Jones, Audsley

Out-Of-Plane Buckling Behaviour of Brb Gusset Plate Connections

Abstract eng:
This paper develops a model of the beam-column joint, gusset plate, connection region and the encased portion of the BRB to determine out-of-plane sway buckling capacity. The model was calibrated and a sensitivity study was undertaken. The model considered the flexural stiffness of each element in the system. A global stiffness matrix was developed from element stiffness matrices including the gusset plates, connection transition regions, and the BRB. Stability functions were used to consider the effects of axial forces on the members to allow a more accurate stiffness matrix. The stiffness matrix was modified to consider the effects of beam-column joint rotational stiffness and BRB end rotational stiffness. The buckling capacity of the system was found when the axial force applied to the stiffness matrix resulted in the matrix no longer being positive definite. The model was then used to determine the influence of the individual stiffness elements in the system on the buckling capacity. It was found that for a particular BRB frame, increasing gusset plate stiffness results in the largest improvement of buckling capacity. It was also found that decreasing BRB end rotational stiffness results in the largest decrease in buckling capacity. Because of the non-linear relationship between element stiffness and buckling capacity, it was shown that increasing an element’s stiffness can have diminishing returns once the element is sufficiently stiff relative to other elements. This indicates that for some BRB frames, increasing gusset plate stiffness to prevent out-of-plane sway buckling will not increase buckling capacity as high as what is calculated from other gusset plate buckling capacity methods. Finally, it is shown that using assumptions described in the paper, effective length factors may be considerably greater than unity for diagonal braces, and may be considerably greater than 2.0 for chevron braces.

Contributors:

Lee, Chin-Long

Conference Title:

Proceedings of the 16th World Conference on Earthquake Engineering

Conference Title:

16th World Conference on Earthquake Engineering

Conference Venue:

Santiago (CL)

Conference Dates:

2017-01-09 / 2017-01-13

Rights:

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