Hydromax-Trim exceeds -45???

Discussion in 'Software' started by Gokhan, Oct 16, 2008.

  1. Gokhan
    Joined: Oct 2008
    Posts: 2
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    Location: Nanjing

    Gokhan New Member

    Hi there!

    I m not a pro in Hydromax, however I have done this many times, I am facing a promlem whilst trying to perform Large angle stability on my small boat design. The error message reads "Trim value exceeds -45...".

    Am I overlooking something?

    Cheers
    Gokhan
     
  2. Andrew Mason
    Joined: Mar 2003
    Posts: 396
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    Location: Perth, Western Australia

    Andrew Mason Senior Member

    Does it trim past 45 degrees in the zero heel state? If so, check that your centre of gravity is in the correct place, your boat is sinking by the bow or stern. Common problems are specifying longitudinal positions for each load item as positive values when the zero point is at the forward perpendicular. The longitudinal co-ordinate system is + forward, - aft, so if the zero point is forward, load positions will need a negative sign.

    Other common problems are specifying loads from a forward or aft perpendicular when the actual zero point is set at amidships.

    All these problems will result in the c.g. of the vessel ending up well beyond the vessel's extremities, generating very large trim angles.

    If the high trim angles only occur at high heel angles, and you are dealing with a multihull, you may have a genuine problem caused by a high VCG and poor longitudinal stability in the heeled state. A less common problem, but one I have seen occur.
     
  3. Gokhan
    Joined: Oct 2008
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    Location: Nanjing

    Gokhan New Member

    Thank you for your reply.

    At zero heel state the trim = 0. After analysing the uprgiht hyrdo. the Cg and Cb seems in right place and then when i try to analyse the Large A. S. it halts and pops up that error. when it halts, i can see on the profile window that the cb and the cg is way heigher (i.e. 4-5 meters above the deck) then the normal.

    So problem persists...
     
  4. Andrew Mason
    Joined: Mar 2003
    Posts: 396
    Likes: 17, Points: 0, Legacy Rep: 206
    Location: Perth, Western Australia

    Andrew Mason Senior Member

    Can you please send your design and loadcase to support@formsys.com so that I can have a look at it.

    thanks
     

  5. pavel915
    Joined: Nov 2006
    Posts: 349
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    Location: Bangladesh

    pavel915 Senior Member

    Gokhan;
    I think you are missing some points.
    At first you should look where the zero point is in.
    YOu can change your zero point by going to Display>Zero point and all the weight allocation should be according to the zero point.
    If you go to Display>Frame of Referance you can see where the 2 perpendiculars are, sometimes they remain at the midship so for this reason trim is shown to be zero.
     
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