# composite bowsprit

Discussion in 'Multihulls' started by ABD, Mar 26, 2018.

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1. Joined: Feb 2018
Posts: 6
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Location: Argentina

### ABDJunior Member

Hello everyone I am designing a composite bowsprit and had a few questions. As a brief problem statement: the bowsprit will have a variable cross section, starting as a C section and switching to an M section (more or less). As I was not able to determine the loads acting on the tack, because the boat it is a cat, i used the breaking load of the furler (45 KN), as it will be stayed the bowsprit will have compressions loads only. In total the compression load will be 65 KN. The transverse area will be of 4125 mm2 and the moment of inertia 33684779 mm4. The total laminate will have 11,28 mm thickness. the sequence is the following

1 - E-TLX 2200 (0/+45º/-45º) GLASS

2 - C-L-09002 x 5 (0º) CARBON

3 - E-WMV 1815 (0/90) GLASS

4 - E-WMV 1815 (0/90) GLASS

5 - C-L-09002 x 5 (0º) CARBON

6 - E-TLX 2200 (0/+45º/-45º) GLASS

I obtained the laminate moduli and through the displacement obtained the tensions on each of the plies, and verify for each against the TSA-HILL criteria and ultimate tensions for compression. Than I obtained the critical load using Euler formula and the laminate moduli and compare against the calculated loads for the bowsprit. Up to that point so far so good the problem is when I calculated the critical tension for buckling using the laminate characteristics that it gives me a SF much more closer to the load than Euler's so I am not sure if its a problem with the equation or the laminate, plus the laminate its very thick so it may be an overkill. Any thoughts???? The weight its not the most important factor

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