Efficient electromagnetic scattering modeling and calculating method for composite target containing wave-absorbing honeycomb structure

Abstract

The invention provides an efficient electromagnetic scattering modeling and calculation method for a composite target containing a wave-absorbing honeycomb structure, and the method comprises the steps: enabling a honeycomb wall to be equivalent to an impedance sheet during modeling of a hexagonal honeycomb structure, only remaining a uniform honeycomb unit as a body, and enabling a whole honeycomb region to become a uniform medium body containing a series of impedance boundary conditions, and simplifying the honeycomb modeling process. A non-conformal region decomposition technology is adopted to independently model a composite target partition containing a wave-absorbing honeycomb structure, so that modeling calculation of honeycomb structures of any shape and size becomes possible, and flexible and free geometric model creation, region division and mesh generation are allowed. After modeling and subdivision, efficient transmission conditions are set for different junctions between the sub-regions to ensure continuity of tangential electromagnetic fields on the surface and normal electromagnetic currents on the line, and the sub-regions are connected together. In the electromagnetic scattering calculation process, a matrix equation is obtained after an equation is dispersed, and the calculation process is simplified by introducing an IBC formula.

Description

technical field [0001] The invention relates to the technical field of electromagnetic calculation, in particular to a high-efficiency electromagnetic scattering modeling and calculation method for a composite target with a wave-absorbing honeycomb structure. Background technique [0002] With the research and development of aircraft radar stealth technology, the shape stealth technology is becoming more and more mature, approaching the optimal limit of the comprehensive balance between aerodynamics and stealth, while the research on material stealth technology is developing rapidly. Among them, structural absorbing materials are more and more widely used in aircraft because they can bear weight and have absorbing properties, which overcome the shortcomings of coated absorbing materials. Honeycomb absorbing materials have been highly valued and widely researched in the field of stealth due to their advantages in structure and performance, such as high stiffness and strength,...

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Problems solved by technology

[0006] Disadvantages of the test inversion method: the reflectivity is not complete in describing the electromagnetic properties of the absorbing material, and can only characterize the reflection part of the scattering, and the more complicated transmission in different directions and multiple reflections cannot be effectively evaluated, and the experimental test period is long , the process is more complicated, time-consuming and labor-intensive, and may be deviated due to the influence of the environment. It is difficult or even impossible to accurately measure the equivalent dielectric constant and magnetic permeability through experiments.

[0008] Disadvantages of the equivalent homogeneous method: In the composite structure containing honeycomb, the frequency of concern is generally 2-18GHz, and when the frequency is higher, the wavelength is smaller relative to the structural period, that is, quasi-static approximate collapse, homogeneous method, etc. The effective preconditions are destroyed, resulting in large errors in accurate calculation results and equivalent calculation results

[0010] Disadvantages of accurate full-wave algorithm: due to the small size of the honeycomb structure unit in actual processing, the honeycomb side length is only a few millimeters, and the honeycomb wall is extremely thin, which is about one hundredth of the honeycomb side length. Using the full-wave algorithm When meshing the honeycomb structure, whether it is FDTD, FEM for the volume of the honeycomb structure or MoM for the surface segmentation, the mesh size at the wall is very small due to the existence of the extremely thin honeycomb wall. Usually on the submillimeter level, it will bring problems such as difficult modeling and subdivision, low solution efficiency, and poor convergence

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