Microvibration Testing and Decoupling for Space Payloads with Large Inertia, High Stiffness, and Discrete Interfaces

Area of Science:

• Space optics and instrumentation
• Vibrational analysis and structural dynamics
• Finite element modeling

Background:

• Microvibrations from the Survey Camera (SC) of the China Space Station Telescope (CSST) degrade imaging quality.
• Accurate microvibration evaluation is critical for telescope performance.
• Structural coupling between large payloads and test systems distorts microvibration test results.

Purpose of the Study:

• To develop a semi-physical simulation method for microvibration decoupling.
• To accurately extract the intrinsic microvibration responses of the SC.
• To enable dynamic decoupling analysis of complex coupled systems.

Main Methods:

• Establish a coupled finite element model of the SC and the test system.
• Iteratively modify the model using modal and transmissibility test results.
• Validate the model through microvibration response tests.

Main Results:

• The modified coupled model accurately reflects the dynamic characteristics of the actual coupled system.
• Microvibration response tests showed good agreement between the model and the actual system (RMS force/torque deviation < 5%).
• The intrinsic microvibration responses of the SC were successfully extracted after decoupling.

Conclusions:

• The proposed semi-physical simulation method effectively achieves dynamic decoupling for complex coupled systems.
• This approach enables accurate microvibration analysis of space-based optical instruments like the CSST SC.
• The findings are crucial for ensuring high-quality imaging in space telescopes.