Damage localization in pretensioned prestressed concrete slabs based on two-dimensional modal curvature

Abstract

This study presents a method for damage localization in one-way pretensioned prestressed concrete slabs based on two-dimensional modal curvature. A finite element model is developed to determine the dynamic characteristics of the slab, including natural frequencies and mode shapes, and is validated through comparison with experimental results. The discrepancies between numerical and experimental results are less than 4.1% for the first three flexural natural frequencies, while the Modal Assurance Criterion (MAC) values exceed 0.836, confirming the reliability of the model. Based on this validated model, two damage scenarios are introduced by creating localized openings in the slab. The results indicate that such damage cannot be effectively detected through changes in natural frequencies or MAC values, whereas the damage index (DI) enables clear identification of damage locations. Furthermore, the study demonstrates that low-order mode shapes are sufficient for accurate damage localization, which is of practical significance since these modes are easier to measure, less sensitive to noise, and allow for a reduction in the number of sensors, thereby enhancing the feasibility and cost-effectiveness of practical applications.