Optimal reliability and efficiency design with experimental validation of a locking mechanism for morphing wings using data-driven surrogate models

Abstract

To satisfy the engineering demand for millisecond-level reliable locking and holding during the fold-to-deploy process of morphing wings in high-speed aircraft, this study proposes a novel spring-taper-pin wedge-locking mechanism (STPWLM). The STPWLM is optimized to enhance locking reliability and efficiency and validated through physical experiments. At supply pressures of 0.4 MPa, 0.6 MPa, and 0.8 MPa, the optimized prototype reduces link rebound oscillations by 100 %, 100 %, and 66.7 %, and shortens locking duration by 100 %, 100 %, and 56.98 %, respectively, compared with the unoptimized prototype. Specifically, a mechanical structure model is established according to the functional requirements and working principle. Through engineering expertise, 11 primary structural parameters are subsequently identified. An analytical model of the force transmission and motion properties of the STPWLM is established to identify four key structural parameters, thereby clarifying the design optimization guidelines. The locking performance metric is defined as a composite measure that combines the number of link rebound oscillations and the locking duration, jointly reflecting reliability and efficiency. To address the difficulty of explicitly calculating this metric, a transient dynamic finite element simulation model is constructed, and comparative simulations are used to verify the design guidelines. Optimal Latin hypercube design (OLHD) coupled with data-driven surrogate models is employed to predict the locking performance metric, significantly reducing the computational cost of simulations. The design of experiments (DOE) method is utilized as a decision support tool for sensitivity analysis of the main and interaction effects of the core structural parameters, taper pin positioning distance and taper angle, thus providing a solid basis for optimal design. A multi-island genetic algorithm (MIGA) is applied to determine the optimal combination of the core structural parameters. Morphing wing prototypes before and after optimization are fabricated, and a series of comparative physical experiments are conducted. Experimental results confirm the accuracy of the analytical model and demonstrate the superiority of the optimal design. These findings provide valuable guidance for the engineering design and application of morphing wings with an integrated locking mechanism.