The legacy version of TMD and additional documentation are available at the NWTC Software Portal.
ServoDyn is the control and Electrical Drive Dynamics Module for the OpenFAST framework.
Included in ServoDyn is the tuned mass damper (TMD) module which adds functionality to OpenFAST that simulates the addition of TMDs in the nacelle and/or tower for structural control. The TMDs are two independent, one-DOF, linear mass-spring-damping elements that act in the fore-aft and side-side directions or one single omni-directional TMD. They can be placed relative to the nacelle reference position or base of the undeflected tower using the options in the input file. The TMD module is added as a sub-module of ServoDyn.