报告题目：Fracture Mechanics based Approach to Assess and Represent FractureFailure in Large-Scale Steel Structures基于断裂力学的大型钢结构断裂失效评估方法
报告人：钱旭东教授
时间：2018年12月5日（星期三）上午10:00—12：00
地点：广东省滨海土木工程耐久性重点实验室会议室C501
学术报告内容：
Fracture failure has emerged as one of themost common failure modes in modern large-scale steel structures subjected tocyclic or extreme loads caused by artificial or environmental actions. Theintegrity assessment of the fracture requires a detailed understanding on thematerial level fracture resistance. However, the scalability between thematerial fracture toughness and the fracture resistance in the structuralcomponent imposes a critical barrier the fracture assessment and representationin large-scale steel structures. This study first embarks on the innovativeapproaches to reveal the material fracture resistance, characterized by thematerial J-R curve, through the experimental approach or theexperimental-computational hybrid method. These material level investigationscover the non-conventional specimens including the mixed-mode fracturespecimens, surface-cracked specimens, and circumferentially welded pipes.Coupling the material fracture resistance curve and the extended η-approach,this study proposes a practical method to embed the material J-R curve in theload-deformation relationship of the critical welded connection, to describephenomenologically the effect of ductile crack extension and the subsequentunstable fracture failure on the load resistance of the welded joint.
断裂破坏是现代大型钢结构在人为或环境循环或极端荷载作用下最常见的破坏形式之一。对断裂进行真实地评估需要对材料层面的断裂承载力有深入的理解。然而，材料断裂韧性与结构构件断裂承载力之间的可扩展性给大型钢结构的断裂评估和表征带来了极大的障碍。本研究首先采用创新的实验方法或实验-计算混合方法，以材料J-R曲线为特征，揭示材料的抗断裂性能。这些材料水平的研究包括非常规试样，如混合模式断裂试样、表面裂纹试样和周向焊接管试件。本研究结合材料断裂承载力曲线和扩展的η-approach,对关键焊接节点提出了一种嵌入材料J-R曲线于荷载-变形曲线的实用方法,进而描述其延性裂纹扩展的影响和后续焊接节点不稳定断裂破坏的极限承载力。
Dr. QIAN Xudong is currently an AssociateProfessor in the Department of Civil Engineering at the National University ofSingapore (NUS), the Co-Director for NUS-JTC (Jurong Town Corporation)Industrial Infrastructure Innovation Centre, and the Director for the Centrefor Advanced Materials and Structures NUS. He received his Bachelor (1st ClassHonors) and PhD in Civil Engineering from NUS in 2000 and 2005, respectively.Prior to joining NUS as a faculty member, he worked as a post-doctoral researchassociate in the Department of Civil and Environmental Engineering, Universityof Illinois at Urbana Champaign (UIUC). Prof Qian’s research interest focuseson experimental fracture mechanics, fracture and fatigue assessment forlarge-scale structural components, welded connections, steel-concrete-steelcomposite structures, and polymer composite materials for deep-waterapplications. Prof Qian has been serving as members in different TechnicalCommittees for the International Ship and Offshore Structures Congress since2009. He is also a member of the technical committee in American Society ofTesting and Material E08 – Fatigue and Fracture.
钱旭东博士现任新加坡国立大学土木工程系副教授，新加坡国立大学-JTC工业基础设施创新中心联席主任，新加坡国立大学先进材料与结构中心主任。他分别于2000年和2005年获得新加坡国立大学一级荣誉学士学位和土木工程博士学位。在加入新加坡国立大学之前，他在美国伊利诺伊大学香槟分校(UIUC)土木与环境工程系担任博士后研究员。钱旭东教授的研究兴趣主要在实验断裂力学、大型结构构件的断裂和疲劳评估、焊接连接、钢-混凝土-钢组合结构和复合材料深海工程应用。自2009年以来，钱教授一直担任多个国际船舶和海洋结构大会技术委员会委员。他也是美国测试与材料协会（ASTM）E08 -疲劳与断裂技术委员会的委员。
学术报告之前钱教授将简要介绍新加坡国立大学及土木工程系情况和特色，包括每年硕士、博士研究生项目申请情况。欢迎感兴趣的师生参加！
联系人：huangzhenyu@szu.edu.cn
土木工程学院
广东省滨海土木工程耐久性重点实验室
2018年12月3日
