Is there an established process in prepomax for maintaining bolt pre-tension in subsequent steps ?
In the second step, you should change the pre-tension type to displacement (if it’s not of this kind already in the first step) and set displacement to Fixed:
There is a long discussion on how pre-tension works with other loads in CalculiX here: Pretension shear/tensile resistance - CalculiX (official versions are on www.calculix.de, the official GitHub repository is at https://github.com/Dhondtguido/CalculiX).
So far, the conclusion is that it’s better to use displacement type in the first step.
The implementation in prepomax seems to be the same as I was doing manually. Thanks.
I had a look at one of the posted models “Clamping Hanger” and thought it odd that the 2nd step contained the correct “*boundary, fixed” for the pretension section but also an amplitude referring back to the initial load application in step 1. This may have led to much confusion for the pretension and associated reactions.
Yep, I removed them. It’s kind of strange that the amplitude were affecting as the value was set to Fixed but it interferes.
I guess its a numerical value fixed from the last step but scaled according to amplitude. I think that’s what I would expect to happen to be consistent but i guess some care is needed.