振动周期

The calculated results show that adopting damping apparatus is a feasible measure for solving aseismic safety of a aqueduct, and that appropriately prolongating period of a vibration-isolationg structure and regulating damping are an effective way of controllong aqueduct vibration.

控振计算表明，采用减隔震装置是解决渡槽抗震安全的可行措施，适度延长隔震结构周期与调整阻尼是控制渡槽振动的有效途径。

The dynamic responses of a two-degree-freedom vibration system with dry friction and the routs from periodic motion to ch...

进而利用数值方法对一两自由度干摩擦振动系统的动力学响应进行了分析，得到系统经周期运动失稳通向混沌的道路。

The end of time bell is a vibration that the Tao sends into all sectors of creation to allow the contraction cycle to begin.

时间结束』的钟声，是一个由道送入某个造物所有部分的振动，以允许收缩周期的开始。

It is disadvantageous to stability of lunar rover.The frequency of wheel wave is a function of velocity of wheel motor, dimension of wheel,density of grousers and wheel slide.

车轮在垂直地面上的周期波动和前进速度的波动对于月球车来说是一个周期性的激励，其频率应与月球车系统的固有频率避开，防止月球车前进时产尘较大的振动。

Periodic fluid pulsation in aeroplane hydraulic piping could induce fluid-construction vibration and lead to fatigue damage. It is impossible to find the error sensor's optimization location because of the pressure standing wave, and the pulsation attenuation effect is not perfect when adopting pulsation attenuation at single point. For this reason, a distributed active control method of fluid pulsation was presented. To avoid stationary point in all aviation states, several fluid pulsation actuators and error pressure sensors were placed along the piping. The second fluid pulsation produced by actuators can counteract the primary pulsation brought by aviation piston pump and make the mean pulsation of whole piping minimum when adopting adaptive feed- forward control and the filtered-X least mean square algorithm.

针对飞机液压能源管路系统中的周期性流体脉动诱发流固耦合振动，导致管路疲劳损伤的问题，针对管路中存在压力驻波特性，在采用单点消振时寻找误差传感器最佳布局位置困难而引起脉动抑制效果不理想的缺点，提出了一种分布式流体脉动主动控制方法，即沿管路不同位置布置多个主动消振阀和误差压力传感器，在任意飞行阶段，避开压力驻波点，以误差压力传感器的脉动测量值为控制目标，采用一种针对周期脉动主动控制的自适应前馈控制法和多通道自适应滤波－X LMS算法，调整控制器参数，使主动消振器产生的次级脉动与管路中的初始脉动相互抵消，达到整个管路中的平均流体脉动最小的效果。

With the increase of vibration frequency, the variation process of Jacobi matrix eigenvalue was calculated. According to the position of eigenvalue crossing the unit circle in the complex plane, the stability of fixed point of the map was discussed and the route from periodic motion to chaos via period-doubling bifurcation was received.

以振动频率为控制参数，计算得到映射Jacobi矩阵特征值的变化曲线，根据其穿越复平面单位圆的位置，分析了映射不动点的稳定性，获得了碰撞运动通过典型的倍周期分岔通向混沌的过程。

Assuming the angular velocity of the beam is given as a harmonic function of time, the rotating sandwich beam is regarded as a parametrically excited system.

假设电流变夹层梁绕固定轴线做随时间变化的简谐周期运动，将变速度转动梁作为一个时变参激振动系统，分析了不同结构和控制参数对失稳区域的影响。

Stability and local bifurcations of the fixed point of periodic impact are analyzed.

建立了两自由度含间隙振动系统对称周期碰撞运动的Poincar啨映射方程，讨论了该映射不动点的稳定性与局部分岔。

Secondly, to analyze seismic response of the concrete gravity dam, subspace iterative method was applied to compute free vibration period of the dam, time integration method was builtup for the seismic time history analysis and formulation of coupled vibration of reservoir water and dam were also deduced.

其次，针对混凝土重力坝的地震响应分析问题，采用子空间迭代法计算了大坝的自振周期，建立了地震时程分析的逐步积分方法，并且推导了库水和坝体耦合振动的理论公式。

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。