固有振动

It is found that there are good relationships between the fundamental frequencies and the structural properties of straight-chain alkanes, and between the sum-frequencies and the additivity properties of straight-chain alkanes as well.

将直链烷烃分子看成是一个多自由度振动系统，用机械振动理论中的传递矩阵法计算了 C2~C32直链烷烃的固有频率，分析了固有频率随化合物结构单元的变化规律。

Due to the complication of the geometric shape and the non-uniform distribution of the mass and stiffness,it is impossible to obtain the exact solution of natural frequencies of low-finned tube s.

针对低翅片管几何形状复杂，质量和刚度分布不均匀，振动特征值不能有封闭解的问题，采用瑞利-里兹法对低翅片管的固有频率进行了数值研究，获得了低翅片管弯曲振动固有频率的数值计算模型。

By the finite element method model, Natural frequency and vibration model of some project fin-stabilitde sabot-discarded penetrator during launching are calculated and analyzed.

利用建立的三维有限元模型，计算分析了30阶尾翼稳定脱壳穿甲弹的振动固有特性，得到了各阶振动的固有频率及响应振型。

By means of the RITZ method,the free frequencies of the first and the second mode of the cables were given.

引用压杆屈曲函数构造两固端刚性拉索的一阶和二阶振型函数，由 RITZ法原理求得其相应的一阶和二阶固有振动频率。

Also the finite element dynamic equations of structure were formulated, and computer code was developed.

应用有限元法对加筋复合材料层合板结构进行固有振动特性和导纳特性分析。

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。

Since the human body and organs in the body can be seen as more focused, more flexible point of vibration whose vibration inherent in the frequency infrasound vibrations, so infrasound have a stronger effect on the human body.

人体和体内器官固有振动频率均在次声震动范围内，次声波对人体有较强的作用效果。

Based on the nature vibrational characteristics of the flat wing calculated by finite element method , generalized unsteady aerodynamic forces matrix induced by the wing deformation is gotten by using strip theory , and thus the flutter model equation of the single wing is given .

文中提出了一种分析亚音速下弹翼颤振临界速度的工程计算方法，其中弹翼的固有振动特性用有限元方法计算，利用片条理论计算弹翼变形诱导的广义非定常气动力矩阵，从而得到单独翼的颤振模型方程。

The Major Planet Carriers Topology Optimization needs to submit to the intensity conditions when its Structure Stiffness and Nature Frequency change as little as it can.

大行星架结构拓扑优化需要在满足强度条件的前提下，使得结构的刚度、固有振动频率改变最小。

The effect of the thickness on the buckling critical pressure is calculated first.

本文还对减压转油线进行了振动特性分析，研究了总体管道系统在刚性支撑和弹性支撑下的固有频率及振动模态，得出了支撑刚度对固有频率和振动模态的影响；计算了进口端竖直管两种不同的约束方式对减压转油线整体固有频率及振动模态的影响，为以后对转油线进行进一步的振动分析提供了宝贵的数据。

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