Yield-Link Moment Connection
(Protected by US and foreign patents and other pending and granted foreign patents.)
Bolting
To account for the connection rotation, all shear plate bolt holes (except the central bolt) shall be slotted to accommodate the connection rotation. Beam web and flange bolt holes shall be standard size holes.
To account for W-beam section depth tolerance and variation, Yield-Link flange-to-column flange bolt holes can be oversized or slotted holes for 2-piece Yield-Links since the shear tab is resisting the shear loads; Yield-Link flange-to-column flange bolts are only designed for tension.
Yield-Link stem-to-beam flange bolted connection shall be pre-tensioned. However, no surface preparation is required since it’s not a slip critical connection. Nevertheless, the contact surfaces between the Yield-Link stem and beam flange shall not be painted since this was how prequalification testing was performed.
Welding
For Yield-Link moment connections, since the design demand is higher than traditional connections (i.e., use of Rt and Fu for Link capacity calculations) the shear plate-to-column weld and stiffener/continuity plate to-column welds can be double-sided fillet welds. These welds are non-demand critical welds for the Yield-Link moment connection.
Yield-Link Moment Connection Additional Applications
Slope Beam Application
At the roof level, structural steel beams often need to be sloped to accommodate drainage. There are many solutions for this application. For example, steel beams can be built up with sloped WT sections welded on top of W-section beams, or beams welded at an angle to the column flange. For the Yield-Link moment connection, Simpson Strong-Tie has evaluated the slope connection using our advanced non-linear finite element programs to validate the Yield-Link moment connection performance. Below are two possible solutions for W-section beam and column connections. Please refer to the installation detail sheets for more information.
Currently, Simpson Strong-Tie has evaluated these two solutions for a beam slope of approximately 2.4° (rise over run of ½˝ per foot or less). Contact Simpson Strong-Tie for applications with greater degree of angle. Link to column bolting requires pretensioning for sloped beam applications.
Multi-Axis Moment Connection
In many cases (such as corner and interior connections), moment connections are required in both directions of the column. Typically, if a moment connection is connected to the column web, the connection is not very effective. This is primarily due to the smaller moment of inertia in the column’s weak axis when it comes to attracting the forces to the connection. To remediate this issue, boxed column, boxed W-shape section columns and flange cruciform columns are used and are prequalified for SMF/IMF connections in AISC 358. To keep the similar detailing, features and benefits for multi-axis moment connections, flange cruciform columns can be used for the Yield-Link moment connections. Welding between the WT sections to the W-Section web can be double-sided fillet welds sized to develop minimum of 1) the column shear strength or 2) the maximum shear that can be developed from the Yield-Link moment connection. Figures below show the Yield-Link moment connection application in the different framing cases. Please contact Simpson Strong-Tie if you need any assistance regarding these situations.
