Problem with Orientation

Hi all,

I am trying write subroutine for anisotropic material using UMAT in ABAQUS. My code works fine when I do not use a local coordinate system( *ORIENTATION). But when use local coordinate (*ORIENTATION option) the program stop conversing after few increments. Is there any difference in coding when local coordinate (*ORIENTATION option) is used? Please help me out.

Thanks

Yes, there are some fundamental differences. One is that the local coordinate system is rotated different. I recommend that you add some print statements to figure out what Abaqus it providing.

-Jorgen