Spring and Damper on a structure in AQWA

- March 9, 2022 at 5:44 pm
  
  Medi
  Subscriber
  
  Hello,
  I was wondering if there is any way to model a linear connection with spring - damper characteristics to a structure in AQWA? As far as I am concerned, we can use cable with stiffness, but there is no option to define damping.
  Thanks,
- March 11, 2022 at 12:35 pm
  
  Ingrid M
  Ansys Employee
  
  Hello Medi,
  could you please tell us more about what you are trying to model?
  In the meantime, if you want to model the damping that acts in extension, you can use the external user force. You have some examples and a README in your installation, under the aqwa\utils folder. You can start the server as a pre-solve command (see section 5.8.1 of the Aqwa User's manual).
  Kind regards Ingrid
- March 16, 2022 at 4:58 pm
  
  Medi
  Subscriber
  
  Dear Ingrid,
  A schematic of what I mean is here. I want to connect two bodies (one floated and the other submerged) with a connection that have stiffness and damping characteristics. Is it possible in AQWA?
  Thanks
- March 21, 2022 at 11:56 am
  
  Ingrid M
  Ansys Employee
  
  Hello Medi,
  the external user force (in your installation directory) is the way forward. Look at the examples provided. This requires a bit of simple python coding though.
  Your spring force is proportional to the elongation (you have access to the position) and your damping force is proportional to the velocity (which you also have access to).
  Kind regards Ingrid