[Towertalk] Strength of fiberglass.

Don Havlicek n8de@thepoint.net
Thu, 28 Feb 2002 09:50:01 -0500

Solid fiberglass rod is HEAVY .. much heavier than the same
length/diameter of aluminum.

WB9UWA Jim Shaffer wrote:
> Hi All,
> I am designing a VHF yagi array and strongly considering using fiberglass
> for the booms. Does anyone have a strength rating for fiberglass that is
> useful
> to the layman? For example, if  10 feet of 1/2" solid rod fiberglass is held
> horizontal,
> how many pounds of weight would cause the end of the rod to deflect 1 foot
> (stiffness rating)?
> Also, and probably of greater importance, because even PVC can be guyed
> if done properly, how much weight at the end of this pole does it take to
> cause
> catastropic failure of the fiberglass (yeild strength)? I have heard stories
> of fiberglass antennas
> bending way over in the wind and recovering fully. This is the sort of low
> windload
> design I have in mind. I have some industry standard numbers for fiberglass,
> but they
> are not something that I can make sense of. The strength rating is something
> like 30,000 PSI.
> 73, Jim Shaffer, WB9UWA.
> _______________________________________________
> Towertalk mailing list
> Towertalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk