I'll put my 2 cents in here, but my opinion is obviously biased ... but here it is anyway.
Plant 4D Stress is, I believe, Triflex. Check out the CEA website to see this.
As Ed says, vendors have been promising transparent CAD-Stress interfaces for years. The only one, to date, that really works is the CADWorx-CAESAR II pair. This is a bi-directional interface, so changes on either side of the fence can be made, retained, and shared. If you don't believe me, download the demo, or contact jbrinlee@coade.com.
Even with these packages, you will never remove the engineer from the process, or eliminate "modeling" completely. The stress analyst still has to define "code specific" details as well as restraint details. This is information that is typically not known when the system is first drawn in the CAD package.
(Now the really cool thing about the CADWorx-CAESAR II pair is that once this "code/restraint specific" data is entered in CAESAR II, it can be passed back and forth. It won't be lost, and the stress analyst only has to define it once.)
Richard Ay
COADE, Inc.