组合式力热动态载荷光学窗口的光学特性研究

Optical properties of combined dynamic thermal dynamic loading optical window

针对在一定压差及温度梯度等复合环境下工作的大口径光学窗口,提出了一种由光学玻璃与亚克力板组成的光学窗口组合方案,并以热光学分析为基础,对光学窗口整体强度及热环境进行了理论分析计算,得出光学窗口玻璃最小厚度。利用有限元软件将压力场及轴向温度场映射至三维结构模型,计算得到直径为380 mm的光学窗口在不同玻璃厚度下力热耦合的面形变化及成像质量评价指标,并通过相应的环境性试验对仿真结果进行验证。实验结果表明:以K9光学玻璃为原材料的大口径光学窗口在此工作环境下的厚度不小于32.5 mm;当光学窗口厚度为35 mm时,其所受热力学影响可以忽略。因此,35 mm的大口径组合式光学窗口既能满足强度要求,又能满足多光谱相机成像质量要求,为该类窗口的设计提供了依据。

Aiming at the large aperture optical window working in the complex environment such as pressure difference and temperature gradient, a combination scheme of optical window was proposed, which was composed of optical glass and acrylic plate. Based on the thermal-optical analysis, the overall strength and thermal environment of optical window were analyzed and calculated theoretically, and the minimum thickness of optical window glass was obtained. The pressure field and axial temperature field were mapped to threedimensional structure model by finite element software. The surface shape change and imaging quality evaluation index of 380 mm diameter optical window under different glass thickness were calculated. The simulation results were verified by corresponding environmental tests. The results show that the thickness of large aperture optical window with K9 optical glass as raw material is not less than 32.5 mm under this working environment;when the thickness of optical window is 35 mm, the thermodynamic effect can be ignored. Therefore, the large aperture combined optical window of 35 mm can not only meet the intensity, but also meet the imaging quality requirements of multi-spectral camera, which provides a basis for the design of this kind of window.