Experimental studies on the vibro-acoustic behavior of a stiffened submerged conical-cylindrical shell subjected to force and acoustic excitation

Xian-Zhong Wang,Ye-Ping Xiong,Xin Gu,Quan-Zhou Jiang

doi:10.1177/1461348419844648

Abstract

An experimental model was made to investigate the influence of force and acoustic excitation on the vibration and underwater sound radiation of the stiffened conical-cylindrical shell. Meanwhile, a coupled precise transfer matrix method and wave superposition method was also proposed to analyze vibro-acoustic responses of combined shells. To test accuracy of the present method, vibration and acoustic results of combined shells are firstly examined. As expected, results of present method are in excellent agreement with the ones in literature and model test. The experimental results show that free vibrations of the experimental test are consistent with the literature data and the present method’s results. Forced vibration and acoustic test results are also well agreed with the numerical results from the coupled precise transfer matrix method/wave superposition method. The comparisons show that the coupled precise transfer matrix method/wave superposition method is reliable and credible to solve the vibro-acoustic response of combined shells. The analysis shows that the acoustic excitation is the key factor for radiated noise in low-frequency range. However, the radiated noise resulted from force excitation is dominant in mid-high frequency band.

Highlights

The traditional way of FEM18 is to transform an infinite domain problem into a finite field problem by defining artificial boundary conditions, while because of its requirement for the Green function, BEM19 is well suited for the infinite domain problem; The vibration and sound radiation
Both the vibration response curves have a little difference at the resonance peak in the range of 500–2500 Hz, the sound pressure results from coupled precise transfer matrix method (PTMM)/WSM are consistent with experiment results
The experimental test of a ring-stiffened conical-cylindrical shell on the vibration and sound radiation is investigated under different types of excitations

Summary

Introduction

Used in aeronautical and naval industries, the ring-stiffened conical-cylindrical shell is one of the most normal structure of mechanical engineering, the radiated noise of which is a classic acoustic-structure interaction problem.[1,2] There is a lot of literature research on vibration and sound radiation of various shells (spherical shell,[3] cylindrical shell[4] and conical shell5) and some attentions on the structure dynamic analysis of conical-cylindrical shells have been made public.[6,7,8,9,10,11,12,13,14,15,16,17]Regarding the numerical analysis of sound radiation of submerged elastic structure, several numerical methods such as finite element method (FEM), boundary element method (BEM) and coupled FEM/BEM are available to predict and analyze the acoustic problem. The present work aims to analysis the noise and vibration results of experiment model, which was constructed to simulate a submerged stiffened conical-cylindrical shell under the acoustic and force excitation. The vibration and acoustic responses of the submerged combined shell can be solved by the coupled PTMM/WSM and effectively over a wide frequency range.

Results

Conclusion