Analysis Of Vibration And Acoustics Radiation For A Submarine In Full-frequency Range

Nowadays, there are two most commonly used methods called deterministic method and statistical method for analyzing ship’s vibration and acoustic response. But for complex combined structure within a broad band, a single method such as finite element method, boundary element method or statistical energy method cannot obtain satisfactory results, such problem is called "vibro-acoustic response in full-frequency" problem. This problem has received many attentions, and gradually become a focus in the field of system dynamic characteristics of structure in recent years. As it is, the research in mid-frequency domain has developed rapidly and made a lot of achievement in both theory and application.As a naval military vessel, submarine is a typical complex combined system. The exciting source of vibration has high magnitude and wide spectrum, the prediction of vibration and acoustic radiation need to be done within the wide band. Using a single method cannot be effective, so how to make an accurate prediction of vibration and acoustic radiation of the submarine within the full frequency has actual significance.At first, this article takes a beam-plate structure as an example for its vibration prediction. We should complete frequency division before modeling. Use deterministic method within low frequency and statistical method within high frequency while using Hybrid model method within intermediate frequency to test the effectiveness of this method within medium frequency and foreshadow for a submarine. Similar with the beam-plate structure, this article predict vibration and acoustic radiation of a submarine within full frequency. Use the existing mature analysis method within the low frequency and high frequency while using Hybrid model method within intermediate frequency. Finally this article completed the analysis within full frequency successfully. The results show that H-model method is effective for the vibro-acoustie forecast of the double-shell submarine. Then this article made a noise control treatment for the double-shell submarine. Select vibration isolation method and sound absorption method according to the economy and effectiveness. Comparing the results before and after noise control, we can see that the control methods we use can reduce the sound radiation effectively.Through the discussion of this article, we can find that H-model method is feasible and effective to solve the problems of complex combined structure within intermediate frequency. Generally we do the analysis with the help of VAONE, in addition to the mid-frequency domain, this software has a strong analysis ability in both low and high frequency domain, so it has an important practical value for analyzing complex combined structures’ frequency response within full frequency.