Re: [Getfem-users] other element types

[Roman Putanowicz]

On Tue, Jul 13, 2010 at 02:59:35PM +0200, Christian Fischer wrote:
> Dear All,
> 
> I recently thought about using the following structural elements:
> 
> * 1D: Euler-Bernoulli or Timoshenko beam
> * 2D: axially symmetric continuum elements
> * 1D: axially symmetric flat plate (like an axially symmetric beam)
> 
> Before I start working on any of these elements. Maybe there is somebody who
> already implemented any of these. (Like the truss element in a recent email.)
> Or somebody has a few hints for me e.g. how to implement axial symmetry in 
> general.
> 
> Best wishes
> Christian Fischer
> 
Dear Christian

I am glad for your posting. I will gladly discuss implementation of the above
elements as any such discussion greatly enhances documentation of GetFEM
internals.

Recently I have implemented 2D frame element. I have attached some source
code (the implementation of frame brick is not complete in the sense that
I do not account for element stiffness). It is sparse of comments but I can
serve any info.

>From my understanding of GetFEM (Yves can correct me for sure :) 
>implementation 
of any of your above problems does not really require adding new elements
to GetFEM. Everything can be implemented on the assembly level.
For beam elements there already Hermite element (in case we agree to skip
axsial displacement - if not it should be possible to handle it via separate
mesh_fem). Of course having true structural elements would be nice to.

I have not implemented axisymmetric problem but If I recall correctly
in some post I have seen comment that functions like Lame coefficients
can be implemented via mesh_fem_global_function. So again it should suffice
to write right assembly routines. That is my five cents.

Regards,

Roman
-- 
Roman Putanowicz, PhD  < address@hidden  >
Institute for Computational Civil Engng (L-5)
Dept. of Civil Engng, Cracow Univ. of Technology
www.l5.pk.edu.pl, tel. +48 12 628 2569, fax 2034

femdk_frame.cxx
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simple_beam.cxx
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