just a friendly question to all of you....

what is your opinion on the journal impact factor...

i personally think is very superficial and skin deep beauty. but i want to know your opinion.

thanks 

What is the reason behind the nonlinearity in the stress-strain curve of elastomers(Molecular Level)

Dear all,

I am trying to code a UMAT subroutine for perfect plasticity with a Tsai-Wu failure surface. I follow the procedure of the closest point projection in Simo & Hughes, Box 3.5, which is quite straight forward. At least I thought so

 The algorithm converges but unfortunately not to the correct point in the (plane-stress) stress space. At first I used an yield surface wich gives a unit sphere in the stress space. It is easy to control the normality of the plastic strain increment and the return-map algorithm is implified to a radial return algorithm.

Abstract

There
are several immediate openings of research-oriented Phds and Post-Doc positions, in the
department of civil engineering, the University of Akron (UA). Please see tha attached file for datails.

This minisymposium, organized by R.A. Sauer and L. De Lorenzis within WCCM 2012 (http://www.wccm2012.com/ ) focuses on computational methods studying the mechanics and physics of interfaces and surfaces (see attachment). All related contributions are welcome. The deadline for abstract submission is November 30th, 2011.