Method for calculating natural frequency of honeycomb sandwich plate

Abstract

The invention relates to a method for calculating a natural frequency of a honeycomb sandwich plate, which comprises the following steps of: by measuring bending rigidities D11, D12, D22 and D66 of the sandwich plate, shear moduli Gxz and Gyz of a core layer in x-z and y-z planes, a length a and a width b of the sandwich plate, a panel thickness t, a core layer thickness h and a panel density rho<f> and a core layer density rho<c> of the sandwich plate, calculating to obtain shear stiffnesses Cxz and Cyz of the core layer and an equivalent face density rho; and substituting the measured data into a formula to calculate so as to solve the natural frequency omega<m> of an mth order of the sandwich plate. According to the invention, a bending vibration equation system form and the process of solving the natural frequency of the sandwich plate are simplified, the influence of the transverse shear deformation of the core layer and the integral orthogonal anisotropy of the sandwich plate on the mechanical property of the sandwich plate is also considered, the calculating process of the natural frequency is simplified, the calculating efficiency is improved, the calculating difficulty is reduced and the calculating accuracy of the natural frequency is improved.

Description

technical field [0001] The invention relates to a method for measuring and calculating the natural frequency of a sandwich panel, in particular to a method for measuring and calculating the natural frequency of a honeycomb sandwich panel. Background technique [0002] Bending vibration analysis is an important basis for structural design and its engineering application. With the wide application of honeycomb sandwich structures in many fields such as aerospace, aviation, high-speed transportation and modern structural engineering, its vibration problems have become increasingly prominent, which has attracted widespread attention and attention from the engineering community. Vibration analysis and natural frequency design have become products. It is a key link in the design and also one of the key mechanical problems in major projects. In the past few decades, scholars at home and abroad have used analytical methods, numerical methods and experimental methods to study the vi...

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Problems solved by technology

Since the most commonly used orthotropic sandwich plate bending vibration governing equations in engineering contain three generalized displacements, the Rayleigh-Leeds method is generally used to solve the natural frequency, and the equation form and solution process are relatively complicated. To a certain extent, it limits the application of this equation system in engineering practice such as composite material design.

Aiming at problems such as multiple displacement functions, complex equations, and difficulty in solving by analytical methods in the governing equations of sandwich plate bending vibration, the Institute of Mechanics of the Chinese Academy of Sciences published a monograph "Bending, Stability and Vibration of Sandwich Plate Shells" (Science Press, 1977) A simplified engineering solution is given in , but this method is limited to the case of isotropic panels, ignoring the influence of the overall orthotropic anisotropy of the sandwich panel; Wu Hui from Lanzhou University et al. A method for simplifying the governing equations of sandwich plate bending vibration was proposed in "Natural Frequency of Cross-Anisotropic Corrugated Sandwich Rectangular Sandwich Plate" (Applied Mathematics and Mechanics, 2001, Vol. 22, No. 9, Page 919-926) , but this method ignores the influence of the transverse shear deformation of the core layer, and the calculation accuracy still needs to be improved

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