Vibration testing for dynamic properties of building floors

Abstract

The paper presents a comparison of testing methods and post processing techniques for modal properties of a fully furnished chipboard floor and an unfurnished prestressed concrete floor. A thorough modal testing required relocation of transducers among test setups to acquire multiple synchronous measurements of floor response due to heel drop excitation or shaker excitation. The comprehensive experimental data was processed by a specialised operational modal analysis software. On the other hand, a simple testing approach only required records of floor response at a single point due to heel drop. The measured response can be easily analyzed using simple procedures of structural dynamics. Whilst valuable information about the floor modal properties including the mode shapes was obtained using the sophisticated approach, the uncomplicated single-point heel drop test was found to provide reasonably accurate evaluation of natural frequencies and damping ratios for both of the test floors, which verifies the attractiveness of the simple technique. Based on experimental results, both of the floors would be considered as low-frequency floors by commonly used guidelines on human-induced floor vibrations. Furthermore, the effect of fit-out conditions and construction materials on the huge discrepancy between damping values of the two floors was also observed.