Type of critical plane model used in fatigue wizard

[Anonymous]

Hello again,

I was wondering if someone could tell me what kind of critical plane model that is utilised in the fatigue wizard? In the help file I found on fatiguewizard.com, it simply refers me to the theory section, but that information seems to be missing. Does the "Critical plane (Normal stress)" for example simply finds the critical plane with the maximum normal stress and compares it against the material value? Is the Findley criterion used?

Any help would be appreciated.

Best regards
Björn

[MikeSmell_ADSK]

Hi Bjorn.

I was just doing some research on this topic today for a colleague in Japan, when this thread popped up in my Google search. I figured I would pass along my findings on this topic for you to review further.

The way I understand the Critical Plane approach is that it is used specifically for multiaxial fatigue scenarios. Essentially, this approach is correlating principal stress directions to averaged value. it seems like you have a similar understanding. The links I have listed below have much deeper details on the academics behind this topic.

In the case of using Autodesk Simulation’s fatigue solution, both stress and strain based fatigue methods have stress correction options for multiaxial fatigue cases that are based on the critical plane approach. Namely, the Smith Watson Topper method is used for strain based calculations and the Goodman method is used for the stress based calculations.

Note: Everything I found is based on doing further research on critical plane and the actual correction methods I have listed above. I hope this helps.

Relevant links:

http://www.gruppofrattura.it/ocs/index.php/gigf/gigf2005/paper/viewFile/637/494

http://people.clarkson.edu/~yliu/paper/ffems-strain.pdf

https://www.efatigue.com/multiaxial/background/strainlife.html#Damage

https://www.efatigue.com/multiaxial/background/stresslife.html#Damage

http://books.google.com/books?id=FKoNL3MXck8C&pg=PA7&lpg=PA7&dq=critical+plane+fatigue&source=bl&ots...

http://www.sciencedirect.com/science/article/pii/S0142112304001756

-MIKE