为解决单纤维热导率不易直接测试的难题，基于两相复合介质串并联等效热导率物理模型，采用瞬变平面热源法对环氧树脂纤维复合体系进行测试，并计算出单纤维轴向和径向的热导率。结果表明，采用该方法可获得纤维热导率，且纤维轴向的热导率要明显大于纤维径向的热导率，验证了纤维热学性能的各向异性。复合体系中两相材料的热导率差异、纤维所占体积比及物理模型、仪器的加热功率、测试时间的设定等对纤维热导率结果影响显著。当纤维和树脂的热导率差异较大时，采用并联模型计算较为准确，且随着体积含量的增加，纤维热导率增加，直到平衡。随加热功率和测试时间的增大，复合体系的热导率增大。%In order to solve the problem of difficulty in the testing of thermal conductivity of single fiber, based on series⁃parallel two⁃phase composite dielectric equivalent thermal conductivity physical model, the paper adopted a transient plane heat source method for testing epoxy resin⁃fiber composites, and calculated the axial and radial thermal conductivities of single fiber. The results show that this method can achieve the thermal conductivity of fiber, and the fiber axial thermal conductivity is significantly greater than the fiber radial thermal conductivity, verifying the thermal properties anisotropy of the fiber. Effect of thermal conductivity differences in the composite system of two phases, the volume ratio and physical models, instrumentation, heating power, test time, etc. on the fiber thermal conductivity results is significant. When the thermal conductivity of fiber and resin are quite different, the use of parallel computing model is more accurate, and with increasing of volume fraction, the fiber thermal conductivity increases to the balance. With increasing of heating power and test time, the thermal conductivity of the composite system is increased.
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