Identification of human-structure interaction from full-scale observations: The impact of modeling errors

• Published in: Journal of physics. Conference series 2024-06, Vol.2647 (12), p.122001
• Main Authors: Nimmen, Katrien Van, Broeck, Peter Van den
• Format: Article
• Language: English
• Subjects: Damping ratio; Errors; Interaction models; Modelling; Parameter estimation; Parameter sensitivity; Pedestrian bridges; Power spectral density; Resonant frequencies; Structural response; Vibration damping
• ISSN: 1742-6588; 1742-6596
• DOI: 10.1088/1742-6596/2647/12/122001

The added-damping effect of human-structure interaction (HSI) is of great importance on the vibration serviceability of footbridges. To account for the interaction effects between the human body and the footbridge, the former is often described by a mass-spring-damper (MSD) system. The parameters of this MSD system are in this contribution estimated by minimizing the discrepancy between the experimentally derived and the numerically simulated power spectral density of the structural response. The methodology assumes that the dynamic behavior of the empty structure, the average weight and the distribution of step frequencies in the crowd are known. This contribution furthermore focuses on the impact of modeling errors. It is shown that the result is mostly sensitive to errors related to the mean value of the distribution of step frequencies and the structural natural frequencies. It is also shown that the impact of modeling errors decreases as the impact of HSI increases. The results are used to refect on the suitability of two real footbridges for the parameter estimation problem. When the impact of the reasonably expected modeling errors is taken into account and the results of both case studies are combined, a natural frequency and damping ratio of approximately 3.0±0.2 Hz and 34±8% are estimated for the MSD interaction model.