挠曲

The tortuosity can be described by bit weight in axial direction and the angle change of drill string bynormal can be considered as the torsion angle of the borehole.

弯曲主要体现为狗腿度，挠曲就体现为井眼的扭转。这种空间挠曲和弯曲特性可以通过测量轴向不受钻压作用的下部钻具组合的变形来描述。

This method is clear in concept, calculated simply , results accurately in calculation, and used on site conveniently, which provides scientific fact for the correct discription of casing string flexural equation ,accurate calculation of casing flexural deform, and reasonable determination of centralizer position.

但这种计算模式都是基于轴向力为零，只考虑了套管自重引起的横向均布荷载对挠曲变形产生的影响，因此，这种方法仅仅适用于计算"中和点"附近套管柱挠曲变形量这种特殊情况。更加普遍的情况是，套管不仅受自重引起的横向分力的影响，还受轴向力的作用。

The impression cylinder of J2108 offset press is regarded as research object in paper,and the deflection of cylinder is researched as simply supported beam with variable cross section .

以J2108型胶印机压印滚筒为研究对象，将滚筒挠曲变形作为变截面简支梁问题来研究，考虑重力载荷影响，通过积分法得到滚筒在印刷压力和重力载荷作用下的挠曲变形方程和曲线，应用MATLAB7.0平台上编写了印刷滚筒挠曲变形计算程序，为滚筒结构的合理设计提供了依据。

This paper studies on the impression cylinder of J2108 offset press. With finite element method, deflection character of cylinder is achieved in static and dynamic load. Active-compensation to improve flexing-change of cylinder is bring forward, and its compensation character is simulated.

本文以J2108型胶印机压印滚筒为研究对象，通过有限元分析获得滚筒动静态挠曲特性，提出用主动补偿方法改善滚筒挠曲变形，并仿真分析了补偿特性。

In terms of the transmission shaft balancing, it exists another problem that the shaft is not looked at as rigid body.When the rotor running at a high-speed ,under the action of unbalance force ,the transmission shaft will bend. It is certainly ideal to balance a transmission shaft as a flexible rotor.However, considering the mass production of automobiles, this method is obviously unpractical. In order to discreasing the flexible deformation, in this theory, the feasibility that double- plane balancing takes method the place of multi-plane balancing on a special place for one segment transmission shaft.

从传动轴平衡的角度来看，传动轴并非刚体，在汽车高速旋转时，由于不平衡力的作用会使传动轴发生挠曲，如果将传动轴作为挠性转子进行平衡当然比较理想，但是不符合汽车大批量生产的实际，为减少挠曲振动，利用挠性转子平衡原理，对于单根传动轴，从特殊位置进行校正，从而以二面平衡代替多面平衡是可行的。

In this method it is assumed that when the rail is bent downward, it will be subjected to the reactive force of elastic support points, and when bent upward, the rail will sustain the reactive force of the fastenings (i.e.the weight of sleepers and the friction between sleepers and ballast).

其中假定钢轨向下挠曲时所受的是支点反力；向上挠曲时所受的是扣件反力(由于轨枕自重和轨枕与道床的摩擦力)，这两种反力按上下方向以不同的非线性关系依赖于钢轨位移。

The model of flexibility of cantilever area, local flatting, and buckling under a pressure load have been presumed. And the influence on flexibility of cantilever of different roller position has been analyzed theoretically.

针对所研究的问题，假设了管坯悬臂段挠曲、局部压扁和受压失稳的力学模型，并从力学上分析了辊轮位置对管坯悬臂段挠曲的影响。

We also prove the degrading mechanism is independent of the effect of parasitical resistance and explain the change of the threshold voltage and mobility by activation energy extraction under mechanical strain.

我们也做了处於挠曲状态下寄生电阻与活化能的参数萃取分析，证明了应力挠曲所造成的劣化效应与寄生电阻无关以及从活化能的改变上进一步地解释了电子迁移率和临界电压的劣化情形。

radical holds the function of resinous bending intensity and material in the palm to concern, different and aggregate method is right base hold resinous bending intensity in the palm to do not have distinct effect.

结论基托树脂的挠曲强度和材料的性能有关，不同聚合方法对基托树脂的挠曲强度没有显著影响。

The analysis model of nonlinear finite element of this structure is established, and the describable method of initial displacement is given. Using the analysis model, the influence of different thickness of steel web and different initial displacement on load bearing capacity and critical load of a steel concrete continuoes composite beam is analyzed.

建立了钢混凝土组合结构的非线性有限元分析模型，给出了初始挠曲的定量描述方法，分析了不同厚度腹板连续组合梁的失稳临界荷载，不同初始挠曲对相同厚度腹板的极限承载力和失稳临界荷载的影响，以及相同初始挠曲对不同厚度腹板的极限承载力和失稳临界荷载的影响

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。