Design and experimental verification of a large-scale coupled morphing-wing mechanism for hypersonic vehicles

Hypersonic morphing vehicle (HMV) can reconfigure aerodynamic geometries in real time, adapting to diverse needs like multi-mission profiles and wide-speed-range flight, spanwise morphing and sweep angle variation are representative large-scale wing reconfiguration modes. To meet the HMV's need for an increased lift and a lift to drag ratio during hypersonic maneuverability and cruise or reentry equilibrium glide, this paper proposes an innovative single-DOF coupled morphing-wing system. We then systematically analyze its open-loop kinematics and closed-loop connectivity constraints, and the proposed system integrates three functional modules: the preset locking/release mechanism, the coupled morphing-wing mechanism, and the integrated wing locking with active stiffness control mechanism. Experimental validation confirms stable, continuous morphing under simulated aerodynamic loads. The experimental results indicate: (i) SMA actuators exhibit response times ranging from 18 s to 160 s, providing sufficient force output for wing unlocking; (ii) The integrated wing locking with active stiffness control mechanism effectively secures wing positions while eliminating airframe clearance via SMA actuation, improving the first-order natural frequency by more than 17%; (iii) The distributed aerodynamic loading system enables precise multi-stage follow-up loading during morphing, with the coupled morphing wing maintaining stable, continuous operation under 0–3500 N normal loads and 110–140 N axial force. The proposed single-DOF coupled morphing mechanism not only simplifies and improves structural efficiency, but also demonstrates superior performance in locking control, stiffness enhancement, and aerodynamic responsiveness. This establishes a foundational framework for the design of future intelligent morphing configurations and the implementation of flight control systems.