32 research outputs found

    Experimental investigation of thermocapillary migration of isolated drops

    Get PDF
    Experimental hardware has been developed to perform experiments on the Marangoni migration of drops in the case of intermediate Reynolds numbers in a microgravity environment. The experiments were conducted using the drop shaft free fall facility with a 4.5 second microgravity period in the Microgravity Laboratory of Japan. In this experiment, the thermocapillary velocity of drop migration was measured for drops of different sizes in a series of temperature gradients

    Experimental investigation on Marangoni drop rations using drop shaft facility

    Get PDF
    Experimental hardware has been developed to perform the experiments of drop Marangoni migration in the case of intermediate Reynolds numbers ina microgravity environment. The experiments were completed using the drop shaft free fall facility with a 4.5 s microgravity period in the Microgravity Laboratory of Japan. A special experimental method was designed for experimenting with a short microgravity period. In this experiment, the thermocapillary velocity of drop migration, driven only by the thermocapillary effect, was obtained. Experimental results show that Marangoni migration velocity depends on the temperature gradient and the drop diameter For fixed experimental mediums; the thermocapillary velocity of this present experiment is obviously smaller than the one suggested by YGB linear theory. This conclusion agrees, in general, with that of the ground-based experiment

    直接散斑法测量各种材料试件的变形

    No full text
    本文给出一种试件表面处理方法,它可以解决对于各种材料试件(例如有色金属、黑色金属、玻璃钢、碳纤维复合材料、陶瓷、岩石、混凝土制品等)使用直接散斑法进行变形测量的问题。文中阐述了基本原理和操作方法,给出了在铝合金材料、碳纤维复合材料、玻璃钢复合材料试件上进行断裂力学实验的结果

    提高直接散斑法全场分析条纹图清晰度的技术途径

    No full text
    本文论述了试件表面处理、全息干板的选择及显影方法、全息干板与试件的固定方式、全场分析条纹图的拍摄技术等因素对于提高直接散斑法全场分析条纹图清晰度的影响,指出了提高直接散斑法全场分析条纹图清晰度的技术途径。介绍了采用本文提出的技术途径取得的实验结果,实验值与理论计算曲线符合良好

    现场用直接散斑法记录仪

    No full text
    本文提出一种实验装置,可在现场或不避光的普通实验室进行直接散斑法实验,解决了必须使用暗室才能进行直接散斑法实验的问题。文中介绍了该记录仪的结构设计,使用方法和效果等

    直接散斑法实验技术推广班在北京举办

    No full text
    1987年3月16日至21日由中国科学院力学研究所科技咨询开发部和技术劳动服务公司在力学所联合举办了“第一期直接散斑法实验技术推广班”,参加这次推广班的有天津大学、北京航空学院、北京水力电力经济管理学院研究生部、华北水电学院、北京钢铁学院等单位的副教授、讲师和研究生。散斑法是近十多年来新发展起来的、以近代光学为基础的新型实验应力分析方法。用该方法测量物体微

    贴片散斑法及其应用

    No full text
    贴片散斑法将一种可剥离铝箔贴附在试件表面,经随机划痕制栅后,以其精细的光学结构和高度的反射本领,在白光或激光照射下,表面辐射率随机分布函数作为散斑场,采取直接记录手段,用全息底片对此作物体变形前后的两次曝光,所得到的散斑底片将包含宽广的空间频谱范围,且全场分析条纹清晰、灵敏度高、量程调节范围大。此方法不仅适用于各种材料的直接散斑法测量,具有经济、可靠、操作简便的特点,还能应用于平面及可展曲面构件的现场量测

    THE APPLICATION OF MOIRE INTERFEROMETRY IN THE MEASUREMENT OF DISPLACEMENT FIELD AND STRAIN FIELD AT NOTCH-TIP AND CRACK-TIP

    No full text
    This paper presents the application of Moire interferometry in measuring the displacement andstrain field at notch-tip and crack-tip before and after crack propagation.The experiment is carried out using athree point bending beam with a notch.The N_x and N_y fringe patterns representing displace..

    用激光散斑法和云纹法测量含裂纹薄板的裂纹张开位移

    No full text
    平面应力的弹塑性断裂理论的研究一直受到广泛重视,正在深入发展,其中很多工作是通过研究裂纹张开位移和裂纹附近的应变场进行的。用光学方法对裂纹张开位移和裂纹周围的变形进行测量具有显著的优越性,不但测量精度高,而且能够把整个裂纹包括裂纹顶端的张开位移都同时测量出来,并得到裂纹周围的位移全场分布。近年来激光散斑法在实验应力分析中发展很快,已被用来测量裂纹张开位移和裂纹周围的应变场,

    白光散斑的直接记录和非相干光分析

    No full text
    近二十余年来,激光散斑法在实验应力分析领域中广为重视.它的突出优点是灵敏度可调,无损以及能给出全场信息.测试者可根据待测应变量的大小,调节滤波孔高度,选择适当的条纹密度进行测量.因而这种方法对于弹性、塑性应变均能适用.是目前较理想、有潜力的测试手段之一
    corecore