Updated shape monitoring of morphing wing structures using iFEM and SSB-iFEM: Applications to composite and modular architectures

Aircraft wings are traditionally designed as compromise configurations, able to provide acceptable performance over a range of flight conditions without being optimal at each operating point. Morphing-wing technologies, and trailing-edge morphing concepts in particular, can reduce this compromise by enabling continuous adaptation of the aerodynamic shape. In practical applications, however, achieving a prescribed morphing shape remains challenging, especially when aerodynamic loads reduce actuation authority and realistic sensor-placement constraints limit direct shape monitoring. This paper presents an updated iFEM-based closed-loop architecture for morphing-wing shape control and assesses it on two structures: a composite morphing trailing edge and a modular morphing wing. The first novelty is an updated control procedure based on the Levenberg-Marquardt algorithm, introduced to improve the stability and efficiency of the load-update process in the presence of aerodynamic disturbances, especially for flexible structures. The second novelty is the integration of Single Sensor Based inverse Finite Element Method (SSB-iFEM), which removes the need for fully back-to-back sensor layouts and enables shape sensing with single-sided or hybrid strain-sensor configurations. The third novelty is the extension of the framework from a single morphing trailing-edge device to a modular wing architecture with constrained sensor placement. Numerical results show that the updated procedure suppresses the oscillatory behavior exhibited by the original controller under severe aerodynamic loading while preserving convergence to the target shape. For the modular wing, the combined use of SSB-iFEM and a weighted load-update scheme enables shape control with limited sensor information, confirming the robustness and applicability of the proposed framework.