題目：A Novel Family of High-order Implicit Time Integration Schemes/Functionally Graded Porous Structures

時間：2025年6月26日 14:00-16:00

地點：機(jī)械與動力工程學(xué)院 B219會議室

邀請人：張文明 教授（振動、沖擊、噪聲研究所）

報告題目：A Novel Family of High-order Implicit Time Integration Schemes

報告人：Prof. Chongmin Song（University of New South Wales）

Biography

Chongmin Song is a Professor of Civil Engineering at the School of Civil and Environmental Engineering, University of New South Wales, Sydney, Australia. He obtained the degree of Bachelor of Engineering from Tsinghua University, China and the degree of Doctor of Engineering from the University of Tokyo, Japan. His research focuses on the development of advanced numerical methods and their engineering applications. His current research interest includes the scaled boundary finite element method, mesh generation, high performance computing, structural dynamics, fracture mechanics and earthquake engineering. He is one of the two original creators of the scaled boundary finite element method.

Abstract

The numerical simulation of time-dependent problems in many disciplines of engineering and science requires the use of direct time integration method. This talk introduces a novel approach for constructing a family of high-order implicit time integration schemes with desirable attributes. The amount of numerical dissipation is controlled by a user-specified parameter, leading to schemes ranging from perfectly non-dissipative A-stable to L-stable. The effective stiffness matrix is a linear combination of the mass, damping, and stiffness matrices as in the trapezoidal rule, leading to high efficiency for large-scale problems. The acceleration is obtained at the same order of accuracy of the displacement and velocity using vector operations (without additional equation solutions and matrix-vector products). The order of accuracy is not affected by the presence of external forces and physical damping. It is found that second-order time integration methods commonly used in commercial software produce significantly polluted acceleration responses for a common class of wave propagation problems. The high-order time integration schemes presented here perform noticeably better at suppressing spurious high-frequency oscillations and producing reliable and useable acceleration responses.

報告題目：Functionally Graded Porous Structures

報告人：Dr. Da（Daniel) Chen（University of New South Wales）

Biography

Dr Da (Daniel) Chen is an ARC DECRA fellow and a Lecturer at School of Civil & Environmental Engineering, UNSW Sydney. He was awarded his PhD at the University of Queensland and worked as a researcher at Technical University of Darmstadt and the University of Melbourne. Daniel is best known for his contributions to the development of functionally graded (FG) porous structures, where the constitutive model he proposed is one of the most adopted ways to assess such structural forms. He has 7 Highly Cited Papers in this field, including 1 Hot Paper. He also published the first book on FG porous structures in 2023, titled: Machine Learning Aided Analysis, Design, and Additive Manufacturing of Functionally Graded Porous Composite Structures. The accumulated amount of research projects he is leading reaches over $2 million. Daniel is ranked among the top 2% scientists (single-year ranking, Stanford University, 2023 & 2024). He is also an Editorial Board Member of two JCR Q1 journals (Engineering Structures, Structures). Daniel aims to bridge the micro-macro divide in the mechanical analysis of functionally graded porous composite materials/structures, and to push this field towards the multi-functional applications and commercialisations.

Abstract

Porous structures made of foams, lattices, and honeycombs are gaining tractions in various industrial sectors, and are featured with light weight, high specific stiffness, good energy absorption, and novel thermal, biological, acoustic characteristics. They give unique flexibility in performance-tailoring and possess great potential in multi-functional applications. Highlighted by non-uniform cellular geometries, functionally graded (FG) porous structures are an important extension of the existing porous structural forms and potentially provide enhanced properties. This presentation is focused on the design and analysis of FG porous structures, providing the big picture in terms of their theoretical, numerical, and experimental studies. Some of the latest applications of FG porous structures are also introduced.