Composite panels for Bulkheads, Decks etc

Discussion in 'Boat Design' started by Mat-C, Dec 4, 2007.

  1. masalai
    Joined: Oct 2007
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    masalai masalai

    I think rwatson & Roly may have missed the point I was making. It is a comparative test against the original material (standard) and the new options as to the appropriateness of these materials in effecting a repair/substitute for the original standard.

    A simple on the job comparison done in a jiffy.
     
  2. Roly
    Joined: Jul 2005
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    Roly Senior Member

    A simple on the job comparison done in a jiffy.

    To do adequate "due diligence", dropping a wt from height is only going to give you limited info.IMHO. I would be more interested in deflection for "x" loading and the change in "X" over "N" M/Nano loadings. Shear strength of both,Distruction in tension for both,perhaps even peel, depending what you are looking for.
    I have been thru this thought process to re-engineer my boat. I am happy with the result. But I wasn't replacing materials with materials of unknown characteristics. So no need to do testing.( Of which the conclusions would be moot) I lie. We did comparative epoxy adhesion tests to various M.C's on timber.But that was all.

    Hey, only my 2cw.You can shoot me for it.
     
  3. masalai
    Joined: Oct 2007
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    masalai masalai

    My point was to Mat_C, the thread instigators question, being the topic? It seemed to me he had the technical advice (not my field) and was after some simple comparisons. On re-reading his post, maybe more than that. Other than detailed technical analysis and consulting by experts not enough information beyond practical demonstration done on site to satisfy personal doubts and worries.
     

  4. rwatson
    Joined: Aug 2007
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    rwatson Senior Member

    Point taken Masalai - in that you were talking about comparison with an existing proven standard, and then Rolys reply was along the lines that I was thinking.
    Really, there is a limitation to the value of mere calculations, and in real life the only certain way to prove a concept is to base it on surviving boats - because as so often mentioned previously, the 'average' boat hull has more to do than just keep all the gear afloat at speed.
    Dont forget, it is also up to the owner/operator to specifiy the usage envelope - and that can vary between ultimate speed performance in calm water through to ice-breaking capability in heavy seas. All points of hull strength between the two extremes could be regarded as 'valid' specification.
    But, unless an "adviser", or the designer is prepared to put his professional indemnity insurance on the line, I wouldnt be prepared to put my life and investment at risk.
    Matt-C - if you get conflicting advice from a couple of advisers - get them to give you one or two examples of surviving boats with similar specs - if they cant, ignore them.
     
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