激光辐照下复合材料热响应的轴对称数值分析

为了模拟激光辐照下碳纤维增强复合材料的瞬态热响应,建立了轴对称计算模型。模型考虑了激光辐照过程中基体热分解、质量迁移、比热容和热导率等物理量的变化情况。采用有限元方法求解控制方程,边界条件包含了激光辐照、对流换热以及辐射换热。在此基础上编写了计算程序,预测了激光辐照下碳纤维增强复合材料的瞬态温度场和基体热分解状况。为了校核模型,开展了激光辐照碳纤维复合材料试验。计算结果与试验数据比较表明,模型预测的复合材料温度-时间曲线与试验结果较好吻合,在较低功率密度激光辐照下复合材料热响应以基体热分解为主,与试验烧蚀形貌观察结果一致。

Axisymmetric numerical study on thermal response of composites to laser irradiation

The investigation into the laser irradiation effects of composites is important to the development of laser application. An axisymmetric model was proposed to predict the thermal responses of carbon fiber resin composite(CFRC) to laser irradiation in time and space domain. The finite element method was used to solve the governing equation. In this model, the boundary conditions were considered, including laser heat flow, heat convection and heat radiation. The progressive change in thermo-physical properties including decomposition degree, mass transfer, specific heat capacity, and thermal conductivity was determined. A code was developed to predict the transient temperature and thermal decomposing area of composites matrix under laser irradiation, and the results were compared to experimental data. The computed temperatures of composites consist with the experimental measurements well. It was found that when laser intensity was low, the thermal response pattern of CFRC composite was matrix decomposing.