Inverse finite element framework for aeroelastic integration of black-box subsystems under intellectual property constraints
Engin Metin KaplanPurpose
In large-scale aerospace integration, prime contractors frequently procure externally mounted subsystems from tier suppliers for major platforms. Accurate aeroelastic assessment requires the subsystem’s Outer Mold Line (OML) and key dynamic properties, specifically mass, stiffness and inertia. However, strict intellectual property (IP) and confidentiality constraints often limit the disclosure of internal structural details, hindering accurate structural dynamics integration. This study aims to propose a novel “Inverse-Finite Element Model (FEM) Reconstruction Framework” to develop a simplified, equivalent surrogate model that reproduces the aeroelastic properties of a subsystem without revealing its internal architecture.
Design/methodology/approach
A decoupled two-stage gradient-based optimization protocol was implemented. First, beam cross-sectional parameters were optimized to minimize the deviation between deflection responses of the reduced-order and high-fidelity reference models at four specific checkpoint nodes. Second, nonstructural mass properties distributed along the beam elements were optimized to reproduce the total mass, center of gravity and inertia tensor. This case was demonstrated with a case study.
Findings
The optimization results demonstrated high fidelity: the simplified model achieved an average deflection error of 1.68%, a mass error of 0.588%, an inertia tensor discrepancy of 0.949% and a center of gravity deviation of 1.02%. Validation under inertial loading and modal analysis indicated that the simplified model exhibits a deflection difference of 1.35%, and a deviation of 1.57% in the first elastic bending mode frequency. These results confirm that the proposed approach successfully bridges the gap between IP protection and high-fidelity aeroelastic analysis requirements.
Originality/value
This paper addresses a critical conflict in the aerospace industry: balancing IP confidentiality with the necessity for accurate structural dynamic data. The proposed Inverse-FEM Reconstruction Framework provides a unique solution for tier suppliers. Crucially, the approach strictly preserves the exact OML of the subsystem while completely hiding its proprietary internal design architecture.