Active Beam Cross-Sectional Modeling

Abstract

A finite-element based analysis formodeling initially twisted and curved active composite beams with embedded anisotropic actuation is presented. It is derived from three-dimensional electroelasticity, where the original problem is reduced via the variational asymptotic method. The resulting cross-sectional analysis takes into consideration passive and active anisotropic and nonhomogeneous materials, and can model general (thin-walled, thick-walled, solid, build-up structure) cross-sectional geometries. The formulation requires neither the costly use of three-dimensional finite element discretization nor the loss of accuracy inherent to any simplified representation of the cross section. The developed formulation is numerically implemented in the Active Variational-Asymptotical Beam Section Analysis code (VABS-A), and several numerical and experimental tests cases are used to support validation of the proposed theory. Also, the effect of the presence of a foam core in originally hollow configurations is presented and counter-intuitive conclusions are discussed. The generality of the method and accuracy of the results increase confidence at the design stage that the active beam structure will perform as expected and, consequently, should lower costs from experimental tests and further adjustments.