固有振动

The structure feature of the sensor was described in comparison with the classical Stewart platform-based six-component force sensor.By using the finite element method,the elastic dynamics theoretical model of the sensor was established based on the conditions of displacement consistency and force balance.According to this model,the numerical analysis was carried out,and the variety relationship curves between the natural frequencies and the structural parameters are plotted.

描述了该传感器相对于经典Stewart平台六维力传感器所具有的结构特点；利用有限元法，采用位移协调和力平衡条件建立了传感器弹性动力学理论模型，依此模型进行数值分析，绘制了固有频率与各结构参数间变化关系曲线；并利用ANSYS软件建立了传感器有限元模型，进行了振动模态分析，得到其固有频率和振型。

Characteristics of free vibration and forced vibration of a damped system with dry frictional damping,viscous damping and c x·2 damping are analyzed and calculated,acceleration response of free-vibration of the dry frictional damped system has a sudden change when x· is zero,the change value is constant and depends only on the natural frequency ωn and the displacement xk due to dry friction.

本文对存在干摩擦阻尼、粘性阻尼和c.x2阻尼系统的自由振动及受迫振动特性进行了解析及数值计算，得到干摩擦阻尼系统自由振动的加速度响应在速度零点有一突变，这一变化量为定值，且只与系统固有频率ωn及摩擦当量位移xk有关。

For free oscillation of various nonlinear conservative systems, the analytical approximate periods and the corresponding periodic solutions were established and they are valid for small as well as large amplitude of oscillation.

提出了结构参数发生较大变化时，计算结构的静力响应，固有频率与固有振型的高效的、适用范围广的方法；对非线性保守系统的自由振动，建立了既适用于小振幅又适用于大振幅的近似解析解法。

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。

Vibration model is established and inherency frequency and main vibration type are obtained, vibration characteristic response is analyzed. Mode respond and harmonious respond of suspension system with package cushioning are analyzed with the help of ANSYS 6.0. At last, design method of suspension system with package cushioning is researched and a detailed design example is provided.

第三，介绍了弹簧吊装系统的振动分析理论，建立了振动模型，得到了系统的固有频率及主振型，分析了系统的振动响应；并利用ANSYS6.0有限元分析软件对悬浮式缓冲包装模型进行了模态分析和谐响应分析。

The sensitivity characteristics of the natural vibration frequencies and mode shapes of vibration structures with respect to mass and stiffness modifications are analysed based on the matrix perturbation method of the linear generalized eigenvalue problem.

基于线性广义特征值问题的矩阵摄动重分析公式，较为系统地分析了振动系统各阶固有振频及固有振型随结构质量和刚度的修改的灵敏度特性，得出了一系列具有重要实用意义的结论，指出了对结构进行摄动修改的最灵敏位置。

The effects of meshing phase on natural frequency and vibration mode of planetary gears were analyzed.

对行星齿轮传动的固有特性进行了研究，分析了啮合相位差对行星齿轮传动的固有频率和振动模态的影响。

According to thermoelastic deflection of the V-shaped titled beam, the forth-factorially partial differentiation equation is used to describe the dynamic performance. Then the natural frequency and the mode of the actuator are obtained through analyzing of free vibration modal.

根据硅微致动器V型斜梁热弹性应力变形，推导出弯曲振动的四阶偏微分方程，通过其自由振动模态分析，得到了斜梁弯曲振动的各阶固有频率和振型。

Inherent frequency characteristics of X2105C-1 diesel crankshaft are carried out by using ANSYS finite element method. The modal analysis includes retortion vibration, bending vibration and lognitudinal vibration.

对x2105C-l型柴油机曲轴在自由模态下的固有频率特性进行了有限元分析，所计算的模态包含了扭转振动、弯曲振动和纵向振动。

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。

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