DB or biaxial

[Roly]

Seems I am always over preoccupied with detail and with the potential reservoir of info available here, to get things right, I can't help myself!

Gerr sayes DB for bulkheads and ring frames and bi-ax for stringers. Then it would follow that bi-ax would be best for keel floors? Given the 0 deg fibre would be parallel with the axis of the floor for athwartship stiffening and the 90 deg as holding down strength (anti peel) for floor, fore an aft?

Or doesn't it really matter using db for both?

[Landlubber]

Roly,

Actually the floor longitudinals are better with 45 bias, the reason being that is the direction of the forces being applied. The boat is trying to bend in the middle, either from the waves or from the fact that it is being displaced. If you look at a boats profile, and place a nice big X from bow to stern, you understand what I am saying.

Sure longitudinal stiffness is important, but if it is created along the actual lines of force, then it is most beneficial.

Don't loose too much sleep over it mate, thousands of boats have been built using 0-90 woven rovings as longitudinals (particularly in Taiwan/China), and they hold together quite well, it is just that they overbuild to obtain this reliability. Most engineered boats are still being built as they feel like it there anyhow, the scantlings supplied are rarely followed.......

[Roly]

Musta read your mind. I just came home with a roll of db625!
Thanks for the reassurance.

[Landlubber]

Good on ya!