Orthogonal linear polarized lasers(Ⅲ) Applications in self-sensing

In this paper, the applications of orthogonal linear polarized lasers in self-sensing are reviewed. The properties for such a laser include the production of a new frequency in one longitudinal mode spacing, the tuning of frequency difference, the change of polarization states as cavity tuning, the control of mode competition intensity, the optical feedback, and so on. The orthogonal polarized lasers have been used as a laser nanometer ruler based on competition between two polarized lights in a HeNe laser and as a displacement measurement tool based on the optical feedback in the orthogonal polarized lasers. They are also used in the phase retardation measurement of a waveplate, the angle measurement, the vibration measurement, the pressure/force measurement, the weak magnetic field measurement,and so on. The structures of these new devices are simple and compact with the great advantages of high resolution and high accuracy.Some of these devices can trace to the source of the laser wavelength. The nanometer laser ruler is an example whose measurement range is 12 mm, resolution is 79 nm and linearity is less than 5×10- 5. The repeatability of the phase retardation measuring system of waveplate can reach 3'.     

高宽比超限高层建筑模拟地震振动台试验研究

对一座高宽比超过抗震规范规定的复杂高层建筑进行了模型模拟地震振动台试验研究．对于一个1：30的高层建筑模型，通过对其动力特性和动力反应的分析，发现短边方向的刚度明显比长方向弱，存在长方向的扇形振动，即出平面的翘曲变形，转换层处的层间相对位移明显大于其他层的位移，顶部的鞭梢效应明显，此外，高振型在加速度反应中作用较大，尤其在短边方向上．针对以上特点，对设计提出了若干建议．     

具有间隙的二元机翼自激振动的数值分析

利用Runge Kutta法分析了具有不对称间隙的二元机翼自激振动的动力学响应,研究了当U /U L从零逐渐增大到1时系统的周期运动和混沌运动,发现在不对称分段线性系统中存在复杂的运动形式,其中包括从P 1到P 2的倍周期分叉,P 4到P 2,P 2到P 1的倒分岔,同时存在混沌运动形式,而且不同的初值条件所对应的运动形式也有所不同.给出了全局分岔图、局部分岔图、混沌运动的功率谱密度图及3种周期运动的时间历程曲线和相平面图,对于实际的飞行结构设计具有重要的指导意义.     

建筑结构TMD振动控制及其新体系减震研究

分析了结构TMD振动控制机理及在结构风振控制中的研究应用；针对建筑结构的TMD减震控制，介绍了研究现状及进展，进一步采用时程分析法和地震波输入，研究了TMD新体系采用摩擦支座和橡胶支座时的减震控制分析理论。通过研究，指出了其在结构强震反应控制中面临的几个问题。     

高水头大流量作用下反拱水垫塘弹性单底板块振动规律研究

对反拱水垫塘单底板块振动特性进行了理论分析,提出了在止水破坏、锚固力失效后,拱圈单底板块失稳分为自由振动、锁定、滑动变形及失稳破坏4个过程。对高水头、大流量作用下,反拱圈弹性单底板块的振动特性进行了试验研究,给出底板块沿流程各振动区域的划分界限,得到拱圈单底板块振动特征值沿流程分布规律及时域和频域特性,为反拱水垫塘失稳机理的研究提供了科学依据。     

Experimental Studies on Ultrasonic Vibration Grinding of the Workpiece Made from Fine-crystalline Zirconia Ceramics

The performances of fme-crystalline zirconia ceramics in workpiece ultrasonic vibration grinding （WUVG） and conventional grinding （CG） with diamond wheel were researched. The effects of WUVG and CG on material removal rate, grinding forces, surface roughness and microstructure of zirconia ceramic were investigated. Experimental results indicated that： （1） The material removal rate （MRR） in ultrasonic grinding process is two times as large as that of in conventional grinding. The material removal rate increases with increasing grinding depth in both ultrasonic grinding and conventional grinding. （2） The ultrasonic vibration grinding force is lower than that of conventional grinding force, and the increase of the worktable speed leads to a decrease of the grinding force, while the grinding force increases with larger grinding depth in both WUVG and CG. （3） The surface of ultrasonic vibration grinding has no spur and build-up edge and its surface roughness is smaller than that of CG significantly. Surface quality of WUVG is superior to that of conventional grinding, it is easy for ultrasonic vibration grinding that material removal mechanism is ductile grinding.     

振动系统非线性特性的神经网络识别法

本文介绍了振动系统非线性特性识别的一种结构化神经网络方法，与标准的前馈网络融进了人们对系统的已知认识，神经网络仅仅用来学习未知部分，本文将其应用于振动系统非线性特性的识别，结果表明该法是可行的。     

基于LQG/LTR方法的结构振动AMD控制Benchmark模型仿真分析

LQG/LTR方法是基于回路传输恢复技术的LQG方法的简称,该方法是为了克服一般的LQG方法稳定裕量低发展而来,该控制方法的优越性已在土木工程结构振动控制领域得到了初步体现,文中主要是结合AMD控制Benchmark模型,对该控制方法在传感器正常工作时和几种失效情况下的控制效果进行仿真分析,仿真结果表明该控制方法具有很好的控制效果并同时兼具较好的稳定性和鲁棒性。     

车载火炮系统动力学仿真

主要对履带车辆在粗糙地面行驶时车载火炮系统的振动问题进行了动力学建模与仿真,主要有:通过基于三角函数相位的随机抽样法建立双侧不平地面模型、建立三维车体、双侧任意车轮、任意位置座椅在内的坦克底盘的振动模型、车体与火炮的相互作用模型。本文的分析方法将履带车辆的振动对火炮运动的影响体现出来,更加全面和客观的反映了履带车辆行进过程中火炮的运动机理。通过对不同参数的模拟结果进行分析,能够定量的得到各参数变化对车载火炮系统在行进间振动与射击的影响程度,这对于车载火炮系统的设计与优化有着积极的作用     

程控双频调相信号发生器的研制及应用

本文论述了基于单片机的双频调相信号发生器的原理、硬件实现以及在物理实验中的应用,给出了实验测量两谐振动在同方向和在相互垂直方向的振动合成的图形数据。