Multi-scale Modeling of Large Deformation in Offshore Geotechnics

海洋岩土工程大变形问题的多尺度数值模拟

报告人：赵吉东副教授，香港科技大学土木与环境工程系

时间：2019年6月20日（星期四）上午10:30；地点：隧道中心楼206

报告人：

赵吉东博士现为香港科技大学土木与环境工程系副教授。他于清华大学水利水电工程系本科毕业并取得博士学位，曾于澳大利亚纽卡斯尔大学从事博士后研究并获聘为该校土木与环境工程系讲师。主要研究方向为颗粒材料宏微观本构关系及多尺度多物理过程数值模拟及其在岩土工程、能源及矿山开采、化工、制药等众多领域的相关应用。迄今已发表国际期刊论文70篇，编辑出版学术专著(Springer)一部及16篇专著章节。其研究曾受到澳大利亚研究资助局(Australian Research Council)、香港研究资助局及国家自然科学基金等资助。曾获清华大学优秀博士论文奖、University of Newcastle Research Fellowship Award、Computers and Geotechnics “Outstanding Paper Award” (2018)及Granular Matter “Top 5 Cited Articles” Award (2018) 。现为Granular Matter(Springer)编辑及Journal of Engineering Mechanics (ASCE)副主编，并任Computers and Geotechnics(Elsevier)及International Journal for Numerical and Analytical Methods in Geomechanics(Wiley) 编委。为多个国际专业技术委员会成员，并多次应邀在国际国内会议上发表特邀报告。个人主页：http://jzhao.people.ust.hk/。

报告简介：

In this talk, we introduce our latest extension of computational multiscale modeling to tackling challenging large deformation problems in granular media, with a special reference to offshore geotechnics. To address major issues suffered by mesh-based methods (e.g., FEM) including severe mesh distortion in large deformation simulations, we have developed a novel hierarchical coupling scheme is developed to integrate Material Point Method (MPM) with Discrete Element Method (DEM). The MPM is employed to treat a typical boundary value problem that may experience large deformation, and the DEM is used to derive the nonlinear material responses from small strain to finite strain required by MPM for each of its material points. The proposed coupling framework inherits advantages of MPM in tackling large deformation engineering problems over the use conventional use of FEM, and meanwhile helps avoid the need for complicated, phenomenological assumptions on constitutive models for soils whose behaviors are frequently highly nonlinear at finite strain. Using this new multiscale-modeling tool, rich grain-scale information and underpinning micromechanics can be directly connected to macroscopically observed phenomena over all deformation regimes of a granular material, from initial small-strain stage en route to large deformation and failure. We demonstrate the key features and capabilities of this new tool by simulations of multiple classic geomechanics examples. We further employ the anchor pullout problem to showcase the great potential of this multiscale-modeling tool in tackling challenges in offshore geotechnics.

 发布人：蔡国庆（实验中心）