# Coupled dynamics simulation using FAST when a blade suddently break down **URL:** \ **Category:** Structural Analysis\ **Created:** [July 9, 2025, 7:39am UTC](https://forums.nlr.gov/t/coupled-dynamics-simulation-using-fast-when-a-blade-suddently-break-down/9058 "2025-07-09T07:39:50Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Lin.Yang](https://avatars.discourse-cdn.com/v4/letter/l/e99b99/32.png) [@Lin.Yang](https://forums.nlr.gov/u/Lin.Yang)\ **Post date:** [July 9, 2025, 7:39am UTC](https://forums.nlr.gov/t/coupled-dynamics-simulation-using-fast-when-a-blade-suddently-break-down/9058/1 "2025-07-09T07:39:50Z")
Dear Dr. jason, I want to simulate the coupled dynamics of IEA-15MW when a blade suddently break down at a specified spanwise position (say 0.5R) using FAST. I find this kind of simulations are rarely reported in wind energy communities, and I am trying to use FAST for such simulations with some code customizations. Now, I have two plans for blade breakup simulation using FAST: (1) Simplyly set the aerodynamic forces and gravity force to zeros for a certain range of blade span, say 0.5R-1.0R. (2) Reconstruct the AeroDyn mesh and BeamDyn mesh (or ElastoDyn? ) when the breakup occures. Could you give me some advice and briefly comment on my two plans whether they correctly representing the real blade breakdown event? Best regards, Lin Yang. ---
**Author:** ![Jason.Jonkman](https://dub1.discourse-cdn.com/nrel/user_avatar/forums.nlr.gov/jason.jonkman/32/3086_2.png) [@Jason.Jonkman](https://forums.nlr.gov/u/Jason.Jonkman)\ **Post date:** [July 10, 2025, 11:41am UTC](https://forums.nlr.gov/t/coupled-dynamics-simulation-using-fast-when-a-blade-suddently-break-down/9058/2 "2025-07-10T11:41:21Z")
Dear @Lin.Yang, Can you clarify what you mean when you refer to blade break down? Are you referring to cracks appearing in the plies? Or you referring to a complete loss of the portion a blade, where the tip separates from the root? The former would require a stiffness change (not an aerodynamic change) and the latter would require not just an aerodynamic change, but a change to the mass of the blade. Best regards, ---
**Author:** ![Lin.Yang](https://avatars.discourse-cdn.com/v4/letter/l/e99b99/32.png) [@Lin.Yang](https://forums.nlr.gov/u/Lin.Yang)\ **Post date:** [July 10, 2025, 12:00pm UTC](https://forums.nlr.gov/t/coupled-dynamics-simulation-using-fast-when-a-blade-suddently-break-down/9058/3 "2025-07-10T12:00:47Z")
Dear jason, Thanks for your quick reply. The blade breakdown i mean is some porpotion of the blade are totally lost, including mass, stiffness,forces…Perhaps I need to prepare two blade files to construct FAST data structures, and switch upon blade break? best regards. Lin Yang. ![](https://europe1.discourse-cdn.com/nrel/original/2X/3/36955b7e83ff9f5053cf23bd870d720a598c53aa.gif) ---- Replied Message ---- > From | [Jason Jonkman via NREL Forum](mailto:notifications@nrel.discoursemail.com)[notifications@nrel.discoursemail.com](mailto:notifications@nrel.discoursemail.com) | > > - | - | > Date | 07/10/2025 19:51 | > To | [yanglin205@163.com](mailto:yanglin205@163.com) | > Cc | | > Subject | [NREL Forum] [Wind & Water/Structural Analysis] Coupled dynamics simulation using FAST when a blade suddently break down | > ![](https://dub1.discourse-cdn.com/nrel/user_avatar/forums.nrel.gov/jason.jonkman/45/3086_2.png "Jason.Jonkman") | [Jason.Jonkman](https://forums.nlr.gov/u/jason.jonkman) > July 10 | > > - | - | Dear [@Lin.Yang](https://forums.nlr.gov/u/lin.yang), Can you clarify what you mean when you refer to blade break down? Are you referring to cracks appearing in the plies? Or you referring to a complete loss of the portion a blade, where the tip separates from the root? The former would require a stiffness change (not an aerodynamic change) and the latter would require not just an aerodynamic change, but a change to the mass of the blade. Best regards, ---
**Author:** ![Jason.Jonkman](https://dub1.discourse-cdn.com/nrel/user_avatar/forums.nlr.gov/jason.jonkman/32/3086_2.png) [@Jason.Jonkman](https://forums.nlr.gov/u/Jason.Jonkman)\ **Post date:** [July 11, 2025, 12:42am UTC](https://forums.nlr.gov/t/coupled-dynamics-simulation-using-fast-when-a-blade-suddently-break-down/9058/4 "2025-07-11T00:42:09Z")
Dear @Lin.Yang, OpenFAST is not really set up to support a complete loss of a portion of a blade. It would require a source code change to implement. Best regards,