Numerical calculation of acoustic radiation from band-vibrating structures via FEM/FAQP method

• Main Authors: GAO Honglin, LI Sheng
• Format: Article
• Language: English
• Published: Editorial Office of Chinese Journal of Ship Research 2017-08-01
• Series: Zhongguo Jianchuan Yanjiu
• Subjects: acoustic radiation; Finite Element Method(FEM); Frequency Averaged Quadratic Pressure (FAQP); Boundary Element Method(BEM); medium and high frequencies
• Online Access: http://www.ship-research.com/EN/Y2017/V12/I4/71

The Finite Element Method (FEM) combined with the Frequency Averaged Quadratic Pressure method (FAQP) are used to calculate the acoustic radiation of structures excited in the frequency band. The surface particle velocity of stiffened cylindrical shells under frequency band excitation is calculated using finite element software, the normal vibration velocity is converted from the surface particle velocity to calculate the average energy source (frequency averaged across intensity, frequency averaged across pressure and frequency averaged across velocity), and the FAQP method is used to calculate the average sound pressure level within the bandwidth. The average sound pressure levels are then compared with the bandwidth using finite element and boundary element software, and the results show that FEM combined with FAQP is more suitable for high frequencies and can be used to calculate the average sound pressure level in the 1/3 octave band with good stability, presenting an alternative to applying frequency-by-frequency calculation and the average frequency process. The FEM/FAQP method can be used as a prediction method for calculating acoustic radiation while taking the randomness of vibration at medium and high frequencies into consideration.