高填充颗粒复合材料导热性能实验与数值模拟研究

Experimental and Numerical Simulation of ThermalConductivity of High Filled Particle Composites

根据颗粒填充型导热复合材料中填充颗粒的空间分布特征,基于代表性体积单元(RVE)法,分别采用不同的算法建立了低填充、高填充复合材料三维细观导热分析模型,对复合材料热导率进行预测,并与实验结果进行对比,验证了分析模型与计算方法的可靠性。在此基础上,进一步探讨了填料体积分数、填料/基体热导率比、填料非均匀分布以及考虑填料接触对复合材料导热性能的影响规律。结果表明,复合材料热导率随填料增多而增大,当填料体积分数大于0.2时,采用接触模型计算结果更加接近实验值;当填料/基体热导率比超过40后,继续提高填料/基体热导率比对复合材料热导率影响较小。

Based on the representative volume element(RVE)method,the three-dimensional mesoscopic thermal conductivity model of low-filled and high-filled composites was established by different algorithms according to the spatial distribution of the particles in the particle-filled composites.The thermal conductivity of the composites was predicted with the help of finite element method,the reliability of the analytical model and the calculation method was verified through the comparison of predictive values and experimental results.On the basis of this,the effects of packing volume fraction,particle/matrix thermal conductivity ratio,nonuniform distribution of particle and the influence of particle contact on the thermal conductivity of the composites were discussed.The experimental results show that the thermal conductivity of the composites increases with the increase of the particle.And when the packing volume fraction is more than 0.2,the results are closer to the experimental value when the contact model was used.In addition,the increase of particle thermal conductivity has little influence on the composites thermal conductivity if the particle/matrix thermal conductivity ratio is more than 40.