• CN:11-2187/TH
  • ISSN:0577-6686

›› 2012, Vol. 48 ›› Issue (14): 192-198.

• 论文 • 上一篇    

结构凸集—概率混合可靠性分析的新方法

李昆锋;杨自春;孙文彩   

  1. 海军工程大学船舶与动力学院
  • 发布日期:2012-07-20

New Hybrid Convex Model and Probability Reliability Method for Structures

LI Kunfeng;YANG Zichun;SUN Wencai   

  1. College of Naval Architecture and Power, Naval university of Engineering
  • Published:2012-07-20

摘要: 对凸集不确定性和随机变量共存的结构混合可靠性模型行研究,以解决部分参量统计信息不足时的结构可靠性评定问题。基于Info-gap理论,建立一种统一的结构非概率可靠性模型,由此导出一种与概率可靠性方法等价的椭球非概率可靠性模型。用一种特定的椭球凸集模型描述随机变量不确定性,与一般性的凸集模型复合,将凸集不确定性和随机变量共存的混合可靠性问题统一为非概率可靠性问题。基于非概率可靠性方法,提出一种一般性的凸集-概率混合可靠性方法。给出的混合可靠性指标同时具有稳健可靠性和概率可靠性意义,可通过含约束的优化问题求解。算例分析显示,当数据分散性较强或较弱时,已有的混合可靠性方法不能有效度量结构可靠性,新方法更具合理性和适用性。

关键词: Info-gap模型, 非概率可靠性, 混合可靠性, 结构可靠性, 凸集模型

Abstract: The reliability assessment of structures with partial statistic information is investigated by establishing a general hybrid convex model and probability reliability model. A general non-probabilistic reliability model for structures is proposed based on the info-gap(information gap) theory. A special ellipsoidal-bound non-probabilistic structural reliability model equaling to probabilistic reliability model is established. The hybrid reliability problem exhibiting both convex model and probabilistic uncertainties is transformed into a non-probabilistic one by applying a special ellipsoidal-bound convex model to describe stochastic variables. Then a new general hybrid convex model and probability reliability model for structures is proposed based on the non-probabilistic reliability model. The hybrid reliability index has both robust and probabilistic reliability meanings and can be obtained by solving an optimization problem. The numerical examples prove that the previous hybrid reliability method can not work properly when the degree of uncertainty of the data is high or low and the new method has superiority and more rationality.

Key words: Convex model, Hybrid reliability, Info-gap model, Non-probabilistic reliability, Structural reliability

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