How do you Determine Composite Thickness?

I am a senior mechanical engineering student working on building a solarpowered double hull boat for a design competition (solarsplash.com). Ive been doing a lot of research on fiberglass and kevlar propoerties and construction techniques. Right now i am planning on doing two moldless foam-core hulls of most likely kevlar with a thin fiberglass veil.

What i need to know is how calculate/determine the composite thickness i am going to need. Ive read that you need multiple layers which makes sense, but i am not sure how to calculate the total thickness of the laminations. If someone could point in the right direction, id appreciate it. Thanks.

 

If you have the patience to learn it, VectorLam http://vectorply.com/lamdesign/vectorlam_sw.htm is an excellent, free tool for laminate design. It runs nicely inside Excel, about 5 MB of code and databases.
It is just a tool, though. You give VLAM a few laminates, it'll tell you what to expect from each of them given perfectly skilled workers, an ideal shop environment, etc. It can't tell you what the layup schedule should be for a target strength, but is very good for comparing the properties of laminates that you yourself have designed, and for checking them against ABS/DNV scantlings. It's the best tool I've found for laminate design so far, but take the results the same way you'd take FEA output- with a touch of caution and common sense.

 

Read Dave Gerr's "The Elements of Boat Strength". It is all there.

 

Scantlings based on the build material, for the non-engineer like me.

This might give some numbers to compare your results to.

 

Laminate thickness & laminate design software

Poster deleted feeling better posted in a different category.