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How to develope a new potential function.

Submitted by prasad matukumilli on

How to develope a new potential function.

For instance, if I want to study a new material system by classical MD, for which the existing potential force fields are not suitable.

I would like to know the standard procedure, how to use the first principle studies/ experimental data and how to select the basic functions...from the experts in this area.

Prasad MVD

How do I run Abaqus 6.7-1 from a DOS Window

Submitted by nitinchandola on
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Hi,

I am tyring to learn Abaqus for my reserach work. I was easily able to work with  Abaqus CAE. However  I am not able to run Abaqus through a DOS window. Also, the tutorials mention commands like 'abaqus fetch' which do not work on the command line when I input them. It always shows an error saying that 'abaqus' is not a internal or external command,operable program or batch file. 

Can somebody help me with this? Is there any particular part of the Manual or help section that I can read to find out how to do this?

Thermostating only a few atoms in MD

Submitted by prasad matukumilli on

I am trying to apply Berendsen thermostat for CNT. When I choose to leave one third of the tube atoms to evolve freely with out distrubing the momentum, I am unable to acheive the target temperature and further temperature increases gradually over the whole simulation run (even with a thermostat parameter equals to the timestep i.e., like a simple scaling). How it is possible to acheive target temperature,by scaling only a part of atoms, using some scaling value which should actually scales all the atoms momenta.

Fortran 90 library for maximum-entropy basis functions

Submitted by N. Sukumar on

Attached is a tar archive for a Fortran 90 library to compute maximum-entropy basis functions.  I have used the G95 compiler. The manual in PDF is also attached and a html version of the same is also available, which provide details on how to install the code and its capabilities. The library is released under the GNU Lesser GPL version 3 license.

The twin of imechanica in biology and bio-engineering is from MIT !!

Submitted by Mike Ciavarella on

OpenWetWare is an
effort to promote the sharing of information, know-how, and wisdom
among researchers and groups who are working in biology &
biological engineering. Learn more about us.

If you would like edit access, would be interested in helping out, or want your lab website hosted on OpenWetWare, please join us.

Review papers

Submitted by RoozbehSanaei on

One of the most important things every researcher does in the beginning of his introduction to a topic is review process. Most helpful papers in this regard are review papers. Review papers are important. They are primary and best way to understand the value of a work for the societyto award and grant. They help researchers to find out needs of people who use our research and goal functions of scientific society. Help researchers to find out good topics and also good solutions. And the final effect of a research on the society.

Modeling polyurethane

Submitted by Andreas Burger on

I've started to look into the modeling of polyurethane.  So far I'v found one paper that specifically looks into how to model the mechanical behavior of PU. It describes a possible constitutive model for PU:

Stress-strain behavior of thermoplastic polyurethanes, Qi,H.J.; Boyce, M.C., Mech. Mater. 2005, 37, 8, 817-839

Does someone know of any other resources on the modeling of PU?  Thanks, Andreas

Elastic deformation of substrate due to rotation of rigid pillar

Submitted by Steffen Brinckmann on

Consider a ridig pillar ontop of a elastic substrate. Applying a moment to the pillar will lead to elastic deformation of the substrate. If the pillar is infinitly large in diameter, then this problem is the same as an infinitely sharp crack, considering the symmetry of the crack problem, i.e. there are square root singularities. However, the infinitly large diameter assumtion does not hold if the global rotation of the substrate under the pillar is of interest, because the both sides of the pillar interact.