固有振动

The flexural vibration of a circular ring that is of axis symmetry is analyzed and calculated, the solid frequency expression of the flexural vibration is obtained.

对一类轴对称圆环的面内弯曲振动进行了分析计算，给出了圆环面内弯曲振动固有频率表达式。

It is built a thin-walled box beam base on ship hull in this thesis, and the frequency of box beam is calculated with some different model building method.

综合以上分析，需要对船体总振动的建模方法进行研究，以便运用合理简便计算模型来计算船舶总振动固有特性。

The formulas of the natural frequency, critical velocity and critical pressure were established by means of direct method .

根据Hamilton原理推导出流固耦合自由振动变分方程，采用直接解法求解自由振动的固有频率、临界流速和临界压力的解析解表达式。

Some methods which are about how to get natural frequency, the computational and experimental methods of the vibration modes, and the computational methods of the critical velocity and the analysis of stability are included.

进一步探讨了圆锯片的振动特性，包括圆锯片固有频率的获得方法，振动模态的实验与理论计算方法，临界速率的计算方法以及稳定性分析等。

It is the basis for designing balance mass. And, the couple between flexure and torsional vibration is calculated, which is QRSs intrinsic zero drift, and is also main considerations of determining scale factor.(3) There is a difference for equivalent elastic compliance constant of quartz crystal between the X-direction and the Z-direction. It is related directly to each parameter of QRS.

2对由机械耦合产生的零漂作了系统的定量描述，指出质量不平衡等因素产生的零漂可以由加质量和去质量来消除，这是我们设计平衡质量的依据；同时，计算了弯曲振动和扭转振动之间的耦合，指出它是QRS的固有零漂，也是确定QRS标度因子时所必须考虑的主要因素之一。

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。

By Galerkin meshless method, the equations of motion of static rectangular membrane is established. The first ten natural frequencies of the different aspect ratios and the different pull ratios of rectangular membrane with four clamped edges, three clamped edges and one free edge, two opposite free edges and other two clamped edges were calculated. It is feasible and valid to solve the transverse vibration problem of membrane by Galerkin meshless method.

采用伽辽金无网格法，建立了矩形薄膜横向自由振动的运动方程，并对四边固支、三边固支一边自由、一对边固支另一对边自由三种边界条件下，薄膜的不同长宽比及不同单位长度拉力比作用下的矩形薄膜的前十阶固有频率进行了数值计算，结果说明伽辽金无网格法用于求解薄膜横向振动问题是切实可行的。

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。

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。