Optimization and Analysis of Large-Aperture Ultrathin Mirror Based on Multiphysics Coupling

As a key component of space telescopes, the rational structure of the mirror is a crucial factor affecting the telescope's environmental adaptability and imaging performance. To address the technical challenges of simultaneously achieving lightweight, environmental adaptability, and surface accuracy in large-aperture ultrathin mirrors, this paper proposes a mirror optimization method based on multiphysics coupling. Based on the finite element method and thermoelasticity theory, the interaction relationship between the temperature physical field and the force physical field was established. The P-norm was used to solve the problems of non-smoothness and inability to solve the sensitivity of the max(·) function. An optimized model for the mirror was determined using a combination of topology optimization and parameter optimization. Compared to a solid mirror, the optimized mirror achieved a mass reduction rate of 82.04%. Under temperature and gravity conditions, the surface accuracy of the optimized mirror met the requirements. In terms of response dynamics, the optimized mirror performs better, with a maximum response amplification factor of 4.39, below the threshold of 4.5 required to maintain structural stability, which is crucial for maintaining the structural integrity of the mirror. This method will provide a feasible approach for the optimized design of lightweight mirrors with strong environmental adaptability.