Seminar - Luming Shen - Multiscale Model-Based Simulation of Material and Structural Failure
Thursday 7 February 2008, 1.00 - 2.00 pm
Civil Engineering Lecture Theatre 3
Modern engineering problems are challenging and multiscale in nature. In many cases, the physical phenomena operate across10-12 orders of magnitude in spatial and/or temporal scales. The conventional single level simulation method which is valid only for limited ranges of spatial and temporal scales is not able to capture the whole picture. Multiscale simulation approaches that integrate nano-, micro- and macro-mechanics are needed in order to bridge the different length and time scales involved in the material and structural failure process. In this presentation, the potential of multiscale simulation methods will be demonstrated through three recent studies, namely, 1) simulation of tungsten thin film delamination from silicon substrate by combining the material point method (MPM) and molecular dynamics (MD), 2) numerical investigation of the grain size and nitrogen-doping effects on the mechanical properties of ultrananocrystalline diamond with a combined kinetic Monte Carlo (KMC) and MD approach, and 3) simulation of glass fragmentation under impact using a bifurcation-based decohesion model with the MPM. In addition to the brief introduction to the MPM, KMC and MD, the implementation of the proposed multiscale approaches will be discussed. Numerical findings from each study will then be presented. Future research topics that aim to promote the application of nanotechnology in the civil and environmental engineering will be proposed at the end.