ElastoDyn + BModes: Tower input file and mode shapes calculation

Wind & Water Computer-Aided Engineering Software Tools
26

Dear @Rad.Haghi,

SubDyn doesn’t output the distributed tower properties and mode shapes needed by ElastoDyn directly, but it does output sectional properties (such as E and Ixx) that you could derive the distributed tower properties from. That said, a tower as modeled in SubDyn makes use of a circular cross section, so, you could calculate the distributed properties by hand quite easily.

The main disadvantages of modeling the full support structure (including the tower) in SubDyn are:

  1. SubDyn is linear whereas the tower in ElastoDyn considers geometric nonlinearities that may play a minor role in the response if the tower deflection is sizeable.
  2. There is no tower-aerodynamic coupling between SubDyn and AeroDyn implemented yet, so, if you model the tower in SubDyn, you must disable the tower influence/shadow and tower aerodynamic load models in AeroDyn.

Best regards,