Custom damage rule in ANSYS fatigue module

[Newuser2007]

I think ansys fatigue module only has Miner's rule type linear damage rule. How can I include a custom damage rule in ansys fatigue model?

Can I do it by APDL ? if yes, how?

 

[Transient1]

I don't know the answer to your question, but I think it would be yes you can do it with APDL. It would be complicated though.

Using APDL you can store the stresses at a particular load step and manipulate them. Get your hands on the APDL Guide from ANSYS. The basic idea would be:

Write a loop to Get stresses at each node for Load Step X
For each node compute the fatigue damage based on fatigue damage rule.
Store this as a fatigue damage matrix.
Repeat for next load step, add results of fatigue damage matrix to previous fatigue damage matrix.
Repeat

Now, dispalying the results at each node is probably tricky. You may actually be able to get into the fatigue module and see what commands ANSYS does for the miner's rule.

 

[Newuser2007]

thanks for your tips. I will look into this. I knowit will take quite some time for me to fully get something going.
hope for the best.