用电子散斑干涉法测量材料热膨胀系数

 利用双光束电子散斑干涉法（ESPI）对试件受热变形进行了实时观测，针对一次实验过程中得到的图片较多（300～500幅）的特点，在图像处理时摒弃了以往的手动识别等位移线的办法，用MATLAB语言编写了批处理程序，能够在采集的大量散斑图片中自动快速准确地标定等位移线，得到相应的位移和应变，并结合实时测量的温度值，获得了45钢和LY12铝合金在不同温升率下的热膨胀系数及其随温度的变化。实验结果表明，在涉及的温升率范围内，温升率的改变对材料热膨胀系数的影响不明显，材料的热膨胀系数随温度的升高略有上升。

Application of electronic speckle pattern interferometry in thermal expansion coefficient measurements

In this paper,the thermal expansion coefficients of LY12 and 45 steel in different temperature-rising ratio are acquired by electronic speckle pattern interferometer(ESPI).for the pictures (300～500 frames) of each experiment,a batch processing code was designed to identify the central lines automatically instead of the old manual recognition. After displacements and real-time temperature measurements obtained,the thermal expansion coefficients can be deduced. It is proved that in the temperature-rising-ratio range concerned in this paper,the thermal expansion coefficients are almost independence of temperature-sising ratio and at the same time,they increase within a narrow range when the temperature rises