The modal coupling effect on the noise radiation of beams under different excitations

Analytical methods are developed to compute the effect of modal coupling on the noise radiation of a beam under various manners of excitation. The effect of modal coupling on the square velocity of the beam is also presented and compared with the effect on noise radiation. The results illustrate that modal coupling can significantly alter the total acoustic power and the square velocity of the beam under some special conditions. The effect of modal coupling on the acoustic power is slight in the high frequency range, and anti-resonances are not as apparent on the acoustic power curve as on the square velocity curve because of the Raleigh's integral in the formula of acoustic pressure.