Chongmin Song (宋崇民)教授系列学术报告通知(2021-28、29)


发布时间: 2021-11-22     浏览次数: 11

学术报告一

报告题目The Scaled Boundary Finite Element Method for Numerical Simulation in the Digital Age

报告人:Chongmin Song (宋崇民)教授 (澳大利亚新南威尔士大学)

时间 :2021年11月24日(周三)10:00-12:00

地点:河海大学江宁校区乐学楼1116室,腾讯会议号:965 711 420

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报告简介:

Since the 1970s, numerical simulation has been more and more widely applied in engineering and science thanks to the progresses of the underpinning numerical methods and the tremendous increase in the speed of digital computers at affordable cost. In this digital age, novel digital technologies have emerged, which provides further opportunities and challenges to the research on numerical simulation. The scaled boundary finite element method is one of the numerical methods proposed to overcome the limitations of the well-established methods. The scaled boundary finite elements are semi-analytical and can have any number of faces, edges and vortices.

This presentation focuses on the development of the scaled boundary finite element method to encompass the modern trends in digital technologies. The concept of the scaled boundary finite element method is briefly introduced. The efficient quadtree/octree mesh generation algorithm is discussed. The scaled boundary finite elements resolve the issue of hanging nodes of the octree meshes in a straightforward manner. The use of the structured octree mesh greatly reduces the amount of computational resource, in terms of computational time and memory, required for large-scale analyses. The specially designed solution algorithms for statics and explicit/implicit dynamics are presented. Numerical examples are shown to demonstrate some of the attractive features of the proposed approach in engineering analysis: 1) The approach is compatible with modern digital formats of geometric modelling such as digital image, STL, point clouds and virtual reality; 2) The process is simple to automate, significantly reducing the human efforts and increasing productivity; and 3) The algorithm is suited to parallel processing in a modern high-performance computing environment. Finally, the outlook of the scaled boundary finite element method and the next generation of numerical simulation is discussed.


学术报告二

报告题目: The Scaled Boundary Finite Element Method for Elastoplastic and Fracture Analysis

报告人:Chongmin Song (宋崇民)教授 (澳大利亚新南威尔士大学)

时间 :2021年11月25日(周四)10:00-12:00

地点:河海大学江宁校区乐学楼1116室,腾讯会议号:997 561 040

欢迎广大师生参加!

报告简介:

In this talk, the development and application of the scaled boundary finite element method for elastoplastic and fracture analysis are presented. Arbitrary polytope elements are constructed. The shape functions are obtained from the solution of the scaled boundary finite element equation for a linear problem. The conditions of partition of unity and linear completeness are satisfied. The material constitutive matrix and internal stresses are approximated spatially by polynomials inside a polytope element. The (tangential) stiffness matrix and internal nodal force vector are integrated semi-analytically. Both an integral-type nonlocal formulation and the phase-field models are incorporated in the scaled boundary finite element method to perform fracture analysis. An effective strategy for adaptive mesh refinement around the failure zone is devised using the quadtree/octree algorithm. Furthermore, the combination of the scaled boundary finite element method and octree mesh significantly reduces the computer time and memory requirement. After the introduction to the fundamental theory, numerical examples will be presented.

The ongoing development of Abaqus UELs using the scaled boundary finite element method is introduced. A data format is design for the input of polyhedron elements. The technique of overlay element is used to handle interface and surface tractions. Applications to interface problems are presented.

报告人简介:

Prof. Chongmin Song(宋崇民),澳大利亚新南威尔士大学土木与环境工程学院教授。Prof. Song主要从事比例边界有限元、断裂力学、波动传播、地震工程与结构动力学等方面的研究。1996年他与瑞士联邦理工学院的Wolf J.P.教授共同创立了比例边界有限元法(Scaled Boundary Finite Element Method, SBFEM)。这种新型数值方法兼具了有限元法与边界元法的优点同时又避免了其缺点,其主要特点包括精度高、计算量节省,并且在处理无限域问题和应力奇异性方面具有突出优点。近年来在Computer Methods in Applied Mechanics and Engineering、International Journal for Numerical Methods in Engineering、Computers & Structures、Computational Mechanics、International Journal of Solids and Structures、Earthquake Engineering and Structural Dynamics等国际著名期刊上发表论文150余篇,独著《The Scaled Boundary Finite Element Method: Introduction to Theory and Implementation》(2018,Song Ch.)、合著《Finite-Element Modelling of Unbounded Media》(Wolf J. P. and Song Ch., 1996)、《The semi-analytical fundamental-solution-less scaled boundary finite element method to model unbounded soil》(Wolf J. P. and Song Ch., 2003)两部。近期主持澳大利亚自然基金等项目20余项。