Transverse frame calculation

Discussion in 'Class Societies' started by DUCRUY Jacques, May 1, 2010.

Thread Status:
Not open for further replies.
  1. LyndonJ
    Joined: May 2008
    Posts: 295
    Likes: 19, Points: 0, Legacy Rep: 233
    Location: Australia

    LyndonJ Senior Member

    Brent


    But once again your boats are 30 something footers. Others have pointed out that similar steel boats to your design were being built in the Uk and in Holland long before you came on the scene, lots of dutch designes were pulled into shape from long flat fabricated panels which pre-date your claim to originality by many decades. Those same yards knew very well where the limits were for no transverse frames and the max bulkhread spacing.

    Class societies didn't alter ship scantlings for smaller boats, boats have always been their own class. Those class societies are not stupid at all. They just know more than you.
     
  2. Brent Swain
    Joined: Mar 2002
    Posts: 951
    Likes: 35, Points: 0, Legacy Rep: -12
    Location: British Columbia

    Brent Swain Member

    I design to 40 ft . I once pulled together a 47 foot origami boat, which has done a circumnavigation and survived several days of pounding on the rocks in Majorca, with zero damage, but since I screwed my back up building that one, I don't build over 36 feet any more. Don't need the cash or the back pain.
    What I'm pointing out is several much larger boats have been successful in extreme conditions, proving conclusively that larger origami boats are feasible and adequate. How much larger is open to debate, but as I have pointed out , there remains the option of building in origami, then adding structural later with a huge savings in time and money.
    The 'Experts" have been proven wrong, time and time again, on many points of design, as they are again this time.
     
  3. dskira

    dskira Previous Member

    Well the difference is: you admit that you have absolutely no clue how it work, engineering speaking, and then you "think" adding structural members later on will save money.
    The expert, Brent, contrary to you they knows in advance what to do and what will happens.
    You just admit your own ignorance on what you do. You just do it and hope for the best.
    Now please back your comment about :
    Show where they are wrong. Please no frames discussion, it is ridiculous at that point. Where the expert are wrong. Who are the expert. Name please.
    For example I can say: Brent is wrong, because he admit himself he has no clue how the hull work together (read above)
    But you? Name please.
    If I go to a designer and he told me about the construction method:
    I will run for my life.
    But thanks Brent, you finally show your true color: you have no clue.
    You certainly bang the steel and weld it and put a deck, I don't discuss that, but it stop at that point. You don't know how it work, so you give as an exemple the come along of twelve tons, or the rock in Majorca. It's little short on the sleave!
    Origami means the art of folding paper, not conical development.
    Try the conical development in Russian, you will be more esoterique.

    Daniel
     
  4. apex1

    apex1 Guest

    Why should I tell someone YOUR drivel?




    So then,

    thanks for the compliment!.........:D
     
  5. LyndonJ
    Joined: May 2008
    Posts: 295
    Likes: 19, Points: 0, Legacy Rep: 233
    Location: Australia

    LyndonJ Senior Member

    Well I can see how people get frustrated by your reasoning.
    Emotion and feeling and anecdotal tall tales are not facts.

    You are a long way from your statement declaring transverse support is not needed up to 60 feet.

    I'm actually a civil engineer like the designer of your first boat that you had such a bad experience with Kinney). I am in NA work becasue I became an FEA structure analyst and I have done enough ship and boat work to know that you are quite lost in yor structural arguments.


    Anyway I am back to hydro generation now, getting it wrong no doubt with surge tanks, bridges, dams and pylons.

    We could save a lot of material with the BS approach.
     
  6. bhnautika
    Joined: Feb 2006
    Posts: 852
    Likes: 57, Points: 38, Legacy Rep: 571
    Location: australia

    bhnautika Senior Member

    It is interesting here we have a man willing to put forward his ideas with empirical evidence to back his hypotheses but so far no one willing to put up any calculations to show where it is flawed and why. Where are figures, defections, shear and stresses, the science and the engineering? Talk is cheap and saying “because” is not a very satisfactory professional answer. Maybe its time for some to warm up the pencil and paper, calculator, computer or what ever weapon of choice and go to it, proof, kudos and an education for all.
     
  7. DUCRUY Jacques
    Joined: Nov 2009
    Posts: 75
    Likes: 1, Points: 0, Legacy Rep: 15
    Location: france

    DUCRUY Jacques Junior Member

    As I am not a specialist, it is not easy for me to try understand the theory of Brent Swain.

    In a roman church, I agree, the vault is in compression, but it seems to me that the plating of the boat is not comparable with a stone vault ...

    Nevertheless, do you know the method "Strongall" of Meta in France : a thick plating of aluminium, with no longitudinals and no frames (only some bulkheads), but the hull is very heavy !
     
  8. apex1

    apex1 Guest

    A very polite description, really.

    And why doing all the math again and again?
    You should know that we had all that drama several times now, here:

    http://www.boatdesign.net/forums/metal-boat-building/welding-steel-hull-23055-17.html#post292784

    and on other occasions.
     
  9. Brent Swain
    Joined: Mar 2002
    Posts: 951
    Likes: 35, Points: 0, Legacy Rep: -12
    Location: British Columbia

    Brent Swain Member

    Many boats were designed, by experts with the same flaws that Kinney designed in , a rudder far too far foreward, a surfy long overhang, a poorly balanced hull shape, etc etc. All were designed by people considered the worlds top experts. It was generally accepted as the "Only , modern" way to design a hull. All could have been drastically improved by moving the rudder further aft, as I has seen as an obvious improvement, with zero cruising experience.I didn't dare second guess the "Experts" of the time.
    We watched them move the mast aft, then declare it was the onlh way to go , the only thing that would sail well. In a few years they move the mast foreward again declaring it was the only way to go , the only thing that would work. This cyle repeats itself regularly. In the 70's a local sailmaker described "Jiffy Reffing", which some were calling"California reefing" , the latest breakthru, which was the same reefing system Sir Francis Drake used on his circumnavigation.
    What have the 'Experts" done to resolve the biggest obstacles first time cruises experience, time and money? The exact opposite of what needs to be done! They have pushed the time and expense of building a good practical seaworthy boat ever higher, further beyond the reach of many would be cruisers, wrecking many cruising dreams and wrecking many families in the process. I am one of a small handfull of designers attempting to resolve the main obstacle wannabe cruisers face, while the rest simply invent more roadblocks to throw in front of cruisers, with their elitist agendas.
    Every time a round the world racer loses her keel in the southern ocean, it is another example of the fallibility of the worlds most reknown 'Experts" using the very same calculations you advocate as a substitute for simply using as your guide , what has proven successful in the past. It is a result of some being so gullible as to buy the "Leave your brains at the door and use our calculations instead" philosophy.
    You can calculate til hell freezes over , but you will never find calculations as reliable as that which as proven itself over tens of thousands of miles in all weather conditions.
    I weld the longitudinals on while the plate is flat on the ground. When I pull the hull into it's longitudinal curve, the longitudinals are under extreme compression. The only time they will ever be in tension is when the curve is all pushed out of them and part of the hull is pushed in ,well beyond flat.This is definitely not the case with straight transverse frames .
    For those of you too dense to get this , you are not the only ones on this site. There are others who get it.

    It's interesting that Daniel still flatly refuses to tell us how many years he has lived aboard a steel boat in winter, how many years he has maintained a steel boat of his own, or how many tens of thousands of miles of ocean cruising he has done, or how many steel boats he has designed and built with his own hands, so we can base our assessment of his expertise, on his hands on experience.
     
  10. dskira

    dskira Previous Member

    I asked one fair question: name some expert, your answer is to attack me about experience. My experience had nothing to do with my question.
    I keep it for myself and share it with friends in this forum and clients. Not with a lunatic.
    You can't stay on the topic, focus and technichal. You just write pages with no mining.
    Since your experience is all in your head, and reading your post I don't think you are genuine and I really think you are slightly off in the head, why I should answer to you?
    What you state is gibberish, untrue, and repetitive without any backing.
    You give us no name of expert as usual. As the matter of fact the only one you named is me:p And Kinney, with a very stupid and untrue assessment.
    I don't ask for people to follow me like you, I do not have the God syndrome like you.
    Sorry but you can say what you want about me, I will not visit you in your sick world by answering to you.
    You sure had a lot of dream miles in the winter of your imagination. But it is your right after all to be delusional, and I don't care.

    Like on the other thread you highjacked with your rambling, I am out of this one since you pathetically can't answer one simple question: Name the experts.
    To late anyway
    Daniel
     
  11. bhnautika
    Joined: Feb 2006
    Posts: 852
    Likes: 57, Points: 38, Legacy Rep: 571
    Location: australia

    bhnautika Senior Member

    Apex1 I read the welding a steel hull thread and I could not find any calculations on this building method and its structural integrity, I could only find a diagram and formula posted by “ad hoc” on bending stress, this was in relation to whether a weld was in compression or tension around the neutral axis and was a some what simplistic jab. You mention other occasions so maybe these may be better.

    Brent, designing is full of hits and misses and experts and pro’s are only human, everybody loves a bit of “schadenfreude” but be careful you don’t become them.
     
  12. Ad Hoc
    Joined: Oct 2008
    Posts: 7,324
    Likes: 1,218, Points: 113, Legacy Rep: 2488
    Location: Japan

    Ad Hoc Naval Architect

    So, when shown the simple figures, stresses, science etc your retort is:

    Or is it that just

    One can only conclude you have a very limited understanding of science and engineering, from your retort. As such more formulae and figures will serve no purpose since you fail to grasp the very simple basic principals of structural engineering.

    So, in the language you do understand.

    Take a curve, an arch, if you like, even better call it a panel of plating. Take this panel of plating, that is curved, applied a lateral load mid span. It does not matter whether a point load or UDL. What happens, it bends. Apply the same load to a flat horizontal plate, what happens, it bends. Which bends the most, the flat panel...no mystery there. This has been proven many times and is used frequently in ship design and other disciplines.

    Now apply an in-plane load. That means apply a load along the edges into the plate, directly into the plate edges (not perpendicular to the panel surface). What happens, the plates resist and then eventually reach a limit of instability called buckling.

    So, the flat plate, this buckles under this in-plane load and the curved panel buckles too. Oh but wait, the curved panel is already curved, ergo it is called pre-buckled. In other words, the load that is applied to the flat plate which eventually causes it to buckle, the same magnitude of load if applied to the curved plate what happens? Well, it is already buckled, it has a curve....so what happens...it deflects much greater and so much more easily...you can try this with simple cardboard, the same you use to form your origami shapes!. The instability of the curved plate from an in-plane load is significantly reduced. In other words, it fails much quicker. Because it has technically already failed.

    So, the boat that has endless curved panels and no internal framing what occurs…..ahh..i see, the boat says, oh hang on, please do not apply an in-plane load to me, just a lateral load, because I can take more of it. Er…..hmmm...well, I don’t know about you, but boats do not cheery pick the loads they want to apply, nor where to apply them. Boats are subjected to a myriad of loads and with 6 degrees of freedom and must be taken into account.

    To assume a boat is subjected to one load and one type of loading is negligent at best and delusion at worst.

    Structural failure is not just about tensile or compressive loads. It can basically be broken down in 4 main categories:

    1 Direct fracture
    2 Fatigue
    3 Instability
    4 Deformation.

    But hey, why bother learning about this when talk is cheap!
     
    1 person likes this.
  13. LyndonJ
    Joined: May 2008
    Posts: 295
    Likes: 19, Points: 0, Legacy Rep: 233
    Location: Australia

    LyndonJ Senior Member

    Impartial and useful Empirical Evidence sufficient to condemn transverse framing in boats to 60 feet?

    Or lots of creative reasoning, misapplied logic and a propensity to get the engineering reasoning wrong.

    The last point is the dangerous one. If your reasoning is wrong and you scale your designs accordingly then somrthing will go wrong. Telling people with no engineering experience that normal engineering doesn't apply becasue its all in compression is just BS. :)
     
  14. bhnautika
    Joined: Feb 2006
    Posts: 852
    Likes: 57, Points: 38, Legacy Rep: 571
    Location: australia

    bhnautika Senior Member

    Ad Hoc I think you are mixing the past and the present. In your post 248 in the Welding a steel hull thread above it was about welds being in compression or tension not about the building method as at that time you were not familiar with it as you state in post 291 a week later
    “Brent
    I don't know anything about these "origami" boats...I'd love to see them being constructed...got any pic's?”
    So here we are in the present I assume you have seen how they are constructed and by your somewhat condescending rant have identified some possible weak points but you haven’t been specific (something I should of known obviously from the diagram). So now after writing paragraphs about your knowledge of beam and plate theory, how about some real work, a diagram showing forces and load paths for a cross section and plan view (this would also get rid of any ambiguity to what is being talked about). Which are the problem areas and what their weakness are. I am interested in how much work is being done by transverse frames compared to the hull shell and longitudinal members.
     

  15. bhnautika
    Joined: Feb 2006
    Posts: 852
    Likes: 57, Points: 38, Legacy Rep: 571
    Location: australia

    bhnautika Senior Member

    LyndonJ he is saying transverse framing is not needed and there is a better way whether that is true is up to others to prove. That is the scientific way, go hard, go fast, rip it down if you can and be prepared for the questions to follow.
     
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.
Thread Status:
Not open for further replies.