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Fatigue analysis

Hello all,
Could anyone tell me what fatigue safety factor criteria is used in NX
NASTRAN?
I would like to use Dang Van 1 (which is not the one implemented)
criteria is there a way to implement it?

Thanks in advance,
regards,
Tamas
5 REPLIES

Re: Fatigue analysis

Tamas,

Nastran does not have a fatigue analysis capability.

Regards,
Jim
--
Jim Bernard
Advanced Applications Engineer

Siemens PLM Software
2000 Eastman Dr., Milford, OH 45150-2712
www.siemens.com/plm

Re: Fatigue analysis

Hello Jim,
So I must be confusing NX6 capabilities for durability with NX Nastan's.
Right?
regards,
Tamas
tsbernar a écrit :
> Tamas,
>
> Nastran does not have a fatigue analysis capability.
>
> Regards,
> Jim
>
>

Re: Fatigue analysis

Dear Tamas,
Just to add to Jim's comments...
NX Nastran do not support Fatigue analysis, it is NX AdvSim that can perform a Durability analysis as a "New Solution Process.." wizard based in the NX Nastran results (like Optimization & Adaptivity). And not too bad, it supports low cycle "Strain life Epsilon-N " & high cycle "Stress life S-N" fatigue analysis assessment at no extra cost, how I should like to have Fatigue analysis embedded in FEMAP .... long term request!!.
Best regards,
Blas.
--
"Tamas" escribió en el mensaje de noticias news:4b0d3c90@bbsnotes.ugs.com...
> Hello Jim,
>
> So I must be confusing NX6 capabilities for durability with NX Nastan's.
> Right?
>
> regards,
> Tamas
>
> tsbernar a écrit :
>> Tamas,
>>
>> Nastran does not have a fatigue analysis capability.
>>
>> Regards,
>> Jim
>>
>>

Re: Fatigue analysis

Hello Blas,
I see, now I understand why there is no way to take mean stress in
consideration (at least I haven't found so far)
when running durability, and also why there is no way to look for a
specific fatigue criteria, except
S-N and epsilon-N.
Would it be doable with API (though I am far from being a good programmer)?

Thanks again,
Regards,
Tamas
Blas Molero Hidalgo a écrit :
> Dear Tamas,
> Just to add to Jim's comments...
> NX Nastran do not support Fatigue analysis, it is NX AdvSim that can
> perform a Durability analysis as a "New Solution Process.." wizard based
> in the NX Nastran results (like Optimization & Adaptivity). And not too
> bad, it supports low cycle "Strain life Epsilon-N " & high cycle "Stress
> life S-N" fatigue analysis assessment at no extra cost, how I should
> like to have Fatigue analysis embedded in FEMAP .... long term request!!.
> Best regards,
> Blas.
>
> --
>
> "Tamas" >
> escribió en el mensaje de noticias news:4b0d3c90@bbsnotes.ugs.com...
> > Hello Jim,
> >
> > So I must be confusing NX6 capabilities for durability with NX Nastan's.
> > Right?
> >
> > regards,
> > Tamas
> >
> > tsbernar a écrit :
> >> Tamas,
> >>
> >> Nastran does not have a fatigue analysis capability.
> >>
> >> Regards,
> >> Jim
> >>
> >>

Re: Fatigue analysis

For a simple example, if you know what your loading extremes are, you can run load cases for each and then use the linear combination tool to take their algebraic difference, then compare this resultant to your endurance limit. You can also examine the vectoral direction of the principal stresses and determine the change in angle between the principal stresses in order to determine collinearity.