Three-dimensional acousto-elastic analysis method of ship for arbitrary damping processing of structure

Abstract

The invention discloses a three-dimensional acousto-elastic analysis method of a ship for arbitrary damping processing of a structure and relates to the technical field of acoustics. The method comprises the steps of performing modal analysis on a finite element model of a ship structure with an initial damping laying layer to obtain a modal damping ratio of modalities at various orders of the ship structure; substituting the modal damping ratio of the modalities at various orders of the ship structure into an acousto-elastic coupling dynamic equation of the ship structure to obtain a composite structure dynamic equation of the ship structure; and performing vibration noise analysis on the coupling dynamic equations by use of a three-dimensional acousto-elastic theory of the ship. A damping laying optimization design scheme for the ship structure with structural acoustic radiation as an optimization objective is provided. According to the three-dimensional acousto-elastic analysis method of the ship for arbitrary damping processing of the structure, the direct vibration noise analysis for the laying-damped ship structure is implemented, and the method can be widely used for processing of the damping structure when the vibration noise of the ship is calculated and can provide a technical support for the damping laying design of the ship.

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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