Industrial Placement (2007/2008)
Supervisor: Henry Tan
School of Mechanical, Aerospace and Civil Engineering
The University of Manchester
Material Point Method for impact, fracture, fragmentation and explosion
Mr. Jayveer Thakoor
Industrial Placement: Optimising superplastic form die shape for next generation aero engine production, a design project from Rolls-Royce plc.
Mr. Waqas Ahmad
The stress-strain behavior and incipient yield surface of nanoporous single crystal copper are studied by the molecular dynamics (MD) method. The problem is modeled by a periodic unit cell subject to multi-axial loading. The loading induced defect evolution is explored. The incipient yield surfaces are found to be tension-compression asymmetric. For given void volume fraction, apparent size effects in the yield surface are predicted: the smaller behaves stronger.
Thank you for your interest shown in my previously posted work. Here's a post-print for an article of an extension to my previous work. Extension in the sense that the MD simulation was performed on "larger" metallic nanowires (2.0 nm to 6.0 nm), and the behavior of gold (Au) nanowires were studied. The mechanism behind strain-induced amorphization was explained and the phenomenon of multiple necking was observed, implying the presence of "localized" amorphization instead of a "globalized" one observed in shorter nanowires.
Dear Colleague,
We want to draw your attention to and encourage your participation in a special session on Multiscale Modeling and Simulation of the thirteenth Pacific Symposium on Biocomputing (PSB), to be held January 4-8, 2008, on the Big Island of Hawaii. PSB is an international, multidisciplinary conference with high impact on the theory and application of computational methods in problems of biological significance.
This paper has been published in Journal of the Mechanics and Physics of Solids 56 (2008), pp. 1609-1623 (doi:10.1016/j.jmps.2007.07.013).
Abstract
An Australian Research Council funded PhD Scholarship is available in the Department of Civil Engineering at Monash University in Australia in the area of computational mechanics. The objective of this project is to develop a multi-scale bifurcation-based decohesion model within the framework of the Material Point Method (MPM), one of the meshfree methods, for simulating glass fragmentation under blast loading.
I am trying to find out the theoretical adhesive strength limit of a few materials, or more precisely the ratio adhesive strength limit to elastic modulus. I think this is after all part of the Lennard-Jones constants potential - theoretical adhesive strength limit is simply the maximum of the curve.
Considering the MD (molecualr dynamics) simulation programs, they enable us to define the initial crack and then using different theories they propagate the crack. This process is actually a dynamic feature at least when the sample is going to fail. Here is the question that present in the most modellers assumptions, which will limit the simulation or maybe it is not possible to simulate the process with out these assumptions. One of them which I would like to know your ideas about is the linear velocity which come into conclusions before the simulations start.
We report the direct molecular dynamics simulations for molecular ball bearings composed of fullerene molecules (C60 and C20) and multi-walled carbon nanotubes. The comparison of friction levels indicates that fullerene ball bearings have extremely low friction (with minimal frictional forces of 5.283×10-7 nN/atom and 6.768×10-7 nN/atom for C60 and C20 bearings) and energy dissipation (lowest dissipation per cycle of 0.013 meV/atom and 0.016 meV/atom for C60 and C20 bearings). A single fullerene inside the ball bearings exhibits various motion statuses of mixed translation and rotation. The influences of the shaft's distortion on the long-ranged potential energy and normal force are discussed. The phonic dissipation mechanism leads to a non-monotonic function between the friction and the load rate for the molecular bearings.
