Damping Characteristics of Timber Flooring Systems with Respect to Low-Frequency Vibration Modes

The vibration serviceability of flooring structures has been of concern for decades. To date, design criteria classifying the dynamic behaviour of different types of timber flooring structures to an acceptable degree have not been well established. Parameters commonly used to investigate and assess vibrational performances of timber floors include natural frequencies, damping ratios, dynamic displacements, velocities, accelerations, mode shapes and static point load deflections. The damping ratio is also used for design purposes, but the value of damping ratio for design is controversial. This paper presents experimental evaluation of the damping ratios on full-scale timber flooring systems for different modes of vibration and details the variation in damping under different dead weights. The test results in this study highlight the need for further research in selecting appropriate values of damping parameters for design purposes.