脉冲X射线辐照铝板气化反冲仿真的不确定度量化方法  

Uncertainty Quantification in Simulation of Blow-off Impulseof Aluminum Plate Irradiated by Pulsed X-Ray

作　　者：王栋 汤文辉[1] 张昆 冉宪文[1] 晏良 WANG Dong;TANG Wen-hui;ZHANG Kun;RAN Xian-wen;YAN Liang(College of Physics,National University of Defense Technology,Changsha 410073,China;College of System Science,National University of Defense Technology,Changsha 410073,China)

机构地区：[1]国防科技大学物理系,长沙410073 [2]国防科技大学体系科学系,长沙410073

出　　处：《现代应用物理》2021年第2期76-85,共10页Modern Applied Physics

摘　　要：为了解决脉冲X射线辐照铝板气化反冲数值仿真高精度样本和高维输入参数不确定性导致的仿真结果不确定度量化问题,本文提出一种改进的蒙特卡罗不确定度量化方法。首先,分析有限元方法的网格收敛性,选出一组较低精度计算网格辅助构造Co-Kriging(CK)代理模型;其次,提出一种基于留一交叉验证准则的序贯试验设计以便提高采样效率,并融合不同精度的仿真数据,构造CK模型;最后,对CK模型进行蒙特卡罗仿真,并对仿真结果的不确定度进行统计分析。以3维X射线辐照动力学仿真程序TSHOCK3D为例,假设12维输入参数服从独立正态分布,给出了在1 keV软X射线辐照下,铝板的气化反冲冲量的期望和标准差的经验概率密度函数及其95%置信区间。计算结果表明,基于高精度网格的仿真结果在显著性水平为5%下是可信的。An improved Monte Carlo uncertainty quantification method is proposed to solve the problem of simulation uncertainty caused by the uncertainty of high-dimensional input parameters under the condition of high-precision sample scarcity in numerical simulation of blow-off impulse(BOI)of Al plate irradiated by pulsed X-ray.Firstly,a set of lower precision computational grids are selected to construct Co-Kriging(CK)model through the finite element method mesh convergence analysis.Secondly,a sequential experiment design method based on leave-one-out cross-validation(LOOCV)criterion is proposed to improve sampling efficiency,and CK model is constructed by fusing simulation data of different accuracy.Finally,Monte Carlo simulation is carried out based on CK model,and the uncertainty of simulation results is analyzed statistically.Taking 3D X-ray irradiation dynamics simulation program TSHOCK3D as an example,the empirical probability density function and its 95%confidence interval for the expectation and standard deviation of BOI of aluminum plate under 1 keV soft X-ray irradiation is given,assuming that the input parameters of 12 dimensions follow the independent normal distribution(3σ=0.1μ).

关 键 词：脉冲X射线 BOI 蒙特卡罗方法 不确定度量化 序贯试验设计 留一交叉验证 

分 类 号：O354.5[理学—流体力学]