After reading carefully John C. Luf article about sustianed stresses in Coade Jan. 01 I have a question. It is said (and I agree) that a seperate new file without the support to check the sustained stress must be run. I suppose that if the lift off during operation is 0.1 inch, 0.5 inch or 1 inch mustn't be the same but in that new file, removing the support completely, there is no difference between them . Moreover, what would happen if the support is lifting in operation i.e 0.2 inch and the sag in the new model is bigger than that in that point? I think that the calculated sustained stresses wouldn't be correct. Instead of completely removing the lifting supports I think they should be considered in the new model but with a Y gap of the same length than the lift-off during operation. What do you think?

Regards