Discussion Forum

I Ivar, I everybody,

Ivar, thank you for your previous answer ...

To be more clear, I tried another way to make my meshage to get better results. The tube (volume) embedded in a cube (which I call the environment and is also a volume). My calculation is simply to solve an integral on the surface of the tube. In the calcul of this integral I have to use the normal vector unit at the surface of my tube.
[I use :

Nx = (up(dom)>down(dom))*unx+(up(dom)<=down(dom))*dnx
Ny = (up(dom)>down(dom))*uny+(up(dom)<=down(dom))*dny
Nz = (up(dom)>down(dom))*unz+(up(dom)<=down(dom))*dnz]


The solution show in the attachement the constraint tension on the surface of the tube.

1) When I mesh my tube (a volume) (I do not mesh the environment), I get a really good solution and no horrible defaults appear in the solution -----> good (see the attachement)

2) If I both mesh tube (fine mesh) AND cube (a volume) (coarse mesh) into which my tube is embedded, I find the same solution to the previous BUT with some horrible defaults located in the solution ! (see the attachement)

Unfortunately I need this additional environment for the rest of my work.

I do not understand why the fact to mesh the external environment gives these defaults in the solution ! The presence of the mesh of the cube should not be a problem... More, I get some results completely incoherent when the tube is meshed only in surface ...and the normal vectors (Nx, Ny, Nz) are not good oriented.

Have you encountered this problem in your models ?
Unfortunately I cannot send you my complete modele due to the property of this work.

Thank you again for your help.
Thank you Ivar again !

Pierre