅值下,测试了该阻尼器的滞回性能.试验结果表明,仅施加预压力时,阻尼器的性能稳定,滞回性能基本不随加载频率的变化而改变,施加随时间变化电压,压电摩擦阻尼器的性能稳定,具有较好的出力性能.     

基于功率MOSFET的磁流变阻尼器控制器的研究

根据磁流变阻尼器的阻尼力与控制电流之间的关系,采用功率MOSFET和脉位调制器设计出磁流变阻尼器的电流控制器.实验测试表明,控制器电流可在0～2A范围连续可调,响应速度快,输出的电流精度高,线性度好,输出电流稳定,能够满足磁流变阻尼器的需要.     

电流变液阻尼器的模糊控制及其工程应用

电流变液阻尼器是利用电流变液材料设计而成的一种智能阻尼器,它能够提供可控阻尼力。本文对电流变液材料、电流变液阻尼器及模糊控制策略下的电流变液阻尼器在汽车工程、土木工程减震结构体系等方面的应用作了简单介绍。     

电流变液阻尼器的模糊控制及其工程应用

电流变液阻尼器是利用电流变液材料设计而成的一种智能阻尼器,它能够提供可控阻尼力.本文对电流变液材料、电流变液阻尼器及模糊控制策略下的电流变液阻尼器在汽车工程、土木工程减震结构体系等方面的应用作了简单介绍.     

0-3型压电复合材料的硬球无规堆积模型

根据换能器用０－３型压电复合材料中压电陶瓷颗粒精度相等及分布均匀的特性,建立了０－３型压电复合槽糕的硬球无规堆积模型,阐明了复合材料中包裹压电陶瓷颗粒的聚合物厚度随压电陶瓷体积比的变化,给出了不同制备工艺（流延法、热压法）制备理想换能器用０－３电压复合材料的最大压电陶瓷的体积比。并基于广义自洽模型分析了０－３压电复合材料的中压电陶瓷颗粒的有效极化场。     

一种数控电位器调节的压电陶瓷驱动电源

设计了一种用于驱动数字共焦显微仪压电陶瓷物镜驱动器,实现数控电位器调节的压电陶瓷驱动电源,由单片机系统、前级高压稳压电路、数控电位器、功率放大电路、高压稳压电源和放电回路组成。采用前级高压稳压代替电压放大级作为输入,通过高分辨率的数控电位器调节,经功率放大和放电回路后驱动压电陶瓷驱动器。该驱动电源输出电压稳定,数控可调且随输入电压呈线性变化,可实现对电压精密控制,适用于驱动压电陶瓷等容性负载。     

Rosen型压电变压器反接降压特性研究

介绍了一种将Rosen型压电变压器反接从而实现降压的方法。从压电变压器的材料参数出发,导出Rosen型压电变压器反接时的等效电路模型。基于此模型,利用MATLAB仿真,得到电压增益、效率、输出功率等特性曲线,预测了在满足较高效率前提下,负载匹配时可实现降压。测试了电压增益的频率特性,测得降压特性与理论计算基本一致,表明将Rosen型压电变压器反接在一定负载范围内可实现降压功能。     

基于压电超声触觉显示的可变摩擦研究

基于超声波润滑机理和挤压膜效应,该文提出了一种新型的压电超声触觉显示分析模型,并进行了理论和实验分析。在高挤压数状态下,推导出挤压力的解析表达式,开展了超声触觉显示分析模型振动特性实验和定性、定量摩擦辨别实验,探究了振动频率和激励电压对摩擦减少的影响,验证了压电超声触觉显示分析模型显著的减摩擦效果,为构建触觉显示剪切力模式提供了理论基础。     

变截面悬臂梁压电俘能器动力学特性分析

提出一种变截面悬臂梁压电俘能器结构,通过有限元仿真分析其振动特性和输出电压,有利于提高发电性能。该俘能器结构固定端为等截面梁,自由端为变截面梁,压电层粘贴在悬臂梁根部等截面梁表面,改变悬臂梁自由端与固定端的宽度比,得到多种不同形式的变截面悬臂梁。对比分析了三角形梁、矩形梁和具有不同宽度比梯形梁的固有频率、应力和应变分布及简谐激励输出电压响应。结果表明,三角形梁固有频率较大,输出电压最大,同时分析了不同变截面段长度对输出电压的影响。该文还分析了具有相同一阶频率、不同宽度比俘能器的输出电压,表明三角形结构单位体积压电层输出电压最大。对比分析了基体层上根部粘贴压电片和全部粘贴压电片的输出电压特性。结果表明,前者输出电压较大,发电性能更好。     

有限元法分析1-3型压电复合材料换能器

1-3型压电复合材料圆柱型换能器由薄片状1-3型压电复合材料沿金属薄壁圆管周期排列粘贴而成。根据换能器实际结构和1-3型压电复合材料等效参数模型,利用有限元法在ANSYS中分别建立了两种仿真模型。为验证等效参数模型的可靠性,实验通过改变模型结构尺寸,使换能器内半径从20mm变化到50mm,每5mm作为一个数据点进行建模。仿真计算相同结构尺寸下两种模型的径向振动频率,比较显示两种模型仿真结果接近,平均相对误差仅2.3%。因此,可利用模型II代替模型I对1-3型压电复合材料圆柱型换能器进行仿真分析,从而简化建模和计算。在此基础上,利用模型II分别模拟了该种换能器在空气和水中径向振动频率附近的导纳、发射电压响应和接收电压灵敏度等性能。     

基于压电阻抗技术的阻尼液黏度监测方法

针对粘滞阻尼器中阻尼液黏度会发生变化且黏度不易被直接监测的问题,该文提出了一种基于压电阻抗法的阻尼液黏度监测方法,在阻尼器中安装压电传感器,通过测量传感器的机电阻抗值来确定阻尼液的黏度。为验证所提方法的有效性,制作了一个阻尼装置的模型并安装压电传感器,在其中放置不同黏度的阻尼液时测量压电传感器的阻抗值。结果表明,随着阻尼液黏度的增大,阻抗曲线的峰值频率逐渐减小,而实部电阻值逐渐增大。定义的黏度监测指标能够成功反应阻尼液黏度。     

电液伺服减振器测试平台的设计与开发

本文设计开发了一种电液伺服减振器测试平台,以xPC Target为控制原型,建立了测试系统仿真模型,同时给出系统软硬件设计,以三挡阻尼可调汽车减振器为测试对象,完成了示功实验和振动实验,为减振器的性能分析提供了有效依据.     

The wind-induced vibration control of feed supporting system for large spherical radio telescope using electrorheological damper

Considering the wind-induced vibration of the feed supporting system with cables for the optomechatronics design project of next generation large spherical radio telescopes, a prototype of adaptive electrorheological (ER) damper is designed to realize additional damping control of this vibration. The model of wind is first developed to implement this design and simulations. The model of the designed ER adaptive damper is described in detail, and the strategy of additional damping control using the controllable field-dependent damping force of the ER damper to counteract the wind force is proposed. The numerical simulation results have shown the validity of the designed adaptive ER damper to suppress the wind-induced vibration of the feed supporting system, and the additional damping vibration amplitude can be suppressed to one-half of the original amplitude without ER damper.     

氯化丁基橡胶基压电阻尼复合材料的研究

根据新的压电-导电原理和焦耳定律,将压电陶瓷粉体复合到传统的氯化丁基橡胶阻尼材料中,制作出了性能更好的新型阻尼材料。实验结果表明,复合材料中的压电陶瓷能将机械能转化为电能,并通过微电路耗散出去。因此,通过压电效应-焦耳定律、氯化丁基橡胶的粘弹性阻尼及陶瓷粉体、乙炔碳黑粒子和橡胶分子之间的粒间摩擦、界面摩擦,复合材料可有效地阻尼外界的振动能。     

Control and experimental study of 6-DOF vibration isolation platform with magnetorheological damper

Vibration is an inevitable excitation in the operation of the mechanical system, which reduces its reliability and service life. Therefore, a heavy-duty 6-DOF semi-active vibration isolation system (VIS) with magnetorheological (MR) damper was proposed in this paper. Firstly, A MR damper with large output force of 27 kN was designed. The properties test results showed that the dynamic range (the adjustable multiple of damping force) of the damper is as high as 15, which has excellent dynamic performance. And a Bouc-Wen model which can accurately describe the mechanical behavior of the MR damper was established. Secondly, the prototype of the MR 6-DOF vibration isolation platform (VIP) with cubic structure was developed. Thirdly, a on-off semi-active control strategy was proposed for the MR 6-DOF VIP. The numerical simulation results showed that the semi-active VIS can effectively isolate vibration in the working frequency domain. Finally, the vibration experiment on shaking table was carried out. The test results showed that the designed heavy-duty MR 6-DOF semi-active VIP can control the load's attitude in real-time according to the system state. Compared with the current of 0 A, the vibration isolation effect of the on-off control is improved by 63.27% in the resonance region. The MR 6-DOF VIP can effectively reduce the vibration transmitted to the isolated system through the platform.     

Passive vibration control via electromagnetic shunt damping

This work will present a new type of passive vibration control technique based on the concept of electromagnetic shunt damping. The proposed technique is similar to piezoelectric shunt damping, as an appropriately designed impedance is shunted across the terminals of the transducer. Theoretical and experimental results are presented for a simple electromagnetic mass spring damper system.     

H∞ control of electrorheological suspension system subjected to parameter uncertainties

Vehicle suspension is normally used to attenuate unwanted vibration from various road conditions. The successful suppression of the vibration leads to the improvement of ride comfort as well as steering stability of the vehicle. One of attractive candidates to formulate successful vehicle suspension is to use electrorheological (ER) damper. This paper presents robust control performances of ER suspension system subjected to parameter uncertainties associated with sprung mass of the vehicle and time constant of the ER damper. After identifying dynamic bandwidth of a cylindrical ER damper operated with two different ER fluids (one has fast response characteristic, while the other slow response characteristic), a quarter car model is established by incorporating with time constant of the damping force. A robust H_∞ controller, which compensates the sprung mass and time constant uncertainties, is designed in order to suppress unwanted vibration of the vehicle. Control responses such as vertical acceleration of the sprung mass are presented in time and frequency domains. In addition, the effect of time constant of the damping force on the vibration control performance is investigated by undertaking a comparative work between fast and slow dynamic characteristics of the ER damper.     

Presliding hysteresis damping of LuGre and Maxwell-slip friction models

In this paper, the damping properties of presliding hysteresis are explored for the LuGre and Maxwell-slip friction models. Taking out of consideration the classical linear viscous damping and Stribeck effect, the nonlinear damping of force–displacement hysteresis is analyzed, in Lyapunov sense, for the motion dynamics. Based thereupon the simple but straightforward criteria of model’s parametrization are derived for kinetic friction to be dissipative. Further we show a related experimental example of presliding hysteresis friction response in vicinity to zero velocity.     

Broadband damping of non-rigid-body resonances of planar positioning stages by tuned mass dampers

In high tech motion systems, the finite stiffness of mechanical components often limits the bandwidth of the control system. This is usually counteracted by increasing the controller complexity, for instance by adding notch filters. The height of the resonance frequencies of the non-rigid body dynamics and the amount of damping significantly affect the achievable bandwidth. This paper describes a method to add damping to the flexible behavior of a motion stage, by using tuned mass-dampers with an over-critical damping value in contrast to a regular TMD with 10–20% damping. This over-critical damping results in a robust damper mechanism which is insensitive for parameter variations in terms of stiffness and damping. The main result is a significant modal damping increase over a broad band of resonant frequencies, with only four dampers added. This results in a bandwidth improvement of over 150% in z-direction, which leads to a disturbance suppression of over 10 times for both force and displacement disturbances. A damper test setup has been realized and tested to validate the possibility to create dampers with this over-critical damping behavior.