Dear Simulia community,

I wish to define an anisotropic material for a pipe (artery) with two symmetrical fiber directions based on Holzapfel's model. My first question is how to we define the number of fiber directions ? Is it done the way I've highlighted in the Edit Material window attached ?

My second question is how do I specify the direction of the two fibers ? Is it supposed to be done as I've shown in the Edit Material Orientation window attached ? I've used a 'discrete' definition and specified the angle as 45deg. Will this procedure specify the fiber direction for both the fibers ? I mean, I want the fibers to be symmetric so I want their orientations be be +45deg & -45deg with respect to circumferential direction. But I wish to know if I need to specify the orientation of the two fibers separately or can it be done in one go ?

I would highly appreciate comments in this regards :)

Thanks with warm wishes,

Aakash