orientation

I have a vibration problem where I have assigned the local material orientation by assigning points a and b. By assigning points a and b, I define one material direction in my local coordinate system - direction 3. From Abaqus documentation, I understand that the other two directions are assigned to be orthogonal to the 3rd direction but are set somewhat arbitrarily. I want to write out the directions so that I know the three vectors defining all three directions of the local material orientation.

I found that I can write out the local orientation averaged at each node by using: 

I have set up a vibration problem. I assign a local material orientation by assigning coordinates a and b to define the 3rd material direction. From documentation, I understand that the other two directions are assigned to be orthotropic to the 3rd direction. Beyond that, I think that they are set somewhat arbitrarily. I want to output each component of the local material orientation.

Dear All,

My name is Ronald, student at Eindhoven University of Technology, master Structural Design and i have an import question about the FEM programme Abaqus, about orthotropic materials.

I defined an orthotropic or anisotropic material in Abaqus by using the option; engineering constants or orthotropic (all linear elastic).

Abaqus asks for the modulus of elasticity in direction 1, 2 and 3 and the shear modulus and poisson ratios.

So far so good.