Research On Bearing Capacity Of Separated Tube-Gusset-Plate Joints With Small Included Angles In Narrow-Foundation Tubular Towers

Narrow-foundation tubular tower has a reasonable structure, a nice shape and can effectively reduce the occupied area. For normal K-typetube-gusset-plate joints, there is a problem that once the included angle is smaller than lower bound, there is no appropriate computing method in the existing codes to well describe the bearing capacity. Besides, normal K-type tube-gusset-plate joints cost more as a result of a too long gusset-plate. This paper put forward a new structure form called separated tube-gusset-plate joints and studied the application in narrow-foundation tubular towers.Based on 230 separated tube-gusset-plate jointscreated by AN SYS program, parametric studies of the bearing capacity was carried out, which contain the ratio of chord diameter to thicknessD/r, the ratio of gussetplate length to chord diameter B/D and the includedangleθ. In addition, the ratio of space ofplatetogussetplate lengtha/5 were considered for separated tube-gusset-plate joints. Research shows that the bearing capacity of Y-typetube-gusset-plate jointsand separated tube-gusset-plate joints increases with5/Dand decreases asD/Tincreased. Moreover, the bearing capacity of separated tube-gusset-plate joints decreases as a/Bincreased.Experiment study and corresponding FEA were done, which including 3K-typetube-gusset-platejoints,12 Y-type tube-gusset-plate joints and 12 separated tube-gusset-platejoints. Comparing the results of experiment and FEA throughfailure mode, bearing capacity and stress distribution shows that Y-typetube-gusset-plate joints broke down because of the depressions occurred on the chord near the gusset-plate. However, for separated tube-gusset-plate joints, in the side of bracing members which under pressure, a large deformation occuredon the chordwhere without gusset-plate. And in another of the chord member, the tube raised. Furthermore, the change of bearing capacity along with each parameter is essentially consistentwith the results of parametric studiesCalculation formulas for Y-typetube-gusset-plate joints were suggested on the basis of von Mises yielding criterion.By Comparing the calculation formula solution with the finite element analysis solution and the experiment result, it is shown that the Calculation methods can well capture the bearing capacity of a Y-type tube-gusset-plate joint.And then the calculation formulas for corresponding sepprated tube-gusset-plate joints were developed by summing the effects of a/B. Finally, It is shown that the Calculationformulas can well capture the bearing capacity of separated tube-gusset-plate joints by comparing the results of the experiment and the formulas.