Re: [Getfem-users] textile structure modelling

[Yves Renard]

On Monday 28 January 2008 16:54, jean-yves heddebaut wrote:
>   Hello everybody,
>
> I don't have much experience in FEM and I would greatly appreciate
> any advice.
> I would like to use getfem to study the stress concentration in a
> structure made of textile fabric.
> I think that we can reasonably neglect the orthotropic caracter of
> the fabric.
>
> I tried to use  the isotropic linearized plate brick , but I wonder
> if it is adapted to the problem
>       1. the load will induce displacements which are not negligible. Is
> this acceptable in the inearized plate brick ?
>       2. how do I extract some stress information (von mises criteria for
> exemple) from the displacements? (ut and u3 are separated fields)
>
> Is there another brick more adaptet to the problem (bilaplacian maybe)
>
>
> Thank you very much for any help
>
>
> jean-yves heddebaut

A textile fabric has a very low  resistance to flexion and usually has large 
déformations. Linearized plate models (including bilaplacien) are for the 
inverse: small deformations and  resistance to flexion. So, I don't think it 
is a good choice, unfortunatelly.

I don't really know what kind of model is usually used for this kind of 
material. The resistance to flexion is often rather negligible, so the 
resistance of the structure is due to the membrane tension. But the 
deformations can be very large and non-smooth. Not easy to represent.

Anyone has an opinion ?

Sincerly,

Yves.

PS : I know someone in Grenoble university who worked on such a problem
is e-mail: address@hidden
There is an excample on his homepage
http://ljk.imag.fr/membres/Emmanuel.Maitre/

-- 

  Yves Renard (address@hidden)       tel : (33) 04.72.43.87.08
  Pole de Mathematiques, INSA de Lyon          fax : (33) 04.72.43.85.29
  20, rue Albert Einstein
  69621 Villeurbanne Cedex, FRANCE
  http://math.univ-lyon1.fr/~renard

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