A structural design approach for a droop nose morphing demonstrator with shape memory alloy patches

An innovative concept has been devised for assisting an actuator to morph a Droop Nose (DN) structure, which is comprised from the skin and three longitudinal omega stringers. The concept is based on the development of a suitable composite patch, with embedded shape memory alloy (SMA) wires, and the appropriate design of a DN configuration for morphing purposes. The integration of composite patches, to the DN structure, has a dual innovative role: (a) it can either provide/extend the morphing capabilities of the structure, in terms of displacement or (b) it can reduce the required actuation forces for obtaining morphing of the DN structure. For determining the most suitable DN configuration, for the application, a sensitivity analysis, with the aid of ANSYS finite element (FE) software and a design of experiments (DoE) approach, has been carried out. The investigated parameters (geometrical and lamination characteristics) are selected to vary the stiffness of the DN structure. Additionally, a numerical parametric FE model, of the SMA patch and its configuration, is developed and analysed. The developed FE models simulated the shape memory effect of SMA wires considering their activation temperature and hence their thermo-mechanical behaviour. Eventually, a possible integration of the SMA patches to the DN structure is proposed and the respective remarks are highlighted.