An Optimized iFEM for High Precision Real-Time Deformation Sensing of Composite Antenna Panel

In recent years, composite structures have gained extensive applications in the aerospace industry owing to their high strength-to-weight ratio, lightweight nature, and superior corrosion resistance. Notable examples include large phased-array antenna panels, composite wing skins, wing box sections, fuel tanks, and rocket fairings, etc. Taking the large phased-array antennas as a representative case, their antenna panels are constructed from multi-layered heterogeneous honeycomb sandwich panel, and serve as critical components for hosting functional elements of satellite antennas, which play a pivotal role in enabling core satellite functionalities. However, during on-orbit operations, these panels are exposed to the harsh and complex space environment, inevitably leading to unpredictable structural deformations that jeopardize satellite performance and operational safety. Consequently, research on deformation sensing for composite antenna panels holds significant engineering urgency. Among various deformation sensing methodologies, the inverse Finite Element Method (iFEM) has emerged as a highly promising technology due to its unique advantages: independence from structural parameters (e.g., mass and stiffness), no reliance on prior information, and capability for three-dimensional deformation reconstruction. The core principle of iFEM involves discretizing the structure into a series of inverse elements, characterizing theoretical strains via nodal displacements, and solving for these displacements by minimizing an error function between theoretical and measured strains, thereby enabling deformation sensing. Nevertheless, in practical aerospace applications, structures often operate under complex loading conditions and boundary constraints. Traditional iFEM approaches face challenges in achieving high-precision deformation reconstruction while maintaining real-time performance, limiting their applicability in mission-critical scenarios. To address these limitations, this study introduces a fundamental optimization of the iFEM framework, which significantly improves the accuracy and real-time performance of deformation sensing of composite antenna panels. Simulation and experimental results show that the proposed iFEM method can further improve the deformation reconstruction accuracy while ensuring real-time performance, and provide a reliable technical support for structural health monitoring under complex working conditions.