Quality control and fatigue design of friction stir welded joints in aluminum bridge decks

铝桥面搅拌摩擦焊接头的质量控制和疲劳设计

• 批准号: 494843-2016
• 负责人: Walbridge, Scott
• 金额: $ 3.1万
• 依托单位: University of Waterloo
• 依托单位国家: 加拿大
• 项目类别: Collaborative Research and Development Grants
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=618111
• 关键词: Quality; control; fatigue; design; friction

Highway authorities in North America are currently faced with significant and pressing bridge maintenance costs. A recent industry report on aluminum use in bridges found light weight decks for new bridges and rehabilitation projects to be an application area with particular promise. A subsequent economic study concluded that: 1) bridge decks are an application where aluminum clearly has a potential for market growth, and 2) friction stir welding (FSW) represents a transformative technology, which could have a significant influence on the durability and economics of aluminum bridge decks. A design code for structural FSW joints does not yet exist in Canada. Existing international codes (e.g. ISO, AWS) include quality control provisions based on "best practice", which have not yet been related to structural performance. This project will be be performed collaboratively by researchers at the University of Waterloo (UW) and Université du Québec à Chicoutimi (UQAC) with the goal of developing improved, "performance-based" code provisions for the quality control (QC) and fatigue design of FSW joints in aluminum bridge decks. To achieve this goal, the following tasks will be performed: 1) specimen preparation and metallurgical analysis; 2) fatigue testing of FSW specimens; 3) statistical and fracture mechanics analysis of FSW test results; and 4) development of improved guidelines for QC and fatigue design of FSW bridge deck joints. A particularly novel aspect of the project will be the plan to fatigue test and analyze welds with varying levels of quality (i.e. various defect types with varying degrees of severity). This project will make a significant contribution to the current state-of-knowledge, which will move the Canadian industry and researchers working on FSW to the leading edge of this field, through the new knowledge acquired and the transformation of this knowledge into design recommendations.

目前，北美的公路当局面临着巨大的桥梁维护成本。最近在桥梁中使用铝用的行业报告发现，新桥梁和康复项目的重量轻巧，是具有特别有望的应用领域。随后的一项经济研究得出的结论是：1）桥甲板是铝显然具有市场增长潜力的应用，而2）摩擦搅拌焊接（FSW）代表了一种变革性的技术，这可能会对铝桥甲板的耐用性和经济性产生重大影响。加拿大尚不存在针对结构性FSW关节的设计代码。现有的国际规范（例如ISO，AWS）包括基于“最佳实践”的质量控制规定，这些规定尚未与结构性绩效有关。该项目将由滑铁卢大学（UW）和QuébecàChicoutimi（UQAC）的研究人员进行协作，目的是开发改进的“基于绩效的”质量控制质量控制（QC）的代码规定（QC）和铝桥甲板中FSW关节的疲劳设计。为了实现此目标，将执行以下任务：1）标本制备和冶金分析； 2）FSW标本的疲劳测试； 3）FSW测试结果的统计和断裂力学分析； 4）开发了改进的QC指南和FSW桥甲板关节的疲劳设计。该项目的一个特别新颖的方面是疲劳测试的计划，并分析质量水平不同的WED（即各种缺陷类型，严重程度不同）。该项目将为当前的知识做出重大贡献，这将通过获得的新知识以及将此知识转换为设计建议，这将使从事FSW的加拿大行业和研究人员将工作的研究人员转变为该领域的领先优势。