Two-Dimensional Crack Monitoring in Concrete Structures Using Conductive Grid Patterns and Inverse Analysis: Theoretical Investigation

Abstract This study proposes a two-dimensional crack monitoring system for concrete structures based on a conductive grid-patterned coating and an inverse analysis framework. The sensing domain is discretized into a grid-based resistance network, enabling the efficient estimation of internal conductivity changes from boundary voltage measurements. Numerical simulations demonstrate that the proposed method can accurately detect and localize crack damage while exhibiting a conservative detection characteristic that avoids missing actual damage. For multiple damage cases, a smearing effect is observed due to the ill-posed nature of the inverse problem. To address this limitation, a two-step selective parameter updating technique is introduced, which significantly improves localization accuracy by reducing the number of unknowns. The results confirm that the proposed approach provides a practical and scalable solution for two-dimensional crack monitoring, while maintaining robust performance under complex damage conditions.