查询词典 natural vibration frequency

The governing equation of in-plane vibration of cable-restraint system is derived by means of D'Alembert principle, and then those partial differential equations are transformed into a set of ordinary differential equations by Garlerkin method. The method of Runge-Kutta integration is applied to solve the equation. The simulation analysis is made to prove that this vibration control has obvious damping effects and then the influence of cable tension, support mass, natural frequency and spring stiffness on the damping are discussed. Eventually, the approximate analytic solution of the optimum damping parameter is obtained to provide a simple and effective reference and design method for the engineers.

通过D'Alembert原理建立拉索－弹性约束系统振动方程，通过Galerkin方法将偏微分方程转化为常微分方程，应用龙格－库塔积分法求解方程；经过仿真分析，验证了该振动控制具有明显的减振效果，并且讨论了初始拉力、支座质量、振动频率及弹簧刚度对减振效果的影响；最后给出了计算最优阻尼参数的近似解析式，为工程师提供了简便有效的参考依据及设计方法。

Firstly, this paper researched the mechanism of tubing string vibration when natural gas flows in horizontal well tubing string. Secondly, established whole tubing string undamped and damped vibration system model according as reasonable assumption data of one horizontal well. Apply finite element analysis software to calculate tubing string natural characters, simple harmonic dynamic behavior of stable gas production and nonlinear dynamic behavior. Finally, this paper carried out the safety varied frequency of gas well and the method of vibration reduction.

本文首先从理论和数值模拟研究了天然气在水平井油管柱内的流动诱发油管柱振动的机理，然后在合理假设的基础上结合某水平井数据建立了全井段油管柱无阻尼和有阻尼振动系统模型，利用有限元软件计算分析了油管柱固有特性、稳产简谐动力学响应和非线性动力学响应，针对油管柱振动规律提出了天然气安全调节频率范围和减振措施。

Characteristics of free vibration and forced vibration of a damped system with dry frictional damping,viscous damping and c x·2 damping are analyzed and calculated,acceleration response of free-vibration of the dry frictional damped system has a sudden change when x· is zero,the change value is constant and depends only on the natural frequency ωn and the displacement xk due to dry friction.

本文对存在干摩擦阻尼、粘性阻尼和c.x2阻尼系统的自由振动及受迫振动特性进行了解析及数值计算，得到干摩擦阻尼系统自由振动的加速度响应在速度零点有一突变，这一变化量为定值，且只与系统固有频率ωn及摩擦当量位移xk有关。

In mechanical vibration, when the natural frequency of plan dynamic frequency and system is consistent, the amplitude of forced vibration reachs great value.

在机械振动中，当策动力的频率和系统的固有频率一致时，受迫振动的振幅达到极大值。

The equations of dynamics for the balance are established by Kane's method, from which derives the characteristic equation of natural frequency by means of linearization of dynamic equations, and the six natural frequencies being developed according to the theory of vibration. The law of the six natural frequencies varying with mass of the upper platform and the stiffness of the elastic element are presented,and the Finite Element Method is employed to testify the validity of theoretical results.

基于 Kane 方法研究天平的动力学及模态，通过线性化动力学方程建立天平的固有频率方程，依据振动理论推导出并联天平的六阶固有频率及其对应的振型，同时研究了天平的六阶固有频率随敏感单元刚度系数及上平台质量的变化规律，并用有限元法验证理论计算结果的正确性。

Application of proportional controller to active vibration control incorporated with passive vibration isolator to suppress its resonant oscillation of natural frequency is proposed in this paper. Vibration acceleration acquired from accelerator is inputted to controller as feedback signal. The processed signal from controller is transmitted to voice coil actuator to control vibration.

本文主要是运用比例控制器进行被动式隔振系统自然频率共振抑制之主动控制研究，控制回馈讯号采用加速规量得之振动加速度值，经由控制器计算输出控制讯号驱动音圈致动器进行主动控制。

In the experimental work, application of proportional controller to active vibration control incorporated with passive vibration isolator to suppress its resonant oscillation of natural frequency is studied in this project. Vibration acceleration acquired from accelerator is inputted to controller as feedback signal. The processed signal from controller is transmitted to voice coil actuator to control vibration. Firstly, based on the theoretical equations which govern the system vibration, the physical mechanism of active control in total system is studied.

在实验部分，则运用比例控制器进行被动式隔振系统自然频率共振抑制之主动控制实验，控制回馈讯号采用加速规量得之振动加速度值，经由控制器计算输出控制讯号驱动音圈致动器进行主动控制。

The distribution of gear's contact stress, root stress, and contact engagement line in the engagement situation of gear pairs, were obtained on the base of explicit integration method. 3. Adopting the method of system matrix, the torsional vibration differential equation of general shafting was gained. The simple harmonic forms of excitation torque under the normal combustion or piston flameout of in-line engine and v-type engine were analysed. The decoupled algorithm of free vibration and forced vibration and the solution to the vibration damper's energy of resistance and the off-resonance calculation were studied. The sensitivity formulations of the natural frequency and vibration mode to physical parameters of system were derived by solving the eigenvalue problem. These sensitivity formulations provided the theoretical base for the dynamic modification of structure.

运用系统矩阵法建立了轴系的扭振微分方程，并对直列和V型发动机在正常发火和气缸熄火工况下的激振力矩进行了详细的简谐分析；基于精确方法推导了自由振动和强迫振动的解耦算法，给出了能量法计算中的减振器阻尼功求解和非共振计算方法；并研究了曲轴系扭振非线性分析中的变惯量问题，得到了单缸转动惯量的精确求解公式以及变惯量和固有频率的关系式；最后，从特征方程和振型正交性出发，推导了固有频率和振型对轴系转动惯量和刚度等物理参数的灵敏度，为扭振系统的结构动力学修改提供了理论基础。

Liu JunHua;Huang ShuGong;Liu JiDongA tri-dimensional model for a jeffcot rotor was reported. A new motion equation of the torsional vibration with natural retation and the conception frequency was presented. The natural frequencies of disk rotors with different geometrical structures and were computed based on the finite-element method, and the factors affecting the coefficient of the natural frequency with rotation were analyzed.

在转轴以一定速度旋转的条件下，推导了考虑转动频率情况下的单质量盘转子扭振运动方程，通过有限元方法对不同几何结构的单质量盘转子在不同转动频率下的扭振固有频率进行了计算，对影响单质量盘转子扭振动频的动频系数进行了分析。

Finite element method is based on the actual ship models, a true reflection of the real ship distribution of the specific structure. This paper also uses empirical formula to calculate the inherent frequency of the catamaran; contrast them in the process of modeling the structural stiffness, and quality of the different treatments, as well as natural frequency calculated from the results of differences analyze the different and the reason between the finite method and the empirical formula method which used to calculate the inherent frequency of catamarans in the vibration analysis.

有限元方法是根据实际船型，较真实的反映了实船结构的具体分布特征；本文还采用经验公式对该船的固有频率进行了计算，对比它们在建模过程中对结构刚度、质量的不同处理，以及计算所得固有频率结果的差异，分析了在双体船振动特性分析中有限元法与经验公式法的结果略有差距及其原因。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。