In order to design and specify vibration abatement solutions (via tuned damping) for a multi-bay floor system, a reasonably accurate knowledge of the dynamic attributes of that floor system is required. These can be evaluated numerically (using finite element analysis) and verified experimentally by vibration measurement. Finite element modal analysis allows for the prediction of the natural frequencies, their corresponding mode shapes and modal masses. Vibration measurement enables the finite element model to be fine-tuned and the inherent level of damping in the structure measured. The correlated model can then be used to design tuned mass dampers for the floor system.
DEICON recently completed the modeling and analysis of a 16-bay dance floor, with some irregularities in its geometry. As in most floor systems, the vibratory motion of a mode was not just confined to a single bay. For example, the first mode shown in Figure has the shape of a spatial sinusoidal wave vibrating the two adjacent bays an out of phase manner, i.e. as one bay is moving up the other is moving down. The outcomes of the analyses are being used in designing 10 tuned mass dampers (TMDs) for the floor system.