脉冲辐照下三维多向碳纤维编织复合材料热激波的实验研究

Experimental Studies of Thermal Shock Wave In Three-dimensional Braided Composite under Pulsed Beam Radiation

在“闪光二号”脉冲电子束加速器上,采用自行研制的保护环式石英压电传感器,对三维多向碳纤维编织复合材料的热激波传播特性开展了实验研究。结果表明: (1)在电子束能注量为382J/cm2 ~953J/cm2范围内,三维编织复合材料的热激波应力峰值在 97~406MPa之间,只是相同能注量下Ly-12铝的 8%左右,这表明该材料具有良好的衰减热激波的性能; (2)三维编织复合材料中的热激波,其波速较低(大约为 2. 78~3. 45km/s),只是Ly-12铝的 0. 4倍左右,其波形上升时间也比Ly-12铝的大; (3)热激波强度和能注量间近似有线性关系,但烧蚀质量却随能注量增加而增加,当能注量足够高时,质量亏损面密度几乎以指数方式增加。

The behaviors of thermal shock wave in the three-dimensional braided composite radiated by pulsed electron beam were experimentally studied on 'Flash II' accelerator with a guard-ring piezoelectric quartz measuring technique. The results show that: 1 As the electron beam energy flux is controlled in the range of 382 J/cm^2 to 953 J/cm^2, the peak stresses of thermal shock waves induced in the braided composite are in the range of 97MPa to 406MPa, which is only about 8% of that in Ly-12. Therefore, the three-dimensional braided composite is really a good material for attenuation of thermal shock waves. 2 The velocity of thermal shock wave in the three-dimensional braided composite (about 2.78~3.45km/s) is indicated to be lower than that in Ly-12 (7.25 km/s). The mean velocity of thermal shock wave in the composite is only about 40% of that in Ly-12, but the rising time of the wave front is obviously larger than that in Ly-12. (3) The intensity of the thermal shock wave is nearly proportional to energy flux but the mass burned off (mass loss) at the surface of the composite is increased nonlinearly with the energy flux. At the beginning, the mass loss is increased gradually with the energy flux. However as the energy flux exceeds a threshold (about 900J/cm^2 in our experiments), the mass loss will be increased dramatically.