In the paper , we expound the total structure design of the measuring instrument , the choose of optics principium , the special optical system which consist of f lens , the design of servo control systemic , and the software and hardware design of light - to - current inversion and control of the servo , and the design of sqc statistical quality control and supervisory system . at last , the accurate of laser beam on - line measuring instrument has been analyzed 本论文完成了检测仪的总体方案设计，仪器工作原理的选择，由f透镜构成的特殊光学系统的确定，伺服机构和伺服控制系统的设计，光电变换及通讯系统的软、硬件设计， sqc统计质量控制与管理系统的设计，最后对激光在线扫描检测系统的精度进行了综合分析。
In chapter 2 , proposes an analytical model to the grillage girder , and then establishes its equations by force method . for the primary structure , the upper longitudinal beam is regarded as the finite length continuous girder by elastic point supporting , and the lower cross girder is regarded as the finite length beam on elastic foundation . a computing program is made by qbasic language 第二章主要提出了弹性支承交叉梁系模型，用力法建立了结构静力求解方程，基本结构的处理上，上层纵梁视为有限长点支承连续梁，下层横梁视为有限长弹性地基梁，用qbasic语言编制了求解程序。
In order to analyze the effect of aberration of amplitude and phase of laser beam on centroid position of focal spot , based on the fraunhofer formula for light wave scaler diffraction theory , according to the definition of first order moment centroid position , the general expression of focal spot centroid position directly depending on the complex amplitude of near field is derived 摘要为分析振幅和相位发生畸变情况下光束焦斑质心位置所受的影响，以光波标量衍射理论中的夫琅和费衍射公式为基础，根据光斑强度分布一阶矩质心位置的定义，推导了直接依赖于光束近场复振幅分布的焦斑质心位置的一般表达式。
Elemental analysis based on the emission from plasma generated by focusing a powerful laser beam on a solid sample surface is known as laser - induced breakdown spectroscopy ( libs ) . when the power density of laser on the sample surface is high enough , the sample is vaporized , and the neutral and ionic species are formed in excited states 利用聚焦的强激光束入射固体靶表面产生激光等离子体，对等离子体中原子和离子发射谱进行杂质元素分析，这一过程叫做激光诱导击穿谱( laser - inducedbreakdownspectroscopy ) ，简称( libs ) 。
As regards to the spheric thin shell structure under external hydro static pressure , basing on flat - plate theory and by using basic von karman equations for large deflection , the equilibrium problem of axisymmetric bending of the spheric shell under uniform external pressure is simplified to an equilibrium problem of bending of elastic basic flat - plate and further converted into an equilibrium problem of beam on elastic fundation taking into consideration of the deformation characteristics 对球形薄壳结构随静水外压的情况，应用平板理论中的vonkarman大挠度基本方程，将球形薄壳在均匀外压下的轴对称弯曲平衡问题简化为弹性基础平板的弯曲平衡问题，进而再根据变形特点将其转化为弹性基础梁的复杂弯曲平衡问题。
After acquainting myself with the research status with regard to beam on two parameter foundation about the computational method , mechanic performance , damage assessment , similitude theory , several aspects will be studied in this paper : ( 1 ) whereas most of the existed researches are based upon winkler ( one - parameter ) foundation model , this paper discusses the computational methods of beam on two - parameter foundation , and compare the different methods with each other 在较为充分地了解了国内外对双参数地基上梁的计算方法、力学性能、破损评估、相似性理论应用的研究现状后，本文主要对以下几个方面进行研究： ( 1 )鉴于已有研究多基于文克尔(单参数)地基模型，本文对双参数地基上梁的计算方法(静力和动力)进行了较为深入的研究，并对各种计算方法进行了比较。
The main contents of this paper is according to the structural characteristic of forced vibration , making use of the varying quantity data of free frequency of two different physical cantilever beam on the structural damage experiment basis , then using the bp network , genetic algorithm and the genetic bp algorithm to build up relation model between position , extent of structural damnification , and the varying quantity of free frequency 其主要内容就是根据结构受迫振动特性,利用试验测得两根不同物理性质悬臂梁在受损伤产生裂纹前后的固有频率改变量,使用bp网络、遗传算法、遗传bp算法,建立了结构损伤的位置、程度与结构固有频率损伤前后改变量之间的关系模型。
A great amount of post tensioned pre - stressing concrete single box beam for double track ( as called the box beam hereinafter ) has been used on the line . it is of infeasibility in adoption of the traditional practice of pre - fabrication in precast factory and erection of the box beam with the track laying machine for that this type of beam is characterized by new structure , complicated workmanship , large volume and difficulty in transportation . therefore , the key and hardest problem to tackle is that what processing should be adopted to precast the box beam on site and that what kind of machinery should be used to transport and erect the box beam 由于该型梁具有结构新、工艺复杂、体积大、运输困难，将常规铁路的桥梁厂制造桥梁、经过铁路运梁到工地、边铺边架进行桥梁制造与架设的传统施工模式应用到该线是行不通的，必须在现场预制桥梁、并采用专门的运架梁设备进行桥梁架设，因此箱梁的制造、架设施工成为该线施工技术攻关的重点和难点。
By means of the measuring the natural frequencies of a beam on a elastic foundation together with the transfer matrix method and the computer algebraic language ， the paper deduces the high - order equation ， which contains unknown quantity of the stiffiness of supports . this method ， the validity of which has feen verified by experiments ， can be applied to identifying the foundation coefficient 本文通过实测弹性地基梁的固有频率，以传递矩阵法为基础，利用计算机代数语言，导出以支承刚度为未知数的高次方程，从而识别出地基系数，并通过实验验证该方法的正确性。
