Subject: [FFC-dev] stable finite element for incompressible nonlinear elasticity?

From: Chong Luo <[email-masked]>
Date: Sun, 23 Mar 2008 15:44:31 -0700 (PDT)

Hi,

I implemented 3D incompressible nonlinear elasticity (for neo-Hookean materials) using FEniCS. 
However, the iteration didn't converge.
The finite element spaces I chose are Lagrange element of degree 1 in tetrahedron.

I saw in P.Le Tallec's book (Handbook of Numerical Analysis, Vol III) that some 
finite element spaces are stable (like Ruas finite element), while others are not.
But it seems that Ruas finite element is not available in FEniCS.

My question is, what are the possible choices of finite element spaces in FEniCS
that would make 3D incompressible nonlinear elasticity stable? 

Thank you!

Best,
Chong Luo

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From: Anders Logg <[email-masked]>
Date: Tue, 25 Mar 2008 00:17:13 +0100

> that would make 3D incompressible nonlinear elasticity stable?

I have absolutely no idea, but why not try Taylor-Hood (P2-P1) or
adding stabilization. See the Stokes demos in DOLFIN.

-- 
Anders