Material orientation; keyword edit

[Stepanka]

Hi,

I am having troubles assigning local material directions when using anisotropic Holzapfel material.
The steps I did are: defining a discrete field which assign local coordinate system to each element; then editting keywords of the model so that two local directions within the CSYS are defined (+-30 deg). Written as could be seen below:

*Orientation, name=Ori-DiscField-Annulus, system=RECTANGULAR, local directions=2
DiscField-Annulus
2, 0
0.866,0.5,0.0
0.866,-0.5,0.0

Still it is not working properly.
Could you please advise me on what I did wrong?

Greatly appreciate any help, I ve been trying for ages already.

Cheers,
Steph

 

[FEA way]

Do you get any errors ? Maybe the distribution referenced in this keyword is incorrectly defined. Also keep in mind that local directions are specified with respect to orthonormal system at the material point.

 

[Stepanka]

Hey,
Thank you for your interest!
No, I dont have any errror. But the thing is that when I tried to verify the results, I kept things simple and defined only one local direction. In the first case, I rotated local coordinate system around y axis by 30 deg without definining the local direction and then kept optional rotation zero and defined local direction which correcpond to 30 deg (0.866,0.5,0).
When I wanted to explain you the problem, now I noticed the bug - the coordinates of the local directions should have been 0.866,0,0.5 as I am rotation around y axis. That is a stupid mistake but thank you for making me realise that.
Cheers,
Steph