Inverse Finite Method Investigation for Adaptive Structures (iFEM)

This research project is evaluating an innovative technique that uses fiber optic strain sensors to measure structural deformations and full field strains. An inverse finite element method (iFEM) analysis reconstructs a deformed structural shape based on the strain measurement data simulated by FEM analysis to represent the in-situ strain measurements. By mapping the iFEM displacement solution onto a full FEM model, without the applied loading, the complete fields of displacement, strain, and stress are reconstructed to a high degree of accuracy. This project supports the work on multiple flight research projects at NASA Armstrong.

Work to date: The team has completed and validated a 1-dimensional beam element test using a compliant slider mechanism.

Looking ahead: Future plans involve developing and validating the algorithm on a full size flight test article.

Benefits

• Accurate: Algorithm is capable of accurate full-field structural shape and strain measurement
• Economical: Uses a minimum number of sensors to recreate the full-field structural deformations and strains
• Improves safety: Enables more efficient health monitoring of control surfaces and flexible structures

Applications

• Aircraft wing flaps
• Helicopter blades
• Motor vehicles
• Trains
• Ships and submersibles
• Wind turbines

This research project is evaluating an innovative technique that uses fiber optic strain sensors to measure structural deformations and full field strains. An inverse finite element method (iFEM) analysis reconstructs a deformed structural shape based on the strain measurement data simulated by FEM analysis to represent the in-situ strain measurements. By mapping the iFEM displacement solution onto a full FEM model, without the applied loading, the complete fields of displacement, strain, and stress are reconstructed to a high degree of accuracy. This project supports the work on multiple flight research projects at NASA Armstrong.

Work to date: The team has completed and validated a 1-dimensional beam element test using a compliant slider mechanism.

Looking ahead: Future plans involve developing and validating the algorithm on a full size flight test article.