Scaling Analysis for Large Membrane Optics

To meet future requirements, space telescopes are envisioned to require optics tens of meters in diameter. Packaging restrictions of current and foreseeable launch vehicles prohibit the use of a single rigid monolithic mirror of that size. Membrane optics research seeks to create large diameter apertures out of thin flexible Aim-like reflective material. For our analysis, we examine those structures with embedded in-plane actuated piezoelectric elements for active surface shape control. By analyzing the non-dimensional form of the governing differential equation, relative effects of linear and non-linear terms are apparent. Then, through a series of MSC.Nastran finite element models, scalability issues are explored to include the effects of non-linear terms, existing membrane pre-tension, and unimorph versus bimorph actuation. Results show small-scale (existing) test articles may respond in accordance with linear models, but may mask the nonlinear characteristics which dominate large full-scale membrane optics in the proposed applications.