固有振动频率

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。

It is pointed out that beacuse the first natural frequency is much smaller than the second one, it bears the primary function in vehicle guideway interaction.

分析指出轨道系统的第一固有频率远小于第二固有频率，在车轨耦合振动中起主要作用。

The thesis studied the woodworking tension band saw blades by means of the vibration theories,made sure the relationship between tension force and inhesion frequency of its system.

应用振动理论，对经过适张处理后的木工带锯条进行研究，确定张紧力与系统固有频率之间的关系，提出将带锯条的振动简化为弦的振动与受拉伸的梁振动。

In the third part of the paper, another novel technology, named as Mould Oscillation-less Electromagnetic Continuous Casting under AMMF was proposed in order to replace the huge mechanical mould oscillation system by AMMF imposing outside the mould in continuous casting.

进行了三种波形高频调幅磁场下的无结晶器振动电磁连铸初步实验研究，实验结果表明：在方波、三角波和正弦波调幅磁场作用下的无结晶器振动电磁连铸过程中，当调制波频率略低于系统固有频率时，弯月面与结晶器壁间断接触距离最大。

The PZT plates were polarized in thickness direction. By using the deformation in the plane perpendicular to the direction of polarization, the rotation around Z axis was generated when the torsional vibration around Z axis mode was excited. And the rotation around X axis or Y axis was generated by combining the longitudinal vibration mode and the bending vibtration mode.

利用压电陶瓷在垂直极化方向平面内的变形，激励定子绕Z轴的扭转振动模态，实现转子绕Z轴的转动；激励在定子中固有频率接近、振动方向相垂直的伸缩振动模态和弯曲振动模态，并通过振动的叠加使定子末端质点产生绕X轴或者Y轴的椭圆运动，实现转子绕水平轴的转动。

The phase of ω0 frequency fluctuates tempestuously. The resonance peaks of flexural and torsional vibrations response are present at 2/3ω0 1/2ω0 1/3ω0 and 1/4ω0 with three kinds cracked rotor models. Near 1/2ω0 frequency, quasi-periodic and chaotic motions maybe appear. Periodic, quasi-periodic and chaotic motions show on alternately when the rotating speed is near to 2/3ω0.Combined step-by-step integral method with traditional transfer matrix method, an increment transfer matrix method is put forward.

研究结果表明：各种故障情况下，华北电力大学博士学位论文弯振和扭振之间都存在祸合关系，但弯扭祸合振动一般不会威胁机组安全运行：在叶片丢失或滑环飞脱故障时，将产生很大的弯振，同时各转子扭振也将被激发出来，它以工倍频和前三阶固有频率为主；在各种电气故障情况下，各转子都很快被激励出较大幅值的扭振来，相应各转子弯振也发生一定的变化，但它的变化明显滞后于扭振，扭振和扭矩主要以前三阶固有频率为主。

The responses properties of coupled vibrations for 120° and 180°asynchronous juxtaposition of 200MW turbine-generator set were analyzed. The results show that the responses properties of flexural and torsional vibrations caused by 120° asynchronous juxtaposition are similar to that of 180° asynchronous juxtaposition. When the fault happened, Former two steps inherence frequencies and whirl speed frequency of torsion are excited. And the first step inherence frequencies of flexural vibration are also excited besides whirl speed frequency. Transient electromagnetism moment peak, torsional and torsional moment responses caused by 180° asynchronous juxtaposition are lower than that of 120° asynchronous juxtaposition.

利用该方法，针对某200MW汽轮发电机组的120°和180°两种非同期并列情况，进行了机组弯扭耦合振动响应特性研究，分析表明：汽轮发电机组的120°和180°两种非同期并列情况下的弯振和扭振响应特性基本相似；非同期并列主要激发出工频和前两阶固有频率扭振，弯振除工频主分量外，第一阶固有频率也被激发出来；180°非同期并列时的暂态电磁力矩峰值比120°非同期并列时低，相应的扭振和扭矩响应也小于后者。

The control of an electromagnetic valve in the ABN brake chamber forces the spring to vibrate at a frequency of 18 times per second while braking, and also with certain natural frequency reciprocating motion.

利用停易ABN制动气室弹簧的振动及电控装置控制电磁阀激振，迫使气室弹簧在整个制动过程中不但以每秒18次的自振频率振动，同时又以一定的固有频率往复运动，利用弹簧的储能作用，将刹车时产生的声能和热能用弹簧的势能和动能来置换，从而达到降低制动噪声、温度和磨损的目的。

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。

The first and second natural frequencies are analyzed accounting for the rotation inertia and shear deformation of Timoshenko model.

本文还讨论梁弯曲振动前两阶固有频率随着梁的刚度变化的情况，并分析梁转动惯量及剪切变形等参数对固有频率的影响。

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。