Loading Cycles on Submarine

Discussion in 'Boat Design' started by amateur mariner, Feb 11, 2009.

  1. amateur mariner
    Joined: Feb 2009
    Posts: 44
    Likes: 1, Points: 0, Legacy Rep: 30
    Location: anywhere

    amateur mariner Junior Member

    Hi everybody!

    I want to ask that what is loading cycles on a submarine?Can anybody refer me some documents?

    Regards,

    Thanx
     
  2. Kay9
    Joined: Oct 2006
    Posts: 589
    Likes: 26, Points: 0, Legacy Rep: 279
    Location: Central Coast Oregon US.

    Kay9 1600T Master

    Dock the Sub, walk to the dock, pick up your package, walk back to the sub, load package.

    K9
     
  3. Olav
    Joined: Dec 2003
    Posts: 295
    Likes: 30, Points: 38, Legacy Rep: 460
    Location: Filia pulchra Lubecæ

    Olav arch. nav.

    The load cycles of (military) submarines are actually quite low: 10^4...4*10^4

    Admittedly I have only very few documents or literature about submarines. I guess you are familiar with "Submarine Design" by Ulrich Gabler (published by Bernard U. Graefe, ISBN 3-7637-6202-7)? Quite a good paper is "Some Aspects of Submarine Design" by Prof. P. N. Joubert of Australia's Defence Science and Technology Organisation (DSTO), consisting of Part 1: Hydrodynamics and Part 2: Shape of a Submarine 2026. The DSTO publications are generally an excellent source.

    Additionally, I have a well-written university hand-out which however is in German. If you can read German (since you are located "anywhere" there is a good chance that you can ;) ) just PM me your e-mail address and I'll send it to you.
     
    1 person likes this.
  4. dskira

    dskira Previous Member

    "Theory of Submarine Design" by Professor Yuri N. Kormilitsin and Professor Oleg A. Khalizev from the Saint-Petesburg State Maritime Technical University.
    Published in English and printed in England in 2001.
    328 pages of highly technical work by two leading designer in submarine.
    Yuri Kormilitsin use to work at Rubin as a General Designer.
     
  5. amateur mariner
    Joined: Feb 2009
    Posts: 44
    Likes: 1, Points: 0, Legacy Rep: 30
    Location: anywhere

    amateur mariner Junior Member

    Sir, unfortunately I cant understand German otherwise it would have been quite beneficial.Can somebody provide me in English or is there anyway I can get a translated version of this and/or the other mentioned handouts??
     
    1 person likes this.
  6. Olav
    Joined: Dec 2003
    Posts: 295
    Likes: 30, Points: 38, Legacy Rep: 460
    Location: Filia pulchra Lubecæ

    Olav arch. nav.

    Sorry, but the hand-out was written by a prof of mine and so there's only the German version available. The paper is 85 pages so a translation of the entire text unfortunately would be too time-consuming for me at the moment.

    However, if there's a certain topic you're interested in I could do a quick translation of the relevant part/chapter.

    Edit: Contents of the hand-out

    1. Introduction
    1.1. Scope of this lecture
    1.2. Characteristics of submarines
    1.3. Development of military submarines
    1.4. Development of civilian submarines

    2. Hydrostatics of submarines
    2.1. Weight situation
    2.2. Weight and trim adjustment
    2.3. Stability

    3. Hydrodynamics of submarines
    3.1. Hullform
    3.2. Resistance and propulsion
    3.3. Manoeuvring characteristics
    3.4. Model tests and trials

    4. Hull
    4.1. Loads on the hull
    4.2. Pressure hull: Strength, stability
    4.3. Non-pressure resistant areas of the hull
    4.4. Materials, welding

    5. Propulsion plants, energy generation
    5.1. Introduction
    5.2. Battery operation
    5.3. Diesel-electric operation
    5.4. Fuel cell propulsion (AIP)
    5.5. Closed-circle diesel engine (AIP)
    5.6. Stirling engine (AIP)
    5.7. Closed-circle gas turbine (AIP)
    5.8. Steam turbine (AIP)
    5.9. Nuclear reactor (AIP)
    5.10. Other propulsion systems

    6. Safety and rescue facilities
    6.1. Safety philosophies
    6.2. Safety facilities
    6.3. Rescue facilities

    7. Equipment and accomodation
    7.1. Breathable air management
    7.2. Equipment
    7.3. Facilities for the crew
    7.4. Control facilities

    8. Sensors / signatures of submarines
    8.1. Signatures
    8.2. Sensors

    9. Construction, quality management and sea trials
    9.1. Construction of submarines
    9.2. Quality management measures
    9.3. Documentation
    9.4. Sea trials
     
  7. amateur mariner
    Joined: Feb 2009
    Posts: 44
    Likes: 1, Points: 0, Legacy Rep: 30
    Location: anywhere

    amateur mariner Junior Member

    I want to know the basic concept about loading cycles? is there any procedure to predict loading cycles?
     
  8. Guillermo
    Joined: Mar 2005
    Posts: 3,644
    Likes: 185, Points: 63, Legacy Rep: 2247
    Location: Pontevedra, Spain

    Guillermo Ingeniero Naval

    1 person likes this.
  9. amateur mariner
    Joined: Feb 2009
    Posts: 44
    Likes: 1, Points: 0, Legacy Rep: 30
    Location: anywhere

    amateur mariner Junior Member

    I am interested in Chapter 4 which is related to hull part of your document.It will be quite nice if you can send me the english version of it.
     
  10. jehardiman
    Joined: Aug 2004
    Posts: 2,353
    Likes: 171, Points: 63, Legacy Rep: 2040
    Location: Port Orchard, Washington, USA

    jehardiman Senior Member

    Ama,
    Tell us the question you are looking to have answered, and we will be better able to point you in the correct direction. There is very little out there available to the amateur on hull design. Try to get copies of Manned Submersibles (1976 ed) by Busby; and Submersible Vehicle Systems Design (1990 ed), PNA (the 1967 single volume ed), SD&C (the 1969 ed) all by SNAME.

    From a pressure loading cycle point of view, there are two seperate and distinct considerations over the life of a submarine/submersible. High load-low cycle loads and Low load-high cycle loads.

    The first, as Olav mentioned, is based upon dive cycles and is measured in the low thousands for submarines and the hunderds for submersibles. It mainly effects material and fabrication requirements. The second is based upon the seaway, and is measured in the 10's of millions for submarines and low millions for submersibles, and is a concern of the fatigue life of the hull material. No material is best suited for these two different criteria given the other operational criteria (i.e. depth, shock, size, etc.)
     
    Last edited: Feb 13, 2009
  11. jehardiman
    Joined: Aug 2004
    Posts: 2,353
    Likes: 171, Points: 63, Legacy Rep: 2040
    Location: Port Orchard, Washington, USA

    jehardiman Senior Member

    Rule of thumb is 1 to 2 dive cycles per operational day. Suppose you have a submarine with a 20 year life undergoing 2 60 day deployments a year with a tech refresh docking every 5 years. So (20-4)*(2*60*2 ) = 3840 dive cycles.

    Wave cycles are a little different, they are based upon a significant wave period (i.e a wave which causes flexture stress to excede a certian threshold) over the entire life of the vessel as long as it is afloat. Using the above 20 year life example with a 10 second significant wave. (20)*(365.25*24*60*6)=63 million
     
    Last edited: Feb 13, 2009
  12. amateur mariner
    Joined: Feb 2009
    Posts: 44
    Likes: 1, Points: 0, Legacy Rep: 30
    Location: anywhere

    amateur mariner Junior Member

    I am looking to learn the basics about the loading cycles.how to use them to predict the life of different materials?how to use these loading cycles in numerical simulations in order to predict and understand their effects.
     
  13. jehardiman
    Joined: Aug 2004
    Posts: 2,353
    Likes: 171, Points: 63, Legacy Rep: 2040
    Location: Port Orchard, Washington, USA

    jehardiman Senior Member

    That is metalurgy, not Naval Architucture. Go read Chapter IV of Submersible Vehicle Systems Design.

    PS, That sounded a little harsh, so I apologize. What I mean is that while Naval Architecture can give you the loads and cycles a particular structure will see, the actual data of material strength, flexture-limits, crack growth propensity, etc are handled in the materials lab and are not directly addressable by hydrodynamic/hydrostatic simulations.

    You chose a material based upon your desired properties and tune the structure to the materials limits, not the other way around becuase it is too difficult to tune a material to get the desired properties. CF structures are a prime example, as little as 2 degrees off axis fiber orientation can cause a 20% reduction in material strength so you must accept lower loads than you could calculate.
     
    Last edited: Feb 13, 2009
  14. amateur mariner
    Joined: Feb 2009
    Posts: 44
    Likes: 1, Points: 0, Legacy Rep: 30
    Location: anywhere

    amateur mariner Junior Member

    Bu How to predict the loads?What all things need to be taken care of?
     

  15. jehardiman
    Joined: Aug 2004
    Posts: 2,353
    Likes: 171, Points: 63, Legacy Rep: 2040
    Location: Port Orchard, Washington, USA

    jehardiman Senior Member

    All the normal ship strength stuff; primary, secondary, and tertiary loads. Nothing really changes except shell plate normal loads become the dominate factor instead of girder bending (but don't ignore it just like you shouldn't ignore wave slap when calculating surface ship bending loads). Get the referenced editions of PNA or SD&C, they both have fairly good design outlines for pressure hull strength in them.

    The design of hull fittings is a whole other matter though, but can be handled seperatly from the actual pressure hull.
     
    1 person likes this.
Loading...
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.