Impact sound insulation prediction and uncertainty quantification using a detailed source model in the modal Transfer Matrix Method

Abstract

The main goal of this work is to provide an efficient and accurate prediction of the impact sound insulation of layered structures for the entire building acoustics frequency range (50-5000 Hz). To this end, the modal Transfer Matrix Method (mTMM) has been developed to predict the impact sound radiation from layered floors resulting from tapping machine impacts, while accounting for simply supported boundary conditions. A detailed source model is presented which accounts for both the impact locations of the individual hammers and the discrete 2 Hz force spectrum. It is also discussed how this detailed source model can be implemented into the mTMM. Monte Carlo simulations provide insight into the uncertainty of the radiated sound power and the impact sound insulation improvement for bare and layered floors, resulting from the impact force location. Numerical validation is provided by comparison to finite element models of various floors. Narrow-band sound pressure level measurements on a layered floor have been performed to validate the detailed source model and its use in the mTMM. A comparison of measured and predicted results indicates the importance of a detailed source approach, especially at low frequencies