YuanTong Gu

Bio: YuanTong Gu is an academic researcher from Queensland University of Technology. The author has contributed to research in topics: Finite element method & Meshfree methods. The author has an hindex of 52, co-authored 550 publications receiving 12583 citations. Previous affiliations of YuanTong Gu include Nanjing Medical University & National University of Singapore.

A New Method for Stress and Deformation Analysis from Nano to Macro Dimensional Scales

Abstract: This paper presents a concurrent multiscale method for the stress analysis of solids using a coupled meshless and molecular dynamic analysis. A new transition algorithm using transition particles was employed to ensure the compatibility of both displacements and their gradients. The equivalent continuum strain energy density was obtained locally based on the atomic potential and Cauchy-Born rule, and hence plasticity can be easily handled in not only the atomic domain but also the continuum domain. Numerical examples demonstrated that the present multiscale technique has a promising potential of application to multiscale systems subjected to deformation.

Atomic investigation on the facet‐dependent melting of ceramic nanostructures via in situ electron irradiation

Abstract: Thermodynamic behavior investigations on nanomaterials are of great scientific interest and possess technological implications for advancing nanoscience and nanotechnology. However, nanoscale thermodynamic studies on ceramic semiconductors are faced with great challenges due to their thermostability, and there lacks a percipient understanding of their atomistic thermal behaviors. Here, the atomic-scale mechanism of the melting and coalescence processes of binary semiconductors, including rutile TiO2(R) and SnSe nanostructures, via real-time electron beam (e-beam) irradiation is reported. Under the e-beam, the inelastic electron-matter interactions and the low thermal conductivity of the samples cause a local temperature increase. The in situ melting process is recorded via high-resolution TEM imaging, which exclusively shows a specific planar melting order of the (001), (011), and (100) for TiO2(R). This measurement provides direct evidence that matches the surface energy differences predicted by existing theoretical calculations and experiments. A similar phenomenon is induced and observed on SnSe, which derives a particular melting order of (210), (211), and (002). Furthermore, the in situ melting and coalescence analysis of ultrafine TiO2(R) nanoparticles suggests surface atom transfer and recrystallization as observed. The demonstration of e-beam directed shape formation and tailoring reveals the possibility for nano/microscale processing of ceramic nanostructures, which are otherwise considered chemically stable and mechanically robust.

A coupled Element Free Galerkin / Boundary Element method for stress analysis of two-dimensional solids

Abstract: Element Free Galerkin (EFG) method is a newly developed meshless method for solving partial differential equations using Moving Least Squares interpolants. It is, however, computationally expensive for many problems. A coupled EFG/Boundary Element (BE) method is proposed in this paper to improve the solution efficiency. A procedure is developed for the coupled EFG/BE method so that the continuity and compatibility are preserved on the interface of the two domains where the EFG and BE methods are applied. The present coupled EFG/BE method has been coded in FORTRAN. The validity and efficiency of the EFG/BE method are demonstrated through a number of examples. It is found that the present method can take the full advantages of both EFG and BE methods. It is very easy to implement, and very flexible for computing displacements and stresses of desired accuracy in solids with or without infinite domains.

Numerical modelling for improved underground-mine ventilation systems

Abstract: Diesel engine is commonly used in the underground mining heavy vehicle. However, particle emissions from combustion engine have been declared to be a serious concern for the human health as well as the environment. Diesel engines are one of the most important sources of particulate and NOx emissions which consumes significant amount of oxygen which is dangerous for the mine workers as they will receive insufficient oxygen supply. Therefore, we need to design a proper ventilation system so that adequate oxygen can be supplied and keep the hazardous gas or ultrafine particles concentration as an allowable level in the mining tunnels. The main objective of this study is to find a high concentration area in the mining tunnel and propose and examine various ventilation strategies to control the concentration level to ensure health and safety, work efficiency and cost related to energy consumption. The well-established computational fluid dynamics (CFD) approach has been carried out to investigate the airflow, particle tracing and the position of the ventilation system. A three dimensional unsteady model is developed in this study for an underground mine tunnel with heavy vehicle is in operation. The commercial CFD software, ANSYS 15 (CFX) has been used for the numerical simulation. An Eulerian-Lagrangian approach is used to respectively model the main flow and particules' trajectories.

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

Fast parallel algorithms for short-range molecular dynamics

Abstract: Three parallel algorithms for classical molecular dynamics are presented. The first assigns each processor a fixed subset of atoms; the second assigns each a fixed subset of inter-atomic forces to compute; the third assigns each a fixed spatial region. The algorithms are suitable for molecular dynamics models which can be difficult to parallelize efficiently—those with short-range forces where the neighbors of each atom change rapidly. They can be implemented on any distributed-memory parallel machine which allows for message-passing of data between independently executing processors. The algorithms are tested on a standard Lennard-Jones benchmark problem for system sizes ranging from 500 to 100,000,000 atoms on several parallel supercomputers--the nCUBE 2, Intel iPSC/860 and Paragon, and Cray T3D. Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems. For large problems, the spatial algorithm achieves parallel efficiencies of 90% and a 1840-node Intel Paragon performs up to 165 faster than a single Cray C9O processor. Trade-offs between the three algorithms and guidelines for adapting them to more complex molecular dynamics simulations are also discussed.

Mitigation and Adaptation Strategies for Global Change

Abstract: ▶ Addresses a wide range of timely environment, economic and energy topics ▶ A forum to review, analyze and stimulate the development, testing and implementation of mitigation and adaptation strategies at regional, national and global scales ▶ Contributes to real-time policy analysis and development as national and international policies and agreements are discussed and promulgated ▶ 94% of authors who answered a survey reported that they would definitely publish or probably publish in the journal again