用云纹干涉法测量和研究双层钴合金的挠度

运用云纹干涉原理对双层钴-合金材料进行三点弯曲试验,测试其常温与高温条件下的挠度值.通过大量试验,且与千分表测试的挠度值进行比较.结果表明,常温条件下的云纹测试挠度值与千分表法可以达到同样的精确度.同时,该实验方法体现了高温云纹干涉法在材料高温力学性能测试方面的优越性.高温云纹法是非接触式测量,在高温环境下有效地解决了量具高温变形的困难,且结合云纹图像可以对试件受力动态变形情况进行实时观测和分析,是一种较为精确测试常温及高温挠度的新方法.     

高温云纹干涉测试系统研究

本文研制了用于高温云纹干涉法的测试系统.所研制的系统包括四光束云纹干涉仪、带观察窗口的高温云纹炉及控温系统、机械加载系统(加载架、测力传感器、冷却装置等)、CCD和计算机图像采集与处理系统.适用不同温度条件下的高温光栅制作技术也将给予介绍.该系统实现了1000℃高温氧化条件下的U、V场的实时测量.     

大电流快速加热条件下LY12铝板动态变形的云纹干涉法实验研究

本文研究了中间带孔受拉铝板在大电流热冲击条件下的动态变形测试．在试件表面制作高温高频光栅，预加机械载荷后放入双光束云纹干涉光路中，用大电流加热器对试件进行快速加热，利用高速摄影机拍摄记录试件表面圆孔附近区域干涉条纹的变化情况，同时利用测温系统对试件的温度变化情况进行了测试记录．实验结果表明，用高速拍摄方法摄影热冲击条件下的云纹干涉条纹变化是可行的．     

高灵敏度,高温全息云纹光栅及其应用

本文简要介绍了高灵敏度，高温全息云纹光栅技术，主要包括旋转点光源激光全息干涉制栅系统，折射率介质超高频光栅制作技术，双镀层抗高温氧化制栅技术，耐高温光刻胶模板及转移技术，现场变形栅转移技术。在此基础上还给出了高灵敏度，高温全息云纹光栅的几个典型应用实例     

云纹干涉制栅新技术

本文介绍了两种新的光栅复制技术,它们具有快速、高质量、低成本、操作简单、使用方便、不需特殊仪器等特点.该技术从我国一般力学实验室条件出发,解决了试件栅制作困难,其中漆栅方法可极大地缩短云纹干涉方法的实验周期,该技术也为光栅测试技术的广泛应用提供了方便.     

云纹／光栅测试技术的几点讨论

本文用信号处理的方法系统地阐述了云纹／光栅测试技术。以面内云纹／光栅测试为例，首先说明了光栅是位移和变形信息的空间载体；位移和应变分别是对载体的相位和频率调制；而云纹现象则是试件栅频谱向零频处平移的结果或说云纹是对光栅载体信号解调的过程；进而讨论了云纹技术与光栅技术的本质区别。其次分析了云纹／光栅测试系统的性能，讨论了条纹分析方法及数字图象处理手段对云纹／光栅系统的测试精度、灵敏度、空间分辨率的影响。     

相移数字云纹测量系统

介绍了一种相位移数字云纹变形测量系统．测试系统采用ＣＣＤ摄像系统记录光栅图像，控制采样的空间频率大约为光栅线密度的整数倍，对试件栅进行采样后用数字信号处理的方法，实现空间相位移及进行实时数字云纹条纹显示，并对相移误差及光栅信号的高阶谐波的影响进行了校正     

定向结晶材料高温蠕变规律研究

利用高温云纹干涉法对航空发动机叶片定向结晶材料的高温蠕变进行了测试，获得该材料不同主方向的高温蠕变性质和规律。实验结果表明定向结晶材料在结晶方向和各向同性平面的蠕变性质有很大差异。     

云纹干涉法现场测量中的变形试件栅复制技术

本文研究了云纹干涉法的现场测量技术.该方法在现场测量过程中复制变形的试件栅.试件栅上保留了载荷引起的变形信息,通过云纹干涉法可以得到这些变形信息.该方法不但具有云纹干涉法的所有优点,并且使云纹干涉法可以在光学实验室以外场合中应用.     

界面剪切实验研究

用云纹干涉法测量了带边裂纹的双材料四点简支梁在剪切作用下界面表面的剪应变分布及界面两侧局部表面的位移场（Ｕ、Ｖ场），试件是由弹性模量相差悬殊的铝合金和环氧塑料两种材料制成。文中给出了试件制备、实验方法和测试结果。     

High resolution, high sensitivity moire method

Based on geometric moire method, moire interferometry and microscopic moire interferometry, a high spatial resolution and high sensitivity geometric microscopic moire method is presented. Geometric micron-moire patterns are produced by the superposition of two high frequency gratings through a microscope system. Compared with other grating-based photo-mechanics methods, microscopic moire method could provide whole-field moire patterns of both high spatial resolution and high sensitivity. The frequency of specimen and reference gratings used in this method can be from 1 line/mm to 10000 lines/mm. Additionally, a 4F optical filter system is used to enhance the contrast of microscopic moire patterns effectively. The project supported by the National Natural Science Foundation of China     

Combined absorption-desiccant solar powered air conditioning system

This article presents a combined absorption-desiccant high performance airconditioning system suitable for hot humid areas. A LiBr-H₂O absorption machine is powered by medium concentrators with a collection temperature of 140°C. The heat released in the absorption system condenser at 75°C is used for firing a silica gel (desiccant) dehumidifier. This consists of 2 silica gel beds of the cross flow type working alternatively in series with the absorption machine one bed at a time.The system is analyzed and the mathematical model with the governing equations are given. Results of the analysis are shown for the silica gel beds over an assumed working period duration.     

Analysis of nano channel formation in quartz cubes by laser-induced process

A novel laser processing technique was developed for making channels in the nano regime in this paper. A Nd:YAG laser was used to dry fabricate micro channels (25μm～100μm di ameter) in a 1 cm^3 fused silica substrate by thermal-induced processing. By controlling the locations of these initiating micro channels on a silica cube, 1D-controllable self-connecting nano fractures can be formed as rectangular channels. These nano channels are smooth and with extremely high aspect ratio (～10^4 depth to width ratio). A possible mechanism is proposed to explain the formation of the nano channels. This laser-based nano channel fabrication technique is fast and inexpensive, and with potential applications in capillary electrophoresis and electro-osmosis driven nano-filtration.     

应用云纹干涉法测量冷挤压孔周残余应力分布

本文就冷挤压加工后紧固孔周的残余应力测量问题进行了研究。文中提出了径向切割法以释放欲求剖面的周向残余应力;采用高灵敏度的云纹干涉法测量残余应力释放后引起的附加变形;用载波错位法获得高反差的应变条纹图。     

Determination of impact parameters by optical measurement of the impactor displacement

In dynamic materials research, high precision impact displacement, velocity and force measurements are often required. In lower velocity testing apparatus, impact force histories are most often obtained through strain gage, piezoelectric force transducer or accelerometer signals. Velocity and displacement histories are then obtained by integration. Non-contact measurement systems have a number of advantages over these more common mechanical contact methods, and can generally be used at higher impact speeds. In this paper a relatively simple optical technique is presented for recording the impactor displacement history, from which the impact velocity and force histories can be readily obtained for a (quasi-) rigid impactor. The technique is based on the relative displacement of two moiré line gratings: one grating attached to the impacting body and the other serving as stationary reference grating. The technique has proven to be useful for impact speeds of a few m/s to well over 200 m/s. Results of transverse impact experiments on composite laminates are presented.     

Numerical study on adsorption enhancement of rectangular adsorption bed

The present paper has dealt with the one-sidewall cooling effect of spherical adsorbent particles packed in a rectangular bed on water vapor adsorption characteristics by a 2-dimensional numerical analysis. The analysis model was considered that one-sidewall of a rectangular packed bed with homogeneous spherical silica gel particles was cooled and another walls were adiabatic. The moist air flowed into the rectangular adsorption bed packed with spherical adsorbent particles. Fuji Sylsia silica gel B was selected as a suitable adsorbent with high adsorption ability over high relative humidity. Numerical results revealed the effects of moist air inlet humidity, airflow velocity, size of spherical silica gel particles, width of the rectangular packed bed, and the side-wall cooling temperature on the amount of water vapor adsorption.     

试件栅刻蚀技术研究

本文研究和实现了在试件表面直接涂布光刻胶制得振幅型低频栅和位相型高频全息栅的基础上，分别利用湿法化学腐蚀和反应离子刻蚀技术蚀刻试件栅的工艺。在几种不同材料的试件表面刻蚀出了试件栅，这种技术的实现使云纹干涉法和精细网格法在高温高压环境下的广泛应用成为可能。     

Experimental and numerical investigations on the performance of dehumidifying desiccant beds composed of silica-gel and thermal energy storage particles

Enhanced efficiency of the adsorption process in the dehumidifier is a key element for improved performance of desiccant cooling systems. Due to the exothermic nature of the adsorption process, the dehumidification and cooling capacity are limited by significant temperature changes in the adsorption column. In the present study, the effects of integration of sensible and latent heat storage particles in the desiccant bed for in situ management of released adsorption heat are investigated. For this purpose, column experiments are performed using an initially dry granular bed made of silica-gel particles or a homogeneous mixture of silica gel and inert sensible or latent heat storage particles. The packed bed is subject to a sudden uniform air flow at selected values of temperature and humidity. Also, a packed bed numerical model is developed that includes the coupled non-equilibrium heat and moisture transfer in the solid and gas phases. Investigations of the heat and mass transfer characteristics are reported using the composite structure and the results are compared with the base case of simple silica gel bed. Improved desiccant cooling system performance can be obtained by appropriate adjustment of desiccant cycle operation and proper choice of the volume ratio of thermal energy storage particles.