Forum

QBlade ForumQBlade: Structural DynamicsLoads at the tower bottom

Please or Register to create posts and topics.

Loads at the tower bottom

#1 · 12. February 2024, 13:16

Hello,
I want to extract the forces and moments at the tower bottom of a floating off-shore turbine. From the names of two structural time graph output variables, it seems that this can be obtained from, for example, “Z_l For. TWR Bot. Constr. [N]” or “Z_l For. TWR pos 0.000 [N]”, so I am wondering what are the differences between this two outputs? And do they include the gravitational force due to the weight of the entire structure?

Thanks.

Best regards,
João Muralha

#2 · 12. February 2024, 15:27

Hi João,

the two sensors that you mention will output the same data. The first sensor (TWR Bot. Constr.) is a default senseor that is automatically included in the simulation. The second sensor (TWR pos 0.000) is a user defined sensor at the same location. Both sensors include the gravitational force acting on all components of the turbine above the tower bottom.

BR,

David

#3 · 13. February 2024, 12:12

Hello David,

I get different forces values for the “Z_l For. TWR Bot. Constr. [N]” or “Z_l For. TWR pos 0.000 [N]” as can be seen in the attached image.

Thanks,

João Muralha

Uploaded files:

You need to login to have access to uploads.

#4 · 13. February 2024, 13:37

Hi João,

it could be that there are point masses attached to the tower bottom node, in which case this mass would not appear in the “POS 0.0000” variable.

I would check the mass/inertia overview in the turbine definition module and the substructure file.

BR,

David