AE Seminar
"Fracture Mechanics of Rare-Earth Permanent Magnets"
featuring
Xing Liu
(Assistant Professor, Department of Mechanical and Industrial Engineering, New Jersey Institute of Technology)
Thursday, September 17
11:00 a.m. - 12:00 p.m.
Guggenheim 442
About the seminar:
High-energy-density rare-earth permanent magnets are critical components across a broad range of applications, including electronics, energy harvesting and generation, and electric vehicles. However, the intrinsic brittleness of these intermetallic compounds limits their structural reliability and service life, making them susceptible to premature failure during manufacturing, handling, and high-speed operation. This vulnerability can be further exacerbated by the combined action of mechanical and magnetic loads. A mechanistic understanding of fracture under such coupled conditions remains lacking, impeding the development of effective strategies for fracture mitigation and lifetime extension in these high-value materials. In this talk, I will present our recent theoretical and modeling efforts to understand fracture in permanent magnets. We established a thermodynamically consistent constitutive framework to capture the coupled magnetic and elastic behavior of magnetically saturated magnets. Building on this framework, we revisited and extended classical concepts in linear elastic fracture mechanics, including the energy release rate and path-independent integrals, to magnet fracture. We further implemented the framework numerically to model the mechanical and magnetic fields in cracked magnets under combined magneto-mechanical loading conditions, providing numerical validation of the theoretical developments. The resulting fracture prediction framework provides a foundation for material certification and fracture management of permanent magnets and may help mitigate vulnerabilities in the global rare-earth supply chain.
About the speaker:
Dr. Xing Liu is an assistant professor in the Department of Mechanical and Industrial Engineering at New Jersey Institute of Technology, where he leads the Computational Mechanics and Physics Lab. His lab integrates computational mechanics and data-driven approaches to uncover the physical mechanisms underlying material deformation and failure and to design safer, longer-lasting structural materials, with a particular focus on multiphysics fracture mechanics. The lab aims to address the growing demand for mechanically resilient and socially responsible materials and structures in aerospace and energy applications. Dr. Liu received his Ph.D. in Solid Mechanics from Brown University and conducted postdoctoral research in the George W. Woodruff School of Mechanical Engineering at Georgia Institute of Technology.