Sensing and Actuation of Chiral Structures

摘要

Modeling of a chiral structure with bonded piezoelectric patches on its ligaments was performed using the ANSYS Multiphysics? finite element code. Two types of chiral structures were analyzed: a hexagonal shape and a quadrangle shape. The two types were analyzed for 2D and 3D structures. The quadrangle was analyzed for two types of hosting structures: foam and aluminum, while the hexagonal shape was analyzed only for foam type hosting structure. Both static and dynamic analysis was applied yielding displacements, stresses, natural frequencies and buckling loads. Beside the mechanical tractions, both structures were calculated for the actuation of the piezoelectric patches (electrical loading) to yield displacements of the structures. Depending on the mechanical loads, it was shown that the piezoelectric patches, acting as sensors, are sensible enough to detect the tractions. In the actuation mode, it was shown that the patches have a low authority, and the resulting displacements were very low. The low authority in the actuation mode is due to the relatively low piezoelectric properties assumed for the patches and the low structural matching between the patches and the hosting structure. It is believed that with improved piezoelectric properties and correctly positioning of the patches will yield the required actuation authority.