In this study, the radiation resistance for a parallel-piped box with a side of the elastic plate is analyzed by using the Stastistical Energy Analysis (SEA) method. For such a coupled system, the mode pairs giving the maximum power flow are very small parts of total mode pairs.
Thus, the SEA by the consideration of the power flow predicts the system responses by a relatively simple analysis, but the method by conventional modal analysis is difficult in the high frequencies involved with many modes.
In the experiment, the clamped plate is excited with the band-pass random noise to be involved with many modes. With the acceleration spectrum and the sound pressure spectrum obtained by the FFT analyzer the radiation resistance of the elastic plate of a parallel-piped box is evaluated.
Analytical and experimental results give relatively good agreements over all frequencies, but excellent agreements in subcritical frequencies and poor agreements in supercritical frequencies.