Strand7 - Fatigue study 1

[bigbal]

Hi again, new to Strand7 i'm afraid. There does not seem to be a large community of users for this package unlike other packages.

Im looking through the help and tut files for a fatigue study explanation. The load is linear, in respect to force and period. What solver should I be using?

Thanks in advance

 

[IDS]

Can you give us more details of what you want to do in the fatigue study?

The link below isn't specific to Strand7, but looks useful:

http://www.randomvibration.com/Papers/NAFEMS_Italy_paper.pdf

Doug Jenkins
Interactive Design Services

http://newtonexcelbach.wordpress.com/

 

[bxtsafe]

Hi bigbal,

There aren't so much fatigue analysis tutorials in the web, because it's quite specific subject in structural analysis. Bishop is a reference in the Vibration Fatigue area and his material is very good.

I recommend to use the book "Fatigue Testing and Analysis, Theory and Practice" from Yung-Li Lee et al (chapter 4) as a reference in fatigue theory for uniaxial fatigue.

The following PDF file shows an example of fatigue analysis in Ansys Workbench.

http://engr.bd.psu.edu/ansysug/2007-11-20/WBEFatigue.pdf

I hope it can help,

 

[bigbal]

Thanks all.

I have good experience and knowledge of fatigue testing (repeated linear static loading of metallic components, LR ratio = -1 etc.)

I am trying to simulate this in Strand 7. I know how to do this in Ansys but am new to Strand.

So i want to do a linear static study for stress, then simulate this 10^6 times say.

 

[IDS]

bigbal - I'm very familiar with Strand7, but not with fatigue analysis, not in the mechanical engineering context anyway.

If you can tell us exactly what you want to do in the analysis I can help but at the moment I'd just be guessing.

Also if you have a supported copy of the program it would be worth contacting Strand7 support!

Doug Jenkins
Interactive Design Services

http://newtonexcelbach.wordpress.com/

 

[bxtsafe]

I have accessed in the Strand7 official site and I noticed that this package doesn't have a fatigue module, unfortunately.

I think the most correct way (and also feasible and economic) is to write a Matlab or Scilab program that uses Strand7 output data to assess the component fatigue life, using multiaxial fatigue criteria.

regards,

 

[IDS]

I think the most correct way (and also feasible and economic) is to write a Matlab or Scilab program that uses Strand7 output data to assess the component fatigue life, using multiaxial fatigue criteria.

Anyone looking at doing that (either for fatigue or any other significant post-processing) should have a look at the API. It allows communication between Matlab (don't know about Scilab) and the Strand7 data and results files. It also has modules for Fortran, C, Delphi, VB and VBA, so will work with most popular programming languages, and also a well-known spreadsheet.

Some examples at:

http://newtonexcelbach.wordpress.com/2011/09/23/using-the-strand7-api/

http://newtonexcelbach.wordpress.com/2012/02/19/strand7-api-getnode-functions/

Doug Jenkins
Interactive Design Services

http://newtonexcelbach.wordpress.com/

 

[bxtsafe]

IDS, very good piece of information!

I need to write a fatigue algorithm/program in Matlab (or Scilab) that read the output of Ansys Workbench. Do you know where (websites, pdfs, books, etc) I can find information to do this?

thank you.

 

[IDS]

bxtguard - I don't have any knowledge of Ansys Workbench I'm afraid, but Google tells me it has a scripting language, so I imagine others here might be able to help.


Link for scripting referrence:

http://www1.ansys.com/customer/content/documentation/121/wb2_js.pdf

Doug Jenkins
Interactive Design Services

http://newtonexcelbach.wordpress.com/

 

[bxtsafe]

IDS, thank you for the file; it'll be useful.