Experimental validation of the vibro-acoustic model of a pressurized membrane

• Validation of a previously published structural acoustic model is carried out.
• The system is validated in two setups: membrane in air and membrane–cavity system.
• Several difficulties in testing are addressed such as obtaining uniform tension.
• Modeling and testing results correlate very well with errors in the 2% range.

In the odyssey of achieving further lightweight space structures and systems, optical-quality membrane mirrors are expected to replace the conventional, metal-based and glass-based, rigid mirrors. These thin film membranes offer an order of magnitude size increase in apertures and in weight reduction. Some of these membrane mirrors are coupled to a pressurized cavity with the end goal of using the pressure in the chamber for shape control. The replacement of rigid mirrors for optical quality membrane mirrors is still a large area of research with many questions thus far requiring further investigation. These areas include modeling, material properties, fabrication due to high tolerances required for imaging, storage, and deployability. The ability to accurately model and predict the dynamics of these space-based membrane mirrors is of great importance. This will lead to more adequate design and manufacturing processes and optimized performance of such systems.The work presented here focuses on the validation of an impedance-based model of a membrane in air and of a coupled membrane–cavity system using experimental results. The impedance based model takes into account sound radiation and energy loss to the far field. This is crucial in earth-based telescopes and also very important when testing and validating these systems on earth before being launched into space.