Learning Forum

[Duncan Gibbons]

Hi all,

I am performing a fatigue life analysis in ansys mechanical (static strcutural) on a bracket. I get a lower life estimate at only one mesh vertex (pic attached). Is this due to the edges of the CAD model and/or a poorly meshed body? It is located at the interface between a flat surface and a curved fillet.

Thanks,

Duncan

[Daniel Shaw]

The Mechanical Fatigue Tool (FT) uses the raw nodal stresses to predict the fatigue life.  If you have a local "hot spot" in the model (for whatever reason - bad mesh, stress singularity, etc.), the FT will use that local stress in the fatigue calculations.  You probably should remove that hot spot from the FE model.  If removing it is impractical, then you should probably remove that node(s) from the fatigue calculations by scoping the results to a Named Selection that does not contain that node(s).

[Duncan Gibbons]

Thanks for the insight!

[Daniel Shaw]

You're welcome.