报告题目：Local Approaches for Cleavage Failure Assessment – Nonconventional Specimens and Applications
The intrinsic statistical characteristics of cleavage fracture have been widely acknowledged during the past decades in various brittle materials, e.g., ferritic steels, ceramics, glasses, and solid chemical catalysts. The observed large scatter in the experimentally measured fracture toughness, in e.g., ferritic steels, drives the development of statistical-based treatment of cleavage failure, represented primarily by two broad categories of approaches, namely the global approach and the local approach. Both approaches have experienced significant advancement over the years and have become commonly adopted in the structural integrity assessments for different applications. This study addresses the following challenges faced in the engineering assessment of cleavage fracture: a) the calibration of the key parameters in the statistical assessment of cleavage failure; b) near-tip fracture driving force incorporating a strain gradient plasticity; c) assessment of cleavage failure in curved surface crack specimens; and d) assessment of cleavage fracture in mixed-mode fracture. This presentation also extends the cleavage assessment to large-scale pressure vessel structures under thermal-mechanical loading conditions.
Dr. QIAN Xudong is currently an Associate Professor in the Department of Civil Engineering at the National University of Singapore (NUS), the Co-Director for NUS-JTC (Jurong Town Corporation) Industrial Infrastructure Innovation Centre, and the Director for the Centre for Advanced Materials and Structures NUS. He received his Bachelor (1stClass Honors) 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 research associate in the Department of Civil and Environmental Engineering, University of Illinois at Urbana Champaign (UIUC). Prof Qian’s research interest focuses on experimental fracture mechanics, fracture and fatigue assessment for large-scale structural components, welded connections, steel-concrete-steel composite structures, and polymer composite materials for deep-water applications. Prof Qian has been serving as members in different Technical Committees for the International Ship and Offshore Structures Congress since 2009. He is also a member of the technical committee in American Society of Testing and Material E08 – Fatigue and Fracture.