Optimization of lightweight floors in the low frequency range with a FEM based prediction model

The impact noise transmission at low frequencies is a well known problem of lightweight floors, which is treated in many publications. A satisfying solution, considering the different construction principles of lightweight floors, could not be found so far. To overcome this problem a FEM based prediction model for the optimization of the floor construction and the improvement of the impact sound insulation has been developed and applied in a current research project at the TU München. The overall approach of the prediction model consists of the three-dimensional modelling of the structure and the excitation source (standard tapping machine), the subsequent modal- and spectral analysis and the computation of radiated sound from the ceiling. The validation of the prediction model has been carried out by comparing the evaluated impact sound pressure levels with results from measurements on 25 different floor constructions. In the next step the prediction model was used for the improvement of established lightweight timber floors. Finally these constructions were tested in a laboratory test stand according to ISO 140-6 at ift Rosenheim centre for acoustics and the ibp Stuttgart. This contribution shows the results of the computations and the construction rules developed for optimized lightweight floors.     «

The impact noise transmission at low frequencies is a well known problem of lightweight floors, which is treated in many publications. A satisfying solution, considering the different construction principles of lightweight floors, could not be found so far. To overcome this problem a FEM based prediction model for the optimization of the floor construction and the improvement of the impact sound insulation has been developed and applied in a current research project at the TU München. The overal...     »