正弦位移激励对编织-嵌槽型金属橡胶隔振系统动态特性的影响

设计、制作了编织-嵌槽型金属橡胶隔振器,并对其进行动态特性试验。通过建立非线性恢复力模型,考察该隔振系统线性刚度系数、三次非线性刚度系数以及一次粘性阻尼系数随正弦位移激励的变化情况,分析振幅和频率对编织-嵌槽型金属橡胶隔振系统动态特性的影响。结果表明:随着振幅或频率的增大,编织-嵌槽型金属橡胶隔振器的刚度逐渐减小,阻尼略有降低,且振幅或频率的增大会使该隔振系统振动响应幅频特性曲线的带宽变窄。     

汽车发动机磁流变悬置动特性研究

针对某型号动力总成,基于阻尼可控、宽频隔振的思想,设计具有解耦膜、可控阻尼通道结构的磁流变悬置新型结构,使磁流变悬置在低频、大振幅时,具有高刚度大阻尼特性,高频、小振幅时,具有低刚度、小阻尼特性,同时悬置的高频动态硬化被有效抑制。采用键合图理论,根据磁流变悬置在不同激振条件下的实际工作状态,建立分段式动态特性集总参数模型,利用键合图理论推导了磁流变悬置的状态方程,并对磁流变悬置的动特性进行了仿真分析与试验验证。结果表明:在0~200 Hz频率范围内,该磁流变悬置具有良好的动态性能,能满足发动机的隔振需求,并论证了分段式磁流变悬置集总参数模型的有效性。     

主动隔振与动力吸振器的联合减振研究

针对单层主动隔振系统，研究主动隔振对隔振对象振幅的影响。发现存在临界频率，对于临界频率以下的激励，主动隔振会加剧隔振对象的振动。临界频率是阻尼的函数，选择合适的阻尼可使临界频率尽量小，但存在下限。引入动力吸振器能有效降低隔振对象低频响应的振幅，分析表明，对于舰船的低频噪声，主动隔振与动力吸振器联合减振是一种有效的综合治理方法。     

空气弹簧液压悬置动特性及隔振特性研究

研究了具有可变刚度阻尼的发动机空气弹簧液压悬置的动特性和隔振特性。针对影响发动机空气弹簧液压悬置动特性的关键参数上液室等效体积刚度,采用理论和试验方法研究了上液室等效体积刚度的等效值,基于该等效值建立了空气弹簧液压悬置的理论模型,对空气腔开闭两种工况进行了空气弹簧液压悬置动特性的仿真和试验研究。搭建了发动机空气弹簧液压悬置系统试验台架,研究了台架各种激励频率下的空气弹簧液压悬置的隔振特性。结果表明:本研究采用的上液室等效体积刚度进行空气弹簧进行建模是正确、可行的,提高了空气弹簧建模效率和准确性;空气弹簧液压悬置在空气腔开启和关闭两种状态下,峰值动刚度增大幅值达78.5%,峰值阻尼角增大幅值达250%。台架试验表明:当台架激励频率小于25Hz时,悬置采用大刚度大阻尼;当台架激励频率大于等于25 Hz时,悬置采用小刚度小阻尼;悬置隔振率提升明显,不同频率下提升幅值达10%～67%。     

抗蛇行液压减振器动态特性试验研究

建立了减振器力学特性试验台。针对某高速动车组抗蛇行液压减振器,进行了静态及动态特性试验。分析不同激励幅值、不同激励频率对抗蛇行减振器动态性能的影响,得到了减振器的静态特性、动态刚度和阻尼特性。试验结果表明:动态刚度在低频时随频率增加而增加,频率高于某个值后,动态刚度趋于平稳;动态阻尼在低频时随频率增加而增加,高频时随频率增大而减小,而随幅值的增加,动态阻尼峰值所对应的频率减小。     

汽车悬架弹簧多级减振刚度的应用性能分析

介绍了汽车非线性减振悬架的性能特点.根据非线性悬架特点设计了一种四级减振刚度弹簧;根据非线性曲线的特点,把汽车的不同工况分解为四减振区域,并分别把每一个减振区域匹配出不同刚度的线性弹性刚度,相当于用一次曲线去逼近空气弹簧的多次刚度曲线,这样就能得到吸振能力非常接近空气弹簧的弹性特性.进一步计算了四级减振刚度悬架汽车的减振频率、静挠度、振幅、阻尼特性.计算结果表明,四级减振刚度悬架比单刚度悬架舒适性能有很大的提高.     

含金属橡胶的双层隔振系统简谐激励响应计算方法研究

针对目前含金属橡胶的双层隔振系统简谐激励响应算法推导过程复杂、求解困难的现状,提出了基于多项式动态模型的等效线性化方法。首先引入多项式模型对金属橡胶的动态力学特性进行了描述,并对不同频率下隔振系统运动方程中的非线性刚度、阻尼进行等效线性化处理,然后求解方程获得系统在相应频率下的振幅,最后由不同频率的振幅组成幅频特性曲线。通过算例,将利用上述方法得到的结果与试验数据进行了对比,证明了多项式模型等效线性化方法对于含金属橡胶的双层隔振系统简谐激励响应计算问题的适用性、简便性和准确性。     

基于PAM和MRD的新型六维宽频隔振系统及其特性

提出了一种刚度阻尼解耦,且可调并能大幅降低支撑频率的基于PAM（气动肌肉）和MRD（磁流变阻尼器）的六维宽频隔振系统,推导了由弹性、阻尼作用空间到支撑平台笛卡尔六维空间的雅可比矩阵,获得了系统的惯性、刚度及阻尼矩阵,在此基础上,建立了系统振动方程,分析了系统的解耦特性、支撑频率的可降特性以及宽频隔振原理,讨论了弹性阻尼元件的参数计算方法。该成果可为车载/舰载/机载精密设备的六维宽频隔振提供理论参考。     

磁流变型发动机悬置低频动特性及参数分析

根据发动机磁流变型悬置的结构,建立了磁流变型悬置的力学模型和数学模型,应用MATLAB/SIMULINK对磁流变型悬置在低频激励下的动特性的影响进行研究。分析了电流强度和激励幅值、橡胶主簧等效面积、激励频率对磁流变悬置动特性的影响。分析结果表明:磁流变悬置较液压悬置在低频大振幅工况下能获得更大的阻尼和刚度。     

悬架液压衬套的液固耦合建模及动态特性分析

传统橡胶衬套由于自身属性的限制,不能同时降低低频抖动和隔离高频振动,而液压衬套可以较好地解决这个问题。结合某乘用车悬架系统采用的液压衬套,介绍液压衬套的结构和工作原理,阐述其动态特性参数动刚度和阻尼滞后角的物理意义。在AMESim软件中建立该液压衬套的模型并进行仿真计算,利用MATLAB软件处理仿真结果并进行分析。在MTS831试验台上完成了该液压衬套的动态特性试验,试验结果验证了所建模型的正确性。最后利用该模型研究了液压衬套相关模型参数对液压衬套动态特性的影响。     

Optimal design of nonlinear hydraulic engine mount

This paper shows that the performance of a nonlinear fluid engine mount can be improved by an optimal design process The property of a hydraulic mount with inertia track and decouplen differs according to the disturbance frequency range. Since the excitation amplitude is large at low excitation frequency range and is small at high excitation frequency range, mathematical model of the mount can be divided into two linear models One is a low frequency model and the other is a high frequency model The combination of the two models is very useful in the analysis of the mount and is used for the first time in the optimization of an engine mount in this paper Normally, the design of a fluid mount is based on a trial and error approach in industry because there are many design parameters In this study, a nonlinear mount was optimized to minimize the transmissibilities of the mount at the notch and the resonance frequencies for low and high-frequency models by a popular optimization technique of sequential quadratic programming (SQP) supported by MATLAB^(r) subroutine. The results show that the performance of the mount can be greatly improved for the low and high frequencies ranges by the optimization method     

Identifying the frequency dependent material property of a hydraulic engine mount through an iterative procedure using 3D finite element modeling

Achieving very restricted noise, vibration and harshness targets in modern vehicles, makes using the hydraulic engine mount crucial. Hydraulic engine mounts have both solid and fluid media in their structures that make their dynamic behavior complex to figure out. We present a three-dimensional model of HEM with using finite element method that encompasses elastomeric material’s nonlinearity and fluid-structure-interaction. Dynamic equivalent modulus of elasticity for elastomeric material is identified through iterative model updating procedure. To do model updating, the results (here, namely, natural frequencies and frequency response function graphs) are compared with real hydraulic engine mount behavior that derived from modal tests. The results showed that the dynamic characteristic of elastomeric material is frequency dependent and can be divided into two distinct regions: below 30 Hz (low frequency) and above 30 Hz (high frequency) with different trends.     

Simulation Research on Dynamic Characteristics of Hydraulic Mount

At present,research on hydraulic mounts has mainly focused on the prediction of the dynamic stiffness and loss angle.Compared to the traditional finite element analysis method,the programming method can be used to analyze hydraulic mounts for a rapid and accurate understanding of the influence of the different mounting parameters on the dynamic stiffness and loss angle.The aims of this study were to investigate the nonlinear dynamic characteristics of a hydraulic mount,and to identify the parameters that affect the dynamic stiffness and loss angle using MATLAB software programs to obtain the influence curves of the parameters,so as to use suitable parameters as the basis for vibration analysis.A nonlinear mechanical model of a hydraulic mount was established according to the basic principles of fluid dynamics.The dynamic stiffness and loss angle of the dimensionless expression were proposed.A numerical calculation method for the dynamic performance evaluation index of the hydraulic mount was derived.A one-to-one correspondence was established between the structural parameters and peak frequency of the evalua-tion index.The accuracy and applicability of the mechanical model were verified by the test results.The results dem-onstrated the accuracy of the nonlinear mechanical model of the hydraulic mount,and the vehicle driving comfort was greatly improved by the optimization of the structural parameters.     

基于ADAMS软件的发动机右悬置总成优化设计

运用MSC Adams/view建立汽车发动机悬置系统多体动力学模型,对发动机悬置系统进行匹配设计,以满足频率合理分布、模态振型解藕、限位等诸多设计要求.通过对发动机右悬置刚度的优化,改善了发动机悬置系统的隔振性能,降低了整车怠速振动,并进行了试验验证.     

Decoupling analysis for a powertrain mounting system with a combination of hydraulic mounts

The existing torque roll axis(TRA) decoupling theories for a powertrain mounting system assume that the stiffness and viscous damping properties are constant. However, real-life mounts exhibit considerable spectrally varying stiffness and damping characteristics, and the influence of the spectrally-varying properties of the hydraulic mounts on the powertrain system cannot be ignored. To overcome the deficiency, an analytical quasi-linear model of the hydraulic mount and the coupled properties of the powertrain and hydraulic mounts system are formulated. The influence of the hydraulic mounts on the TRA decoupling of a powertrain system is analytically examined in terms of eigensolutions, frequency, and impulse responses, and then a new analytical axiom is proposed based on the TRA decoupling indices. With the experimental setup of a fixed decoupler hydraulic mount in the context of non-resonant dynamic stiffness testing procedure, the quasi-linear model of the hydraulic mount is verified by comparing the predictions with the measurement. And the quasi-linear formulation of the coupled system is also verified by comparing the frequency responses with the numerical results obtained by the direct inversion method. Finally, the mounting system with a combination of hydraulic mounts is redesigned in terms of the stiffness, damping and mount locations by satisfying the new axiom. The frequency and time domain results of the redesigned system demonstrate that the torque roll axis of the redesigned powertrain mounting system is indeed decoupled in the presence of hydraulic mounts (given oscillating torque or impulsive torque excitation). The proposed research provides an important basis and method for the research on a powertrain system with spectrally-varying mount properties, especially for the TRA decoupling.     

Optimization Design and Performance Analysis of Vehicle Powertrain Mounting System

The design strategies for powertrain mounting systems play an important role in the reduction of vehicular vibration and noise. As stiffness and damping elements connecting the transmission system and vehicle body, the rubber mount exhibits better vibration isolation performance than the rigid connection. This paper presents a complete design process of the mounting system, including the vibration decoupling, vibration simulation analysis, topology optimization, and experimental verification. Based on the 6?degrees?of?freedom vibration coupling model of the powertrain mounting system, an optimization algorithm is used to extract the best design parameters of each mount, thus rendering the mounting system fully decoupled and the natural frequency well configured, and the optimal parameters are used to design the mounting system. Subsequently, vibration simulation analysis is applied to the mounting system, considering both transmission and road excitations. According to the results of finite element analysis, the topological structure of the metal frame of the front mount is optimized to improve the strength and dynamic characteristics of the mounting system. Finally, the vibration bench test is used to verify the availability of the optimization design with the analysis of acceleration response and vibration transmissibility of the mounting system. The results show that the vibration isolation performance of the mounting system can be improved effectively using the vibration optimal decoupling method, and the structural modification of the metal frame can well promote the dynamic characteristics of the mounting system.     

High frequency testing of rubber mounts

Rubber and fluid-filled rubber engine mounts are commonly used in automotive and aerospace applications to provide reduced cabin noise and vibration, and/or motion accommodations. In certain applications, the rubber mount may operate at frequencies as high as 5000 Hz. Therefore, dynamic stiffness of the mount needs to be known in this frequency range. Commercial high frequency test machines are practically nonexistent, and the best high frequency test machine on the market is only capable of frequencies as high as 1000 Hz. In this paper, a high frequency test machine is described that allows test engineers to study the high frequency performance of rubber mounts at frequencies up to 5000 Hz.     

汽车动力总成悬置系统隔振设计分析方法

动力总成是汽车的主要振源。动力总成隔振悬置系统的布置设计与发动机缸数、发动机布置方式、汽车动力传动系的型式及整车隔振性能要求等诸多因素有类。在讨论动力总成悬置系统的设计理论与优化方法的基础上，系统地分析了这些因素对于动力总成悬置系统隔振性能设计目标的影响。并针对两种动力总成进行了优化设计计算分析，通过调节悬置的安装位置，安装角度及悬置的三向主刚度，使系统的解耦程度提高。     

基于遗传算法的某车型悬置系统优化设计

悬置系统的设计对车辆NVH性能起着重要作用,影响着整车振动大小及噪声水平。以某车型动力总成悬置系统为载体,基于Virtual.Lab建立的系统分析模型,分别计算了悬置系统固有频率分布、模态解耦率及系统位移量,结果显示:悬置系统固有频率分布不合理,重要方向的解耦率小于80%,且位移量大于10mm,均不满足要求;应用遗传算法,对悬置系统进行优化分析,将系统变量设定为悬置橡胶刚度,固有频率及位移量所要求的范围设定为约束条件,目标为解耦率最大。通过优化悬置橡胶刚度参数,悬置系统的固有频率、位移量可以控制在要求的范围内,并且模态耦合的程度大大降低。     

Vibration and noise control of structural systems using squeeze mode ER mounts

This paper presents vibration and noise control of flexible structures using squeeze mode electro-rheological mounts. After verifying that the damping force of the ER mount can be controlled by the intensity of the electric fild, two different types of ER squeeze mounts have been devised. Firstly, a small size ER mount to support 3 kg is manufactured and applied to the frame structure to control the vibration. An optimal controller which consists of the velocity and the transmitted force feedback signals is designed and implemented to attenuate both the vibration and the transmitted forces. Secondly, a large size of ER mount to support 200 kg is devised and applied to the shell structure to reduce the radiated noise. Dynamic modeling and controller design are undertaken in order to evaluate noise control performance as well as isolation performance of the transmitted force. The radiated noise from the cylindrical shell is calculated by SYSNOISE using forces which are transmitted to the cylindrical shell through two-stage mounting system.