Session: 04-15-01: Congress-Wide Symposium on NDE & SHM – NDE and Prognostics in Structural Applications

Paper Number: 73502

Start Time: Tuesday, 10:55 AM

73502 - Beam Element-Based Inverse Finite Element Method for Shape Reconstruction of a Wing Structure 

Shape sensing technology can provide real-time structural deformation information which can serve as the feedback for the control system of the morphing aircraft. It realizes accurate deformation control under different flight tasks, and finally maintains the optimal comprehensive performance of the morphing aircraft in the whole flight envelope. Compared with traditional deformation monitoring technology, the deformation monitoring based on strain information can better meet the requirements of lightweight and real-time aerospace vehicle deformation monitoring. The main families of approaches to shape sensing are identified as the inverse Finite Element Method (iFEM), the Modal Method (MM), Ko's displacement theory (Ko) and Surface Fitting Algorithm Based on Surface Patches Splicing. Among the currently available methodologies to perform shape sensing, iFEM has the advantages of not requiring data on the material properties and on the applied loads, and high reconstruction accuracy, which has been widely paid attention by researchers. However, there are few researches on deformation reconstruction of complex structures, most of which simplify the structure into simple plates and beams, without considering the complexity of the structure. Besides, it is difficult to apply iFEM to complex structures, such as the inability to place sensors both on the upper and lower surfaces of the specified structure and the large amount of calculation. To solve this problem, this paper proposes a beam element-based iFEM on the single surface strain construction error function, which is suitable for pure bending deformation.This paper uses the beam element-based iFEM to study the method of realizing the accurate inversion of the global deformation of the fishbone structure which is the adaptive deformable wing's main load-bearing structure. This paper focuses on the actual deformation state of the fishbone structure and using the classical beam bending theory to establish a 2-node inverse-beam element. As long as the strain distribution on the upper surface of the fishbone structure is measured, it can be used as the input of the algorithm to construct the error function. The least square variational principle is used to solve the transfer function between the strain field and the displacement field of the structure, and the deformation shape of the fishbone structure is reconstructed, which provides a basis for the deformation monitoring of the whole wing in the future.This paper carries out the deformation experiment and the COMSOL finite element simulation of the fishbone structure respectively. Then, the reconstruction results of iFEM are compared with the experimental results and simulation results.The experimental results show that using the 2-node inverse-beam element can accurately reconstruct the deformed shape of the fishbone structure which verifies that iFEM is effective and reliable in the deformation reconstruction of complex adaptive deformed wing structure.

Presenting Author: Tianyu Dong Nanjing University of Aeronautics and Astronautics

Authors:

Tianyu Dong Nanjing University of Aeronautics and Astronautics
Shenfang Yuan Nanjing University of Aeronautics and Astronautics
Tianxiang Huang Nanjing University of Aeronautics and Astronautics