Boundary Conditions and Temperature profiles manipulation?
The first question I have is if I have a temperature profile at SS can I create a linear ramp vs. time in ANSYS?
For example claim the system is at room temperature at 0 seconds and that my steady state file is at 25 minutes. Thus there is a linear ramp for 25 minutes at each node. My current solution has been creating CSV files in MATLAB to create this linear ramp.
I am preforming fatigue life analysis on a large pressure vessel used for a super sonic nozzle rig. However, the goal is to preform this with out fixed boundaries. The bolt holes will be expanding radially, and the pipe is free to expand axially as the entire rig will be on wheels. When fixing the bolt holes there are large stress concentrations that occur about the boundary conditions and virtually no stress downstream.
I believe the large stress concentration of the pipe to derive from the inability of the flange to expand outwards due to the fixed bolt holes. In reality our system will be expanding as the flange connection will be a similar temperature.
When using free displacement I result in errors about preventing rigid body motion. In conclusion is there a way in ANSYS to focus more on thermal generated stress and not have these boundary condition issues?