Search found 16 matches

by Greg.Hayman
Tue Mar 27, 2018 8:41 am
Forum: Computer-Aided Engineering Software Tools
Topic: MLife Fatigue DEL Calculation
Replies: 26
Views: 10393

Re: MLife Fatigue DEL Calculation

Hello Simon, Unfortunately, we do not have the resources to supported pre-compiled versions of MLife at this time. The good news is that you can still use MLife! You simply need to create your own version of the Weibull cumulative distribution function, wblcdf() function. https://www.mathworks.com/h...
by Greg.Hayman
Mon Aug 14, 2017 11:24 am
Forum: Computer-Aided Engineering Software Tools
Topic: Announcing MExtremes
Replies: 24
Views: 4029

Re: Announcing MExtremes

The tilde operator was introduced with MATLAB Version 7.9 (R2009b). https://www.mathworks.com/help/matlab/matlab_prog/ignore-function-outputs.html You will need to place dummy variables where ever you see ~ in a function output list for this code to work with your version of matlab. There may be add...
by Greg.Hayman
Tue Jun 20, 2017 7:56 am
Forum: Computer-Aided Engineering Software Tools
Topic: MLife Fatigue DEL Calculation
Replies: 26
Views: 10393

Re: MLife Fatigue DEL Calculation

For item (1), you need to modify Test02.mlif to use the StrNames functionality. It should now run without any errors. true StrNames Use channel names following a "$" instead of numbers when specifying channels in this input file. 2) You can access the binned rainflow counts via the data st...
by Greg.Hayman
Tue May 09, 2017 7:11 am
Forum: Computer-Aided Engineering Software Tools
Topic: Problems running MLife without MatLab
Replies: 3
Views: 1343

Re: Problems running MLife without MatLab

Dear Tohid, Unfortunately I cannot reproduce your errors. I've 1) downloaded the MLife archive with the precompiled binaries ( https://nwtc.nrel.gov/system/files/MLife_v1.00.00f-gjh_1.exe ), 2) extracted the archive to a local folder. 3) Copied the contents of the Data folder into the CertTest folde...
by Greg.Hayman
Fri Jan 20, 2017 1:44 pm
Forum: Computer-Aided Engineering Software Tools
Topic: Problems running MCrunch CertTest
Replies: 6
Views: 3339

Re: Problems running MCrunch CertTest

Simon,

I have not run MCrunch with a version of MatLab newer than 2014a. Can you paste the error message you are receiving with your version of MatLab?

Thanks,

Greg
by Greg.Hayman
Thu Aug 25, 2016 9:33 am
Forum: Computer-Aided Engineering Software Tools
Topic: Water ballasting & buoyancy loads
Replies: 6
Views: 1911

Re: Water ballasting & buoyancy loads

Romain, Thank you for reporting this issue. I have verified the problem in the current version of HydroDyn (v2.05). This bug was created when we added user supplied wave kinematics and with our wave stretching implementation. Some additional code is needed in the WriteSummaryFile() subroutine of Mor...
by Greg.Hayman
Wed May 11, 2016 2:23 pm
Forum: Computer-Aided Engineering Software Tools
Topic: fatigue calculation
Replies: 15
Views: 3273

Re: fatigue calculation

Dear Srinivasa,

wblcdf() is a MatLab function found in the statistics toolbox. You will need to have a license for this toolbox, or replace the wblcdf() call with your own code to calculate the weibull distribution.

Greg
by Greg.Hayman
Mon May 18, 2015 9:20 am
Forum: Computer-Aided Engineering Software Tools
Topic: MLife CertTest
Replies: 1
Views: 2319

Re: MLife CertTest

Hello Scott, Thank you for pointing out the discrepancy between the User's Guide and the archive. At some point, I changed the name of the script to: mlife_regression_test.m This script is identical to the original mlife_certification_tests.m script. I'll be sure to update the documentation for any ...
by Greg.Hayman
Mon Sep 22, 2014 8:51 pm
Forum: Computer-Aided Engineering Software Tools
Topic: damage equivalent load
Replies: 3
Views: 3104

Re: damage equivalent load

Dear Mehdi, You might want to look at the certification tests under the CertTest folder of the MLife distribution. Test02.mlif and Test05.mlif both generate short-term DELs. If you examine the MLife_User.pdf, located in the documentation folder, you will be able to interpret the various parameters. ...
by Greg.Hayman
Wed Jul 09, 2014 2:11 pm
Forum: Computer-Aided Engineering Software Tools
Topic: Output hydrodynamic forces
Replies: 5
Views: 3403

Re: Output hydrodynamic forces

Dear Shining.Zhang, In terms of your first item, the HydroDyn manual, https://wind.nrel.gov/designcodes/simulators/hydrodyn/HydroDyn_Manual.pdf , Appendix C has a complete list of available HydroDyn outputs. There are channels for all the various load contributions due to potential flow theory as we...
by Greg.Hayman
Mon Apr 08, 2013 10:32 am
Forum: Computer-Aided Engineering Software Tools
Topic: MLife Fatigue DEL Calculation
Replies: 26
Views: 10393

Re: MLife Fatigue DEL Calculation

Yulin, Your questions about the specification of both L_MF and L_Ult is a common one. Unfortunately, there is no general answer that I can give you. In my opinion, the answer depends on the nature of your analysis/study, and the available information you have about your turbine design. For generaliz...
by Greg.Hayman
Mon Apr 08, 2013 10:07 am
Forum: Computer-Aided Engineering Software Tools
Topic: Mlife
Replies: 1
Views: 1116

Re: Mlife

Florian, as stated in the MLife User's Guide on page on page 6, "If you wish, DELs can be outputted as peak-to-peak ranges (DEL_AsRange = true) or as one-sided amplitudes (DEL_AsRange = false)." The rainflow counts themselves are tracked based on the number of full cycles (valley-to-peak-t...
by Greg.Hayman
Mon Oct 22, 2012 1:05 pm
Forum: News and Announcements
Topic: Software Releases
Replies: 17
Views: 94136

Updated version of MLife software (v1.00.00f-gjh)

We are happy to announce an updated alpha-version release of MLife (v1.00.00f-gjh), a MatLab-based tool that can efficiently process statistical and fatigue-related output needed for wind turbine certification. MLife's calculations follow the method required by the IEC in their 61400-1 Edition 3, An...
by Greg.Hayman
Tue Dec 13, 2011 2:03 pm
Forum: Computer-Aided Engineering Software Tools
Topic: New NWTC/NREL Fatigue-life estimation tool
Replies: 3
Views: 3895

Re: New NWTC/NREL Fatigue-life estimation tool

We have discovered a bug in the v1.00.00b-gjh release related to the calculation of wind speed bin probabilities. Currently the scale factor for the Weibull distribution is set to 2*Vave / sqrt(pi), but this should only be the case when a shape factor of 2 is used (in other words a Rayleigh distribu...
by Greg.Hayman
Mon Dec 05, 2011 1:45 pm
Forum: Computer-Aided Engineering Software Tools
Topic: New NWTC/NREL Fatigue-life estimation tool
Replies: 3
Views: 3895

New NWTC/NREL Fatigue-life estimation tool

Call for Alpha Testers (NWTC/NREL Fatigue-life estimation Tool) We are happy to announce an alpha-version release of MLife, a MatLab-based tool that can efficiently process statistical and fatigue-related output needed for wind turbine certification. MLife's calculations follow the method required b...

Go to advanced search