Performance of enhanced modal participation ratio in multiple-story damage localization

This study evaluates the effectiveness of the Modal Participation Ratio (MPR) and Enhanced Modal Participation Ratio (EMPR) methods for damage localization, specifically in multi-story structures with combined story damage scenarios.The originality of this work lies in its combined use of numerical and experimental validation on the same four-story steel frame model, focusing on complex multidamage conditions rather than single-story or simulation-only studies.MPR values were derived from dynamic responses of a finite element model of a steel frame, obtained through numerical simulations using randomized white noise acceleration, while EMPR values were derived from experimental tests conducted on the same steel frame model, utilizing ambient vibrations.Thirteen damage scenarios, including single-, two-, and three-story combinations, were investigated.The results show that damaged degrees of freedom consistently exhibit the highest MPR values, and that combined damage scenarios often produce additive MPR patterns that aid in damage separation.First-story damage had the most dominant effect on overall MPR variation, occasionally reducing the visibility of higher-story damage.The findings confirm that both methods are reliable tools for structural health monitoring and damage identification, even in complex multi-damage configurations.