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

Area of Science:

• Optical engineering
• Materials science
• Aerospace engineering

Background:

• Space telescope mirror design faces challenges in balancing lightweight properties, environmental adaptability, and surface accuracy.
• Large-aperture ultrathin mirrors are critical for advanced space optics but present significant structural and performance hurdles.

Purpose of the Study:

• To develop and validate an optimization method for large-aperture ultrathin mirrors using multiphysics coupling.
• To achieve simultaneous lightweighting, enhanced environmental adaptability, and high surface accuracy in space telescope mirrors.

Main Methods:

• Finite element method and thermoelasticity theory were employed to model the coupled thermal and mechanical fields.
• Topology optimization and parameter optimization techniques were combined to determine the optimal mirror structure.
• P-norm was utilized to address non-smoothness issues in sensitivity analysis.

Main Results:

• The optimized mirror design achieved an 82.04% mass reduction compared to a solid mirror.
• The optimized mirror met surface accuracy requirements under simulated temperature and gravity conditions.
• The mirror demonstrated improved dynamic response with a maximum amplification factor of 4.39, ensuring structural stability.

Conclusions:

• The proposed multiphysics coupling optimization method offers a feasible approach for designing lightweight, environmentally adaptable, and high-accuracy mirrors.
• This method is crucial for advancing the structural integrity and performance of mirrors in demanding space environments.