高强度钢桥面板疲劳损伤机理及热点应力评价方法研究

项目名称： 高强度钢桥面板疲劳损伤机理及热点应力评价方法研究

项目编号： No.51278166

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 建筑科学

项目作者： 吉伯海

作者单位： 河海大学

项目金额： 80万元

中文摘要： 我国大跨径缆索承重桥梁建设规模已处于世界前列。随着服役年限增长，该类桥梁运营安全与维护成为桥梁工程领域备受关注的重大课题，其中钢桥面板疲劳损伤是该领域亟待解决的核心难题。高强度钢桥面板结构性能优越、应用前景广阔，但疲劳损伤机理与普通钢桥面板差异明显。本项目引入疲劳研究前沿热点应力理论，研究其疲劳损伤机理与评价方法。 项目拟采用新型振动型疲劳试验机，进行多轴应力状态下高强度钢桥面板焊接接头疲劳试验，研究其疲劳损伤机理及疲劳强度；建立考虑焊趾残余应力转移与释放特点的焊接接头多轴疲劳损伤临界面与损伤参量；提出考虑残余应力重分布与多轴应力状态的疲劳受力模型与热点应力计算式，建立高强度钢桥面板疲劳的热点应力评价方法。在此基础上，提出高强度钢桥面板抗疲劳焊缝处理措施及构造设计参数。 本项目预期研究成果将进一步完善高强度钢桥面板疲劳设计理论，对于提高其运营安全性、延长服役寿命具有重要的科学意义。

中文关键词： 高强钢；钢桥面板；疲劳；损伤机理；热点应力评价

英文摘要： Construction scale of long-span cable-supported bridges in China has stepped into world's first rank .With increase of service life, operation safety and maintenance of bridges has become a compelling and significant subject in bridge engineering. Fatigue damage of steel bridge deck is the crucial problem needed to be solved urgently. High-strength steel deck has distinguished structural behavior and extensive application prospects. However, its fatigue damage mechanism is different from normal strength steel deck. Hot spot stress theory, which is the frontier of fatigue research, is introduced into this project to carry out study in fatigue mechanism and assessment method of high strength steel bridge decks. New type vibration fatigue test machines are applied in multi-axial welded joint fatigue tests, to investigate fatigue damage mechanism and fatigue strength of high-strength steel decks. Critical damage surface and damage parameters of multi-axial fatigue are built considering residual stress transfer and release in weld toes. Fatigue mechanical model and hot spot stress calculation are established, considering residual stress redistribution and multi-axial stress state, to set up hot spot stress fatigue assessment method of high-strength steel deck. Eventually, post process of weld and structural design p

英文关键词： High strength steel；steel bridge deck；fatigue；damage mechanism；hot-spot stress assessment