A Construction Method of Equivalent Permittivity Model of Carbon Fiber Composite Material

Abstract

The invention provides a construction method of a carbon fiber composite material equivalent dielectric constant model. A common equivalent dielectric constant model is established from the axial direction of carbon fibers and the radial direction of the carbon fibers aiming at a composite material with the carbon fibers in the cross section, which are arrayed in a rectangular shape; a shielding efficiency expression formula of a carbon fiber composite material is established according to a transmission line theory; actual shielding efficiency of a plurality of frequency points on the carbon fiber composite material is calculated through simulation; the shielding efficiency expression formula of the carbon fiber composite material is combined according to actual shielding efficiency of a plurality of frequency points, which are calculated by the simulation; and unknown parameters in the common equivalent dielectric constant model of the carbon fiber composite material are obtained by utilizing least squares inversion, and construction of the common equivalent dielectric constant model of the carbon fiber composite material is finished. By adopting the construction method provided by the invention, the difficulty that excessive meshes are divided, caused by an inner micro-geometry structure of the carbon fiber composite material in an actual numerical value simulation process, is overcome; and numerical value simulation of shielding efficiency, magnetic wave transmission property and the like of the composite material is convenient to realize, and the construction method is simple in calculation and convenient to realize.

Description

technical field [0001] The invention relates to the technical field of electromagnetic environment and electromagnetic compatibility, in particular to a method for constructing an equivalent dielectric constant model of a carbon fiber composite material under the condition that carbon fibers are arranged in a rectangle. Background technique [0002] Carbon fiber composites are widely used in aircraft, satellites, automobiles and other industries. Due to the high electrical conductivity of carbon fibers, carbon fiber composites often replace precious metal materials for the electromagnetic shielding performance of structures. In theory, the existing numerical calculation software can accurately calculate the electromagnetic properties of composite materials such as shielding effectiveness, transmission coefficient, etc. However, carbon fiber composite materials have complex mesoscopic geometric configurations, and the meshing of the internal fine structure needs to be consider...

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Problems solved by technology

The Chinese invention patent "Extraction method of equivalent electromagnetic parameters of asymmetric artificial electromagnetic materials" (application number: 201510291977.8) published in 2015 uses numerical iteration method to extract equivalent electromagnetic parameters of artificial electromagnetic materials, and performs inversion by simulating a large number of S parameters , the amount of data required in the early stage is large

The Chinese invention patent published in 2014 "a method for calculating the equivalent dielectric constant of a through-hole dielectric support" (application number: 201410422551.7) proposed a theoretical calculation formula for the equivalent dielectric constant. The Chinese invention patent published in 2016 "one A Calculation Method for Equivalent Electromagnetic Parameters of Honeycomb Absorbing Structure” (Application No.: 201610130516.7) uses strong disturbance theory to calculate the equivalent electromagnetic parameters of honeycomb absorbing structure, and these methods can only be applied to composite materials with specific structures

The "Calculation Method for Dielectric Properties of High-Concentration Fiber Reinforced Materials" published in "Acta Physica" in Volume 65, No. 2 of 2016 proposed an analytical formula for the equivalent dielectric constant of carbon fiber reinforced composite materials, but only applied to carbon fibers in transverse direction. The case where the cross section is arranged in a square

[0004] For the case where the carbon fibers are arranged in a rectangular shape on the cross-section of the composite material, the equivalent dielectric constant is not only affected by the electromagnetic parameters of the carbon fibers and the matrix, but also affected by the structural parameters, which cannot be calculated with a single theoretical formula

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