Method for Predicting the Vibration Characteristics of Composite Soft Sandwich Structures Containing Cavities in Fluid

Abstract

The invention belongs to the technical field of composite material vibration, and specifically discloses a method for predicting the vibration characteristics of an underwater cavity-containing composite material soft sandwich structure. Including: the soft sandwich structure constituting the cavity-containing composite soft sandwich structure is equivalent to an orthotropic homogeneous material, and its motion equations under vacuum conditions are constructed, and then according to the homogeneous The radiated sound field and the fluid-solid coupling conditions of the sandwich structure with a soft sandwich, reconstruct the motion equations of the sandwich structure with a homogeneous soft core in the fluid along its thickness direction, thereby reorganizing the equations of motion; according to the obtained equations of motion, Calculate the natural and forced vibration responses of sandwich structures with homogeneous soft cores, and use them to predict the vibration characteristics of composite soft core structures with cavities in fluid. The invention improves the accuracy of calculating the vibration characteristics of the composite material soft sandwich structure, can deal with the equivalent problem of the sandwich structure containing multiple cavities, and has a wide application range.

Description

technical field [0001] The invention belongs to the technical field of composite material vibration, and more specifically relates to a method for predicting the vibration characteristics of a cavity-containing composite material soft sandwich structure in a fluid. Background technique [0002] With the rapid development of sonar technology, modern ships have higher and higher requirements for acoustic stealth performance. In order to reduce the radiated noise and acoustic target intensity of the ship, the composite material acoustic structure with better acoustic performance is gradually applied to the ship structure. The cavity-containing composite soft sandwich structure is a kind of composite acoustic structure with good application prospects. Its soft core is a viscoelastic rubber material with a large loss factor, which can achieve vibration and sound absorption by using the shear energy dissipation mechanism; the periodically distributed cavities in the core can play...

AI Technical Summary

Problems solved by technology

At present, for the vibration characteristics of composite sandwich structures, the equivalent single-layer plate theory is the most commonly used research method, but this method has a large error when dealing with soft sandwich problems

At the same time, the vibration analysis of related composite material sandwich structures is mainly concentrated in the air, and the research in water is more difficult due to the complex fluid-solid interaction problems involved.

The finite element method can deal with the underwater vibration of composite soft sandwich structures, but modeling the flow field requires a large number of meshes and consumes a lot of computing resources and time, which is not conducive to the study of characteristics

In addition, the periodically distributed cavities in the core complicate the underwater vibration study of the structure

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