K9玻璃在脉冲CO_2激光作用下的热应力分析

根据已建立的理论模型,计算得到了K9玻璃受脉冲CO_2激光辐照时产生的热应力分布,研究了热应力的时间特征,在分析样品尺寸对损伤结果影响的基础上,提出了K9玻璃抗激光损伤的最佳半径。结果表明:K9玻璃产生的热应力损伤主要由环向应力控制,热应力以热冲击波的形式在样品内传播,大小随时间变化而来回振荡,且激光脉冲结束后比激光作用时间内产生的热应力要大。这说明若样品在激光加热期间产生的热应力不足以造成材料破坏,则有可能会在其后的冷却过程中产生更大的热应力,材料将会在冷却过程中发生破裂。根据样品参数对损伤结果的影响,进一步验证了K9玻璃抗激光损伤最佳半径的通用性。

Analysis of thermal stress in K9 glass irradiated by pulsed CO2 laser

According to the theoretical model of K9 glass irradiated by pulsed CO2 laser, a numerical simulation was performed to calculate thermal stress distribution in K9 glass sample irradiated by pulsed CO2 laser. The time characteristic of the thermal stress was demonstrated. On the basis of the analysis of damage results, an optimal radius was presented to express the laser-induced damage resistance of K9 glass. The simulation results indicated that the damage effect was dominated by circular stress. Moreover, this thermal stress would diffuse as shock wave and oscillated obviously inside of the K9 glass sample. The simulation results also showed that the effect of laser irradiation on samples can be affected considerably by the change of radius of the sample. Finally, the universality of the proposed optimal radius of K9 glass was validated.