Hello all, this is my first thread.

I'm currently trying to develop a UMAT for a functionally graded, Neo Hookean material to model a graded rubber material. This requires that I change the properties of the material at each of the Gauss integration points. Since I am considering large deformations, the UMAT seems to only provide me with the current coordinates (COORDS) of the Gauss points, but I require the original coordinates.

I searched the forums but wasn't able to come up with a solution on my own. Does anyone know how I can determine the original coordinates within the UMAT when NLGEOM is invoked?

Any advice is appreciated.

dspring