thickness calculation

Discussion in 'Metal Boat Building' started by naupigos_gr, Dec 10, 2011.

  1. naupigos_gr
    Joined: Feb 2009
    Posts: 45
    Likes: 1, Points: 0, Legacy Rep: 9
    Location: N/A

    naupigos_gr Junior Member

    How I can calculate thickness (t) of my plates in case i know the maximum bending stress?

    I also have a chart with components of a the midship section( girders, deck plating etc etc) with dimensions, levers, 1st and 2nd moments of area, for each component. But everything is bonded with "t".
    My given maximum bending stress given is 160 MN/m2
    160 x 10^6 N/m2.

    thanks and best regards

  2. Olav
    Joined: Dec 2003
    Posts: 319
    Likes: 46, Points: 38, Legacy Rep: 460
    Location: Filia pulchra Lubecæ

    Olav naval architect

    Maybe I got you wrong, but the bending stress you talk about (longitudinal strength) is just one of several areas of strength/scantling calculation that need to be performed. Think of loads normal to the plate surfaces due to static and dynamic (= slamming) water pressure, deck load etc.

    I suggest you make yourself familiar with the scantling rules of a classification society (personally, I'm quite comfortable with Germanischer Lloyd, but any other class will do as well) which allow you to calculate plate thicknesses according to your inner structure (i.e. section spacing etc.), type and intended use of the vessel, material properties and so on.

    To satisfy the longitudinal strength requirements those rules will demand a minimum main section modulus, so you have to check if your design meets this demand and increase plate thickness (usually of the uppermost deck) or use larger longitudinal stiffeners if necessary.
  3. naupigos_gr
    Joined: Feb 2009
    Posts: 45
    Likes: 1, Points: 0, Legacy Rep: 9
    Location: N/A

    naupigos_gr Junior Member

    thanks for your reply.

    well its just an coursework with assumptions it will not be applicable to "real life" . he just gives as the maximum bending stress and says make the table with regards to t(which is an unknown) and then calculate it through the maximum bending stress (160 NM/m2)

    I asked here, because professor is not the best you can find if you know what i mean
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.