Speaker: Dr. Yichao Zhu (朱一超博士)
Time: 11:00-12:00, 2 February 2021 (Tuesday) (Beijing time)
Venue: T2-202, UIC
Abstract
In this talk, the mathematical linkage between traditional asymptotic homogenisation approaches and the emerging machine learning tools is exploited, so as to devise a general treatment on mimicking the macroscopic behaviour through summarising the underlying fine-scale mechanisms. The presentation begins with the modelling of the long-term irradiation-induced behaviour of polycrystalline materials, where the collective behaviour of the atomic radiation-induced point defects is formulated [1]. The topic is then extended to simulate the long-term bubble behaviour within crystalline materials exposed to irradiation [2]. For demonstrating the wide applicability of the treatment, an algorithm used for efficiently evaluating the behaviour of graded microstructural configurations, another multiscale system motivated in a completely different engineering context, is introduced. The presentation concludes with a summary over the mathematical analogies behind other physical phenomena where cross-scale modelling is desired [3-6].
[1] Y. C. Zhu, J. Luo, X. Guo*, Y. Xiang, S. J. Chapman. “Role of grain boundaries under long-time radiation”, Phys. Rev. Lett., 120, 222501-5, 2018.
[2] J. Luo, Y. Xin, Z. C. Zhou, Y. C. Zhu*, X. Guo*. “Attempts on representing sink strengths with machine learning formulations and the long-term role of crystalline interfaces in the development of irradiation-induced bubbles”, Journal of Nuclear Materials., 544, 152676, 2021.
[3] Y. C. Zhu, S. S. Li, Z. L. Du, C. Liu, X. Guo*, W. S. Zhang*. “A novel asymptotic-analysis-based homogenisation approach towards fast design of infill graded microstructures”, J. Mech. Phys. Solids, 124, 612-633, 2019.
[4] D. C. Xue, Y. C. Zhu*, X. Guo*. “Generation of smoothly-varying infill configurations from a continuous menu of cell patterns and the asymptotic analysis of its mechanical behaviour”, Comput. Methods Appl. Mech. Engrg., 366, 113037, 2020.
[5] D. C. Xue, Y. C. Zhu*, S. S. Li, C. Liu, W. S. Zhang, X. Guo*. “On speeding up an asymptotic-analysis-based homogenisation scheme for designing gradient porous structured materials using a zoning strategy”, Struct. Multidiscip. Optim., 62, 457-473, 2020.
[6] Z. C. Zhou, Y. C. Zhu*, J. Luo, Y. Xiang, X. Guo*. “Characterisation of dislocation patterning behaviour with a continuum dislocation dynamics model on two parallel slip planes equipped with a deep neural network resolving local microstructures”, Int. J. Solids Struct., 198, 57-71, 2020.
About Dr. Zhu
Dr. Yichao Zhu got his B.A. from School of Mathematical Science at Fudan University, then got his PhD on Applied Mathematics at University of Oxford. After acting as a postdoctoral research fellow at the Hong Kong University of Science and Technology, Dr. Zhu is now an associate professor based in Department of Engineering Mechanics at Dalian University of Technology. Dr Zhu’s major research interest lies in modelling and simulation of physical processes involving multiple time and spatial scales, and using them for cross-scale design. The research field Dr. Zhu gets his foot in includes infill graded microstructural design for additive manufacturing, dislocation dynamics for modelling plasticity, defect dynamics for designing irradiation-tolerant materials, density functional theory for quantifying surface elasticity, etc.. Dr. Zhu’s works see their publications in a number of high-rank journals in the related fields, such as Physical Review Letters (PRL), the Journal of the Mechanics and Physics of Solids (JMPS). Dr. Zhu has been the principal investigator of two NSFC funds, and is awarded with Changjiang young scholar in 2020.
