Vibroacoustic Simulation

11 Hybrid Systems

Basically, we have already applied the hybrid theory in preceding sections, for example Section 7.4. In many cases there were deterministic systems in the junction, for example a plate that we have considered as deterministic connection between the two cavity SEA systems and using the deterministic transfer matrix of the plate.

The twin chamber is an excellent test case for the hybrid method, as it constitutes a clear separation between random and deterministic subsystems and provides all the details of how to deal with each single step of hybrid FEM/SEA simulation.

11.1 Hybrid SEA Matrix

For pure SEA models the matrix from equation (6.113) is applied. The hybrid SEA matrix is similar except one additional damping contribution caused by the damping from the connected FEM-subsystems.

  (7.35)

All other impacts of the FE parts of the hybrid model are hidden in the hybrid coupling loss factors or an additional power input that may come from radiation of FE-subsystems into the SEA-subsystems.

11.2 Twin Chamber

Figure 11.1 Twin chamber arrangement for TL tests of panel.Source: Alexander Peiffer.

The twin chamber set-up is such a perfect example for the hybrid method, because both chambers are designed to be random by the large size and irregular shape. So, the ...