Shape sensing and damage detection of composite pressure vessels using inverse finite element method coupled with physics-based strain pre-extrapolation

This study presents an advanced strategy for shape sensing and damage detection of composite Type IV pressure vessels using the inverse finite element method (iFEM) coupled with a novel physics-based strain pre-extrapolation approach. The pre-extrapolation methodology, developed based on Kirchhoff plate bending theory, enhances the accuracy of full-field displacement and strain reconstruction by addressing the need for strain input across all structural regions. By incorporating discrete experimental measurements, this framework enables precise residual strain estimation, facilitating damage localization in composite structures. The proposed inverse model is validated through both numerical and experimental investigations, leveraging fiber optic sensor networks strategically placed along axial and circumferential segments of the pressure vessel. Quasi-static compression and low-velocity impact (LVI) tests are conducted to evaluate the model's performance under complex loading conditions. The reconstructed displacement and strain fields demonstrate the exceptional capability of iFEM in accurately capturing structural deformations and detecting damage initiation and progression. Notably, the method effectively identifies damage induced by LVI by analyzing residual strain distributions at critical post-impact time instances. Overall, the results underscore the robustness of the iFEM framework in capturing complex shape deformations and damage patterns that might otherwise remain undetected, highlighting its potential for real-time structural health monitoring of composite pressure vessels.