查询词典 natural vibration

Considering that both the solution of the structure natural vibration frequency and mode as well as its elastic stability coefficient can transform into eigenvalue problem of the structure dynamic equilibrium equation, taking the fundamental frequency and the elastic stability coefficient of the structure as the evaluation criteria, the possible arrangements of Mi-brace and X-brace for halfthrough CFST arch bridge with 360 m span were comparatively analyzed, and the advices for the reasonable space of the Mibrace and the X-brace were advanced.

鉴于结构自振频率、振型及弹性稳定系数的求解均可转化为源自结构动力平衡方程的特征值问题，先以结构基频及弹性稳定系数为衡量标准，对一座360 m跨的中承式钢管混凝土拱桥可能的米字撑及X撑布置方案进行了分析对比，并据此提出了X撑及米字撑的合理间距。

Based on the space finite element analysis model, we have studied the natural vibration characters of the building .

研究成果对类似工程结构设计有一定的指导意义。

A finite element model using the structural analysis software,SAP2000,was created to study the headframe's natural vibration characteristics and the state of member forces.

应用SAP2000有限元软件，建立三维有限元模型，对其自振特性和加固前后的杆件应力进行了对比分析，加固后杆件最大应力大大降低；通过加固前后不同荷载下的动力测试，对加固后井架的运行状况作出评估与分析，在原提升荷载和新提升荷载下，井架工作时平均振动频率都有很大幅度的减小。

Transient heating has a serious effect on the characteristic of structural natural vibration.

瞬态加热会严重影响结构的固有振动特性。

The main research contents are stated asfollow: 1. Simplified analysis method of space grids structuresDouble-layer space grids have been assumed as sandwich plate, and are analyzed bythe nontraditional theory of plate with consideration of shear deformation and threegeneralized displacements. Using the theory of energy variation, simplified methodsfor bending, stability and vibration analysis of double-layer space grids have been putforward based upon the idea of split rigidity. The formulas for calculating internalforces, displacements, critical load and natural frequency have been given out. Set thestable cables and bearing cables in hyperbolic paraboloid cable nets are all replaced bytruss-cable to form truss-cable nets structures. Natural vibration analysis method fortruss-cable nets structures has been put forward using the energy variation method andRayleigh method.

主要内容包括： 1、空间网格结构静动力简化分析方法把网架结构简化为夹层板，采用考虑剪切变形的具有三个广义位移的平板弯曲理论进行分析，基于分解刚度思想利用能量变分原理提出了网架结构弯曲、稳定与振动分析的简化计算方法，给出了位移、内力、屈曲临界荷载和固有频率的计算公式；将双曲抛物面索网中的稳定索与承重索均用劲性索代替形成劲性索网结构，基于能量变分法和Rayleigh法给出了劲性索网结构固有振动分析的简化计算公式。

And the inclination angle on nonlinearly natural vibration characteristic of an inclined cable in plane.

研究斜拉索在平面内的非线性固有振动特性。

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 calculations of torsional vibration of crankshaft systems of 12V240ZJ6E diesel engines were carried out with TVCA programme and I deas software to obtain system natural vibration frequencies, vibration amplitudes of various concentric masses at different rotational speeds, and torques and torsional stress es of various crankshaft sections at different rotational speeds.

运用TVCA程序和Ⅰ deas软件对 12V2 4 0ZJ6E型柴油机轴系的扭转振动进行计算，求出系统的自振频率、各集中质量在不同转速下的振幅和各轴段在不同转速下的扭矩、扭转应力值，对自振频率、自由端振幅和扭转应力最大轴段进行了分析，对轴系的扭转振动情况作出总结与评

The concept of influence degree of natural vibration period by cables is shown,and the influence of cables to the property of natural vibration of extradosed cable-stayed bridge s is analyzed by taking Xiaoxihu extradosed cable-stayed bridge in Lanzhou City as an example.

以小西湖矮塔斜拉桥为例，通过引入拉索自振频率影响度的概念，分析了拉索的存在对矮塔斜拉桥自振特性的影响，探讨了矮塔斜拉桥的自振特性与相应连续梁桥的区别；在分析矮塔斜拉桥地震反应的基础上，通过引入振型贡献率的概念，分析了高阶振型对矮塔斜拉桥动力性能的影响；分析了矮塔斜拉桥的振型耦联效应。

First, this paper presents three girders model with double cable planes which main girder and side girder is connected by rigid arms, analyzes the dynamic characteristic of Yonghe cable-stayed bridge and obtains its natural vibration modes (i.e., frequency, damping values and the mode shapes ) by ANLSIS structural analysis program and uses these parameters as dynamic dactylogram of the intact case of cable-stayed bridge. Using the passage of random as the ambient vibration ,the dynamic properties of Yonghe Bridge is measured and the modal parameter of its 15 years after is identified and used as dynamic dactylogram of the damaged case. By the finite element analysis and locale vibration test, damaged and undamaged modal parameter is analyzed and curvature mode shape, which is sensitive to damage state, is introduced as possible candidate for identifying and locating damage in the cable-stayed bridge. Selecting the branch of part measured point from modal parameter, this paper deduces the damaged index which can detect the possible damaged location of the cable-stayed bridge deck and identifies the damaged region and degree for Yonghe Bridge. For the purpose of structural condition monitoring in in-situ , from another viewpoint, this paper introduces the method called the best optimization vector to detect damaged location and degree. The accuracy and reliability of the method presented in this paper are demonstrated by static analysis and test and the healthy state of Yonghe Bridge can be evaluated.

建立了双索面通过刚臂与主梁及边梁相连的三梁式力学模型，采用ANSYS结构分析程序对永和斜拉桥进行动力分析，对其振动模态参数进行识别，以此作为斜拉桥完好状态下的动力&指纹&；采用自由交通流作为环境振源，对永和斜拉桥动力特性进行测试，识别出永和斜拉桥使用15年后的模态参数，确立了破损状态下的动力&指纹&；利用有限元分析、现场振动测试，对破损前后的模态参数进行分析，提取对破损状况较敏感的模态曲率作为斜拉桥破损诊断的参数；并从模态参数中选取部分点的分量，导出可以指示斜拉桥桥面大概损伤位置的Index损伤指标，识别出斜拉桥发生破损的区段及破损程度；考虑大型斜拉桥在线监测要求识别破损的具体位置，从另一角度提出采用最优矢量法具体确定破损发生的位置及程度；为验证本文研究成果，对永和斜拉桥进行静力分析及静力测试，对其健康状况提出可靠的评价。

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