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Hi,

I am currently working on a FEM  2d plane strain elastic model in matlab. The next step would be to use a non linear constiutive law (Mohr-Coulomb). As far as I have been reading non linearities, are solved with iteration schemes. My question is how to compute the tangent matrix with the N.Raphson method? I have seen only case for polynomials, but not for matrices.

Regards!

Anna

Can I use DEM using Abaqus 6.14?? If yes how?? 

Thank you

Like we have the elastic strain energy density for small deformations  defined as 0.5* σ :e  .

Is the equation PK2:E valid for the total work energy density for elastoplastic regimes ? If not, what would be a valid equation for total energy density ?

How can we decompose total work density into elastic work and plastic work densities for a large deformation case.

Where,

PK2 is the second piola kirchoff stress tensor

E is the Green-Lagrange strain tensor

Thanks,

Prithivi

Hello everybody,

 UPDATE :   Question can be deemed as closed.. :)

                       I have a very simple doubt in 3D model simplification. I believe plane stress and plane strain conditions are the two extreme states to simplify a 3D model to 2D case.

Hello,

I am trying to produce results for problems with analytical solution to validate my FE code. One of the problmes is the classical plate with a hole configuration with tractions applied at boundaries. However, presently, I can only impose BC in terms of nodal forces and displacements. Therefore I must transform the applied stress in statically equivalent nodal forces.