Yield Link for Providing Increased Ductility, Redundancy, and Hysteretic Damping in Structural Bracing Systems

摘要

A yield link connection for use in bracing structures against lateral loads, the connection comprising a first structural member fixed to a base or foundation, and to which a yield link is connected. The yield link connects the first structural member to the structure in need of bracing. The yield link is created by cutting out a portion of material from a standard rolled steel structural section. The shape and dimensions of the cutout are designed so that the remaining elements of the yield link become separate bending elements. These separate elements behave as fixed-fixed members with predictable yielding, creating four plastic hinge zones around the cutout. High hysteretic damping is achieved through designing the cutout so yielding occurs in a large amount of the steel volume remaining adjacent to the cutout. The cutout is further designed so that yielding occurs in the yield link before it occurs in the first structural member. Clearance is provided between the first structural member and the yield link to limit relative movement between the members to a predetermined amount. Should the yield link need to be replaced after an episodic event, removal of the damaged yield link is easy compared to prior art.

主权项

1. A lateral bracing system used in constructions, the lateral bracing system being capable of mounting to a first surface at a first end and capable of mounting to a second surface at a second end, the lateral bracing system comprising:
a first member including a first rolled structural member including a first web as a central portion of at least one of a “W,” “H” or “C” shape, a first long axis of the first member being oriented vertically, the first member being connected to the first surface; a second member including a second rolled structural member oriented having a second long axis parallel to the first long axis of the first rolled steel structural member, having a planar portion as a second web of the second member in mating contact with the first web of said first member and having a fixed connection to the first web of said first member, having a pinned connection to the second surface, and having material removed to form a void in the second web the second web being sized such that forces acting perpendicular to the long axis of the first and second members and acting substantially parallel to the second web result in portions of material of the second member remaining on either side of the void yielding primarily in bending of the material of the second member remaining on either side of the void, based on structural sections of the material remaining on either side of the void rather than gross section properties of the second member without said void; wherein the second member is captured between projecting elements of the first member such that movement of the second member is limited by the projecting elements of the first member; wherein the void in the second member is sized in a manner that causes the second member to yield under a predetermined magnitude of applied lateral force, such force being lower than that which would cause the first member to yield and; a third member, substantially identical to the second member, to include a void therein, is attached to an opposite side of the first member, the second and third members being aligned and sandwiching the first member having the voids in the first and third members sized such that yielding occurs in the second and third members together before yielding occurs in the first member.