Predicting the sound insulation of finite double-leaf walls with a flexible frame

Abstract

With double-leaf wall systems such as plasterboard walls, a high sound insulation can potentially be achieved with a relatively low weight. The accurate sound transmission analysis of this type of wall is challenging since the leafs are usually coupled to a common frame, and since the finite dimensions play a role at lower frequencies. Existing analytical models for sound insulation prediction account for the deformation of the wall in an approximate way, while detailed numerical models are computationally very demanding. In this work, a sound insulation prediction model that achieves a high prediction accuracy at a low computational cost is developed. The wall components that display low geometrical complexity, such as the wall leafs and the cavity, are modelled in a analytical way. Sound absorbents in the cavity are modelled as equivalent fluids. The metal studs, which have a highly deformable cross section, are modelled in full detail with finite elements. The sound fields in the sending and receiving rooms are modelled as diffuse; they are rigorously coupled to the deterministic wall model by employing a hybrid deterministic-statistical energy analysis framework. With the resulting room-wall-room model, the airborne sound insulation is predicted for a range of double-leaf plasterboard walls with single, double and triple plating and with different cavity depths. The obtained transmission losses are validated against the results of an extensive set of experimental tests. A very good agreement between predicted and measured transmission loss values is observed. The single number ratings for the airborne sound insulation for nearly all walls differ from the experimental values by 0 to 2 dB, which is close to the average experimental reproducibility. At the same time, the computational cost is more than three orders of magnitude lower than for recently proposed models of similar accuracy.

Perforated Steel Stud to Improve the Acoustic Insulation of Drywall Partitions

“…Looking at prediction models for sound insulation suitable for building walls, the vast majority do not consider studs or structural links between the plasterboards [18,37,38]. However, work by Wyngaert [39] developed a model with finite walls and flexible frames demonstrating reasonable accuracy in comparison to experimental tests. Other notable models that consider structural links include Lin and Garrelick [40], Takahashi [41], Skelton [42] and Arjunan et al [43].…”

A review of the different approaches to predict the sound transmission loss of building partitions

“…Alimonti et al 105,106 proposed a hybrid FE-TMM approach to evaluate the vibro-acoustic descriptors of flat structures, combining the accuracy and versatility offered by FEMs with the efficiency of the TMM, in order to significantly reduce the computational effort. Van den Wyngaert et al 107 employed a deterministic-SEA hybrid approach to couple the analytical model of wall leaves and the FE model of the metal frame with the diffuse sound field in the emitting and receiving room, in order to determine the sound insulation of a double-leaf wall with a flexible frame. This approach, consisting in a deterministic description of the partition coupled by means of power balance to a stochastic modelling of the rooms, was previously used to evaluate sound transmission through different kinds of building partitions by Reynders et al 108 The WBM 109 was used by Dijckmans et al 110 to compute the sound transmission loss of cavity walls by taking into account coupling between the rooms, the panels, and the air cavities.…”

Design and Additive Manufacturing of Porous Sound Absorbers—A Machine-Learning Approach

“…A second important aspect is the application of porous materials with the effect of decoupling vibrating structures. This effect is commonly employed for improving sound insulation of double panel walls, for example in aircraft fuselage sidewall panels [ 4 , 5 ] or in building acoustics [ 6 , 7 ]. Thereby, the two wall panels are separated by the porous material.…”