关键词: 结构变形监测, 变形重构, 逆向有限元算法, 自适应智能结构, 变形机翼

Abstract: Benefiting from the ability of providing reference information for deformation-control system, shape sensing technology is considered as an important way to guarantee the safety and improve the operational performance of self-adaptive morphing structures. However, the conventional optical imaging based shape sensing technologies are unable to meet the need of real-time shape sensing of self-adaptive morphing structures. In this paper, a shape sensing technology based on the inverse Finite Element Method (iFEM) and the idea of superposing segmented displacement is proposed to reconstruct the deformation of morphing wing’s major load-bearing structure of fishbone. Firstly, a four-node quadrilateral inverse-shell element is developed based on Mindlin deformation theory for the major load-bearing structure of the morphing wing. Secondly, strain sensors are used to obtain strain distribution of the structure surface as the input of the proposed method. Then the transfer function between the strain field and the displacement field can be obtained by adopting the least square variational equation. Finally, the corresponding displacement of the major load-bearing structure is reconstructed, based on which the reconstruction of wing deformation can be realized. The proposed method is verified through experiments performed on the major load-bearing structure of a morphing wing. The results show that under the deflection angles of 5°, 10°, and 15° of the morphing wing, the reconstructive displacements have a strong consistency with measured displacements, which verifies the feasibility and accuracy of the proposed method.

Key words: structure shape sensing, shape reconstruction, inverse finite element method, self-adaptive smart structures, morphing wings