Dear Marcos,
OK, thanks for clarifying.
To model this blade, the easiest thing to do is probably to upgrade to FAST v8 and AeroDyn v15, where you can specify nonstraight blade geometries. If the chord does not pass through the pitch axis near the tip of the blade, my guess is there is some in-plane sweep to your blade geometry that would also effect the structural definition of the blade, in which case the use of the BeamDyn module in FAST v8 to model the blade structural dynamics is recommended.
Test26 in the FAST v8 CertTest is a model of the NREL 5-MW turbine that makes use of BeamDyn and AeroDyn v15. While this model includes a straight blade geometry in BeamDyn, there is an example on our forum where we introduced out-of-plane curvature–see my post dated Jan 28, 2016 in the following forum topic: pre-bended & sweep blade simulation with BeamDyn &aerodyn 15.
Best regards,