模态

Based on the theory of finite element method and modal analysis, the model of a piano soundboard is established in the ANSYS, then the models' natural frequency, mode shape are calculated. What is more, the influence of tree species on the piano soundboard's fundamental frequency is discussed.

基于有限元法和模态分析的基本理论，利用有限元分析软件ANSYS建立了钢琴音板的有限元模型，然后对钢琴音板进行模态分析，得到了它们的固有频率、模态振型等参数，分析了树种对于钢琴音板基频的影响。

The paper also simulate the vibration response of frame when suspension point were changed, which indicates, through comprehensive consideration with the mode of frame, that it can get better oscillation damping affection to position the suspension points to the node of mode shape.

本文还在模态集成模型上模拟分析了发动机悬置点的变化时车架振动响应，表明通过与车架的模态综合考虑，把发动机的位置变换到车架模态振型的节点位置也有较好的减振效果。

In the part of the vibration experiments and analysis, firstly, used the simple-beam theory to estimate the natural frequency of the beam of the 20-headed computerized embroidery machine.secondly, measured the beam of its low rank natural frequency, the beams horizontal vibrating acceleration amplitude, speed amplitude and the displacement amplitude in different rev and different turn parts. Found that it is sympathetic vibration, which bring on the thread-broken rate rise rapidly. On this base, established the finite element analysis modle of the vibrating beam, and took on hamonic analysis and modal analysis with the mold. The rusult of test and analysis offer the basis for farther improvement of the computerized embroidery machine.

振动分析部分，首先由简单梁理论出发，对横梁的固有频率进行估算；接着通过测振仪器对20头电脑刺绣机横梁进行了试验模态分析和不同工况振动测试；获得了横梁前四阶固有频率和模态振型，以及在不同工作转速、不同回转部件下横梁振动的加速度幅值、速度幅值和位移幅值；找到了横梁振动加剧的原因——共振；在此基础上建立了符合实际情况的横梁有限元模型，对模型进行了模态和谐响应计算，证实了模型的可靠性，为下一步的改进设计提供了依据。

The NNMs associated with internal resonance can be classified into two kinds: coupled an uncoupled.

研究发现，内共振模态可分为耦合内共振模态和非耦合内共振模态。

The first-order of the modal flexibility for a real symmetric undamped structure with distinct eigenvalues was derived based on an efficient algebraic method. The formulae are simple and compact, and it is easy to program. Moreover, it only requires one eigenvector to be known to calculate the sensitivity of modal flexibility.

代数方法解析推导出无阻尼线性系统模态柔度一阶灵敏度的解析表达式，该表达式简洁紧凑，便于编程，而且在计算阶模态柔度的灵敏度时，只需一阶模态信息，具有显著的优点。

A new multi-degree of freedom ultrasonic motor using in-plane deformation of lead zirconate titanate elements was introduced.

介绍了一种新型基于压电陶瓷平面内应变特性的多自由度超声波电机，该电机通过两个平面内的弯曲振动模态的叠加实现转子绕Z轴的转动；并利用伸缩振动模态分别与上述弯曲振动模态叠加实现转子绕X轴和绕Y轴的转动。

AO mode haves the obvious seasonal variability. From winter to summer, the height of AO modes conversion becomes low, and the pleion in the boreal Pacific moves from the ocean to the East Asian land.

AO模态有明显的季节变化特征，从冬季到夏季，AO模态的转变层高度由高变低，北太平洋地区的正距平中心从海洋移到东亚大陆，从夏季到冬季，AO模态的转变层高度由低变高，东亚大陆上的正距平中心又移回到海洋上空。

Here's where we see an opening for a new approach to modeless interactivity. Toolbars are modeless, but they don't introduce the conundrums that modeless dialogs do.

我们在工具栏上看到一种新式的非模态交互活动的机会，工具栏是非模态的，但它们没有非模态对话框存在的问题。

The calculation results on the fixed wheel plane gate of Deqing gate showed that t...

对德清大闸定轮平面闸门的数值计算结果表明：水头对闸门的影响总趋势是使其自振频率降低、振动模态发生变化；闸门局部开启工况第 1阶频率较低，振型主要是门叶沿竖直方向的整体振动；低阶振动模态中除门叶竖直方向的整体振动模态外，其余各阶均显示为门叶的弹性变形振动。

In this paper, the state equation of simply supported rectangular panel is established by using the control strategy that is canceling the first k radiation modes.

本文利用声辐射模态的特性，通过抵消前k阶声辐射模态伴随系数的控制策略，以四面简支板为研究对象，在声辐射模态领域首次建立了该物体的状态空间数学模型。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。