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研究了气流环境下碳纤维/环氧树脂复合材料激光烧蚀羽烟对透射率的影响。由射流理论得到光学路径长度关系式,由碳纤维/环氧树脂复合材料的激光烧蚀模拟得到羽烟密度及速度关系式,进而利用Lambert-Beer定律得到了羽烟透射率的计算模型。利用模型计算了激光辐照过程中的羽烟透射率,并与实验结果进行比较,验证了模型的合理性。进一步计算了外部参数对激光透射率的影响,计算结果表明,激光辐照开始后,热解区域在表面,烟气易于逸出,透射率快速下降到最低值,随后热解区域内移,由于材料渗透率较低,烟气逸出困难,透射率逐渐回升;激光功率密度越大,最小透射率越低,辐照期间的平均透射率越低;气流速度较大时,整个辐照期间的透射率都较高;总功率一定时,光斑半径越大,最小透射率越高,辐照期间的平均透射率越低。
The influence of laser ablation of carbon fiber / epoxy composites on the transmittance was studied in airflow environment. The relationship between the optical path length and jet path length was obtained by jet theory. The relationship between the plume density and velocity was obtained by laser ablation simulation of carbon fiber / epoxy composites. The Lambert-Beer law was used to calculate the plume transmittance. The model was used to calculate the plume transmittance in the laser irradiation process and compared with the experimental results to verify the rationality of the model. The influence of external parameters on the laser transmittance is further calculated. The results show that after the laser irradiation, the pyrolyzed region on the surface, the flue gas is easy to escape, the transmittance drops rapidly to the lowest value, then the pyrolysis region moves inward, due to The material permeability is low, the flue gas escapes difficult, and the transmittance gradually rises; the larger the laser power density, the lower the minimum transmittance, the lower the average transmittance during irradiation; the larger the air velocity, When the total power is constant, the larger the spot radius is, the higher the minimum transmittance is, and the lower the average transmittance during irradiation is.