查询词典 natural vibration

According to elastodynamics theory, the dynamic model of machining the slender rod is founded by axial turn -milling, the calculation formula of the natural frequencies and the main vibration mode are ob- tained, and the dynamic response of the slender rod forced vibration is studied under simple harmonic excitation.

根据弹性体动力学理论，建立轴向车铣细长杆的动力学模型，得到了各阶固有频率和主振型的计算公式，分析了在简谐激励下细长杆强迫振动的动力学响应。

Firstly, the natural frequencies and normal mode shapes of the fluid-conveying pipe with zero fluid velocity (i.e. U=0) were determined with the transfer matrix method. Next, these natural frequencies and normal mode shapes were used to derive the equation of motion for the fluid-conveying pipe with fluid velocity U.neq.0 by using the expansion theorem. Finally, the free and forced vibration responses of the pipe with flowing fluid were obtained by means of the Jacobi method and the Newmark direct integration method.

首先吾人使用转移矩阵法来求取一流速等於零(即U=0)、跨距数为N之流体输送管的自然频率及其所对应之正规化振态，然后利用振态重叠法原理来推导流速不等於零(即U.neq.0)时，整个流体输送管在外力作用下的运动方程式，最后再以Jacobi法及Newmark直接积分法来计算该水平流体输送管的自然频率及强迫振动反应。

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。

An incremental-iterative method based on the Newton-Raphson method combined with constant arc length of incremental displacement vector is employed for the solution of nonlinear equilibrium equations. The subspace iterative method is used for the solution of natural frequencies and vibration modes for the free vibration of beam structures.

本研究推导元素的节点惯性力时，先将元素扰动位移表示成当前固定元素座标的扰动位移和旋转之函数，故可直接求得元素的节点惯性力，元素的一致性质量矩阵可由元素节点的惯性力对元素节点的加速度微分求得。

The natural frequencies, the equation of motion and the node of vibration are discussed for the vibration system of a cradle dynamic balancing machine. Some general remarks concerning the design are make. An analysis by the method of four measuring plane are given together with the actual electric circuits. Furthermore, the general ideas about the KQD-1 type cra-dle dynamic balancing machine are introduced as an example.

本文讨论了框架式动平衡机振动系统的自然频率运动方程、振动中心等问题；指出设计时应注意的事项，对四测量平面法作了理论分析，并给出其实际电路：以KQD—1型框架式动平衡机为实例作简要的介绍。

The major works in this thesis are: The effect of the straight and skew cracks on the vibration properties are studied for the cantilever beam, clamped-clamped rectangular plate, simple-supported rectangular plate and triangular plate. The effect on the natural frequency and vibration mode shapes of the bracket in the presence of cracks is discussed Based on the available index of crack diagnosis, a new index, is proposed.

本文主要的工作有以下几个方面：★研究了工程中常见的悬臂板、四边刚性固定矩形板、四边简支矩形板和三角形板的直裂纹和斜裂纹对振动特性的影响。

In this paper, a free vibration equation of the semi-rigid frame structure is built. The formula to calculate the natural periods is deduced. Furthermore, the effects of semi-rigid connection on natural periods are studied.

建立了半刚性连接框架结构的自由振动方程，推导出半刚性连接框架结构基本自振周期的计算公式，分析了连接刚度对基本自振周期的影响。

Because the portal frame is also used in the rig for bogie fatigue strength testing, in which the imposed load is harmonic, the modal analysis is necessary. The fundamental vibration mode shapes and corresponding frequencies are calculated to validating that the natural frequencies of the structure have enough difference comparing to the load frequency, so sympathetic vibration can be avoided.

由于龙门架还要在疲劳试验台中用来进行转向架的疲劳试验，因此对龙门架进行了模态分析，计算龙门架结构的固有频率和振型，确保龙门架的固有频率远离转向架疲劳试验的加载频率，避免在试验中发生共振。

The purpose of opening the orifice was to sluice. The influence of fluctuating pressure upon the dam was another problem which was concerned by engineer. The paper analyzed Shuangkoudu masonry arch dam. The result indicated that the dam natural frequencies which consider the dam and the reservoir water interaction have great different from the preponderant frequencies of fluctuating pressure, the dam's first rank of vibration was far away from the high energy region of the fluctuating flow, so the sympathetic vibration would not take place.

坝身开设孔口主要目的是为了泄洪，泄洪时水流脉动压力对坝体结构动的影响是设计人员关心的另一课题，论文针对双口渡浆砌石拱坝进行了分析，研究结果表明：在考虑坝体一库水相互作用时坝体自振频率和水流脉动压力的优势频率相差较大，坝体的一阶振动远离脉动水流的高能量范围，二者不会发生共振。

Through the model analysis on the structure of torpedo cars body with Block Lanczos method, the first fifteen natural frequency and vibration modes are calculated. Moreover, it also looks for the idiographic measures to boost up torpedo car against vibration by analyzing the reason for that.

运用分块Lanczos法对混铁车罐体结构进行了模态分析，得出了罐体的前15阶固有频率和振型；分析了引起混铁车罐体振动的原因，以寻求增强混铁车罐体抗振性能的具体措施。

In the negative and interrogative forms, of course, this is identical to the non-emphatic forms.

。但是，在否定句或疑问句里，这种带有"do"的方法表达的效果却没有什么强调的意思。

Go down on one's knees;kneel down

屈膝跪下。。。下跪祈祷