报告题目：A Digital Twin Approach to Monitor Crack Siz-es in Welded Joints for Offshore Applications

报告人：Xudong Qian， National University of Singapore

邀请人：周波教授

时间：2024年7月10日10点-11点30

地点：A字楼101会议室

Abstract

The welded joints in offshore structures often experience cyclic loadings caused by environmental actions, which frequently lead to fatigue crack initiation and propagations in these welded details. To optimize the lifecycle cost of inspection and maintenance of the structure, and at the same time to ensure safe and sustainable operations, accurate sizing of cracks in these critical welded details becomes essential. This lecture starts by examining the practical nondestructive testing techniques in measuring the crack sizes in the welded connections, e.g., the alternating current potential difference and the ultrasonic phased array. Using the nondestructive testing results as a benchmark, the lecture will present a physics-informed data-driven digital twin to determine the size of surface cracks with complex shapes in the welded connections. The digital twin represents a replica of the physical asset interfaced through sensor data. The digital twin approach deploys a machine learning algorithm and treats the crack sizing as a classification problem. The crack sizes estimated from the digital twin shows close agreement with the measured crack size in the physical specimens. This presentation will also touch on the application of the digital twin in a generic large-scale offshore structure.

报告人简介：Dr. QIAN Xudong is currently an Associate Professor in the Department of Civil and Environmental Engineering (CEE) at the National University of Singapore (NUS), Deputy Head of CEE at NUS, Group Head of the Structural and Offshore Engineering, Director for Centre for Offshore Research and Engineering (CORE), and Director for Centre for Advanced Materials and Structures (CAMS) NUS. He received his Bachelor (1st Class 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 data driven digital twins for damage quantification and integrity assessment, fracture and fatigue for large-scale structures, and floating structures. Prof Qian is a member of the editorial board in a number of premier journals including Engineering Fracture Mechanics, Fatigue and Fracture of Engineering Materials and Structures, etc. Prof Qian has been serving as members in different Technical Committees for the International Ship and Offshore Structures Congress from 2009 to 2018. He is also a member of the technical committee in American Society of Testing and Material E08 – Fatigue and Fracture and F42 – Additive Manufacturing.