Piezoelectric axis definition

Hi All,

I have some questions regarding the piezoelectric physics in the COMSOL. I'm using COMSOL multiphysics 4.3

Correct me if I'm wrong, in 3D model, the axes are 1 (x) (horizontal axis), 2 (y) (out of the plane), and 3 (z) (vertical axis). However, in 2D model, x is horizontal axis and y is vertical axis and z is out of plane axis.


For the piezoelectric stiffness coefficient tensor, the matrix components are defined according to the axis in 3D model. The question is that when I use 2D model, how to make sure that the z axis will stay as vertical axis? (so i need to work on x-z plane for my 2D model)


Thank you very much in advance,
Best regards,
Govindo