Active metal structures

Morphing of metallic wing structures has fascinated generations of researchers; numerous and sometimes bizarre architectures have been proposed, tailored to specific end-applications and aircraft type. Although different for layout, all of them can be categorized in two basic groups: mechanized architectures and compliant mechanisms.Mechanized architectures implement morphing through the rigid-body motion of stiff subcomponents interconnected by suitably designed kinematic chains and actuation leverages.Each subcomponent of the kinematic chain is sized to provide its own contribution to the adsorption of the external solicitations arising in operative conditions; actuators and actuation transmission line are sized to enable the motion of the system and to preserve given shape configurations while counteracting aerodynamic loads with the minimum need of power.Compliant mechanisms involve the deformation of structural elements to enable the required shape-change; mechanical properties of the structure have to be properly distributed in order to assure adequate morphing compliance and adequate stiffness to withstand external loads.In this chapter, the design philosophy behind each type of morphing structure has been presented, together with practical applications to wing trailing edge camber adaptation.By referring to similar end-application, the adopted design strategies and obtained outcomes are compared, thus better highlighting the advantages and weak points of each morphing solution