A study of the coincidence effect and critical frequency of a dash panel using the hybrid FEA–SEA and experimental methods
This paper provides a new method to determine critical frequencies of any engineering structures by identification of peak frequencies of their internal damping loss factor curves. The novelty embodies the following aspects: first, the indirect method was applied to measure the critical frequencies of large complex thin–walled panels; second, the hybrid FEA–SEA was applied to analyse the sound insulation characteristics which provide an important approach to solve the middle frequency engineering problems. A hybrid of finite element analysis and statistical energy analysis was applied to calculate the dash sound transmission loss in the middle frequency range of 100∼2,000 Hz. A sound transmission loss experiment was conducted to verify the analysis. The trough of the sound transmission loss curve appeared at 200~250 Hz where the internal damping loss factor curve reached its peak. Therefore, the coincidence of the dash panel is proved to be at the critical frequency of 210 Hz.
Keywords: vehicle dash panel, vehicle dashboard, coincidence effect, critical frequency, vehicle noise, hybrid FEA–SEA, peak frequencies, damping loss factor curves, thin–walled panels, finite element analysis, FEA, SEA, statistical energy analysis, sound transmission loss, interior acoustics, magnesium alloy panels, vehicle cabin acoustics