Simulating a tool cutting away a chip on a detailed level involves large deformation and very large strains. I doubt that it is possible to create a model that converges in creo simulate. Some software tools, have the ability to remesh as elements gets too distorted, but Creo Simulate does not have this capability. As a first step, I would use Creo to simply calculate the path and orientation of the tool relative to the workpiece, and calculate the chip thickness. There are school book formulae for tool forces as the tool cuts away a chip. Apply those forces, multiply with velocity of the tool edge and you get the power. If this power makes sense in comparison to measurements, you are on the right track. A more advanced study would involve measuring forces on the machine, one way or another, using strain gagues or similar, to get an understanding of what's going on. Another difficulty you will be facing is that the material properties of the work-piece may be velocity dependent. A slow tensile test might produce a certain stress-strain curve, but at high cutting velocities, this curve might look different.
Here's an open access research paper that perhaps gives some insight into the complexity of this topic.
http://www.sciencedirect.com/science/article/pii/S2212827115002206
