摘要
为分析多脉冲飞秒激光切割加工炸药过程的安全性,建立多脉冲飞秒激光切割加工炸药装药的二维数值计算模型,对飞秒激光切割加工HMX、TATB、RDX和TNT 4种炸药装药的情况进行数值计算,获得不同加工状况下炸药装药的热响应规律.实验结果表明:飞秒激光切割加工炸药装药过程中,当激光光斑的移动速度为80～300 mm/min时,4种炸药均未发生点火,反应光斑移动速度越慢,热累积效应越明显,且HMX相比其他3种炸药,动态分析区内HMX的热累积效应最明显;当激光重复频率和能量分别为0.1～200 kHz和50～200µJ/pulse时,提高飞秒激光的重复频率和能量对切割速率提升效果呈先上升后降低趋势;飞秒激光对炸药装药的切割加工速率和安全性,会受到炸药的性能参数的影响,切割速率与炸药的激光吸收系数呈正相关,切割安全性与炸药的热感度呈负相关.
Abstract
In order to analyze the safety of multi-pulse femtosecond laser cutting of explosive charge,a two-dimensional numerical calculation model is established for the numerical calculation of femtosecond laser cutting HMX,TATB,RDX and TNT charges.The thermal response rules of explosive charge under different processing conditions were obtained through experiment.The results show that all the four kinds of explosives above are not ignited when the moving speed of laser spot is 80-300 mm/min.The slower moving speed of reactive spot led to the more obvious heat accumulation effect.The heat accumulation effect of HMX is the most obvious in the dynamic analysis area as compared with those of other three kinds of explosives.When the repetition frequency and energy of femtosecond laser are in the range of 0.1-200 kHz and 50-200 μJ/pulse,respectively,the cutting rate increases first and then decreases by increasing the repetition frequency and energy of femtosecond laser.In addition,cutting rate and safety of femtosecond laser on explosive charge are affected by the performance parameters of explosive.Cutting rate is positively correlated with the laser absorption coefficient of explosive while cutting safety is negatively correlated with the thermal sensitivity of explosive.
基金项目
爆炸科学与技术国家重点实验室基金项目(KFJJ20-04M)
维普
万方数据