Superelement Reduction of Substructures for Sequential Load Calculations in OpenFAST

Emmanuel Branlard, Matthew Shields, Benjamin Anderson, Rick Damiani, Jason Jonkman, Walter Musial, B. Foley, F. Wendt

Research output: Contribution to journalArticlepeer-review

5 Scopus Citations


This article presents the superelement formulation newly implemented in OpenFAST to simulate fixed-bottom substructures with a reduced-order model similar to a common industry practice. The Guyan and Craig-Bampton methods are used to reduce the number of degrees of freedom and generate a so-called "superelement". The formulation allows manufacturers to exchange such superelements to perform load calculations without revealing sensitive information about the support structure (e.g., foundation, substructure, and/or tower) or turbine. The source code is made publicly available in the OpenFAST repository. Test cases with varying degrees of complexity are presented to validate the technique, and accuracy issues are discussed.

Original languageAmerican English
Article numberArticle No. 012033
Number of pages14
JournalJournal of Physics: Conference Series
Issue number1
StatePublished - 3 Mar 2020
EventNorth American Wind Energy Academy, NAWEA 2019 and the International Conference on Future Technologies in Wind Energy 2019, WindTech 2019 - Amherst, United States
Duration: 14 Oct 201916 Oct 2019

Bibliographical note

Publisher Copyright:
© 2020 IOP Publishing Ltd. All rights reserved.

NREL Publication Number

  • NREL/JA-5000-75173


  • FEM
  • foundations
  • substructures
  • superelements


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