Study On Heat Transfer Performance Of Three-dimensional Fabric Reinforced Composites

This research perspective fabric reinforced composite material thermal conductivity,the fabric structure having a shape and design of simple preparation process,the use of three-dimensional fabric woven quartz fiber-reinforced composite material with high temperature,corrosion resistance,thermal shock and microwave-transparent characteristics,to meet a certain role in the external environment protection radome.Three-dimensional fabric as a rising star in the field of reinforcement materials,its weaving parameters and structure of the material heat conduction performance of the need to be further studied.The influence of fiber volume fraction,angle internal braiding angle and other process parameters,fabric structure and different yarn reduction methods on the thermal conductivity of the three-dimensional braided reinforced composite with quartz fiber and epoxy resin was analyzed by using the thermal constants analyzer TPS2500S,and some meaningful conclusions are obtained.These conclusions provide the necessary basis for the design and application of the three-dimensional braided reinforced composites in heat conduction research.The main conclusions are as follows:The thermal conductivity of the three-dimensional braided composites is positively correlated with the fiber volume fraction.The axial thermal conductivity of 3D5D composite increases from 13.9%to 21.9%,and the radial thermal conductivity increases from 15.6%to 23.5%as the fiber volume fraction increases from 45%to 60%.When the fiber volume fraction is 50%and the braiding angle is increased from 20° to 30°,the radial thermal conductivity of the composites is increased by 20%and the axial thermal conductivity is reduced by 18%.The thermal conductivity of the tree-dimensional braided composites exhibits anisotropy along the axial and radial directions.The smaller the braided angle is,the more anisotropy is.The yarn reduction can reduce the thermal conductivity of the 3D braided composites.The effects of concentrated reduction were most pronounced,with axial and radial reductions of 3.2%and 3%,respectively.The effect of the fineness reduction was not significant and the axial and radial directions were reduced by 1.5%and 1.0%,respectively.The thermal conductivity of the three-dimensional braided composites is lower than that of the 2.5D composites on the same fiber volume content.The 3D5d braided composites have better axial thermal conductivity than 3D4d and 3D6d braided composites.The thermal conductivity of 2.5D composites is higher than that of laminated composites in both axial and radial directions.The 3D5d braided composites was simulated by using a unit cell model in which the braiding yarn was hexagonal and the axis yarn was a octagon.Explore the use of LBM methods and "The half lattice division scheme" to predict 3D5d composite thermal conductivity.In this thesis,it can be applied in the parameter selection,the properties’ design,and the structural optimization of this material during the manufacture process,and to push the further application of three-dimensional composites in the aerospace industry.