1200℃高温环境下部件受热前表面应变的光学测量

Optical Measurement of Heated-Front-Surface Strains for Components in High Temperature Environments up to 1 200 ℃

在大气层内飞行的高超声速飞行器外表面因气动加热处于极为恶劣的高温环境中.而气动热模拟试验中,飞行器部件受热前表面在高温环境下的变形测量非常重要且十分困难.通过建立水冷式高超声速飞行器部件受热前表面应变测量系统,结合数字图像相关方法,实现了有氧环境下耐高温Al_2O_3陶瓷材料受热前表面温度高至1 200℃的应变测量.为了验证试验结果的正确性,与Hillman给出的Al_2O_3材料热膨胀系数-温度关系式进行了对比,具有良好的吻合性.所建立的1 200℃高温应变测试系统及氧化环境下部件受热前表面应变测试方法,为高超声速飞行器受热部件的热强度分析及安全可靠性设计提供了非常重要的试验测试手段.

The external surface of a hypersonic vehicle flying in the atmosphere is facing a severe hightemperature environment due to aerodynamic heating. While in the aerodynamic thermal simulation test,the deformation measurement of heated front surface of aircraft components under high temperature conditions is extremely important and difficult. A heated-front-surface strain measurement system for hypersonic vehicle components was established,and by means of the digital image correlation method,the strain measurement for heat-resistant Al_2O_3 ceramic material with the front-surface temperature up to 1 200 ℃was realized under the oxidizing environment. To demonstrate the correctness of the measuring method,the experimental results were compared with the calculation results from the relation between the thermal expansion coefficient and the temperature of Al_2O_3 material given by Hillman,and good agreement was obtained. The proposed 1 200 ℃ high temperature strain measurement system and the heated-front-surface strain measurement method for components under oxidation environments provide a important experimental method for the thermal strength analysis and safe reliability design of the hypersonic vehicle＇s heated parts.