Multi-objective optimization for the geometry of trapezoidal corrugated morphing skins

Abstract

Morphing concepts have great importance for the design of future aircraft as they provide the opportunity for the aircraft to adapt their shape in flight so as to always match the optimal configuration. This enables the aircraft to have a better performance, such as reducing fuel consumption, toxic emissions and noise pollution or increasing the maneuverability of the aircraft. However the requirements of morphing aircraft are conflicting from the structural perspective. For instance the design of a morphing skin is a key issue since it must be stiff to withstand the aerodynamic loads, but flexible to enable the large shape changes. Corrugated sheets have remarkable anisotropic characteristics. As a candidate skin for a morphing wing, they are stiff to withstand the aerodynamic loads and flexible to enable the morphing deformations. This work presents novel insights into the multi-objective optimization of a trapezoidal corrugated core with elastomer coating. The geometric parameters of the coated composite corrugated panels are optimized to minimize the in-plane stiffness and the weight of the skin and to maximize the flexural out-of-plane stiffness of the skin. These objective functions were calculated by use of an equivalent finite element code. The gradientbased aggregate method is selected to solve the optimization problem and is validated by comparing to the GA multiobjective optimization technique. The trend of the optimized objectives and parameters are discussed in detail; for example the optimum corrugation often has the maximum corrugation height. The obtained results provide important insights into the design of morphing corrugated skins.

Shape optimisation of composite corrugated morphing skins

“…For the current work a Pareto based GA technique known as 'gaoptimset', was chosen in MATLAB to solve the optimisation problem. According to paper by Dayyani, Friswell [17] all settings for the optimisation were set as default except only two: the crossover function, which was set to 0.3, and the population size, set to 200. Since GA randomly generates the initial population set of individuals [18], for the identical setting parameters the optimised shape was too different.…”

Shape optimisation and buckling analysis of large strain zero Poisson’s ratio fish-cells metamaterial for morphing structures

“…There are limited studies available on mechanisms for maximising strain range with constant ZPR behaviour. Adjusting the deformation mechanism can improve and potentially extends the range of ZPR deformations that a metamaterial has due to the inherent unit cell architecture [25]. However, the methodologies used for large strain NPR may be applied to ZPR metamaterials.…”

Free-edge effects of corrugated laminates

“…Dayyani et al [35] suggested and investigated a wing design with skins made from trapezoidal cores coated with elastomeric skins. Dayyani and Friswell [36] considered static as well as aerodynamic aspects within their multi-objective optimization for the geometry of trapezoidal corrugated morphing skins. Filipovic and Kress [16] suggested a corrugation design and manufacturing method for corrugated laminates with a circular-sections corrugation shape and added scales for an aerodynamically smooth surface.…”