世界计算力学著名学者李少凡教授学术报告通知
报告题目： Multiscale Crystal Defect Dynamics and Simulations of Dislocation and Fracture
报 告 人： 李少凡 教授 （加州大学伯克利分校）
报告时间： 11月15日 10:15
报告地点： 河海大学校本部闻天馆104 室
主办单位： 江苏省力学学会
河海大学力学与材料学院
江苏省重大基础设施安全保障协同创新中心
水资源高效利用与工程安全国家工程研究中心
报告人简介：
李少凡教授，1997年获美国西北大学（NWU）机械工程博士学位，1997-2000年在西北大学伊文斯顿分校从事博士后研究。2000年加盟加州大学伯克利分校（UC-Berkeley）土木与环境工程系，现任该校终身教授。教育部长江学者讲座教授。
李少凡教授于2003年获得美国科学基金总统奖，并获A. Richard Newton研究突破奖(2008)、世界计算力学大会计算力学奖（2013）、美国计算力学学会奖（2013）、ICCES Distinguished Fellow奖（2014）等，H因子高达38。
报告简介：
Recently the author and his co-workers have developed an atomistic based multiscale crystal defect dynamics (MCDD), which is based on an interphase process zone model. In this work, we formulate a quasi-crystal model for defect formation in a perfect crystal solid, and this multiscale quasi-crystal defect dynamics model provides insights on dynamics behaviors of lattice defects and their evolutions. In particular, in this approach, we adopt various coarse grain materials models for both bulk media and material interphase or process zone. In bulk elements, the first order Cauchy-Born rule is adopted, so we can formulate an atomistic enriched continuum constitutive relation to describe the material behaviors. All the nonlinear deformations are assumed to be confined inside the process zone, and the process zone between the bulk elements is remodeled as a finite-width strip whose lattice constants and atomistic potential may be the same or different from those of the bulk medium. Inside the interphase zone, the higher order Cauchy-Born rules are adopted in process zones, and a higher order strain gradient-like coarse grain constitutive model is derived, which can capture the size-effect at the small scales. All interphase or process zones are constructed such that they are part (a subset) of slip planes in a lattice space.
The multiscale crystal defect dynamics has been applied to simulate both dislocation motion and crack propagations in both single crystals and polycrystals. We have employed the MCDD method to study and to simulate the impact and fragmentation of polycrystals and powder alloys under extreme conditions.
报 告 人： 李少凡 教授 （加州大学伯克利分校）
报告时间： 11月15日 10:15
报告地点： 河海大学校本部闻天馆104 室
主办单位： 江苏省力学学会
河海大学力学与材料学院
江苏省重大基础设施安全保障协同创新中心
水资源高效利用与工程安全国家工程研究中心
报告人简介：
李少凡教授，1997年获美国西北大学（NWU）机械工程博士学位，1997-2000年在西北大学伊文斯顿分校从事博士后研究。2000年加盟加州大学伯克利分校（UC-Berkeley）土木与环境工程系，现任该校终身教授。教育部长江学者讲座教授。
李少凡教授于2003年获得美国科学基金总统奖，并获A. Richard Newton研究突破奖(2008)、世界计算力学大会计算力学奖（2013）、美国计算力学学会奖（2013）、ICCES Distinguished Fellow奖（2014）等，H因子高达38。
报告简介：
Recently the author and his co-workers have developed an atomistic based multiscale crystal defect dynamics (MCDD), which is based on an interphase process zone model. In this work, we formulate a quasi-crystal model for defect formation in a perfect crystal solid, and this multiscale quasi-crystal defect dynamics model provides insights on dynamics behaviors of lattice defects and their evolutions. In particular, in this approach, we adopt various coarse grain materials models for both bulk media and material interphase or process zone. In bulk elements, the first order Cauchy-Born rule is adopted, so we can formulate an atomistic enriched continuum constitutive relation to describe the material behaviors. All the nonlinear deformations are assumed to be confined inside the process zone, and the process zone between the bulk elements is remodeled as a finite-width strip whose lattice constants and atomistic potential may be the same or different from those of the bulk medium. Inside the interphase zone, the higher order Cauchy-Born rules are adopted in process zones, and a higher order strain gradient-like coarse grain constitutive model is derived, which can capture the size-effect at the small scales. All interphase or process zones are constructed such that they are part (a subset) of slip planes in a lattice space.
The multiscale crystal defect dynamics has been applied to simulate both dislocation motion and crack propagations in both single crystals and polycrystals. We have employed the MCDD method to study and to simulate the impact and fragmentation of polycrystals and powder alloys under extreme conditions.
(作者：邬萱 )