Laminate Layup

[dlynch]

Hello all

Im currently creating a presentation for a degree project, about taking a run of the mill vessel such as a moody, and then suggest an alternative laminate layup schedule that would serve the purpose better.

The problem is i have spent quite a while speaking to design offices, brokers and manufactures to extract a schedule, but of course they want to restrict what the public know about their technical data.

Any relevant sources or ideas would be appreciated.

Regards Dave Lynch

[SailDesign]

That sounds a little nebulous. When you say "serve the purpose better", what purpose are you referring to? If it is that of a boat that must be production-built at low-ish cost but still be relatively strong for its weight, then you may have some trouble bettering Moody'd techniques.
If you have a pre-defined purpose for the boat (Arctic travel, coral-bouncing, etc.) then you can have fun designing a new laminate.
As far as references go, try "Modern boatbuilding materials and methods" by Steve Sleight, look at the ABS "guide to building and classing offshore racing boats" and at Dave Gerr's ""Elements of Boat Strength".
Steve

[dlynch]

Thanks Steve

Sorry i didnt make the question clear.

The aim is to alter the schedule i.e. use stitched quadraxial rather than laying down extreme amounts of chopped strand, just to get the same strengths required.

Doing so will save hull mass and hopefully give the vessel better performance without to much design changes.

All i need is an existing schedule that has potential to be improved.

Regards

Dave Lynch

[SailDesign]

Dave,
Why not start with the boat, a rule (even Lloyds will do to start with) and calculate basic laminate. Then you have a starting point for improvement.
Steve

[Not A Guest]

Most commercial layups are based on economics not weight.

I think you would be better served to take a set of scantlings like Gerr's and improve them based on weight.

Remember that "strength" covers several issues including stiffness, static strength, and dynamic strength (toughness).

[gonzo]

Many boat manufacturers publish their laminate scantlings as part of the advertisment.
http://www.skinautique.com/
http://www.regalboats.com/
http://4wings.com.phtemp.com/tip/core.html
http://www.shannhttp://www.hallberg-...com/39tp_c.htm

[dougfrolich]

"Fiberglass Boat Design and Construction" by Robert Scott availible thru S.N.A.M.E. is short and sweet in its content, I would recomend it.

[BrettM]

A note on quads, They sound good on paper but are probably a little more of a fashion material. It is my belief that in most (not all) cases that there is one fibre orientation that is not really adding to the laminate strength due to the aspect ratio/loadings of the panels in question. (Always try to get the bulk of the laminate running across the small dimension of the panel). You will also find that the quads do not tend to lay on compound curves very well. A triax is often a better bet on both respects.

[dlynch]

Just a note

Thankyou all for your help, comments and sources of info.

I have just completed the presentation, all went to plan

Regards

Dave Lynch