Human-induced vibration of cold-formed steel floor systems: Parametric studies

摘要

Designing a lightweight floor to prevent annoying vibrations induced by human activities is still a challenge because numerous factors need to be considered. In consequence, there is still a lack of reliable models and adequate design guidelines pertinent to the vibration serviceability of cold-formed steel floor systems. To facilitate understanding the fundamental concepts of lightweight floor vibrations for serviceability design, a newly proposed damped plate-oscillator model was adopted in this research to predict dynamic responses of cold-formed steel floors induced by human walking. Three loading methods were developed based on this model. By using these loading methods, comprehensive parametric studies involving step frequencies, mass ratios, damping ratios, walking paths and end-support restraints were conducted. The present analytical studies show that the influence of moving or stationary occupants depends on the mass ratio of occupants to the floor and its significance could be negligible for small mass ratios. In addition, the boundary restraints at floor end-supports may not always reduce floor responses. On the contrary, relatively larger responses could be excited by human walking for the restrained floors having the fundamental frequency close to the multiple of the footstep frequency.