不同结构参数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/LS-DYNA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。建立新型减振器模型,在一定冲击强度下,脉冲力主瓣频率为150 Hz时分别改变弹簧刚度、橡胶Mooney-Rivlin参数、下接头质量进行有限元分析,并讨论减振效果。     

摩托车减震器摩擦力构成分析(1)

摩擦力在减震器制造与质量控制中是一种非常复杂难以控制的力,也是一种有害于乘骑舒适性的力,摩擦力构成的因素很多,因此,有关摩托车减震器摩擦力的量化指标介绍甚少,也少有介绍摩擦力如何理论计算、测试、控制等方面的文献。通过对QC/T 62—2007标准学习,结合实践经验,提出了摩擦力的计算、测试、控制方法。摩擦力大小代表减震器制造与装配工艺水平的高低,直接表现了乘骑舒适性和平顺性;同时,减震器行业一直不断提升设计能力,引入新材料,从机群普通单机工序分散加工,到数控加工中心工序集中生产,提高了自动化程度,也降低了摩擦力。     

新型纳米吸波材料研究现状与进展

介绍了纳米微波吸收材料的吸波机理及其优异的吸波性能。综述了纳米材料(纳米铁氧体及其复合物、纳米金属、纳米陶瓷、纳米导电聚合物)作为吸波介质的特点和应用背景,提出了高性能纳米微波吸收剂的发展方向。     

Characteristics of new-type energy absorber for vehicle collision

A new type energy absorber was introduced, which is composed of thousands of thin ring plates with different diameters. Because it can switch the impact to thousands of shearing actions among thin ring plates inside the absorber, the impact energy is decentralized and dissipated gradually, the impact acting time is extended and the peak of acceleration is reduced obviously. Numerical simulations by finite element method (FEM) coupled with smoothed particle hydrodynamics (SPH) method were preformed to predict the energy absorption characteristics. Energy absorption ability with different impact velocities was studied and the effects of thickness and material of ring plates were discussed. The sled crash test was carried out to validate the result of simulations. The new type absorber is effective for collision that impact velocity is lower than 40 km/h.     

On the performance of rheological shock absorber models in full vehicle simulation

A comparative study of the performance of three rheological automotive shock absorber models as well as of an extended force-velocity relation in full vehicle simulation is performed. Simulation results for both the shock absorber test rig and a full vehicle crossing a single obstacle are compared with measured data. While the gain of accuracy by the extended force-velocity relation is marginal, the rheological models in general yield a noticeable improvement, which, however, in full vehicle simulation is less significant than in test rig simulation. Among the rheological models studied here, the one consisting of a nonlinear spring-dashpot element with an element modelling friction by a continuous transition from the compression to the extension range in parallel and a quadratic approximation of the static gas force exhibits the best global performance.     

橡胶试样尺寸对测试结果的影响

研究橡胶试样尺寸对高温压缩永久变形、脆性温度、氧指数等性能参数的影响,分析作用机理。结果表明,试样尺寸越厚,高温压缩永久变形越小,脆性温度和氧指数越高。使用时应严格控制试样尺寸,以得到科学、重复性好的结果。     

虎伯拉19．5简易型铰接盘的控制电路设计

通过对加装减震系统的目的及减震系统的结构、控制的要求的分析，设计了减震控制系统的控制电路，并分析了控制原理。     

振动磨机橡胶衬套的磨损失效分析与研究

简要介绍了振动磨机的特性、用途和工作原理，阐述了振动磨机系统中橡胶衬套的磨损失效理论。结合实例详细论述了橡胶衬套的设计方法。     

摩托车橡胶制品"喷霜"现象树图分析及质量改进

“喷霜”是指胶料中的液体或固体配合剂由内部向外部迁移到表面的现象,有喷粉、喷油和喷蜡3种形式,它不仅影响摩托车部品的外观质量,还会影响胶料的工艺性能和硫化胶的物理性能,降低胶料的自粘性,给成型带来困难。     

Circuit racing,track texture,temperature and rubber friction

ABSTRACT

Some general observations relating to tyre shear forces and road surfaces are followed by more specific considerations from circuit racing. The discussion then focuses on the mechanics of rubber friction. The classical experiments of Grosch are outlined and the interpretations that can be put on them are discussed. The interpretations involve rubber viscoelasticity, so that the vibration properties of rubber need to be considered. Adhesion and deformation mechanisms for energy dissipation at the interface between rubber and road and in the rubber itself are highlighted. The enquiry is concentrated on energy loss by deformation or hysteresis subsequently. Persson's deformation theory is outlined and the material properties necessary to apply the theory to Grosch's experiments are discussed. Predictions of the friction coefficient relating to one particular rubber compound and a rough surface are made using the theory and these are compared with the appropriate results from Grosch. Predictions from Persson's theory of the influence of nominal contact pressure on the friction coefficient are also examined. The extent of the agreement between theory and experiment is discussed. It is concluded that there is value in the theory but that it is far from complete. There is considerable scope for further research on the mechanics of rubber friction.