講座題目：Dynamics of Grain Boundaries Based on Underlying Microstructures
主講人：項(xiàng)陽(yáng) 教授
工作單位：Hong Kong University of Science and Technology
講座時(shí)間：2024年7月3日（周三）15：30-17：00
講座地點(diǎn)：清水河校區(qū)六號(hào)科研樓A344
主講人簡(jiǎn)介：項(xiàng)陽(yáng)，香港科技大學(xué)數(shù)學(xué)系教授，港深協(xié)同創(chuàng)新研究員機(jī)器學(xué)習(xí)和自動(dòng)駕駛算法研究實(shí)驗(yàn)室負(fù)責(zé)人?，F(xiàn)任東亞工業(yè)與應(yīng)用數(shù)學(xué)學(xué)會(huì)主席。主要研究方向是計(jì)算數(shù)學(xué)，機(jī)器學(xué)習(xí)理論及應(yīng)用，應(yīng)用領(lǐng)域包括材料科學(xué)和人工智能等前沿方向。項(xiàng)陽(yáng)教授在與缺陷相關(guān)的材料結(jié)構(gòu)建模與計(jì)算和基于深度神經(jīng)網(wǎng)絡(luò)的高性能計(jì)算上取得了一系列具有重要意義的原創(chuàng)性成果。項(xiàng)陽(yáng)教授是2021年美國(guó)工業(yè)與應(yīng)用數(shù)學(xué)協(xié)會(huì)(SIAM)材料科學(xué)中數(shù)學(xué)問(wèn)題會(huì)議大會(huì)報(bào)告人，入選斯坦福大學(xué)發(fā)布的全球TOP 2%科學(xué)家。
講座內(nèi)容：Grain boundaries are the interfaces between grains with different orientations in polycrystalline materials. Energetic and dynamic properties of grain boundaries play essential roles in the mechanical and plastic behaviors of the materials. These properties of grain boundaries strongly depend on their microscopic structures. We present continuum models for the energy and dynamics of grain boundaries based on continuous distributions of the line defects (dislocations or disconnections) on them. The long-range elastic interaction between these line defects is included in the continuum models. The continuum models are able to describe the shear coupling motions of grain boundaries, which were observed in atomistic simulations and experiments and cannot be explained by the classical motion by mean curvature models. We further present a unified continuum model based on variational framework to account for all these microscopic mechanisms.
