Coordinate system for Staad.Offshore

Hi,

I am using Staad.Pro V8i (SELECTseries 5), Version 20.07.10.66 and Staad.Offshore version 3.0.2.0.

I am trying to generate the motion loads on a Staad.Pro model using the Transport Module of Staad.Offshore. Can anyone help to confirm if:

  1. The "center of rotation" input in Staad.Offshore, is based on the coordinates already defined in Staad.Pro's input model? The reason I am asking is that the technical reference in Staad.Offshore seems to point out that "pitch" is about Z-zxis and "roll" is about X-axis, which indicates that it is fixed, regardless of the coordinates defined in Staad.Pro's model. Any ideas?
  2. If the coordinates are indeed per the defined Staad.Pro model, therefore, if the motion criteria was entered correctly on the "motion" stages, they should correspond to the coordinates already defined from the Staad.Pro model, correct?

Thank you.

Parents
  • Yes, the center of rotation specified is based on the co-ordinates defined in the STAAD.Pro model. The relative position of the masses w.r.t the center of rotation is calculated to be used in equations for the calculation of the resultant translational accelerations. In STAAD.Offshore, the X axis is considered as the vessel axis and thus, rotational motion about the X axis will be the "Rolling" motion. The structure needs to be modelled as would be positioned on the barge with X as the acis of the barge.

    Sudip Narayan Choudhury

    Answer Verified By: MorganK 

Reply
  • Yes, the center of rotation specified is based on the co-ordinates defined in the STAAD.Pro model. The relative position of the masses w.r.t the center of rotation is calculated to be used in equations for the calculation of the resultant translational accelerations. In STAAD.Offshore, the X axis is considered as the vessel axis and thus, rotational motion about the X axis will be the "Rolling" motion. The structure needs to be modelled as would be positioned on the barge with X as the acis of the barge.

    Sudip Narayan Choudhury

    Answer Verified By: MorganK 

Children
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