Reliability Analysis Method for Degrading Structures Taking Combination of Load Processes into Account

考虑荷载过程组合的退化结构可靠性分析方法

• 批准号: 11650582
• 负责人: MORI Yasuhiro
• 金额: $ 2.24万
• 依托单位: Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11650582/
• 关键词: Structural Reliability; Limit State Design; Structural Degradation; Load and Resistance Factors; Load Combination; Stochastic Process; Inspection and Maintenance

The deterioration of infrastructures is a widespread problem in many countries. In order to assess such structures for continued future service, simple and practical tools need to be developed for evaluating the time-dependent reliability and performance of the structures.When more than one time-varying load act on a structure, the maximum intensity of the combination during the reference period needs to be considered. This project first developed the theoretical expressions of the cumulative distribution function (cdf) of the maximum intensity of the combination. Numerical examples show that the theoretical expression of the cdf provides fairly good estimate regardless of the statistical characteristics of the load intensity and stochastic processes.Then the concept of a resistance reduction factor due to degradation of a component is introduced to approximate a time-dependent reliability problem as a time-independent one. With the factor the time-varying resistance can be equivalentl … More y replaced with a time-invariant resistance, and load and resistance factors can be determined for the assessment applying simple AFOSM.An approximation method to determine the factor is proposed, and numerical example shows that the target reliability level can be achieved fairly accurately using an approximate reduction factor.Periodic in-service inspection followed by suitable maintenance may restore a degraded structural component to near-original condition. Since inspection and maintenance are costly, there are tradeoffs between the extent and accuracy of inspection, required level of reliability, and cost. To design an optimum inspection/maintenance strategy, generally non-linear optimization problem must be solved. The approximation method can be applied to estimate a resistance reduction factor including the cases when the strength of a component changes discontinuously in time due to, such as, restoration. Using the proposed method, the optimization can be simplified avoiding time-dependent reliability analysis. Less

在许多国家，基础设施的定义是一个广泛的问题。为了评估这种结构的持续服务，需要开发简单且实用的工具来评估结构的时间依赖性可靠性和性能。当对结构上有多个时间变化的负载法，则需要考虑参考期间组合的最大强度。该项目首先开发了组合最大强度的累积分布函数（CDF）的理论表达。数值示例表明，无论负载强度和随机过程的统计特征如何，CDF的理论表达提供了相当良好的估计。然后引入了由于组件降解而引起的电阻降低因子的概念，以近似时间依赖时间的可靠性问题作为时间无关。使用因素，时间变化的电阻可以等效地……更替换了时间传播的阻力，并且可以确定适用简单AFOS的评估的负载和电阻因素。一种提出了该因子的近似方法，并且数值示例表明，可以在近似近似的内部进行近似启用因子来确定目标可靠性水平。成分至近乎原状的条件。由于检查和维护成本高昂，因此在检查的程度和准确性，所需的可靠性水平和成本之间存在权衡。要设计最佳检查/维护策略，必须解决通常非线性优化问题。近似方法可以应用于估计耐药性降低因子，包括由于恢复等及时而不连续变化的情况。使用提出的方法，可以简化优化，以避免时间依赖时间的可靠性分析。较少的

项目成果

M.Nonaka, Y.Mori, & Y.Funahashi.: "A Study on LRFD Taking Structural Degradation into Account"Summary of Technical Papers of Annual Meeting, AIJ. B-I. 19-20 (2000)

M.野中，Y.森，

Yasuhiro Mori & Kazuko Murai: "Load and resistance factors taking combined load processes into account"Proc.8th Int.Conf.on Applications of Statistics and Probability. 973-980 (1999)

森泰弘

野中桃子,森保宏,舟橋洋祐: "構造部材の耐力劣化を考慮した荷重・耐力係数設計法"日本建築学会大会学術講演梗概集. B-I. 19-20 (2000)

Momoko Nonaka、Hiroshi Mori、Yosuke Funahashi：“考虑结构构件强度恶化的载荷和强度系数设计方法”日本建筑学会会议学术讲座摘要 19-20 (2000)。

M.Nonaka, Y Mori, K.Baba, & Y.Funahashi.: "A Study on LRFD for Structural Component Taking its Strength Degradation into Account"Proc. AIJ Tokai Chapter Archiectural Research Meeting, AIJ. No.38. 133-136 (2000)

M.Nonaka、Y Mori、K.Baba、

野中桃子,森保宏: "劣化影響係数を用いた構造部材の荷重・耐力係数設計"日本建築学会東海支部研究報告集. 201-204 (2001)

野中桃子、森泰宏：《利用劣化影响系数的结构构件的荷载和强度系数设计》日本建筑学会东海分会研究报告书201-204（2001年）