基于MEP法的在役桥梁时变可靠度研究

发布时间：2018-05-20 14:55

本文选题：在役桥梁 + 时变可靠度　；参考：《中国铁道科学》2015年04期

【摘要】：基于最大熵原理和概率理论,提出用于分析在役桥梁结构时变可靠度的最大熵概率密度迁移法(MEP法)。采用有限元法求出较为精确的响应量,用数理统计法求得响应量的各阶矩;以4阶原点矩为最大熵约束条件,结合最小二乘法推导结构响应的概率密度函数解析式;基于时变可靠度原理,得出1组迁移的概率密度曲线族;根据"安全—损伤—失效"三级工作模式确定积分限值,计算结构的时变损伤概率与失效概率,进而得到相应的可靠度。运用MEP法和Monte Carlo法对在役桥梁算例可靠度的比较计算结果表明:2种算法结果较为吻合,且符合在役桥梁现状;MEP法可避免Monte Carlo法的大规模取样,并解决数值积分法所面临的复杂结构功能函数难以获得的问题。
[Abstract]:Based on the maximum entropy principle and probability theory, a maximum entropy probability density migration method is proposed to analyze the time-varying reliability of existing bridges. The finite element method is used to obtain the more accurate response quantity, the mathematical statistics method is used to obtain each order moment of the response quantity, the fourth order origin moment is taken as the maximum entropy constraint condition, and the probability density function analytic formula of the structural response is derived by combining the least square method. Based on the principle of time-varying reliability, a group of transition probability density curve families is obtained, and the integral limit value is determined according to the "safe-damage-failure" three-level working mode, and the time-varying damage probability and failure probability of the structure are calculated. Then the corresponding reliability is obtained. The comparison of reliability of in-service bridges with MEP and Monte Carlo methods shows that the results of the two algorithms are in good agreement and accord with the present situation of existing bridges. This method can avoid the large-scale sampling of the Monte Carlo method. The problem that the complex structure function is difficult to obtain is solved by numerical integration method.
【作者单位】：佛山科学技术学院环境与土木建筑学院;
【基金】：广东省交通厅科技项目(2011-02-050)
【分类号】：U441

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