Volynkin, Dmitry

Cyclic Performance of Shear Links With Contact Stiffeners

Abstract eng:
Shear yielding links are widely used as seismic energy dissipation components in eccentrically braced frames, linked column frames and in coupled shear walls. Typically, shear links are strengthened with intermediate stiffeners welded to the web. The stiffeners are useful in delaying the onset of buckling and associated failure modes as the shear link is cycled with increasing inelastic deformations. However, these intermediate stiffeners have been shown to be a source of early fracture initiation in the web at the stiffener to web welds. The typical mode of failure of shear links that do not exhibit web buckling is a web fracture that initiates near the stiffener welds. This paper examines the possibility of not welding the intermediate stiffeners to the web (ie welded only to the flanges) and instead to rely on the contact interface between the stiffener and the web; with pairs of stiffeners placed at each location to suppress web buckling out of plane in both directions. Large scale experiments were conducted on two links, one with stiffeners conventionally welded and another with flange welded only contact stiffeners. The links consisted of 42in long W14x48 sections stiffened on both sides by stiffeners that dimensionally conformed to AISC specifications. Both links exhibited stable hystereses. The rotation at which the strength of the link with contact stiffeners degraded was 0.114 rad, well above the 0.090 rad achieved by a conventionally welded link. The contact stiffeners also reduced the overstrength developed by the active link under high shear demand. These positive outcomes indicate the potential for adoption of contact stiffeners for design, the procedures of which would only require minor modifications to fabrication procedures and minor implications on cost. For larger wide flange links, code requirements dictate the use of stiffeners on both sides of the web, in any case, meaning cost neutrality.

Contributors:

Clifton, G. Charles

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:

Text je chráněný podle autorského zákona č. 121/2000 Sb.