A three-dimensional acoustoelastic analysis method for ships with arbitrary damping treatment

Abstract

The invention discloses a three-dimensional acoustoelastic analysis method for a ship with arbitrary damping of the structure, and relates to the technical field of acoustics. The method includes: performing modal analysis on a finite element model of a ship structure with an initial damping laying layer, and obtaining various orders of the ship structure. The modal damping ratio of the modal is obtained by substituting the modal damping ratio of each mode of the ship structure into the acousto-elastic coupling dynamics equation of the ship structure to obtain the composite structural dynamic equation of the ship structure. The vibration and noise analysis is carried out using the structural dynamic equation, and the optimization design scheme of the ship structure damping laying is provided with the structural sound radiation as the optimization goal; the invention realizes the direct vibration and noise analysis of the ship structure with the damping laid, and can be widely used in the calculation of ship vibration and noise. At the same time, it can provide technical support for the design of ship damping laying.

Description

technical field [0001] The invention relates to the technical field of acoustics, in particular to a three-dimensional acoustoelastic analysis method for ships with random damping treatment of structures. Background technique [0002] Underwater radiated noise is one of the most important performance indicators of ships. The underwater radiated noise of ships is mainly divided into three categories: structure noise, propeller noise and flow noise. Among the structural noise, the vibration of the ship structure caused by the operation of the ship's power plant, and the noise radiated from the hull shell to the underwater is one of the most important sources. In order to reduce the vibration and sound radiation of the ship structure in engineering, often in the A viscoelastic damping material is laid on the hull to form a damping layer. [0003] At present, in the vibration and noise reduction engineering of ship structures considering viscoelastic damping, most of them only ...

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Problems solved by technology

[0003] At present, in the vibration and noise reduction engineering of ship structures considering viscoelastic damping, most of them only stay in the analysis of the modal and vibration frequency response of the structure, and rarely directly analyze the vibration-acoustics of the acoustic-solid coupling system of the viscoelastic damping structure. Although the three-dimensional acoustoelastic theory and calculation methods of ships have been widely used at present, it is still difficult to accurately reflect the dynamic parameters of the viscoelastic damping structure. The current solution is generally based on engineering experience. The corresponding modal damping ratio is applied to the eigenmodes. This method can only be used for a few modes, and the accuracy is difficult to guarantee. It is often difficult to simulate complex structures. On the other hand, the current calculation method is difficult for the damping layer. Generally, according to engineering experience, the damping layer is laid at the position with greater vibration, but whether this position has the same impact as the sound radiation is unknown. The current analysis method is highly subjective and has poor accuracy.

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