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A strained film grown on a vicinal substrate: Steps bunch or not to bunch?

Submitted by Zhenyu Zhang on
research
thin film epitaxy
roughening via step bunching

When a strained film is grown on a vicinal substrate, the steps advance like a train when the deposited atoms have sufficient mobility to reach the step edges. However, as the steps advance, the strain-induced force monopoles associated with the steps cause the steps to attract to each other (J. Tersoff, PRL 74, 4962, (1995)), resulting in a thermodynamic instability of the steps in the form of step bunching (J. Tersoff, et al., PRL 75, 2730 (1995)).

20th Annual Melosh Competition at Duke University

Submitted by John E. Dolbow on
education

The 20th Annual Melosh Competition for the Best Student Paper on Finite Element Analysis will be held at Duke University on April 25, 2008.  The competition has become one of the premier graduate student events in the broad area of mechanics.   We have held the competition at a variety of locations over the past several years, and this year we are returning to Durham.   

Banding in FEM

Submitted by Ajit R. Jadhav on
Forums
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FEM
Banding

I know the following: In linear FE analysis with linear constitutive law, say CST, there will not be any discontinuity across the adjacent (or neighboring) elements, for any of the fields---displacements, strains or stresses. But I do have certain questions that are not very well addressed in the introductory FEM texts:

(i) Assuming a displacement-based formulation, under what conditions would you expect discontinuities (or inter-element banding) to possibly appear in: (a) stresses? (b) strains? (c) displacements?

Ph.D. positions

Submitted by Stephane Bordas on
job
Ph.D. position; computational mechanics; fracture mechanics; faults; solder joints; XFEM; meshfree; crack propgation; cracks;

Dear fellows,

A short note to let you know that I have now three Ph.D. positions available to fill between now and March 2008 (sonner=better) (Students from the EU only -- fully funded). 

http://people.civil.gla.ac.uk/~bordas

http://people.civil.gla.ac.uk/~bordas/composites.pdf

http://people.civil.gla.ac.uk/~bordas/bosch.pdf

Congratulations to launch of SEAS

Submitted by Markus J. Buehler on
education
Harvard SEAS
congratulations

I just read Teng Li's entry regarding the launch of SEAS at Harvard.  Thanks for posting this interesting information!  

On this occasion, I'd also like express my congratulations to Harvard
University in launching the School of Engineering and Applied Sciences
(SEAS) last week!  It is terrific that the engineering science community in the Boston area is thriving and developing.  Best of luck, and looking forward to fruitful interactions in the future!  

Markus Buehler of MIT

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