Hello.
I am a PhD student working on various aspects related to the support structure of monopile-supported Offshore Wind Turbines (OWTs), including vibration suppression, optimised redesign, and soil-structure interaction.
I aim to implement a Tuned Mass Damper Inerter (TMDI) in the OpenFAST Structural Control Module. To this end, I have thoroughly reviewed the equations of motion of a classical TMD to understand the underlying physics and developed the modified equations of motion for TMDI. Notably, TMDI relies on the same state vector as the classical 3-DOF StC TMD, with minor modifications to state matrix A and no changes to input matrix B. Furthermore, the resulting forces F⃗_PG and moments M⃗_PG acting on the component are identical to those in Equation 4.218 of the ‘Theory Manual for the Tuned Mass Damper Module in OpenFAST’. However, an additional output for TMDI is required.
The TMDI implementation reuses the existing StC TMD source codes for all operations except two inerter-induced modifications: one algebraic change in state matrix A and one new reaction load. Additionally, setting the inertance to zero reduces TMDI to the classical StC TMD.
I have prepared 2 brief documents introducing the inerter and the equations of motion for TMDI, which could be integrated into OpenFAST. I have also drafted a work plan outlining possible code modifications required to implement TMDI in the Structural Control Module.
At this stage, I would appreciate guidance on whether to compile OpenFAST from source or pursue the Conda installation.
I was wondering if NREL will be interested to discuss the potential incorporation of TMDI in future releases of OpenFAST. If yes, I would be glad to get in touch and discuss further via email or message.
Best regards,
Hisham