摆动式动力吸振器参数优化研究

为了提高空中缆车等设备的运行舒适性和安全性,降低摆振响应,设计了一种用于控制结构摆振的摆动式动力吸振器。通过建立吸振系统动力学模型,理论分析了吸振器的转动惯量、固有频率和阻尼参数对摆振结构振动响应的影响。利用定点理论,研究了吸振器的最优固有频率和最优阻尼。数值模拟了最优参数的精确性及吸振器的控制效果。研究表明此动力吸振器方案可以有效地减小摆振结构发生的强迫摆振响应。     

干摩擦阻尼叶片周期振动响应的解析计算

研究一个描述干摩擦阻尼器叶片振动的质量-弹簧-阻尼器振动系统。阻尼器摩擦力由黏滞模型描述,由接触面滑动或黏滞状态决定。将滞后摩擦力分为四个阶段,从而得到各个阶段上的线性振动系统,给出求干摩擦阻尼叶片周期响应的解析公式。计算表明,阻尼端压力取适当值时,阻尼器会处于最优的摩擦接触状态,获得较好减振效果。同时引入阻尼器处对叶片还起到调频作用,也可以起到使激振频率避开共振频率的作用,减小振动幅值。     

阻尼吸振器吸收机械阻尼振动的频率特性分析与试验研究

从两自由度双阻尼弹簧振子振动系统的振动频率特性分析入手,探讨了用阻尼吸振器吸收机械阻尼振动的性能,并对阻尼吸振器参数的选择作了分析。同时,通过模型试验对理论分析的结果作了验证。     

阻尼吸振器吸收机械阻尼振动的频率特性分析与试验研究

从两自由度双阻尼弹簧振子振动系统的振动频率特性分析入手,探讨了用阻尼吸振器吸收机械阻尼振动的性能,并对阻尼吸振器参数的选择原则作了分析,同时,通过模型试验对理论分析的结果作了验证。     

多级立式泵动力吸振器设计与分析

以某多级立式水泵为研究对象,在ANSYS Workbench中完成了泵组的模态分析,并按照最优阻尼原则计算出动力吸振器的参数,对含有吸振器的泵组进行谐响应分析,结果表明动力吸振器有效地抑制了振动。     

连续梁的动力吸振器参数研究

通过分析连续系统在简谐激励下无阻尼动力吸振器吸振的特点,以梁为研究对象,建立了以梁的最大动能为减振目标函数的理论公式,通过对目标函数中较为敏感的参数分析,详细阐述了无阻尼吸振器的位置参数、刚度参数和质量参数对减振目标函数的影响.该研究内容在动力吸振器参数优化及振动控制理论的研究中具有一定的应用价值.     

基于动力吸振器的中空轴系纵向减振研究

针对中空轴系的纵向振动,在轴系内部安置阻尼动力吸振器对其进行了减振设计。结合子结构综合法和传递矩阵法建立了附加阻尼动力吸振器复杂轴系的动力学模型,分析了阻尼动力吸振器与轴系的耦合系统在简谐激励下的动力学响应,并采用了有限元仿真,表明阻尼动力吸振器的加入使得轴系的纵向共振峰得到抑制,轴系共振频率附近的频响曲线趋于平缓。试验结果表明,附加阻尼动力吸振器后的轴系一阶纵向共振峰值下降显著,阻尼动力吸振器对轴系的纵向减振具有显著的效果。在中空轴系内部空间安装吸振器,既不占用多余的空间,又能获得较好的减振效果,可以作为船舶推进轴系纵向减振的一种新选择。     

连续参数型吸振器吸振分析及优化

针对连续参数型动力吸振器与弹性薄板构成的耦合系统,以功率流理论为基础,结合有限元方法,分析了连续参数型动力吸振器变阻尼复合梁的吸振特性。与试验结果进行对比可知,变阻尼层复合梁具有吸振频带宽、吸振效果好的特性。为了提升吸振器的吸振效果,通过ANSYS的优化模块,对连续参数型动力吸振器的吸振性能进行了优化设计,优化后的吸振器在多个频率段内吸振性能得以提升,验证了优化方法的有效性。     

无阻尼动力吸振器吸振的理论分析与实验研究

本文分析了无阻尼动力吸振器吸振的频率特性以及无经动力吸振器参数的选择。模型试验结果与理论分析结果吻合。     

被动式动力吸振技术研究进展

综述被动式动力吸振技术的研究概况及其发展.根据结构特点和参数形式将动力吸振器分为单自由度型、组合型、多自由度型、连续参数型和非线性参数型等几种类型,针对其安装于不同主振系、在不同激励下的优化设计问题,总结归纳前人的相关研究成果,梳理当前的研究进展,并提炼今后的发展方向.目前用来抑制主振系单个振动模态的单自由度动力吸振器设计理论已经基本成熟,组合型动力吸振器的优化设计问题也得到了较充分的研究,多自由度型、连续型和非线性动力吸振器的设计和应用成为了研究热点.多自由度动力吸振器能够降低吸振代价,提高吸振效率,其结构设计、参数优化和工程应用等问题都有待进一步充分研究.非线性动力吸振器具有更丰富更复杂的动力学行为,有可能产生新现象、新效应,尤其值得更深入地研究.另外,附加多个吸振器后整个系统的动态响应分析方法也是值得关注的问题.     

高速大功率密度齿轮传动系统的干摩擦阻尼环减振特性研究

以干摩擦阻尼环对高速大功率密度齿轮传动系统减振特性的影响为研究对象,在考虑干摩擦阻尼环减振作用、轮齿时变啮合刚度、啮合传动误差的基础上,建立干摩擦阻尼环齿轮传动系统的弯扭轴耦合多体动力学模型。设计一套输入最高转速为36 000 r/min、油润滑的齿轮传动系统干摩擦阻尼环减振试验系统,并验证了动力学模型的有效性。研究干摩擦阻尼环结构参数对齿轮传动系统减振特性的影响。结果表明：针对高速大功率密度齿轮传动系统,干摩擦阻尼环具有良好的减振特性,降幅比可以达到20%;通过优化阻尼环结构参数如外圆直径（阻尼环与轮缘间的过盈量）、厚度、宽度等可使齿轮传动系统获得最优减振效果。     

An optimal placement of CLD treatment for vibration suppression of plates

A study on optimal placement of constrained-layer damping (CLD) treatment for vibration suppression of plates is presented. A mathematical model is derived using the energy approach. This model allows both the constraining layer (CL) and the viscoelastic layer (VEM) to be either as thick as the host or very thin. The influence of treatment thickness on damping effects is particularly addressed. From the simulated results, it is found that the best damping performance occurs as the CL thickness is twice that of the VEM thickness. As to the optimization process, an objective function including structural damping ratios, resonant frequencies’ shift, and CLD thickness is defined. In optimization, the structural damping plays the main performance index and the frequencies’ shift and CLD thickness play as penalty functions. A topographical method in conjunction with the complex method is used to search for the global minimum. Examples are illustrated and the effects of weighting factors are discussed. Individual effects of weighting factors can be useful for designers, since the designers can build up a better sense of how CLD treatment improves the vibration suppression.     

金属橡胶隔振器干摩擦阻尼特性的研究

探讨了描述金属橡胶材料干摩擦迟滞特性的数学模型，并通过单向和双向加载的实验，研究了金属橡胶隔振器阻尼元件的干摩擦阻尼特性，为金属橡胶隔振器的设计及推广应用提供了理论及实验依据。     

基于摩擦耗能原理的抑振镗杆

讨论了摩擦耗能镗杆的原理,建立了有非线性库仑干摩擦环节的力学模型,并以摩擦参数为变化量,通过数值分析的方法考察了模型的吸振效果。研制了一种基于摩擦减振的新型镗杆,结合颤振发生的机理与切削稳定性理论,分析了不同摩擦条件下镗杆的抑振效果。将不同摩擦条件下的镗杆切削实验结果与理论模型仿真结果进行对比,发现在既定的摩擦阻尼器中,有滑动摩擦与粘接两个状态,而且存在一个最优正压力使得滑动摩擦消耗能量达到最大值又不处于粘接的状态,此时系统抑振效果达到最佳。切削实验发现基于摩擦减振原理的镗杆有良好的颤振抑制效果。      

粘弹性阻尼安装架结构设计及减振效能分析

粘弹性阻尼材料的最大优点是可以在很宽的频域和温域内对振动进行抑制,特别适用于机载电子设备结构减振问题.文中阐述了在某机载电子设备安装架上敷设粘弹性阻尼材料的方法和典型工艺,并利用有限元仿真方法对安装架敷设阻尼层前后的减振效能进行了对比,结果表明敷设阻尼层后的安装架有更好的减振效能.     

基于压电摩擦阻尼的四参数隔振系统等效建模与频变阻尼特性分析

在轨卫星搭载的高精度有效载荷对环境微振动异常敏感,从而对隔振系统的振动衰减性能提出了更高的要求。传统两参数被动隔振系统提高隔振性能时,常采用添加定常阻尼进行能量耗散的方式,但存在低频共振峰抑制与高频快速衰减不能兼顾的固有矛盾问题。为了解决这一问题,一种能够实现阻尼特性基于频率变化的四参数隔振系统被提出,采用归一化方法建立其系统传递率与等效阻尼理论模型,并与两参数和三参数隔振系统进行对比分析。基于四参数系统的频变阻尼等效理论,设计一种基于压电陶瓷致动器产生摩擦阻尼的具象化四参数隔振系统,考虑非线性摩擦阻尼的融合问题,并分析中间等效质量参数对阻尼频变特性的影响规律,最后对其频变阻尼特性和隔振性能进行了仿真与实验验证。结果表明：时域上,四参数隔振系统对随机信号的隔振率达到91.1%;频域上,相较常值小阻尼系统,四参数隔振系统在低频共振处的峰值性能提升5.46dB,且高频段保持相近的快速衰减,表现出低频大阻尼、高频小阻尼的频变阻尼特性。仿真与实验结果均表明,系统能够解决被动隔振系统中存在的高低频隔振性能之间的矛盾问题。     

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.     

新型磁流变液多间隙双质量飞轮研究

针对目前磁流变液双质量飞轮装置中普遍存在的刚度突变和可传递阻尼力矩较小的问题,提出了一种具有多工作间隙及可获得良好多级非线性扭转刚度的新型多间隙磁流变液双质量飞轮。通过对其磁感应强度及阻尼力矩进行理论分析,并对其结构设计进行优化,得到优化后结构的磁感应强度分布并实现了阻尼力矩的最大化,进而将磁感应强度和阻尼力矩的计算值与仿真值分别进行对比,最后对其固有特性及受迫振动进行分析。结果表明：新型多间隙磁流变液双质量飞轮有利于改善车辆动力传动系减振效果,不同工况下提供相匹配的输入电流可使减振效果达到最佳,可传递的阻尼力矩远大于普通磁流变液双质量飞轮。研究成果可为新型多间隙磁流变液双质量飞轮的设计提供理论参考。     

Research on the design of non-traditional dynamic vibration absorber for damped structures under ground motion

An analytical approach is presented to investigate the optimal problem of non-traditional type of Dynamic vibration absorber (DVA) for damped primary structures subjected to ground motion. Different from the standard configuration, the non-traditional DVA contains a linear viscous damper connecting the absorber mass directly to the ground instead of the main mass. There have been many studies on the design of the non-traditional DVA for undamped primary structures. Those studies have shown that the non-traditional DVA produces better performance than the standard DVA does. When damping is present at the primary system, there are very few works on the non-traditional dynamic vibration absorber. To the best of our knowledge, there is no study on the design of non-traditional DVA for damped structures under ground motion. We propose a simple method to determine the approximate analytical solutions of the nontraditional DVA when the damped primary structure is subjected to ground motion. The main idea of the study is based on the criterion of the equivalent linearization method to replace approximately the original damped structure by an equivalent undamped one. Then the approximate analytical solution of the DVA’s parameters is given by using known results for the undamped structure obtained. Comparisons have been done to validate the effectiveness of the obtained results.     

低频重载下黏弹性减振器阻尼缓冲性能分析

为研究黏弹性减振器的非线性阻尼缓冲性能,根据其结构特点和非线性特征,建立单自由度分段非对称非线性振动模型,并由平均法推导出系统固有频率共振区附近的幅频特性方程。以安装在某300kW履式拖拉机的黏弹性减振器为应用对象进行研究,分析系统在固有频率共振区附近的非线性特性和阻尼减振性能。讨论了幅频特性分别和激励幅值、刚度系数、阻尼系数、质量之间的关系,并提出改善系统减振性能的建议。