为了准确掌握高温条件下防热复合材料的热响应行为，对基体和纤维束分开建模，利用能量和质量守恒方程，并考虑热解过程中酚醛基体密度和材料热属性的变化，计算高温条件下三维编织碳/酚醛复合材料的热响应行为，预测复合材料温度场和热解度的分布规律，并给出质量损失率、炭层生成位置以及厚度的变化情况。结果表明：加热过程中，三维编织碳/酚醛复合材料的温度分布极不均匀，在加热面上基体温度明显高于纤维束温度，而在材料内部竖向纤维束温度反而高于基体温度；加热开始时炭层没有立刻产生，而是需要一段时间的过渡，在此过渡时间内炭层平均厚度为0。%In order to accurately calculate the thermal response of 3D braided carbon/phenolic composite under high temperature, the matrix and fiber bundle of composite were established separately and a mathematical model was adopted based on the conservation of energy and mass, changes in phenolic matrix density as well as material thermal properties in pyrolysis process. The distributions of temperature field and pyrolysis degree were predicted, and the mass loss rate, the formation position and the thickness of char layer were shown. The results show that the temperature distribution of the 3D braided carbon/phenolic composite is extremely uneven, and the matrix temperature on the heating surface is significantly higher than the fiber bundle temperature, while the vertical fiber bundle temperature inside the material is higher than the matrix temperature. At the beginning of heating, the char layer is not generated immediately, but requires a transition period, during which the average thickness of the char layer is zero. The calculation of thermal response can better understand the behavioral characteristics of the composite, and provide reference and basis for the design and optimization of the thermal protection materials.
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