Hi everyone,

Now I am trying to implement Ogden model in Comsol Multiphysics, but I had some problem.

Then I realized that in Comsol, it's possible to implement a nonlinear young's modulus.

But I am a little confused.

If you have a nonlinear Young's modulus, in the stress-strain curve, E is the tangent of this curve.

For hyperelastic material, let's say Ogden material. It's usually a nonlinear stress-strain curve as well.

I am trying to combine UMAT and UEL in my Abaqus calculation to simulate crack propagation by using a damage criterion. My UMAT calculates the damage variable in each time increment and whenever the damage variable violates the damage criterion in one or more elements, I should seperate the damaged element(s) via XFEM theory which can be implemented into a UEL code; therefore, I should use both UMAT and UEL in my calculation. Is there any way to combine these two codes together?

In the finite element analysis of a transient problem, the usual procedure is to discretize the space (domain) using finite elements, while in the time direction, a time-stepping scheme based on finite differences is used. Is it possible to use a finite element type discretization in time also?  Is there any work done in this manner?

Shanghai University

Shanghai Institute of Applied Mathematics and Mechanics

and Department of Mechanics

Position:

Since early 60’s the world of structural engineering has been revolutionised. The advance development in science and technology resolved those issues raised by pioneer engineers but at the same time introduced complications into the world of engineering never known before. The question is where we see structural engineering within the next decade. How do we think it will evolve?

The School of Civil Engineering at the University of Sydney, Australia, is currently looking for a Post-Doctoral Fellow to study the effect of dislocation-precipitate interaction on the strength of Aluminium alloys using Molecular Dynamics.

The Third International Conference on Mechanics of Biomaterials and Tissues will take place in Clearwater Beach, 13-17 December, 2009.  Further information available at http://www.icmobt.elsevier.com

Contributions are invited for oral and poster presentation - extended abstracts should be submitted online at http://www.icmobt.elsevier.com by April 24, 2009.

Look forward to seeing you in Florida!

why the stifffness matrix is foutrh order ?