查询词典 elastic force

In this topic, the dynamic analysis methods for piezoelectric vibrator are studied systematically based on the theoretical model, FEM numerical experimentation and FEM governing equation for given compound-mode vibrator, and some valuable conclusions are obtained. The main work accomplished is summarized as follows: 1.Elaborate the main modeling methods for piezoelectric vibrator and the significance and necessity to study the dynamic characteristics of piezoelectric vibrator which emphasize the urgency of this paper. 2.Take the bending deformation induced by piezoelectric ceramic as example, the energy transfer mechanism of electric energy to mechanical energy are analyzed; the motion and force transfer mechanism are analyzed for the longitudinal-bending vibrator. 3.Based on mode assumption and Hamilton principle, the coupling model of piezoelectric vibrator of linear USM is built; moreover, the equivalent circuit model is obtained and a coupling equation represents the relation between electric parameters and mechanical parameters is derived which provides foundation to match the vibrator and driving circuit. 4.Combine the constitutive equation of piezoelectric ceramic with elastic-dynamical equation, geometric equation in force field and the Maxwell equation in electric field and the corresponding boundary condition equation, the FEM control equation for piezoelectric vibrator of USM to solve dynamic electro-mechanical coupling field is established by employing the principle of virtual displacement. The equation lays the foundation to study the non-linear constitutive equation of piezoelectric ceramic driven by high-power. 5.Define the dynamic indexes of characteristic of vibrator and carry out variable parameters simulation by calculating the model parameters and the electric characteristics of vibrator are simulated according to the equivalent circuit model. By numerical experimentation, the working mode of vibration of vibrator and the shock excitation results of the working frequency band which provides the mode frequency to realize bimodal are analyzed. Detailed calculation of the electro-mechanical coupling field parameters is made by programming the FEM control equation.

本课题从理论模型、有限元数值试验、有限元控制模型等方面以复合振动模式振子为例对超声电机压电振子的动力学特性及其分析方法进行了全面系统地研究，得出了许多有价值的结论，主要概括如下： 1、阐述了目前针对超声电机压电振子的主要建模方法，对压电振子动态特性的研究意义和必要性进行了论述，突出了本文研究内容的迫切性； 2、以压电陶瓷诱发弹性体发生弯曲变形为例，分析了压电陶瓷通过诱发应变来实现机电能量转换的机理；对基于纵弯模式的压电振子的运动及动力传递机理进行了分析； 3、基于模态假定，利用分析动力学的Hamilton原理，建立了面向直线超声电机压电振子的机电耦合动力学模型，并据此建立了压电振子的等效电路模型，导出了电参量与动力学特性参量的耦合方程，为压电振子与驱动电路的匹配提供了依据； 4、从压电陶瓷的本构方程出发，综合力场的弹性动力学方程、几何方程、电场的麦克斯韦方程以及相应的边界条件方程，采用虚位移原理，建立了压电振子动态问题机电耦合场求解的有限元控制方程，为研究其大功率驱动下的非线性本构模型奠定了基础； 5、界定压电振子的动力学特性指标，对压电振子的机电耦合动力学模型参数进行计算及变参数仿真；依据等效电路模型，对压电振子的电学特性进行了仿真分析；通过有限元数值实验，对压电振子工作模态附近的模态振型及工作频率附近的频段进行了激振效果分析，找出了实现模态简并的激振频率；利用有限元控制方程，通过编程计算，对压电振子的力电耦合场参数进行了详细计算，得出了一些有价值的结论。

Base on summarizing the development state of assembly skew hollow slab bridge, the research content of this dissertation has been determined. Taking Tuan Shan River Bridge, in Hubei province, China, as an example, the finite element method of space slab shell programmed in Ansys Parameter Design Language is adopted to analyze the elastic properties. By calculating the internal force influence surface of assembly skew hollow slab bridge, the internal force-controlling section is attained.

本文在对装配式斜交空心板桥的发展现状进行了详尽的综述后，确定了本文的研究内容，以团山河大桥为工程背景，采用ANSYS提供的参数化语言APDL，用空间板壳有限元法，对装配式斜交空心板桥弹性阶段的受力特性进行全面分析，计算了装配式斜交空心板桥的内力影响面，得到内力控制截面。

Basing on the exploring of the functions of cohesion force and friction force during rheology course and the assumptin that viscosity lost according viscosic strain, a constitutive model for viscous, elastic and plastic rock is set up,which can simulate the third course of creep.Then the impact of transcient damage to rheology is discussed and corresponding creep model for rock is proposed.

在探导岩石颗粒间粘聚力和颗粒间摩擦力在岩石发生流变过程中的作用基础上假设粘性失效按流变应变统计概率分布，建立了岩石粘弹塑性本构关系，能够描述岩石蠕变加速阶段特征；讨论了瞬时损伤对岩石流变的影响和相应的损伤蠕变模型建模问题。

In order to take the influence of the internal force from translation into consideration, the design of in-plane buckling of unbraced frame s adopted a new second-order elastic method to calculate the structural internal force, e.

为考虑变形对内力的影响，对无支撑框架的平面内稳定计算提出采用假想水平荷载法进行二阶弹性内力分析，以与国际上钢结构设计相接轨。

The rock-crushing process of dynamic impacting load is simplified, By means of elastic mechanics and wave theory, the axial force and shearing force of ro...

建立的破岩力学模型对旋冲钻井的进一步发展具有重要的现实意义。

Absctrct: Objective This study was designed to investigate the stress distribution in the surface of tooth and peridental tissues and the initial displacements of tooth in the maxillary under two orthodental simulating force rectangular archwire with T loop and II class elastic used clinically by the 3-D finite element method so as to clarify the biomechanism of orthodontic tooth movement and component of optimal orthodontic force system.

目的：通过有限元分析法比较两种工况下上颌各牙齿的位移趋势和牙根及牙周支持组织内的应力分布规律，为临床治疗中合理选用矫治力系统以便有效的控制牙齿移动类型提供可靠的理论依据。

He described the cold:"Ridging through the Ardennes, I wore woolen underwear, a woolen uniform, armored force combat overalls, a sweater, an armored force field jacket with elastic cuffs, a muffler, a heavy lined trenchcoat, two pairs of heavy woolen socks, and combat boots with galoshes over them — and I cannot remember ever being warm."

他描述了当时的寒冷：&颠簸走过阿登，我穿着羊毛内衣，毛料制服，装甲兵作战用连身裤，毛衣，松紧袖口的装甲兵野战夹克，一条围脖儿、一件厚重的长风衣，两双羊毛袜子，一双有鞋套的战斗靴——我不记得曾经暖和过。&

Spring-loaded safety valve spring is delivered to the valve on the container or force to balance the pipeline pressure by adjusting the elastic springs to balance the medium on the pressure valve control media pressure to achieve the objective of safety valve lever weights Is to use a heavy hammer through the transmission lever to force the valve to balance the pipe or container medium pressure by adjusting the weights of the valve to balance the role of media from the valve on the pressure, media pressure to achieve the purpose of control ; Pilot of the main safety valve by valve components and sub-valve, to promote the role of Vice valve main valve action, also known as the pulse safety valve.

弹簧式安全阀是利用弹簧传递到阀瓣上的作用力来平衡容器或管道内压，通过调节弹簧的松紧来平衡介质对阀瓣的压力从而达到控制介质压力的目的；杠杆重锤式安全阀是利用重锤通过杠杆传递到阀瓣上的作用力来平衡管道或容器内介质的压力，通过调整重锤对阀瓣的作用距离来平衡介质对阀瓣的压力，从而达到控制介质压力的目的；先导式安全阀是由主阀和副阀组成，借副阀的作用带动主阀动作，又称为脉冲式安全阀。

According to the practical characteristics and parameters during hot finishing rolling process of aluminium alloy JP1235, a three-dimensional thermo-mechanical coupled elastic-plastic FEM model was established with the software Marc. And this model was used to simulate the rolling state of F1 stand without back tension. The lateral distribution of rolling force、contact friction force and other mechanic parameters were calculated. Meanwhile, simulated the rolling state considering the influence of mill tilt, and studied the distribution of the mechanics under this state, discussed the effect of mill tile on mechanic parameters and strip steering, which can provide some reference to steering control strategy.

根据JP1235铝合金板带热精轧过程的实际工艺特点和工艺参数，采用非线性有限元软件Marc，建立一个三维热力耦合弹塑性有限元模型，模拟了精轧机组第一机架（F1机架）失去后张力作用后的轧制状态，计算出轧制过程中轧制力、摩擦力等力能参数沿板宽方向上的分布情况，在此基础上，模拟初始轧辊倾斜影响下的轧制状态，并对该轧制状态下的力能参数分布情况进行研究，探讨轧辊倾斜对力能参数分布及跑偏规律的影响，为纠偏控制提供了一定的理论依据。

Experimental results show that: bearing capacity of JPP is thirty percent higher than that of cast-in-place pile which has the same length and diameter with JPP. The deformation of JPP is controlled by core pile; axial force distribution of PHC is different with soil-cement; and their axial force ratio in same section is their elastic modulus ratio. Distribution of inner and outer friction resistance is similar; and the inner friction is about 1.62 times of the outer one; it is about the ratio of JPP diameter and PHC diameter. Furthermore, the relation between friction resistance and relative displacement is similarly hyperbolic; and the relation between dip resistance and displacement is also hyperbolic.

试验结果表明，JPP桩与同桩长、同桩经灌注桩相比承载力高30%以上；JPP桩变形由芯桩控制，管桩轴力分布与水泥土轴力分布规律不一致，但同一截面上管桩和水泥土的轴力比值约为其弹性模量的比值；内外摩阻沿桩身的分布规律类似，内摩阻是外摩阻的1.62倍左右，约为JPP桩直径和管桩直径的比值；桩侧摩阻力与桩土相对位移近似双曲线分布，桩端阻力和桩端位移也近似双曲线分布。

What are your goals and strategies for growth?

你的成长目标和策略是什么？

And unto the angel of the church in Sardis write; These things saith he that hath the seven irits of God, and the seven star I know thy works, that thou hast a name that thou livest, and art dead.

3：1 你要写信给撒狄教会的使者，说，那有神的七灵和七星的，说，我知道你的行为，按名你是活的，其实是死的。