Numerical modelling of the radiation efficiency of asymmetrical structures

Abstract

The radiation efficiency of a structural element is required by some models in order to predict its sound insulation. A common assumption is that the radiation on both sides of the element is the same. This is not true for asymmetrical structural elements like lightweight floors consisting of a beam-supported flat board. The radiation efficiency is larger on the beam side, because the beams act as exciters and increase the pressure level in the room. These different radiation efficiencies are calculated here for a two-dimensional cross-section by using finite elements and boundary elements. The obtained preliminary results illustrate that considering a single radiation efficiency can be a source of errors and that further investigation is required in order to improve predictions.

Using spectral finite elements for parametric analysis of the vibration reduction index of heavy junctions oriented to flanking transmissions and EN-12354 prediction method

“…For example, vibration reduction index must be defined taking into account the wall types [18] (i.e. vibration transmission from a floor to each of the parts of a double wall can be different) or radiation efficiencies can be different depending on the shape in each side of a wall [31,32]. Other aspects that are important to adapt current techniques and regulations for lightweight constructions are discussed in [33,34,11,35].…”