Impact testing on various materials

Discussion in 'Fiberglass and Composite Boat Building' started by ondarvr, Nov 18, 2022.

  1. ondarvr
    Joined: Dec 2005
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    ondarvr Senior Member

    A friend of mine did this testing recently. Kind of a "let's see what happens adventure".

     
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  2. gonzo
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    gonzo Senior Member

    That material property is called "toughness". It is the amount of energy it can absorb before breaking.
     
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  3. KD8NPB
    Joined: Mar 2018
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    Location: South Carolina

    KD8NPB Senior Member

    I'd be curious to see production deck laminate.

    approximate;
    skin 450g csm
    bulk 900g csm
    bulk Press in wet ; 1/2" 6 lb PET foam (Airex T92.100 or Armacell GR100)
    bulk 900g csm
    bulk 24 oz WR, 2408 0/9o, or 3610 0/90
     
  4. rxcomposite
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    rxcomposite Senior Member

    usually it is a ball or rounded end of a cylinder as it is more indicative of point load or local impact. With a sharp edge of a cylinder, that will cause shear.
     
  5. ondarvr
    Joined: Dec 2005
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    ondarvr Senior Member

    Yes, in this he was talking about hitting rocks and using what he had.
     
  6. rxcomposite
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    rxcomposite Senior Member

    The video showed he was testing and talking randomly. Airex has the lowest shear strength but the greatest tenacity. Meaning it just stretches and refuses to give up. That is why there is that "rubbery" feel. If you want a flexible boat, use Airex.

    A more exhaustive and scientific test on sandwich laminate was made before and was published in PBB a long time ago. Attached is the inset of the article.

    A complete study of impact testing on various laminates (includes CF) and cored composites and its effect was in the first edition of Marine Composites by Eric Green and associates. Unfortunately, only the second edition can be downloaded in the net. The impact test and formula was omitted. I have the hard copy of the first edition.
     

    Attached Files:


  7. gonzo
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    gonzo Senior Member

    The toughness is the area under the curve for each material. That is the amount of energy it absorbs before breaking.
     
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