Hybrid modelling of transmission loss with acoustic treatment
* Presenting author
Hybrid methods are an excellent approach to determine the sound transmission loss of complex structures.In order to simulate the effect of acoustic treatment lay-up consisting of fibre material, foams and heavy layers the hybrid theory needs some modification to stay efficient. This presentation deals with the modal implementation of hybrid theory and the adaptations that are required to implement the modal approach for acoustic treatments.The treatment will be modelled as infinite layer using the transfer matrix method under consideration of possible simplifications to reduce the calculation time tremendously. This requires the mode shape mapping to regular grids.The method is implemented as locally and non-locally reacting trim showing that the non local approach is too strict for valid results.