This paper presents an experimental study on the detection and localization of damage in a steel plate using vibration-based methods. Dynamic impulse tests were conducted on both undamaged and damaged plate to determine changes in modal parameters, such as eigenfrequencies and mode shapes. Several damage detection methods, including the Modal Assurance Criterion (MAC), Coordinate Modal Assurance Criterion (COMAC), Mode Shape Curvature (MSC), Mode Shape Curvature Square (MSCS), and Damage Index (DI), were applied. The results showed that while MAC and COMAC effectively detected damage, they did not provide information about the location. MSC and MSCS indices demonstrated improved damage localization, with the MSCS being particularly effective. The DI index provided the clearest and most accurate representation of the damage location. These findings highlight the potential of these methods for non-destructive testing and structural health monitoring.

This study presents a data-quality-aware methodology for non-contact identification of the catenary parameter and horizontal force in multi-span railway traction networks using terrestrial laser scanning. It establishes a quality-assessment and decision-support layer that lays the foundation for future automated inspection systems. The introduced closed-loop framework uses geometric and statistical quality indicators, such as visible cable length and relative confidence interval (CI) width, to determine whether a result is accepted, reacquired, or referred for manual review. Validated against laboratory dynamometer measurements across multi-span configurations, TLS-derived forces showed a 4.6% mean absolute relative difference. In field test on 16 traction segments, local root-mean-square errors remained consistently low (3.4–3.9 mm), yet relative CI widths varied substantially. Visible length strongly negatively correlated with CI width (ρs = -0.81, p < 0.001). Joint evaluation of visible length, fit uncertainty, and point-distribution uniformity supports metrologically informed interpretation of TLS-derived catenary parameters under field acquisition constraints.