Structural health assessment of large-scale civil structures using inverse finite element method (iFEM)

The role of Structural Health Monitoring (SHM) is crucial in ensuring the safety and serviceability of civil infrastructure by identifying, localizing, and quantifying structural damage. In this study, an isoparametric framework for plane strain inverse elements is developed and implemented for full-field displacement reconstruction and damage assessment in large-scale civil structures, such as tunnels and gravity dam retaining walls. In contrast to conventional model-based or vibration-driven SHM techniques, iFEM does not require prior knowledge of loading conditions or material properties, making it well-suited for complex structures with material variability and limited sensor accessibility. The inverse formulation minimizes a weighted least squares error functional between experimentally measured and numerically estimated strain fields, enabling accurate reconstruction even under sparse sensor configurations. Numerical validation is conducted against a benchmark case using a fundamental two-dimensional inverse element. Subsequently, SHM and damage assessment studies are performed using higher-order inverse elements with limited sensor data. Findings indicate that the iFEM framework can accurately detect early-stage damage for real-time maintenance interventions, providing a cost-effective and scalable model-based tool for real-world SHM applications in the civil sector.