brace geomTransf in 2D model

[senior]

i want to model some braces in my model which is 2d.in the geomTransf part for my braces, is it ok to write:
geomTransf PDelta 1

or i should define a vector for it ?

[hnaderi]

I think you should use Corotational transformation :
http://opensees.berkeley.edu/wiki/index ... sformation

[vesna]

corotational is more appropriate for brace modeling in case you want to capture buckling of the brace.

if in 2D you do not need to specify the vector.