1200℃高温热环境下全场变形的非接触光学测量方法研究

Study of non-contact optical metrology for full-field deformation measurement at 1200℃

将数字图像相关方法这一基于图像的非接触全场光学测量方法与瞬态气动热试验模拟系统相结合发展了一种用于1200℃高温环境下全场高温变形测量的新技术。为减小高温物体热辐射对数字摄像机所采集图像亮度增强的影响,采用了带通光学滤波成像技术,该技术可使图像采集系统在物体表面温度高达1200℃时仍可获得高质量的数字图像,这些图像可被数字图像相关方法直接分析处理得到全场变形。为验证该非接触光学测量方法的精度,测量了铬镍奥氏体不锈钢试样在不同温度下其表面的全场热变形以及从室温到1200℃温度范围内的热膨胀系数,并与航空材料手册中的数据进行比较,结果显示该非接触光学测量方法原理简单、抗干扰能力强、测量精度高,在航天航空领域具有重要的应用前景。

A non-contact full-filed high-temperature deformation measuring technique is developed based on the combination of transient aerodynamic heating simulation device and digital image correlation（DIC）.In the technique,band pass optical filter imaging system is designed to eliminate the influence of black-body radiation of high-temperature objects on the intensity of captured images.Thus,high-quality digital images of an object at high temperatures up to 1200℃ can be easily acquired and directly processed using DIC technique to extract full-field deformation information.To verify the performance of the proposed technique,full-field thermal deformation and coefficient of thermal expansion（CTE） of a chromium-nickel austenite stainless steel sample,heated from room temperature to 1200℃,were determined.Experimental results indicate that the proposed technique is easy to implement and can be applied to practical full-filed high-temperature deformation measurement with high accuracy.