非接触水下爆炸下舰船冲击环境的不确定度量化

The uncertainty quantification of ship shock environment subjected to non-contact underwater explosion

  • 摘要:
      目的  为挖掘和量化舰船非接触水下爆炸建模与模拟中的不确定性因素,开展高维随机变量对系统输出结果的影响研究。
      方法  根据变量统计特征和工程经验,使用对数正态分布描述物理量的不确定度,使用Beta分布描述唯象参数的不确定度,并使用Rosenblatt变换将不同类型的相关随机变量组转化为服从独立同分布的正态分布变量组。此外,考虑到模型的复杂性且不确定性因素众多,使用基于二次自适应基函数的齐次Wiener混沌方法处理不确定度的传播, 以提高计算效率。以甲板上弹簧系统试验装置为例,应用所提方法研究试验装置的冲击响应量的期望值、标准差、置信区间和概率密度函数。
      结果  结果显示,舰船遭受水下爆炸冲击后,甲板一直处于振荡状,标准差的振荡相比期望值更大。
      结论  研究结果可为非接触水下爆炸冲击影响以及评估舰船抗冲击性能提供依据。

     

    Abstract:
      Objectives  To identify and quantify uncertain factors in the modeling and simulation of ships suffering a non-contact underwater explosion, the influence of high dimensional random variables on the output of the system is studied.
      Methods  Following statistical characteristics and engineering knowledge, the normal distribution log is used to describe uncertain physical quantity, and Beta distribution is utilized to depict uncertain empirical parameters. Rosenblatt transformation is explored to transform these correlated random variables into Gaussian variables, satisfying identical and independent distribution. There are a variety of uncertain factors due to the complexity of the model. The computational efficiency is greatly improved when homogeneous Wiener chaos with quadratic adaptive basis function is used to tackle improbability propagation of these input uncertainties. Concerns over a spring device in the deck, expectation, standard deviation, confidence interval, and the probability density function of the quantity of impulsive is presented via the proposed method.
      Results  Oscillation of the ship always exists after the arrival of a shock wave. The oscillation of the standard deviation is much more forceful than the mean value.
      Conclusions  The result can be used to predict the impact of a detonation and provide guidance for the reinforcement ability of the ship.

     

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