Medium-high frequency optimization of a passenger cabin mock-up using response surface models of SEA coupling loss factors

Statistical Energy Analysis (SEA)is the most suitable technique to solve medium-high frequency dynamic optimisation problems. The subsystem energies of a SEA model are controlled by (coupling) loss factors (CLF and ILF) that depend on physical parameters of the subsystems. If it is required to bring the energy of some subsystems under prescribed levels, it is proposed to proceed according to the following steps. (Here it is assumed to use commercial software for SEA: in this case explicit relations among CLFs and physical parameters are not available). In the first step, the sensitivity of subsystem energies to CLFs can be computed to recognize the most effective CLFs, i.e. those giving rise to the largest energy variations. Having selected a set of ”effective” CLFs, approximate relations between these CLFs and the relevant physical parameters can be determined after performing appropriate numerical experiments with the SEA software. In this phase Design of Experiment (DoE) can be fruifully used. Consequently an approximate relation between subsystems energies and physical parameters is available. This last relation can be used to formulate an optimisation problem in order to lower the energies of some subsystems. This technique is applied to medium-high frequency optimization of a passenger cabin mock-up.