基于数字图像相关方法的非接触高温热变形测量系统

 为测定高速飞行器材料与结构的高温变形，将基于图像的变形测量的数字图像相关(DIC)方法与基于红外辐射加热装置和闭环控制的瞬态气动热试验模拟系统相结合建立了一套非接触高温热变形测量系统。该系统通过瞬态气动热试验模拟系统中的红外辐射加热装置对被测试样施加快速和精确可控的热载荷，温度加载范围从室温到1 200 ℃。在热加载过程中用数字摄像机记录不同温度下被测试样表面的数字图像，随后用DIC方法对这些记录的数字图像进行分析，从中提取被测试样表面的全场热变形。为验证该高温变形测量系统的性能，测量了铬镍奥氏体不锈钢在20～550 ℃温度范围内的热变形和热膨胀系数(CTE)，结果显示该系统可快速方便地对航空航天材料的全场高温热变形进行精确测量。

A Non-contact High-temperature Deformation Measuring System Based on Digital Image Correlation Technique

A novel non-contact high-temperature thermal deformation measuring system that combines a transient aerodynamic heating simulation device and the digital image correlation (DIC) technique is proposed for the high-temperature thermal deformation measurement of structural materials used in high-speed vehicles. A test sample can be heated rapidly and accurately from room temperature up to 1 200 ℃ using the infrared radiator of the transient aerodynamic heating simulation device, and the digital images of the test sample surface at various temperatures are recorded and subsequently analyzed by DIC technique to extract full-filed thermal deformation. To validate the performance of the system, the full-field thermal deformation and coefficients of thermal expansion of a chromiumnickel austenite stainless steel sample at the temperature range of 20-550 ℃ is measured. The results indicate that the proposed system can be used easily and quickly for the accurate full-field high-temperature thermal deformation measurement of aerospace materials.