Design and Optical Performance Analysis of Large-Aperture Optical Windows for Structural Vibration Reduction

In order to address the issue of large-aperture optical windows operating in wind tunnel environments with dynamic responses, the damping ratio between the vibration isolation device and the mass of the system was calculated by the passive vibration isolation principle. Two isolation models using circular rubber pads and rectangular rubber pads were proposed, and it was proven that the stiffness value of the circular rubber pad is superior to that of the rectangular rubber pad. A three-dimensional model of the optical window was established using finite element analysis software to simulate the working vibration environment of the optical window. Modal analysis and harmonic response analysis were carried out on the optical system with the isolation device installed, and the nodal data of the optical glass surface changes in the optical window were input into the Zemax 19.4 optical design software in the form of Zernike coefficients to calculate imaging quality evaluation indicators. Through finite element structural analysis of the optical window and evaluation of optical performance indicators, it was demonstrated that under the background of the wind tunnel working environment, the isolation performance of the circular rubber pad in the isolation device of the optical window is superior to that of the rectangular rubber pad. This study can provide a design basis for the isolation analysis methods and isolation measures of optical windows in wind tunnel working environments. These research results have implications for the development of large-aperture optical windows in high-speed wind tunnel applications.