*Abaqus Cyclic Loading Method Verification Query*

[PMc7]

Hi,

I have modeled an ex service power plant t-piece which I'd like to analyse in Abaqus under realistic loading conditions but I have a query about cyclic loading in Abaqus.

I am trying to simulate 10 power plant cold start cycles where 1 cycle contains 8 hours (28800 seconds) of ramp up from 0 to 17 MPa (17 MPa is the internal pressure I have applied), just under 22 hours ( around 79200 seconds) of constant pressure at 17 MPa before a drop off to 0 MPa at 30 hours.

I'd like to know if my methods are technically correct and will result in accurate solutions and if my methods are incorrect can anyone suggest the most accurate and time efficient method? So here is what I've done to simulate 1 cold start cycle so far:

Using a static general step I have set the time period to 10 with an initial and maximum increment size of 0.025. I have then inputted the values which can be seen in the attachment to the amplitude part of the load module for the applied 17 MPa internal pressure.

Personally I'm not convinced that my methods are correct (however the analysis runs without errors) and I'm not sure if a time period of 10 is correct (can I reduce/increase this number without a change in results?? or does it need to be 10 as I'm trying to simulate 10 cylces??) so I hope someone can help, thanks!

 

[Mustaine3]

A static analysis uses a time scale.

And when you try to model some kind of fatigue or material behavior, that changes with repeated loading, then this is not working that way.

See Abaqus Analysis Users Guide
6.2.6 Direct cyclic analysis
6.2.7 Low-cycle fatigue analysis using the direct cyclic approach