Full-field Deformation Perception via Flexible Sensing Film Integrating Modified Inverse Finite Element Method

Journal paper

Jingjing Ji

YongAn Huang

Jiafeng Zhu,Bangyan Niu,Jin Lu

IEEE Transactions on Instrumentation and Measurement

SCI

1 - 1

Strain, Skin, Deformation, Sensors, Aerodynamics, Surface, reconstruction, Shape

10.1109/TIM.2024.3374308

2024-03-12

Full-field deformation can support the adjustment of morphing aircraft’ shape which has significant impacts on the aerodynamic performance. A deformation perception system (DPS) combining an intelligent flexible sensing film (iFlexSense) and a displacement reconstruction algorithm is proposed. The iFlexSense features ultra-thin, low elastic modulus, and geometric conformality. A strain observation has been realized simply by pasting the sensing film to the inner surface of the wing skin. A single-side inverse finite element method (ssiFEM), is proposed for displacement reconstruction from discrete strain observations on just one side of the target structural component, circumventing the requirement of precisely paired sensors in the vanilla iFEM. The full-field displacement is formulated as a closed-form solution combining an offline quasi-stiffness matrix and discrete strain observations. Hence a rapid estimation for the displacement is achieved. The ssiFEM has been validated in simulations on a platy cantilever. The relative error of ssiFEM reaches no more than 3.5% at the maximum deflection point under two typical cases, and after a data densification (DD) step, the mean absolute error averaged the whole cantilever can be reduced. The DD-enhanced ssiFEM has been employed with the prototyped iFlexSense for a practical deformation perception system of a morphing wing skin. The peak error of the perception system was less than 2mm out of a ±30mm deflection range. The application prospects of the system for perceiving smooth shapes can be envisioned.