红外窗口功能膜的热/力响应(英文)

Thermal-mechanical response of microscale functional film for infrared window

高超音速导弹在服役过程中其红外窗口承受着复杂的气动热/力环境。利用有限元方法对不同气动热/力情况下的窗口进行数值模拟,获得了不同热流密度下窗口的温度和热应力分布,应力沿膜厚方向几乎相同,但是在膜基界面附近会产生突变。在膜层表面,最大应力出现在边界旁。不同的膜层材料在相同条件下有相同的温度和应力分布规律,但是应力大不相同。比较发现,Y_2O_3比ZrN膜层具有更高的温度和应力。同时,进行了地面热冲击实验来观察红外窗口的破坏情况,10 s之后,发现窗口表面已经发生破坏,有些局部产生裂纹,有些局部会产生破碎的斑点。

Infrared window in hypersonic missile usually suffers complex aerodynamic force/heat during high-speed flight.A finite element method was adopted to simulate the thermal and stress response of microscale functional film for infrared window under different aerodynamic heats/forces conditions.Temperature and stress distribution were obtained with different heat fluxes.There is almost constant stress distribution along the film thickness except a sudden decrease near the substrate.The maximum stresses are located at the points which are 0.3 mm away from the edges.Different film materials result in different stress values.The temperature and stress in ZrN are larger than those in Y2O3.Besides the numerical simulation,an oxygen propane flame jet impingement test was performed to investigate thermal shock failure of the infrared window.Some place of the window surface has spots damage and some place has line crack damage after thermal shock.