Spectral Radiation Of Three-dimensional Braided Carbon Fiber Composites Based On FDTD Characteristic Research

With the gradual improvement of three-dimensional braiding technology,the most representative three-dimensional braided carbon fiber composite material in its application,with its excellent mechanical properties,high temperature resistance,radiation resistance,etc.,has grown rapidly in the aviation industry and many civilian fields.,But this also brings more security risks.Through the study of the spectral radiation characteristics of three-dimensional woven carbon fiber and its composite materials,it provides a theoretical basis for improving the structure of composite materials and enhancing its thermal radiation performance,thereby enhancing the intrinsic safety and reliability of the system and reducing hidden risks.This paper uses the finite difference time domain method(FDTD)to simulate the three-dimensional braided carbon fiber and its composite materials.Two-dimensional and three-dimensional carbon fiber structure models were established in the research,including two-dimensional uniform and random arrangement of different contents and different radii,three-dimensional random arrangement,three-dimensional orthogonal weaving,three-dimensional multi-directional weaving and three-dimensional multi-directional weaving carbon fiber composite resin.Analyze the influence of each structure on the scattering and absorption properties of carbon fiber materials,compare the simulation results of different structures under periodic and absorptive boundary conditions,and optimize the simulation scheme.Aiming at the influence of carbon fiber content on the thermal radiation characteristics of the material,the scattering and absorption factors of 7 carbon fibers with uniform content and the relative deviation of each group of data are calculated,and the influence degree of different content on the material performance is analyzed.Discuss the scattering and absorption efficiency of three-dimensional orthogonal woven and multi-directional woven carbon fiber,and compare it with the three-dimensional random arrangement structure of equal content,and analyze the performance difference caused by the two structures.The scattering and absorption cross sections of the three-dimensional multi-directional woven carbon fiber composite PS and PEI materials are calculated,and the effects of the braided structure,carbon fiber content and matrix on the heat resistance of the composite are analyzed.The study found that the carbon fiber content has a different effect on the heat radiation characteristics of the material,and the heat radiation performance of the braided structure is significantly better than the random arrangement.If the fiber spacing of the braid is too close,the material performance will deteriorate.The heat radiation performance of the six-way braided carbon fiber in the multi-directional braided structure is better,and the deviation from the absorption section of the same content randomly arranged is up to 50%.For carbon fiber composite resin materials,the radiation characteristics of the material are also greatly affected by the nature of the resin matrix itself,and the overall heat resistance of the three-dimensional and six-directional woven carbon fiber PEI material is stronger.