航空学报 > 2013, Vol. 34 Issue (7): 1605-1615   doi: 10.7527/S1000-6893.2013.0224

认知不确定性下可靠性灵敏度分析的新指标

锁斌, 曾超, 程永生, 李世玲   

  1. 中国工程物理研究院 电子工程研究所, 四川 绵阳 621900
  • 收稿日期:2012-08-27 修回日期:2013-04-22 出版日期:2013-07-25 发布日期:2013-04-27
  • 通讯作者: 锁斌 E-mail:suo.y.y@163.com
  • 作者简介:锁斌,男,博士,助理研究员。主要研究方向:不确定性信息处理、系统可靠性分析与评估。Tel:0816-2487513,E-mail:suo.y.y@163.com;曾超,男,博士,研究员,博士生导师。主要研究方向:复杂系统的分析、综合与仿真。Tel:0816-2496603,E-mail:zch_bob@163.com;程永生,男,博士,研究员,博士生导师。主要研究方向:探测与控制技术。Tel:0816-2487556,E-mail:chys_iee@163.com
  • 基金资助:

    国防预研项目 (426010401);中国工程物理研究院科学技术发展基金(2012B0403058)

New Index for Reliability Sensitivity Analysis Under Epistemic Uncertainty

SUO Bin, ZENG Chao, CHENG Yongsheng, LI Shiling   

  1. Institute of Electronic Engineering, China Academy of Engineering Physics, Mianyang 621900, China
  • Received:2012-08-27 Revised:2013-04-22 Online:2013-07-25 Published:2013-04-27
  • Supported by:

    National Defense Pre-research Foundation (426010401); China Academy of Engineering Physics Foundation for Development of Science and Technology (2012B0403058)

摘要:

传统的可靠性灵敏度指标只考虑了随机不确定性,当结构中还存在认知不确定性时,该指标难以反映出基本变量中认知不确定性对结构可靠性评估结果的影响程度。针对这一问题,引入概率包络来表达结构中的随机不确定性和认知不确定性,在此基础上建立了可靠性灵敏度分析的新指标——认知灵敏度系数,给出了其定义和代表的意义,并基于证据理论提出了认知灵敏度系数的计算方法。算例分析表明,认知灵敏度系数可以反映出基本变量中认知不确定性对结构可靠性评估结果的不确定性的影响程度,从而为有针对性地提高可靠性评估结果的准确性提供依据。另外,基于证据理论的认知灵敏度系数的计算方法适用于极限状态函数为单调、非单调的结构,以及变量服从正态、非正态的结构,具有普适性。

关键词: 可靠性, 灵敏度分析, 证据理论, 认知灵敏度系数, 认知不确定性, 随机不确定性

Abstract:

Conventional index for reliability sensitivity analysis considers only aleatory uncertainty, which cannot show the impacts of epistemic uncertainty in basic variables on structural reliability in the condition of epistemic uncertainty. In view of this, probability boxes are introduced to represent aleatory and epistemic uncertainties in structure, on the basis of which a new index for reliability sensitivity analysis, epistemic sensitivity coefficient, is constructed. The meaning and significance of the new index are explained, and a method based on evidence theory is proposed to calculate it. Numerical examples show that the new coefficient can reveal the contribution of each basic variable to the uncertainty of structural reliability, and it provides a direction to improve the accuracy of reliability calculation. The simulation results also show that the proposed method of epistemic sensitivity calculation is applicable to structures with monotonic as well as non-monotonic limit state equations, and with normal as well as non-normal variables.

Key words: reliability, sensitivity analysis, evidence theory, epistemic sensitivity coefficient, epistemic uncertainty, aleatory uncertainty

中图分类号: