Sorry if this is a dupe, but I never saw it reflected back to me...
Many thanks to Kurt, K7NV, for his recent tower load analyses.
Verrrry interesting...
In his examples of guyed Rohn 45 with the base in concrete, the
weakest point was the lower sections, related to movement of those
sections.
His analyses assume the usual standard of the guys being adjusted
to 10% of their ultimate strength, in these cases 400 lb for 3/16
EHS or 4000 lb. Phillystran. When larger guys were used, tensioned
at 600 lbs., the safety factor was improved, not surprisingly.
This brings me to the following: I wonder if there is
engineering/scientific basis for the 10% tension rule? What if 3/16
EHS or 4000 lb Phillystran were tensioned to 600 lb? Is this unsafe?
Tnx/Barry
--
Barry Kutner, W2UP Internet: w2up@mindspring.com
Newtown, PA FRC alternate: barry@w2up.wells.com
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