基于长期动态应变监测数据的大跨钢桥时变疲劳可靠度评估

项目名称： 基于长期动态应变监测数据的大跨钢桥时变疲劳可靠度评估

项目编号： No.51308493

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 建筑科学

项目作者： 叶肖伟

作者单位： 浙江大学

项目金额： 25万元

中文摘要： 本项目以青马大桥结构健康监测系统获取的15年长期监测数据为基础，应用理论分析、数值模拟以及模型试验相结合的方法，围绕交通荷载与环境因素共同作用下钢桥结构构件的疲劳性能退化机理这一关键科学问题开展系统性的理论研究。在充分挖掘监测数据内在特征及长期变化规律的基础上，提出多组分数据结构分析方法及应力谱多模态概率建模理论。发展针对钢桥焊接构件的主S-N曲线通用热点应力疲劳寿命分析方法，有效解决钢桥焊接构件疲劳寿命评估现存的结构热点应力确定随机性和S-N曲线选择受限性的问题。建立考虑多因素共同作用的钢桥结构构件疲劳可靠度评估模型，基于结构可靠度理论建立疲劳损伤极限状态方程，研究应力谱概率模型时变特性及疲劳抗力退化模型，以贝叶斯理论为基础，发展基于数据驱动的钢桥结构构件时变疲劳可靠度分析方法。本项目的研究成果将为基于概率的钢桥结构构件疲劳设计理论与评估方法提供依据，具有重要的理论价值和现实意义。

中文关键词： 结构健康监测；钢桥；概率建模；时变疲劳可靠度；主S-N曲线

英文摘要： Based on the 15-year monitoring data from the long-term structural health monitoring system instrumented on the Tsing Ma Bridge, this research project aims to investigate the fatigue performance deterioration mechanism of the structural components in steel bridges under the combined effect of traffic loading and environmental factors using theoretical analysis, numerical simulation, and model experiments. In recognition of the excavated inherent characteristics and long-term variation rules of the monitoring data, the method of multi-component data structure analysis and multi-modal probabilistic modeling of stress spectra will be developed. Additionally, a general hot spot stress method for fatigue life assessment of welded components in steel bridges based on the master S-N curve method will be exploited to effectively solve the randomness in determining the structural hot spot stress of welded components in steel bridges as well as the restriction in selecting the S-N curves. Furthermore, an analytical model considering multiple effects for fatigue reliability assessment of the structural components in steel bridges will be established, and the limit state equation of fatigue damage will be formulated based on the structural reliability theory. The time-variant characteristic of the probabilistic model of str

英文关键词： Structural health monitoring；Steel bridge；Probabilistic modeling；Time-dependent fatigue reliability；Master S-N curve