Composite utility pole

A utility pole having butt and tip portions made by a process comprising the steps of:

• determining the length of the pole to be fabricated;
• selecting a mandrel having a representative diameter and length on which to make the pole;
• establishing test stations spaced incrementally from the tip portion to the butt portion;
• applying resin-coated, fiber reinforcing strands over the mandrel;
• determining, at each of said test stations, if the thickness-to-diameter ratio for the wall thickness of the resin-coated, fiber reinforcing strands laid on said mandrel is equal to or less than 0.015;
• the step of determining if the thickness-to-diameter ratio is satisfied being accomplished at all test stations before proceeding with the remaining steps of the process;
• applying additional circuits of resin-coated, reinforcing strands as are necessary to satisfy the thickness-to-diameter ratio at the first test station;
• calculating the stress resistance at each of said test stations by virtue of the formula:
• ##EQU11## determining if the acceptable stress resistance under a predetermined load calculated at said same test station is greater than the stress resistance required for said test station;
• applying additional circuits of resin-coated, reinforcing strands as are necessary to satisfy the required stress resistance at said test station before proceeding;
• calculating the critical load at each of said test stations by virtue of the formula:
• ##EQU12## determining if the actual loading to be applied to the pole is lower than the critical load at which the pole would buckle at said station;
• adjusting the acceptable stress if the preselected, rated load is not less than the projected failure load and the rated load does not exceed the projected failure load by a predetermined margin of safety;
• applying additional circuits of resin-coated, reinforcing strands as are necessary to assure that the calculated and adjusted maximum stresses satisfy the margin of safety criterion;
• continuing the testing and applying steps at each test station until the pole is satisfactorily laid up on the mandrel;
• curing the resin to complete the pole;
• and
• recalculating the thickness-to-diameter ratio at all test stations after any additional circuits are determined to be necessary as a result of any of the remaining steps of the process.