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Hi all,
this is a question probably mostly for Martin but a lot of people here sure can give their point on this.
I know from here: https://www.orbiter-forum.com/showthread.php?t=38762 how Orbiter computes the PMI for a superstructure made of multiple docked vessels.
I think I understand the procedure quite well, so that's quite clear.
Now, since I am in the middle of development of a similar thing I was wondering if I can use this other method (which seems much simpler to me). Since I know the original PMI of each vessel, I (think) can simply use the Huygens-Steiner theorem and calculate the value of each PMI relative to the combined COG. Once I have all of them there I can simply add them up.
So the procedure would be:
1) find the COG of the combined vesse structure
2) for each vessel "translate" the PMI relevant to the new combined COG by making for example Ix = Ix0 + y^2 + z^2 where Ix0 is the x component of the original PMI of the vessel.
3) once I have all the Ix, the Iy and the Iz add them up.
is it something reasonable or is it crazyness?
Thanks in advance
Fred
PS: I made a test with the integration of shipedit and the result from the integration is almost identical to what I calculated with the above method
this is a question probably mostly for Martin but a lot of people here sure can give their point on this.
I know from here: https://www.orbiter-forum.com/showthread.php?t=38762 how Orbiter computes the PMI for a superstructure made of multiple docked vessels.
I think I understand the procedure quite well, so that's quite clear.
Now, since I am in the middle of development of a similar thing I was wondering if I can use this other method (which seems much simpler to me). Since I know the original PMI of each vessel, I (think) can simply use the Huygens-Steiner theorem and calculate the value of each PMI relative to the combined COG. Once I have all of them there I can simply add them up.
So the procedure would be:
1) find the COG of the combined vesse structure
2) for each vessel "translate" the PMI relevant to the new combined COG by making for example Ix = Ix0 + y^2 + z^2 where Ix0 is the x component of the original PMI of the vessel.
3) once I have all the Ix, the Iy and the Iz add them up.
is it something reasonable or is it crazyness?
Thanks in advance
Fred
PS: I made a test with the integration of shipedit and the result from the integration is almost identical to what I calculated with the above method