Analysis Of The Sound Power And Its Sensitivity Of Thin Plate Structure

Thin plate structure have a wide range of applications in the field of aerospace,automotive manufacturing industry, plate structure will be stimulated inevitably by theexternal excitation and have acoustic radiation, the acoustic radiation of thin platestructure is always the focus of engineering. Research sound radiation power and soundradiation sensitivity of different parameters to solve low noise design will become themost promising issue. In this paper, sound radiation power and sound radiationsensitivity of thin plate structure was considered.Firstly, the finite element model of single layer plate structure was established, andsolved the rectangular element stiffness matrix and mass matrix. In this paper theory ofacoustic radiation modes was introduced, and the formula of sound power was builtbased on the acoustic radiation modes.Secondly, analyzing dynamic response and sensitivity of thin plate structure, soundpower sensitivity was gained by sound power partial derivated about the differentparameters. Taking a bi-material thin plate as a example, the sound power and soundpower sensitivity according to the material distribution density and thickness of plateand external excitation frequency was analyzed based on four sides simple supportedand fixed supported. The numerical examples show that: sound radiation power hascomplex linear relation to material distribution density and thickness at a particularfrequency under the external excitation. The sound radiation power was peak in somefrequency close to the natural frequency under the external excitation frequency. Thechange trend of sound power sensitivity is almost consistent with the change trend ofsound power.Lastly, the finite element model of laminated plate was built based on the singlethin plate analysis, and solved the laminated plate element stiffness matrix and massmatrix, the sound power of laminated plate and sound power sensitivity about anglesand thickness was built based on the acoustic radiation modes. Taking T300compositelaminated plate as a example, the sound power and sound power sensitivity according toangles and thickness of plate and external excitation frequency was analyzed based onfour sides simple supported and fixed supported. The numerical examples show that: thesound radiation power is peak in the first mode natural frequency, at the same time, thesound power sensitivity have significantly lifting process.