Local effects of piezopolymer patches on inflatable space-based structures

摘要

Inflatable structures are often characterized as membranes (that is, structural elements that cannot resist bending moments). This simplification raises the question of whether membrane theory can account for the effects of active, surface-mounted piezopolymer patches. This work discusses these effects on the dynamic behavior of a flat, rectangular coupon section and assesses the patch's ability to sense and actuate transverse deflections of the thin-film substrate using traditional membrane theory. The Rayleigh-Ritz method was employed to approximate the natural frequencies and mode shapes of this layered system. Although including the additional mass of the patch, traditional membrane theory was unable to account for the added stiffness of the patch layer. When the piezoelectric behavior of the patch was considered, membrane theory failed to model the piezopolymer as a useful sensor. Also, excitation of transverse vibrations was not possible using membrane theory, which does not allow application of bending moments. However, piezoelectric actuation was modeled as applied in-plane forces, which enabled the patch to suppress out-of-plane disturbances by altering the tension in the base layer as a function of applied voltage. References: 12