查询词典 dynamic friction

The friction characteristics of polyurethane for the friction liner of hoisting were studied. It was found that the dynamic friction coefficient of polyurethane increases with sliding velocity in the range of 0.01 to 0.4 mm/s and decreases beyond 0.4 mm/s.

本文研究了聚氨酯弹性体摩擦衬垫材料的摩擦特性，发现聚氨酯弹性体材料的动摩擦系数是和滑动速度有关的，在0.01～0.4mm/s的速度范围内，速度提高摩擦系数上升，在更高的速度下摩擦系数还会下降。

The field of machinery industry of the friction coefficient of PTFE small, the static coefficient of friction lower than the dynamic friction coefficient, can be used for low-speed high-load areas, such as in construction, chemical, bridges and other structures to resolve cases arising from thermal expansion and vibration of the stretching problem.

机械工业领域聚四氟乙烯的的摩擦系数小，其静摩擦系数低于动摩擦系数，可用于低速高负荷领域，如在土建、化工、桥梁等结构件中可解决热膨胀和震动引起的伸缩问题。

Thirdly, a new type base isolation system, i. e., slide-limited friction base isolation system is presented in this paper. Based on this system, harmonic and subharmonic periodic response of S-LF subjected to harmonic motion is investigated by using Floquet theory. Dynamic response of sliding structure subjected to earthquake ground motion is calculated with a precise high order direct integration method, and the numerical results are presented in terms of maximum acceleration response spectra of supcrstructure and maximum sliding displacement response spectrum. By comparison with isolating effects of pure-friction base isolation system and resilient-friction base isolation system , it shows that the isolating characteristic of S-LF is superior to P-F and R-FBI. Through analyzing an engineering example, it is observed that the maximum inter-storey shear force and absolute acceleration of sliding structure to earthquake ground motion are very different from those of traditional structures.

提出了一种新型基础隔震模型，即带限位装置的摩擦隔震体系；基于此隔震模型，利用Floquet理论研究地面谐运动下S-LF结构的运动特性；并利用高精度的精细时程积分法，通过对地震作用下S-LF动力响应的计算，绘制了上部结构最大加速度反应谱和基底最大滑移量反应谱，并研究了各种结构参数对隔震的影响；通过与恢复力摩擦隔震系统和纯摩擦力滑移隔震系统的比较表明，S-LF的隔震性能优于P-F和R-FBI；对计算实例的分析发现，地震作用下S-LF结构的层间最大剪力和最大绝对加速度反应分布较一般传统结构有很大区别。

At present, although finite element methods is a kind of effective measures in analyzing metal plastically forming problems with friction, dynamic friction in the process of metal forming is substituted with static friction and constant frictional force as one of independent constraint conditions is transposed to equivalent node-load or FEM unit is divided into contact unit and inner unit in numerous studys and applications, so that it result in relative bad accuracy and awkward operation. These defects mostly attribute to the fact that FEM bases on the variational equality principles, however frictional constraint will actually result in variational inequality energy functional.

目前，应用于分析金属塑性成形的有限元法是一种有效的处理摩擦效应的定量计算方法，但是许多应用和研究是用常摩擦来代替金属塑性成形过程中的动态摩擦；把常摩擦力作为单独的约束条件移置到等效结点载荷上或把有限元单元划分成接触单元和内单元，这些将导致解的精度相对不高及实际操作不方便等一系列问题，产生这些不足的重要原因之一在于它的理论基础是变分等式原理。

By making use of multi-points backward pressure of one dry gas well, this paper introduces how to confirm dynamic friction coefficient of downhole tubing at the exact moment through stable testing material, gives the productivity and the corresponding bottom hole pressure by using productivity equation, calculates wellhead pressure in combination with dynamic friction coefficient of tubing, establishes the correct wellhead outflow performance equation for this well, draws out wellhead outflow performance curve and discusses how wellhead outflow performance equation or wellhead outflow performance curve changes with the decrease of formation pressure or the change of wellhead outflow performance curve.

借助1口干气井的多点回压法试井资料，介绍了如何利用气井稳定试井资料，确定该气井此时此刻井下油管动态摩阻系数；利用产能方程给出产量和对应的井底压力，结合油管动态摩阻系数计算井口压力，建立该井准确的井口流出动态方程并编绘井口流出动态曲线；讨论了随着地层压力递减和井下油管动态摩阻系数变化规律，井口流出动态方程或井口流出动态曲线的变化规律。

In order to analyze the result caused by the frictional dynamic character in servo system,and test the validity of various friction compensation methods,a simulation scheme for dynamic friction model is required.

为了深入分析摩擦力动态特性在高精度的伺服系统控制中造成的影响，检验摩擦补偿方法对动态摩擦的补偿效果，需要建立一个有效的动态仿真摩擦模型。

In this paper, the following experimental and theoretical investigations have been carried out: friction materical behavior tests, structure model experiments under low frequency cyclic and reversed loading, structure model dynamic experiments on shaking talbe, researches on dynamic analysis method and engineering design method for braced frame structure with friction control.

对二级摩擦控制支撑框架结构进行了摩擦材料的试验研究、低周反复荷载下结构模型的试验研究、振动台的动力试验研究、结构动力分析方法的研究以及摩擦控制支撑框架设计方法的研究。

The thesis studies the difference between GWSs composition and traditional workflow applications, proposes the implement mechanism and technical architecture of GWSs composition and defines the reference model of GWSs composition platform, which provide holistic framework and top-level guidance for studying dynamic GWSs composition technology, designing GWSs composition platform, and implementing representative composite service applications.2、Theories and methods of composite process modeling and process analysis. This thesis proposes a meta-model of Geo-spatial Web services composition process defining from two aspects, i.e. process and resource. According to the process definition meta-model, we propose a new Geo-spatial Web services composition Process/Resource model based on extended WF-net, which effectively resolves the problems on uncertain activity option and dynamic variation of service in composite process model. A notion with regard to soundness of process model is proposed from three aspects, i.e. the structural correctness of process model, validity of data link and validity of resource. The notion of soundness definitely gives a dividing line on correctness of composite GWS process. This thesis analyzes sufficient and essential terms of soundness, and studies compositional property of WSCP/R-net models which provides an effective method to construct a soundness WSCP/R-net model. According to WSCP/R-net, the thesis proposes composition algebra and studies the properties of it. Based on the composition algebra, 6 kinds of composite process reduction rules are induced to optimize the process.3、Geo-spatial Web service QoS model and its application architecture. This thesis proposes an extendable GWS QoS model from three aspects, i.e. Geo-spatial Web Service itself, networking conditions and service consumer which can be used to distinguish GWSs with overlapping or identical functionality. We work over the QoS evaluation methods of composite GWS process which can be used to guide the execution, monitor and service selection of composition process. Aming at some disadvantages in traditional Web service discovery model for its lacking of QoS supporting, this thesis proposes a new service discovery model SDMQ supporting QoS constraints.4、Technologies of composite service executing. SSPL, a new composite service process language, is defined to overcome the disadvantages of existing composite services process languages which can not adapt to the dynamic variation of Geo-spatial Web Services. An algorithm is described to translate WSCP/R-net model into SSPL. The thesis studies the model of dynamic services selection with QoS global optimization, presenting an algorithm GODSS to resolve dynamic services selection with QoS global optimization in GWSs Composition.5、Design and implement experimental system and representative applications. According to the research findings presented above, we design and implement an experimental system and construct two representative applications to show that our achievements are effective and practical.

针对当前空间信息服务聚合研究中存在的若干不足，本文重点在基于工作流的空间信息服务聚合框架、空间信息服务聚合流程建模和分析技术、空间信息服务QoS模型及应用体系以及空间信息服务聚合流程执行等几个方面进行深入研究，主要工作和创新点包括：1、基于工作流的空间信息服务动态聚合框架：研究了空间信息服务动态聚合和传统工作流应用的不同，在此基础上提出了基于工作流技术的空间信息服务动态聚合实现机制、技术体系和参考模型，为研究空间信息服务聚合的关键技术、开发服务聚合支撑平台以及在此基础上构造特定的空间信息服务聚合应用提供了总体框架和顶层指导。2、空间信息服务聚合流程建模和分析技术：首先基于动态服务聚合流程建模的需求和空间信息服务动态变化的应用实际，从服务聚合的过程维和资源维出发定义了服务聚合流程定义元模型；与之相对应，对基本的WF-net进行扩展，提出服务聚合流程/资源网作为空间信息服务聚合流程的形式化描述模型，有效解决了现有的基于基本Petri网和工作流网的服务聚合建模方法所不能解决的不确定路径选择和服务的动态变化性问题；从流程结构正确性、数据依赖有效性和资源实现有效性三个方面提出了WSCP/R-net健壮性的概念，明确界定了聚合流程正确性的标准，并对WSCP/R-net模型的健壮性分析方法和WSCP/R-net模型的组合特性进行了研究；提出了空间信息服务聚合代数算子并对其性质进行了研究，在此基础上提出了6种聚合流程约简规则，从而可达到优化聚合流程、提高聚合流程执行效率的目的。3、空间信息服务QoS模型和应用体系：从服务本身、网络环境和服务消费者三个层次出发，提出了一个可扩展的空间信息服务QoS模型GSQM，实现了对空间信息服务的度量和评价，并对GSQM不同质量要素信息的客观、公正采集方法进行了研究；研究了空间信息服务聚合流程QoS评价方法，有效支持了空间信息服务聚合流程的执行、监控以及服务选择等操作；针对目前的服务发现模型仅支持服务功能性描述、不能有效满足空间信息服务应用需求的现状，提出了一种新的支持QoS约束的服务发现模型SDMQ，并对模型的实现框架进行了研究。4、空间信息服务聚合流程执行技术：针对现有的服务聚合流程描述语言不能有效满足空间信息服务动态聚合流程描述的特点，基于BPEL4WS提出了一种新的空间信息服务聚合流程描述语言SSPL；研究了满足健壮性要求的WSCP/R-net模型向SSPL的转换算法，在此基础上可以满足用户无显式编码来实现空间信息服务聚合应用的目的；研究了服务动态选择QoS全局优化模型，并在此基础上提出了一种解决服务动态选择QoS全局优化问题的实现算法GODSS.5、基于论文研究成果，设计实现了"空间信息服务聚合实验系统"，并构建了"矿产资源评价"和"城市消防应急响应"两个典型应用案例，对论文所述模型、方法的可行性和有效性进行了验证。

Firstly, the equation for stress intensity factors under static uniform pressure is used as the reference case, and then the weight function for a thick-walled cylinder containing a radial edge crack can be worked out. Secondly, the dynamic stresses in uncracked thick-walled cylinders are solved under internal impulsive pressure by using mode shape function method. The solution consists of a quasi-static solution satisfying inhomogeneous boundary conditions and a dynamic solution satisfying homogeneous boundary conditions, and the history and distribution of dynamic stresses in thick-walled cylinders are derived in terms of Fourier–Bessel series. Finally, the dynamic stress intensity factor equations for thick-walled cylinder containing a radial edge crack subjected to internal impulsive pressure are given by dynamic weight function method.

首先采用静态内压下的应力强度因子作为参考解，得到了带径向边裂纹厚壁圆筒的权函数；然后用振型函数方法推导无裂纹厚壁圆筒在冲击内压下的动应力响应，分析中将相应的弹性动力学方程解分为满足非齐次边界条件的准静态解和满足齐次边界条件的动态解的叠加，利用傅立叶-贝塞尔级数展开，推导出了厚壁圆筒内动应力的响应历程和分布规律；最后由动应力权函数方法导出带径向边裂纹厚壁筒在冲击内压下的动态应力强度因子计算公式。

Firstly, the meaning of dynamic analysis on the steam turbine-generator set foundation is pointed out. Review and comment on the present research on dynamic analysis of domestic and international steam turbine-generator sets are presented Then a dynamic calculating model of the framed foundation of the steam turbine-generator set is set up based on finite element theory. Then dynamic analysis methods are put forward based on dynamics theory. The dynamic design of the foundation of the specific 12,000KW steam turbine-generator set is carried out.

论文首先指出汽轮发电机组基础动力分析的意义，并对国内外汽轮发电机组基础动力分析的研究现状进行了回顾及评述；其后，利用有限元原理建立了汽轮发电机组框架式基础的动力计算模型，根据动力学理论对该模型提出了自由振动分析和动力响应分析的方法，针对某工程12000KW汽轮发电机组的动力基础进行了动力设计。

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。