A novel design of an actively deformable honeycomb structure with application to a variable thickness leading-edge wing

Abstract

This work develops a novel design method for the actively deformable honeycomb structure to realize the variable thickness leading-edge wing. Firstly, the classical Gibson theory is extended to be applicable for the non-regular hexagonal honeycomb single-cell with the positive Poisson’s ratio and the concave hexagonal honeycomb single-cell with the negative Poisson’s ratio. The equivalent mechanical properties of the above two types of single-cells are deduced. Then, the concept of the deformation unit composed of positive and negative Poisson’s ratio honeycomb multi-cells is proposed. The shape memory alloy is assigned as an actuator to produce the in-plane incompatible deformation which excites the out-of-plane bending of the deformation unit. The relationship between the in-plane driving displacement and the bending angle of the deformation unit is investigated. The segmented two-layered honeycomb-core plate composed of positive and negative Poisson’s ratio honeycomb layers is constructed using deformation units. Finally, the initial configuration of the leading-edge is simulated by the segmented honeycomb-core plate. The driving displacements required to be imposed to each deformation unit are determined according to the target shape of the leading-edge. The proposed method is validated by changing the leading-edge from the blunt shape to the sharp shape, using finite element simulations.