舰船非接触水下爆炸系统的混合不确定度量化

Mixed uncertainty quantification of ship non-contact underwater explosion system

  • 摘要:
    目的 舰船非接触水下爆炸建模与仿真(M&S)中同时存在品目繁多的认知不确定度和偶然不确定度,在M&S过程中引入的不确定度导致系统响应量(SRQ)的数值模拟结果与试验真值间产生较大偏差,影响M&S的性能。而使用非接触水下爆炸不确定度量化(UQ)方法能提高M&S的可靠性和可信度。
    方法 首先,针对无物理意义、通过试验直接标定的唯象参数,使用D−S 证据理论(DSTE)融合不同学科专家(SME)的建议,得到唯象参数赋值区间和基本信度分配(BBA)函数。鉴于SME 的个人工程经验和知识结构的局限性,采用多证据、多周期性融合方法,提高认知不确定度量化的客观性。其次,使用蒙特卡罗法研究非接触水下爆炸中高维输入偶然不确定度的传播。最后,当偶然不确定度和认知不确定度同时存在时,将唯象参数作为外层,不确定的物理量作为内层,使用双层循环法执行非接触水下爆炸的混合不确定度量化。
    结果 结果表明,改进后的DSTE方法缩小了认知不确定度的取值范围,对SME初始意见改动较大,计算所得认知不确定度的BBA更精确、客观性更强。双层循环法可计算得到舰船非接触水下爆炸SRQ的可信置信区间和BBA,结果与常识吻合。
    结论 研究结果可用于指导舰船防护设计和提高水下兵器爆炸毁伤能力。

     

    Abstract:
    Objectives Substantial epistemic and aleatory uncertainties coexist in the modeling and simulation (M&S) of ship non-contact underwater explosion (UNDEX). Such uncertainties can lead to large deviations between the numerical results and true experimental data for system response quantity (SRQ), which can deteriorate M&S performance. However, the uncertainty quantification (UQ) of non-contact UNDEX can improve the reliability and credibility of M&S.
    Methods First, the D−S theory of evidence (DSTE) combined with subject matter expert (SME) opinion is utilized to obtain the basic belief assignment (BBA) function and value interval of the phenomenological parameters, which have no physical meaning and cannot be directly calibrated through physical experiments. In view of the constraints of engineering experience and knowledge structure of SME, the multiple source fusion and periodic fusion methods are used to further improve the objectivity of the epistemic UQ. Furthermore, the Monte Carlo method is applied to study the high-dimensional uncertainty propagation of the non-contact UNDEX of the ship. Finally, the double-loop method is applied in the mixed UQ when the ship non-contact UNDEX is disturbed by both aleatory uncertainty and epistemic uncertainty; to be specific, the phenomenological parameters are solved in the outer loop and the aleatory uncertainty is handled in the inner loop.
    Results The results show that the range of epistemic uncertainty is shortened and the initial opinion of SME substantially altered. The BBA of epistemic uncertainty computed from altered DSTE becomes more accurate and objective. The credible confidence interval of SRQ and corresponding BBA function in the non-contact UNDEX calculation can be obtained by double loop approach, and the results indicate that it agrees with the common sense.
    Conclusion This study can provide guiding references for ship protection design and improve the explosive damage power of underwater weapons.

     

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