Seismic braces including pin and collar connection apparatus
A connection apparatus includes a frame-side member securable to a steel structural frame, a brace-side member securable to a seismic brace, and a coupling element that secures frame-side and brace-side members to each other. By way of example, the connection element may provide a hinge-type connection, which substantially isolates a seismic brace from nonaxial loads. As another example, the connection element may be a ball-and-socket type connection, which substantially isolates a seismic brace from nonaxial loads and absorbs any shear and moment applied thereto when the seismic brace drifts out of an intended plane of the steel structural frame. The connection element may also include a collar to stabilize the brace-side member and prevent shears and moments from causing the same to buckle in an unintended direction. Methods of installing and using the connection apparatus are also disclosed.
1. A seismic brace, comprising:
an elongate, substantially hollow exterior shell;
a buckling-limiting element within said exterior shell;
at least one yielding core including:
a central region located centrally within said buckling-limiting element and at least partially spaced apart therefrom; and
two end regions at opposite ends of said central region, said two end regions extending beyond ends of said buckling-limiting element and said exterior shell;
at least one connection element at at least one end region of said two end regions of said at least one yielding core; and
a support collar laterally surrounding at least a portion of a length of said at least one end region and including:
a first end secured to a portion of said at least one connection element; and
a second end overlapping at least an end portion of said exterior shell.
2. The seismic brace of claim 1 , wherein said at least one yielding core comprises a substantially planar member.
3. The seismic brace of claim 1 , wherein each end region of said two end regions of said at least one yielding core is substantially planar.
4. The seismic brace of claim 1 , wherein said at least one connection element comprises at least one end region of said two end regions of said at least one yielding core.
5. The seismic brace of claim 1 , wherein said at least one connection element is secured to at least one end region of said two end regions of said at least one yielding core.
6. The seismic brace of claim 5 , wherein said at least one connection element comprises:
an end plate secured to said at least one end region of said at least one yielding core; and
a plurality of substantially planar members extending from said end plate and oriented substantially perpendicular to said end plate and substantially parallel to one another.
7. The seismic brace of claim 6 , wherein each substantially planar member of said plurality of substantially planar members includes an aperture formed therethrough, each said aperture being in substantial alignment with apertures of each other substantially planar member of said plurality of substantially planar members.
8. The seismic brace of claim 7 , further comprising:
an elongate coupling element configured to be received within apertures of each of said plurality of substantially planar members and within an aperture of at least one complementary connection element secured to a member of a steel structural frame so as to pivotally secure at least one end of the seismic brace to said steel structural frame.
9. The seismic brace of claim 1 , comprising a plurality of elongate, substantially hollow exterior shells, each including a buckling-limiting element and at least one yielding core therein.