Academic Masters Forum No.32
CONSTITUTIVE AND FRACTURE MODELING FOR ANISOTROPIC METALS
Guest Speaker：Prof. Jeong Whan Yoon,KAIST, Korea
Inviter: Prof.Jun Chen, Assoc.Prof. Qi Hu
Date&Time: Wednesday，30.Oct., 14:00-15:30
Venue: Meeting Room 211 ,Zhong Shi Building, Xu Hui Campus(徐汇校区中试楼 221)
Biography:
Jeong Whan Yoon is currently a professor in the Department of Mechanical Engineering at KAIST, Korea and a joint research professor at Deakin University, Australia. He is a fellow of the Korean Academy of Science and Technology. Dr. Yoon's research areas include high-reliability design and manufacturing of lightweight materials and structures. He has been responsible for the High-Speed Mechanical Properties Data Center at KAIST since 2019. He has been leading the GM-chaired Research Center for Innovative Manufacturing (ICIM) at Deakin University since 2015. He also led research at the Boeing-chaired Manufacturing Research Center (AusAMRC) at Swinburne University. Dr. Yoon has published more than 300 technical papers in international academic journals and conferences. He received the “2008 International Journal of Plasticity Young Researcher Award”. He was also awarded the “2023 Khan International Award” for his lifetime outstanding contributions in the field of plasticity. He is currently Associate Editor of the International Journal of Plasticity. As a guest editor, he also edited over 15 special issues including Int. J. Plasticity and Int. J. Solids and Structures. Dr. Yoon has diverse industry experience, including LG Electronics (Korea), MSC Software Corporation (USA), and Alcoa Technical Center (USA). He has served as Chair of major conferences including NUMISHEET2014 held in Melbourne, Australia, APEA2018 held in Jeju Island, Korea, and ICPDF2023 & ICPDF2024 held in the Dominican Republic and Panama, respectively. He received his PhD from KAIST in 1997.
Abstract:
This presentation reviews the popular approaches for constitutive and failure modeling, focusing on the use of non‐associated flow rules to enable greater flexibility to capture the anisotropic yield and flow behavior of metals using less complex functions than those needed under associated flow to achieve that same level of fidelity to experiment, and on the use of path-independent spaces to more reliably predict failure limits under complex conditions of non‐linear forming. The paper discusses motivating factors and benefits in favor of both associated and non‐associated flow models for metal forming, including experimental, theoretical, and practical aspects. The paper also shows constitutive models to capture both anisotropic hardening response and Bauschinger effect. This review is followed by a discussion of the topic of the failure limits, the limitations of strain analysis, the evidence in favor of stress analysis, and the path-independent space to incorporate non-proportional loading paths for any ductile fracture models.
Academic Masters Forum No.33
Heterostructured Material Design of High Entropy Alloys and Additive Manufacturing by Processing-Structure-Property Linkage
Guest Speaker：Chair Prof. Hyoung Seop Kim, Pohang University of Science and Technology (POSTECH), South Korea
Inviter: Prof. Haiming Zhang
Date&Time: Wednesday，30.Oct., 15:30-17:00
Venue: Meeting Room 211 ,Zhong Shi Building, Xu Hui Campus(徐汇校区中试楼 221)
Biography:
Professor Hyoung Seop Kim earned his PhD from Seoul National University in 1992 and currently serves as the Chair Professor in the Department of Materials Science and Engineering at Pohang University of Science and Technology (POSTECH), South Korea. He is a distinguished member of several prestigious academies, including the Korea Academy of Science and Technology, the Korean Academy of Engineering, and a foreign member of the Indian Academy of Sciences. Professor Kim also serves as the Director of the National Engineering Research Center for Additive Manufacturing of Heterogeneous Metal Materials in South Korea and visiting professorships at Yonsei University, South Korea, and Tohoku University, Japan.
As a prominent figure in the academic community, Professor Kim is actively involved in various leading organizations and journals. He is the Editor-in-Chief of Metals & Materials International and editorial board members of multiple international renowned journals such as Materials Research Letters, Materials Science & Engineering A, Intermetallics, and Journal of Materials Science.
His research group has achieved significant breakthroughs in high entropy alloys, additive manufacturing, machine learning, plastic forming, etc. He has authored over 1,000 papers and monographs in leading international journals, with more than 29,000 citations and an H-index of 78.
Abstract:
This presentation summarizes innovative research on designing and analyzing heterogeneous microstructures in high entropy alloys to enhance mechanical properties like strength and ductility. Using representative volume element modeling and finite element methods (FEM), the study focuses on optimizing core-shell structures by controlling geometry, size, and shape in soft and hard domains. A novel approach integrates 3D numerical modeling with machine learning, incorporating hetero-deformation induced strengthening features to predict the best microstructures for superior performance. The research also develops a physical-based constitutive model that captures deformation mechanisms and dislocation density evolution. Through FEM simulations, the study analyzes the relationship between grain size, volume fraction, and spatial distribution in bimodal structures, leading to the discovery of optimal designs. This combined approach of computational modeling, empirical analysis, and machine learning provides a powerful framework for creating high-performance materials.