Effective length factors for solid round diagonals in guyed communication towers.

摘要

The objective of this investigation is to determine the effective length factors for solid round diagonals in all-welded communication towers. A total of thirty-three welded towers were tested in the investigation with all the towers in a horizontal position and concentrated load at mid-span. Two specimens were fixed with strain gauges on every member, while all other specimens were tested with strain gauges fixed on only one panel. After the test, tensile specimens were cut from the diagonals of the tower, and tested for the yield stress and tensile strength. Axial forces in the diagonal and leg members were calculated based on the actual yield stress and strain readings, assuming an elastic perfectly-plastic stress-strain curve for steel. The buckling loads were determined from the maximum axial forces in the tested members, and effective length factors were calculated according to CSA-S37-94 Standard and AISC-LRFD Specifications. The average effective length based on CSA-S37-94 for cross-braced diagonals is 0.35 of the total diagonal length, while the effective length is 0.37 of the total diagonal length based on AISC-LRFD. The effective length factor for single-braced diagonals is 0.50 and 0.56 based on CSA-S37-94 and AISC-LRFD, respectively. (Abstract shortened by UMI.) Paper copy at Leddy Library: Theses u26 Major Papers - Basement, West Bldg. / Call Number: Thesis1999 .S86. Source: Masters Abstracts International, Volume: 40-03, page: 0750. Adviser: M. K. S. Madugulor. Thesis (M.A.Sc.)--University of Windsor (Canada), 1999.