Current advances in the structural optimization of aircraft structures have led to the introduction of sandwich panels into the optimization process. This study attempts to extend the possibilities of sandwich optimization by proposing an analytical model which predicts the homogenized properties of a sandwich panel with a honeycomb core and CFRP skins. The model is based on a combination of Classical laminate theory and a 1-D beam model of the honeycomb core. The finite-element equivalent of tensile and shear tests is used to validate the proposed model on a broad range of core geometries with different combinations of core thickness, wall angle, cell elongation, and cell wall thickness. The results of 425 different geometries showed the overall precision of the proposed model, highlighted effects in the behavior of the core that drive the sandwich properties further from the predicted values, and suggested which parts of the model are suitable for optimization and where are their limits of applicability.

This paper provides an insight into ongoing research aimed at designing a morphing wing with the ability to continuously adapt its aerodynamic shape. The wing is targeted at a general purpose unmanned aerial vehicle. The morphing wing concept outlined in the paper is based on continuous camber changes of the wing leading and trailing edges, allowing optimal performance in different flight regimes. The aeroelastic tailoring method is used to design the load carrying structure of the wing in order to define the optimal stiffness and strength of the structure, which are considered as fixed in subsequent design steps. The research proposes a novel modular design approach that combines aerodynamic shape optimisation and aeroelastic considerations for designing morphing wing surfaces.

Metamaterials show a considerable potential in the field of complex optimization of aerospace structures. To fully exploit this potential, the authors present a novel approach to modeling the structural response of a sandwich panel with metamaterial core and CFRP skins that could be used within a single-step optimization process. The proposed approach is illustrated using a model of a panel with aluminum honeycomb core. Obtained results confirm the high potential of the inclusion of the core optimization into the optimization framework. Simple preliminary validation utilizing the finite element analysis presented in the closure of this study yielded a satisfactory agreement with the results of the proposed analytical model. The maximum reached difference of five percent can be attributed to a different shape of deformation of the honeycomb core within the sandwich as opposed to a deformation of the honeycomb core alone.