Showing results for 
Search instead for 
Do you mean 
Reply
Solved! Go to solution

Fatigue and Durability

[ Edited ]

Hi all,

First of all, huge congrats for the start of this community and the tool put in place.  As an old SAMTECH marketeer, I am jealous with what you guys are putting in place.  I was pushing at the time to start a community and now it is there !

 

Now to my question: I was wondering, out of curiosity, what is behind the "Durability Fatigue Analysis".  It was, at the time, one of the weak points of our offer, WindTurbines dedicated stuff excepted.  It seems that there has been a lot of improvement on the matter.  Can you tell us a bit more?

 

Cheers to the whole team

 

Sebastien

9 REPLIES
Solution
Solution
Accepted by AllisonFassin (Community Manager)
‎08-28-2015 06:14 AM

Re: Fatigue and Durability

That's a good question.

 

The Fatigue and Durability solutions from LMS include

  • LMS Virtual.Lab Durability
  • LMS Tecware Fatigue Life Analysis

For the evaluation of CAE models of Wind Turbines, LMS Virtual.Lab Durability would be the right tool.

If it is about the analysis of load data acquired from e.g. strain gauges, accelerometer, ... then LMS Tecware is the right tool.

 

Both make use of the stain life and the stress life approach, offering a large set of parameters for different life analysis calculations.

 

More information is available here.

Re: Fatigue and Durability

Hi Sebastien,

 

Thanks a lot for your support, we really hope this Forum will federate our users community and help people be more efficient in their daily use of our LMS products.

Hope you found the answer to your question.

Have a nice day.

 

J.

Solution
Solution
Accepted by AllisonFassin (Community Manager)
‎08-28-2015 06:14 AM

Re: Fatigue and Durability

Durability Fatigue Analysis is all about understanding the structural performance under cyclic loading. As Holger points out Siemens has two main solutions; 1) A virtual, CAE approach and 2) a physical, test/measurement approach.

 

The Durability/Fatigue performance is governed by 3 things; 1) Material, 2) Geometry and 3) Loads. Any one of these or a combination of these can cause a Durability/Fatigue performance issue.

 

Material - determines the stress-life (Wöhler) or strain-life curve characteristics (a curve of the number of cycles to failure). Choose a material that is fatigue resistant. This is often balanced against the cost, weight and manufacturability of the material.

 

Geometry - determines how stress is formed. External load applied is transformed to high stresses due to geometry often referred to as "notches" or "stress risers". Use thicker cross sections and nicely rounded curvatures to reduce the stress and "manage" the load.

 

Loads - the only thing you can't completely control! Knowing how your part is loaded and which loads are fatigue relavant is important. Sometimes high loads are important. Sometimes low loads with many cycles are important. Both LMS Virtual.Lab and LMS Tecware have dedicated methods for analyzing the loads and detrmining which ones are important - sort of like putting a pair of fatigue goggles on to see what's important.

Solution
Solution
Accepted by AllisonFassin (Community Manager)
‎08-28-2015 06:14 AM

Re: Fatigue and Durability

Dear Sebastien,

 

in addition to Holger's and Paul's answers, let me also tell you that we have fully integrated the durability analysis into the wind turbine application LMS Samcef for Windturbines.

 

That means that after setting up a template fatigue analysis for a selected component all wind load cases defined in Samcef for Windturbines will automatically run through a fatigue analysis. Standard results (e.g. min fatigue life per wind event)  3D plot (e.g. fatigue life) are automatically generated and may be directly viewed.

For the most damaging wind events you can open the fatigue tool LMS Virtual.Lab Durability directly and do dedicated fatigue post processing like seeing which of the loads and/or which parts of the wind history are most damaging.

 

So indeed a lot happened to make the analysis more realistic and give the engineer the tools to understand and improve his/her components.

 

Michael

Dr.Michael Hack
Business Product Line Manager Durability
Simulation and Testing Solutions

Re: Fatigue and Durability

[ Edited ]

First of all,

I'd like to thank Michael for having me here. I'm truly honored.

I'd like to ask Michael whether there are any plans to add the Ansys constraint equations as a modelling way to simulate the seam welds. I'm talking about the RBE3 equivalent which is available in Ansys. This would be an easier way way to simulate the welds than one row of shells that is current way to go.

Thank you very much

 

Riccardo

Re: Fatigue and Durability

[ Edited ]

Dear All,

 

Thanks a lot for your nice answers.  I am in fact not at all busy with Wind Turbines, but I was referring to SAMCEF for WT as the only product that could deal with fatigue issues in the whole SAMCEF offer.  I see that there are several nice solutions in the whole Siemens/LMS Portfolio on the subject now.

 

 Sebastien

Re: Fatigue and Durability

Caro Riccardo,

 

nice to have you here.

 

As you know we take for the seam weld analysis the load flow through the weld from the finite element model. For getting good results, it is essential that this load flow is captured as good as possible, where the direct connection, or the indirect connection with shells (compatible meshes) are the best and therefore supported.

 

Nevertheless we have added in 13.2 a special RBE2-RBE3 connection as they are created e.g. by our NX CAE tool. These are intended for a first fast analysis, where still the most critical positions should be re-meshed with compatible meshes. Let us collect some experience with this kind of connection for seam welds before deciding on further new modelling possibilities.

 

ciao Michael

 

P.S.: Don't be shy to open a new thread in the future Smiley Wink 

 

Dr.Michael Hack
Business Product Line Manager Durability
Simulation and Testing Solutions

Re: Fatigue and Durability

Hello Michael

 

I have a doubt...

Can you tell me if  LMS has a module that can create an SN Curve? 

Which parameters does a customer need to introduce or measure in order to obtain SN Curve?

 

Thank you.

Regards.

 

Abdiel Nolasco.

Re: Fatigue and Durability

See other discussion : How to create SN curve
Dr.Michael Hack
Business Product Line Manager Durability
Simulation and Testing Solutions