Measurement,simulation on dynamic characteristics of a wire gauze–fluid damping shock absorber

A new kind of shock absorber with Coulomb–fluid damping through coupling oil, wire gauze, rubber and spring by ingenious tactics is designed for reinforcement of electronic-information equipment in atrocious vibration and impact. The physical mechanism of the shock absorber is systematically investigated. The key-model machine shows complex non-linear dynamic characteristics in multi-parameter coupling dynamic test; otherwise, it has a good dynamic performance for attenuating vibration and resisting violent impact. Based on this, the non-linear dynamic model for attenuating vibration mode of the shock absorber is presented by analysing coupling physical mechanism of fluid and Coulomb friction and other factors for designing the shock absorber with high validity. The analytical results obtained in experimental data have been compared with the numerical ones obtained by performing the Runge–Kutta method with the mathematical model. As the model results agree well with the test data, it can be used for engineering design.     

EXPERIMENTAL AND MATHEMATICAL EVALUATION OF DYNAMIC BEHAVIOUR OF AN OIL-AIR COUPLING SHOCK ABSORBER

The physical mechanism of the actual shock absorber with multi-types of damping and non-linear stiffness through coupling the oil, air, rubber and spring by ingenious devices is systematically investigated. The experimental results of the key-model machine in multi-parameter coupling dynamic test show complex non-linearity dynamic characteristics. Based on this, the non-linear dynamic model for the shock absorber is presented by analysing the internal fluid dynamic phenomenon with respect to the shock absorber. Comparisons with experimental data confirm the validity of the model. Using the model, it is possible to evaluate the importance of different factors for designing the shock absorber.     

带缓冲簧的汽车减振器外特性及其敏感度分析

基于带缓冲簧的汽车减振器的结构和工作原理,应用流体力学和弹性力学的理论,推导出了受均布载荷作用的环形薄板阀片的挠曲变形解析式,建立了该减振器在复原和压缩工况下阻尼特性的数学模型。在MATLAB环境下对模型进行了模拟仿真,并与实测的减振器的外特性进行了比较分析,仿真与实测结果的一致证明了数学模型正确可靠。同时用该模型分析了减振器活塞杆直径、内部气压、油液温度及摩擦力等因素对其外特性的影响规律及敏感程度,得出的结论可以为减振器的设计和性能预测提供参考。     

Simulation and experimental validation of vehicle dynamic characteristics for displacement-sensitive shock absorber using fluid-flow modelling

In this study, a new mathematical dynamic model of shock absorber is proposed to predict the dynamic characteristics of an automotive system. The performance of shock absorber is directly related to the car behaviours and performance, both for handling and ride comfort. Damping characteristics of automotive can be analysed by considering the performance of displacement-sensitive shock absorber (DSSA) for the ride comfort. The proposed model of the DSSA is considered as two modes of damping force (i.e. soft and hard) according to the position of piston. For the simulation validation of vehicle-dynamic characteristics, the DSSA is mathematically modelled by considering the fluid flow in chamber and valve in accordance with the hard, transient and soft zone. And the vehicle dynamic characteristic of the DSSA is analysed using quarter car model. To show the effectiveness of the proposed damper, the analysed results of damping characteristics were compared with the experimental results, which showed similar behaviour with the corresponding experimental one. The simulation results of frequency response are compared with the ones of passive shock absorber. From the simulation results of the DSSA, it can be concluded that the ride comfort of the DSSA increased at the low-amplitude road condition and the driving safety was increased partially at the high-amplitude road condition. The results reported herein will provide a better understanding of the shock absorber. Moreover, it is believed that those properties of the results can be utilised in the dynamic design of the automotive system.     

车用双筒液力减振器的建模与试验

为解决"在设计阶段就能预测减振器的阻尼特性"的问题,基于Easy5软件建立减振器的数学模型并进行仿真研究。其中该模型的建立是基于对双筒液力减振器的结构和工作原理的分析,使用能描述减振器内部结构的基本参数,同时用小挠度理论对其核心元件环形节流阀片的变形进行求解。计算结果与试验结果符合较好,该模型可进一步应用于研究液力减振器的动态阻尼特性对整车动力学性能的影响。     

神经网络在汽车平顺性仿真分析中的应用

本文从研究双向筒式减振器入手,利用神经网络对于非线性系统有很强逼近能力的特点,采用神经网络对减振器进行建模,然后把减振器的神经网络模型应用到整车入自由度模型中,利用MATLAB／SIMULINK对汽车平顺性进行了仿真分析。     

新型气—液耦合减振器的抗冲击动态特性试验与建模研究

针对实现抗大冲击并兼顾衰减振动的减振器件技术要求,通过结合空气阻尼和油阻尼及橡胶元件和金属弹性元件设计了结构微小的气－液耦合减振器原理样机,多参数匹配冲击试验研究表明其具有强非线性动态特征,在此基础上结合理论分析建立了样机非线性动态冲击特性模型,该建模方法直接引入结构参数,为直接设计具体的器件建立了理论基础,研究表明该耦合减振器性能优越并具有良好的设计可控性,具有广泛的应用前景。     

基于混合模式的汽车磁流变减振器阻尼特性分析与测试

根据牛顿流体模型和滨汉塑性流体模型 ,分别对混合工作模式的汽车磁流变减振器进行了理论分析研究。按照长安微型汽车的技术要求 ,设计和制作了汽车磁流变减振器 ,并对此进行了试验测试。试验结果表明 ,应用所提出的理论分析模型是可行的 ,对设计特殊阻尼特性的磁流变减振器有一定的指导意义。     

惯性平台橡胶减振器弹性特性的有限元分析

以某型号惯性平台减振器为研究对象，探讨了橡胶减振器弹性特性的有限元分析方法。利用有限元ANSYS分析软件，进行了橡胶减振器有限元建模的数值试验分析。为了精确描述橡胶的特性，采用了弹性应变能函数方法，选取本构方程拟合试验数据，对橡胶材料特性曲线进行评估。预测的计算结果与试验吻合较好，表明所建的数学模型和有限元计算方法能较理想地获得橡胶减振器静态、动态解。该方法对同类减振器度其复杂结构系统的静态、动态计算奠定了基础，同时为以后同类减振器的设计提供一定的参考。     

汽车磁流变减振器设计原理与实验测试

根据磁流变体的滨汉塑性模型描述，提出了混合工作模式的汽车磁流变减振器的设计原理，按照长安微型汽车的技术和磁流变体的性能设计和制作了微型汽车磁流变减振器，并根据长安微型汽车前悬架减振器的技术条件对此进行了实验测试。实验结果表明，提出的设计原理是可行的，对设计特殊阻尼特性的磁流变减振器有一定的指导意义。     

阀系参数对汽车减振器阻尼特性的影响

为了高效研究汽车减振器阀系参数变化对其阻尼特性的影响.以汽车广泛使用的非线性液压减振器为研究对象,结合减振器阻尼元件受力分析,运用MATLAB软件建立减振器特性仿真模型,通过仿真数据与台架试验数据拟合度分析验证了所建模型的可靠性;进而利用仿真模型对减振器阀系展开敏感性因素分析,得到了对阻尼特性影响显著的阀系参数;研究了...     

PARAMETRIC MATCHING SELECTION OF MULTI-MEDIUM COUPLING SHOCK ABSORBER

To achieve the dual demand of resisting violent impact and attenuating vibration in vibration-impact-safety of protection for precision equipment such as MEMS packaging system, a theoretical mathematical model of multi-medium coupling shock absorber is presented. The coupling of quadratic damping, linear damping, Coulomb damping and nonlinear spring are considered in the model. The approximate theoretical calculating formulae are deduced by introducing transformation-tactics. The contrasts between the analytical results and numerical integration results are developed. The resisting impact characteristics of the model are also analyzed in progress. In the meantime, the optimum model of the parameters matching selection for design of the shock absorber is built. The example design is illustrated to confirm the validity of the modeling method and the theoretical solution.     

减振器试验台的动态仿真分析

为了对汽车减振器的性能进行准确测量，设计出了一种能精确实现简谐运动的机械式减振器试验台，并运用MATLAB软件分别对该试验台的激振机构和飞轮建模，分析其动态特性。仿真结果表明，该试验台能实现精确的简谐激振运动，同时该仿真结果也为试验台的机械设计（如飞轮的设计、电机功率的选择等）提供了理论依据。     

基于磁流变液减振器的抑制深孔钻削颤振研究

深孔机床在钻削加工中出现颤振,会导致加工精度和效率降低、刀具与机床寿命缩短和有害噪声的产生。因此对颤振和其抑制技术的研究至关重要。通过对磁流变液效应机理以及工作原理的研究,设计出基于挤压模式的自适应磁流变液减振器,将其安装在深孔机床上。建立动力学模型并求得动力学方程,通过MATLAB的Simulink平台对动力学模型进行仿真,对比分析在不同转速下安装减振器的系统与未安装减振器系统的振动图形。结果表明:磁流变液减振器可以大幅、迅速地衰减振幅并缩短振动周期,因此自适应磁流变液减振器对机床切削颤振具有很好的抑制作用。     

DESIGN METHOD OF MAGNETO- RHEOLOGICAL FLUID SHOCK ABSORBER FOR CAR SUSPENSION

The Bingham constitutive model, which is previously used in depiction of magnetorheological （MR） fluids rheological behaviors for design devices, exhibits discontinuous characteristics in representation of pre-yield behaviors and post-yield behaviors. A Biviscous constitutive model is presented to depict rheological behaviors of MR fluids and design automotive shock absorber. Quasi-static flow equations of MR fluids in annular channels are set theoretically up based on Navier-Stokes equations and several rational simplifications are made. And both flow boundary conditions and flow compatibilities conditions are established. Meantime, analytical velocity profiles of MR fluids though annular channels are obtained via solution of the quasi-static flow equations using Biviscous constitutive model. The prediction methodology of damping force offered by MR fluid shock absorber is formulated and damping performances are predicated in order to determine design parameters. MR fluid shock absorber for Mazda 323 car suspension is designed and fabricated in Chongqing University, China. Measurements from sinusoidal displacement cycle by Shanchuan Shock Absorber Ltd. of China North Industry Corporation reveal that the analytical methodology and design theory are reasonable.     

回转叶片式磁流变减振器的研究

磁流变液是一种新型智能材料,在外加磁场作用下,液体粘度发生很大的变化.将其应用于履带车辆减振器上,通过理论及试验分析,这种叶片式磁流变减振器提供的阻尼力可完全替代被动式减振器,并具有更优良的控制性和适应性.     

减振器双节流孔闭式油路稳态行为特征有限元分析

本文以汽车减振器工作状态为基础原型，用高级有限元分析软件ANSYS建立了双节流孔闭式油路稳态模型，分析了不同阀振速度下减振器模型的内部流场、压力场、剪应力场分布的变化规律，为复杂闭式油路边界形状设计提供理论依据；同时也分析了计算了此模型中节流孔壁剪应力与减振速度的函数关系以及壁压力与节流孔长度的关系，为以后的节流流孔阻尼力计算提供数值基础。     

COMPLEX NONLINEAR MATHEMATICAL MODEL FOR A KIND OF VEHICLE SHOCK ABSORBORS

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COMPLEX NONLINEAR MATHEMATICAL MODEL FOR A KIND OF VEHICLE SHOCK ABSORBORS

A nonlinear mathematical model for the shock absorber in TJ7100 is developed. The oil compressibility and the entrapped gas in the oil are considered in the model. As a result, the hysteresis in the force-velocity diagram is included. The results of computer simulation and the experiment are basically identical. The MATLAB/SIMULINK is used for the development of the simulation software. It is found that the pressure inside the cylinder is high if the inputs of velocity or displacement are big by simulation. This is certainly one of the main reasons for which the leak is appeared between the rod and the seal of the shock absorbers for a relatively short time in China.     

冲击载荷下的石油测试管柱减振系统的数值模拟

基于有限元分析软件ANSYS研究冲击载荷下石油测试管柱减振系统的动力学性质,在模拟过程中涉及几何非线性、材料非线性、状态非线性和动态加载等问题.建立新设计研制的减振器和以往现场用的减振器三维有限元模型,在ANSYS/LS-DYNA中进行仿真计算,讨论在冲击强度一定的条件下,三种不同频率范围内的半正弦脉冲力对减振效果的影响,并比较两种减振器的减振效果.并用实验结果验证模型.