查询词典 dynamic friction

Dynamic reliability under Littlewood-Paley wavelet is the biggest, dynamic reliability under modified meyerwavelet and harmonic wavelet are close. Analyzing the dynamic reliability of structure under odd exponent wavelet is very simple, it doesn't calculate Power Spectral Density function integral, it is only to calculate the square of displacement standard deviation and the square of velocity, then the dynamic reliability of structure can be concluded by max distribution. In addition the effects of upper limit is considered, when upper limit is smaller, the dynamic reliability of structure is less, that is, the damage possibility is bigger.

通过结构地震反应在小波基下的动力可靠性分析说明：无论是单自由度还是多自由度从理论上推导在这四种小波下的结构动力可靠性是可行的，而且考虑的结构地震反应都是非平稳的高斯过程，方法实现也比较容易；在Littlewood—Paley小波基下求得的结构的动力可靠度比较大，由改造的meyer小波和谐波小波求得的动力可靠度略有差异；单边指数小波下的结构动力可靠性分析非常简单，不用求功率谱函数来积分，只需求得结构地震反应的位移方差，速度方差，利用最大值分布公式就可得到结构的动力可靠时程；另外也考虑了超越界限对结构动力可靠度的影响，超越界限越小，结构的动力可靠度越小，即破坏概率越大。

Dynamic reliability under Littlewood-Paley wavelet is the biggest, dynamic reliability under modified meyerwavelet and harmonic wavelet are close. Analyzing the dynamic reliability of structure under odd exponent wavelet is very simple, it doesnt calculate Power Spectral Density function integral, it is only to calculate the square of displacement standard deviation and the square of velocity, then the dynamic reliability of structure can be concluded by max distribution. In addition the effects of upper limit is considered, when upper limit is smaller, the dynamic reliability of structure is less, that is, the damage possibility is bigger.

通过结构地震反应在小波基下的动力可靠性分析说明：无论是单自由度还是多自由度从理论上推导在这四种小波下的结构动力可靠性是可行的，而且考虑的结构地震反应都是非平稳的高斯过程，方法实现也比较容易；在Littlewood—Paley小波基下求得的结构的动力可靠度比较大，由改造的meyer小波和谐波小波求得的动力可靠度略有差异；单边指数小波下的结构动力可靠性分析非常简单，不用求功率谱函数来积分，只需求得结构地震反应的位移方差，速度方差，利用最大值分布公式就可得到结构的动力可靠时程；另外也考虑了超越界限对结构动力可靠度的影响，超越界限越小，结构的动力可靠度越小，即破坏概率越大。

A new mathematical model is put forward numerically to simulate the wheel ovalization.. In the numerical simulation, the dynamic model of a half railway vehicle coupled with a tangent track is employed. Using the new numerical method investigates vehicle-track coupling system dynamic responses including lateral and vertical displacement of wheelsets and the vehicle, lateral and vertical vibration acceleration of the track at different phase angle of the two side wheels of the same wheelset, which are compared with that of the traditional model. The numerical results show that the discipline and frequency of dynamic responses are accordant, amplitude and phase of lateral dynamic responses are different. It is concluded the traditional track geometric irregularity excitation model does not simulate the effect of periodic wheels ovalization on vehicle-track coupling system dynamic behavior truly, the new model is more accurate and reasonable.

本文研究了车轮二阶周期性非圆化—椭圆化，建立了一个新的模拟车轮椭圆化的数学模型，结合车辆－轨道空间耦合动力学模型，计算了同一轮对左右车轮不同相位和车轮椭圆度下轮对和车体的横、垂向位移，钢轨横、垂向振动加速度，并与传统模型计算结果作了对比，分析表明两种模型的动力响应变化规律和频率一致，但横向动力响应幅值和相位均存在不同程度不可忽略的差异，因此传统的轨道几何不平顺激励模型不能真实模拟车轮的周期性椭圆化对车辆－轨道耦合动态行为的影响，而本文模型更能反映实际椭圆车轮与钢轨接触情形，计算方法准确而合理。

The results show that the vehicle acceleration, the dynamic wheel load and offload factors increase with train speed, and distribute linearly. The safety of train operation and running comfort can meet the requirements when the high-speed train under secondary suspension passing through ballasted track subgrade structure. The dynamic displacement of the system is less influenced by train speed. The dynamic stress of subgrade surface increases with speed improving, and it is distributed as saddle along the lateral direction and as parabola along the longitudinal direction of subgrade surface. The dynamic stress of subgrade declines sharply along the depth of subgrade. The dynamic stress on 3 m depth below subgrade bed surface is about 16 percent of that of subgrade surface.

结果表明：车体加速度、动轮载和轮重减载率均随车速的提高而增大，呈线性分布；具有二系悬挂的高速列车通过有砟轨道路基结构时，列车的安全性及舒适度均能满足要求；系统动位移受速度影响较小；路基面动应力随速度的提高而增大，并在横向呈马鞍形分布，在纵向呈抛物线形分布；路基动应力沿路基深度方向衰减较快，在基床表面下3 m处，动应力只有基面的16%左右。

Initially, assuming that the contact between cam and tappet is"dry contart", a dynamics model of Hertzin contact stiffness and impact damping is established. Next, with dynamic load on cam—tappet pair from the model, an analysis is made both to unsteady EHD oil film in cam—tappet pair under condition of full and partial lubrtication and to wear characteristics of cam profile. then, according to the fact that the lubrication in cam—tappet contact surface is EHD lubrication, taking the interaction between stiffness and damping of unsteady EHD oil film and rigidity of solid object contact into account, a dynamics equation of valve train relating to the dynamic effect of EHD oil film is built up and solved. Consequently, a further study is made on the dynamic characteristics of valve train under interaction of EHD oil film dynamic behavior and the problem of EHD lubrication in cam—tappet pair. Finally, the dynamic effect of full and partial EHD oil film is studied accordingly.

首先，通过对凸轮—挺杆接触为&干接触&的假设，建立了考虑赫兹&接触刚度&和冲击&阻尼&的配气机构动力学模型，用由此求得的凸轮—挺杆表面动载荷对凸轮—挺杆进行了全膜状态和部分膜状态非稳态弹流润滑分析，并研究了凸轮轮廓的磨损规律；然后，是在凸轮挺杆表面存在弹流动压油膜这一事实的基础上，相当于在动力学方程中考虑非稳态弹流油膜的&刚度&、&阻尼&和固体接触&刚度&的耦合作用，建立并求解了考虑弹流润滑行为动力学效应的配气机构的动力学方程，从而深入地研究了弹流润滑行为与动力学行为耦合作用下的配气机构动力学特征以及凸轮挺杆弹流润滑问题；作为前面工作的对应部分，考虑弹流油膜动力学效应的研究工作也同样分为全膜状态和部分膜状态进行。

It is focused on a valve-controlled asymmetric cylinder system. The cause and compensation method of friction are researched, and the influence of system friction on electro-hydraulic servo system is analyzed. Then the friction is outline measured and online observed.

以阀控非对称缸系统为研究对象，探讨了摩擦力的产生原因和补偿方法，分析了液压缸的摩擦力对电液伺服系统的影响，对摩擦力进行了离线计算和在线观测两方面的研究。

The experts at home and abroad and friction material production unit test and application show that calcium hydroxide is an excellent performance of friction material raw materials, Add friction material products role

经国内外摩擦材料专家和生产单位的试验和应用证明，氢氧化钙是一种性能优良的摩擦材料原材料，加入摩擦材料产品中的作用

The components of the amianthine cat whisker-free friction material of the invention mainly contain binding agent, reinforcing material, frictional property regulating reagent, cat whisker material and fillings, and contain no asbestos fiber, the cat whisker material is adopted to be filled in the friction material to improve the wear resistance of the friction material, protect the environment, and prolong the service life of an arrester gland.

本发明的无石棉晶须摩擦材料其组成为：主要含有粘结剂、增强材料、摩擦性能调节剂、晶须材料及填料，不含有石棉纤维，采用晶须填充在摩擦材料中以提高其耐磨性、保护环境、延长制动器衬片的使用寿命。

In order to reduce production cost of ceramal friction material,the cost optimization solution for Cu-base ceramal friction material is introduced,and the effect of the optimization solution on performance of the friction material is studied.

为降低金属陶瓷摩擦材料的制造成本，介绍了Cu基金属陶瓷摩擦材料成本优化方案，并研究了优化方案对Cu基金属陶瓷摩擦材料性能的影响。

Before using a friction cone hoisting system, release the control lever of planetary mechanism, then operate the friction cone clutch's lever to engage the friction cone and the drum's cone surface, driving the drum to rotate and therefore start to hoist.

使用摩擦锥式提升系统时，将行星机构的操作手柄都松开，操纵摩擦锥离合器手柄，使摩擦推面与卷筒内锥面结合，从而带动卷筒回转，达到提升的目的。

The circulation, consumption and reproduction of the trilogy have not only testified to its historical significance and literariness, but also invested it with new meanings.

该三部曲的流通、消费与再生产不仅验证了其历史意义及文学性，而切还赋予它以新的意义。

If he thought that he could buy me off, he would be wrong.

如果他认为他可以收买我，那他就大错特错了。