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vicky.nguyen's picture

Choosing a Universal Testing Machine

I am in the process of buying a universal testing machine, and have found the process to be quite confounding.  My main area of expertise is computational mechanics, but I decided to add a materials testing capabiity to my program to support my constitutive model development efforts.  I am surprised that, given how expensive these machines are, that there's isn't a user generated comparison website or online forum relating experiences or comments regarding these machines, their software, accessories, etc....  

Arash_Yavari's picture

On geometric discretization of elasticity

This paper presents a geometric discretization of elasticity when
the ambient space is Euclidean. This theory is built on ideas from
algebraic topology, exterior calculus and the recent developments
of discrete exterior calculus. We first review some geometric
ideas in continuum mechanics and show how constitutive equations
of linearized elasticity, similar to those of electromagnetism,
can be written in terms of a material Hodge star operator. In the
discrete theory presented in this paper, instead of referring to

Non Local Model Vs Implicit Gradient Model

Hi All :


I was wondering why some people prefer to use Non Local Model while some others use Implicit Gradient Model (which can be derived from Non Local Model) .

When implicit Gradient Model is itself derived from Non Local Model ,and its FE implimentation just involves an additional average to be calculated and what is the need to introduce gradient terms ??


Thanks Alot



Zaoyang Guo's picture

Ph.D. studentship in smart material at University of Glasgow, UK

A three-year
PhD studentship is available within the Glasgow Research Partnership in
Engineering (GRPE) as part of the Joint Research Institute in Mechanics of
Materials, Structures and Bioengineering at the University of Glasgow. 
specific goals of the PhD will be to manufacture MREs and determine the
influence of manufacture conditions on the micro-structure and magnetic-sensitivity
of the magnetorheological elastomers (smart material).

Super Plastic Forming Die Cleaning

I am working on a project for a more efficient process for cleaning supe plastic forming dies. Currently, we are cleaning them manually with an electric drill motor and a brush on the end of that. This process is ergonomically doing a number on our employees, not say that the process is lengthy. Is there anyone that has had any luck with any other process cleaning dies? Thanks.....

Zhigang Suo's picture

Collapse of the Tacoma Narrows Bridge, 7 November 1940

In today's class of complex analysis, my co-instructor Scott Norris was lecturing on resonance.  He mentioned a YouTube video of the Tacoma Narrows Bridge.  Also instructive is the entry of the bridge on Wikipedia

Temesgen Markos's picture

GRE Verbal, how much does it count?

I am in the process of applying for a PhD in computational solid mechanics in the US and I am about to take the GRE. Well I have been kind of busy at my work and didn't really get time to study the word list.

My question is, how much weight does the verbal part have in admission/fellowship/assistantship decisions? If I have really good GPA's and research experience with enthusiastic refrees, can I still make it with medicore results on the verbal part?

Rui Huang's picture

Influence of Interfacial Delamination on Channel Cracking of Brittle Thin Films

H. Mei, Y. Pang, and R. Huang, International Journal of Fracture 148, 331-342 (2007).

Following a previous effort published in MRS Proceedings, we wrote a journal article of the same title, with more numerical results. While the main conclusions stay the same, a few subtle points are noted in this paper.

Recruiting PhD students for Cell Mechanics Lab at Rensselaer

Full support is available for 2 PhD students in cellular mechanics group in Biomedical Engineering Department at Rensselaer Polytechnic Institute.  

The applicants should have mechanics, materials or soft matter physics background, with some experimental experience at micro-scales.  Experience with any of the following is considered a
plus: computational mechanics, cell/tissue culture, microscopy, image analysis, photonics.

Yonggang Huang's picture

program ranking of universities

The Chronicle of Higher Education just published its ranking of all programs (fields) of universities in the States.

This ranking is based on the productivity (publications, citations, grants and awards, nothing else), rather than people perceptions (department head's evaluations) as US News and World Report. 

Of course one should never take any ranking very seriously, but it is interesting to take a look at this website.


Marino Arroyo's picture


Two four-year doctoral fellowships at the LaCàN Research group (, Universitat Politècnica de Catalunya (UPC, Barcelona, Spain).

These two fellowships, funded by the Spanish Ministry of Science and Education ("beca FPI"), coverfull tuition, a monthly stipend and provide funds for short international research stays. The starting date is expected in the Summer-Fall 2008.

Marino Arroyo's picture

Rippling and a phase-transforming mesoscopic model for multiwalled carbon nanotubes

Dear colleagues, 

I would like to share the following paper, in press in the Journal of the Mechanics and Physics of Solids. It can be found at the publisher's web at

 A preprint is also attached below.


Zhigang Suo's picture

Writings of scientists on doing research

In a previous post, Learning to be a PhD advisor, I wrote about learning to do my job from students.  Over the years, I have also learned from writings of other scientists on doing research, its dynamics:  competition, despair, and exhilaration...  Here is a small sample that occurs to me this morning. 


Choose a channel featured in the header of iMechanica: 

Dear all,

Do you have any reference about the theory of plasticity? Especially about flow theory and von Mises yield criterion?

For example if I have an effective stress - plastic strain relationship, and I after yielding, I increase my strain again, how can I obtain the increment of the plastic strain and the stress deviator tensor?

Thanks a lot.



Rui Huang's picture

AAM: Newly Elected Fellows

The American Academy of Mechanics is pleased to announce that
Jacob Fish, the Rosalind and John J. Redfern Chaired Professor of Engineering at
Rensselaer Polytechnic Institute, and Martin Ostoja-Starzewski, Professor of
Mechanical Science & Engineering at University of Illinois have both been
elected as Fellows of the Academy. They will be presented with certificates


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