Hard to say without seeing the contoured shape you are trying to flatten.
One method is to use the UNFOLD tool in the Developed Shapes product. (If you have the DL1 license, the Developed Shapes toolbar shows up in the GSD workbench)
1. switch to GSD workbench
2. extract the inside or outside face from the the solid
3. offset the extracted surface to obtain the neutral surface
4. use the UNFOLD tool to flatten the neutral surface. (you can also flatten any reference curves, such as holes)
5. if you want a solid of the flat pattern; switch back to Part Design workbench and use the ThickSurface tool.
Thanks for the information and I do use the technique you mention, but I was wondering if there was any other method or function using a different module i.e., composite or sheet metal design?
OK, as far as I know, the only quick option is what jackk already suggested and you know. Otherwise, to import the model in SMD, use feature recognition, repair model... it seems to be a long way...