Buckling restrained braced frame

Abstract

A buckling restrained braced frame for use in light-framed constructions which includes a ductile load bearing core surrounded by a lightweight casing which resists buckling of the core under compressive loads.

Description

BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to hysteretic damping elements for use in light-framed constructions, and in particular to a buckling restrained braced frame for use in light-framed constructions which includes a ductile load bearing core surrounded by a lightweight casing which resists buckling of the core under compressive loads. [0003] 2. Description of the Related Art [0004] Shear stresses due to natural phenomena such as seismic activity and high winds can have devastating effects on the structural integrity of light-framed constructions. Lateral forces generated during such natural phenomena may cause the top portion of a wall to move laterally with respect to the bottom portion of the wall, which movement can result in structural failure of the wall and, in some instances, collapse of the building. One method of preventing damage due to shear stresses is through the use of buckling restrained braced frames. Ori...

AI Technical Summary

Benefits of technology

[0008] It is therefore an advantage of the present invention to provide a buckling restrained braced frame specifically adapted for use in light-framed constructions.

[0009] It is a further advantage of the present invention to provide a buckling restrained braced frame providing stable and predictable hysteretic behavior.

[0010] It is another advantage of the present invention to provide a buckling restrained braced frame which is easy to manufacture and which may be easily retrofit into existing light-framed constructions.

[0011] It is a still further advantage of the present invention to provide a buckling restrained braced frame which allows the integrity of the core to be inspected without having to replace the entire braced frame.

[0012] It is another advantage of the present invention to provide an effective buckling restrained braced frame without the use of a slip layer between the core and the casing composed of a separate material layer.

[0013] These and other advantages are provided by the present invention which in embodiments relates to a buckling restrained braced frame for use in light-framed constructions. The buckling restrained braced frame includes a frame and a buckling restrained brace diagonally mounted to opposed corners of the frame. The buckling restrained brace includes a ductile load-bearing core surrounded by a lightweight casing which resists buckling of the core under compressive loads. In embodiments of the present invention, the core may be formed of a steel rod having a circular cross-sectional area, and the casing may be formed of wood or other lightweight material having an opening defined through its longitudinal center for receiving the core. The casing may be formed from two separate halves which are affixed together to prevent slip with respect to each other by various affixation methods. Alternatively, the casing may be a single, unitary construction. Both the casing and the core may have a variety of cross-sectional shapes, and the opening in the casing in which the core is positioned may or may not conform to the shape of the core in alternative embodiments.

Problems solved by technology

Shear stresses due to natural phenomena such as seismic activity and high winds can have devastating effects on the structural integrity of light-framed constructions.

Lateral forces generated during such natural phenomena may cause the top portion of a wall to move laterally with respect to the bottom portion of the wall, which movement can result in structural failure of the wall and, in some instances, collapse of the building.

Owing to their construction, conventional buckling restrained braced frames are not well suited for use in light-framed constructions.

While effectively used in large-scale, multistory buildings and skyscrapers, the expense and offsite manufacturing requirements of conventional braces, together with their weight, have prevented their use in light-framed constructions.

Moreover, upon a seismic event, it is impossible to inspect the steel core of conventional braced frames without having to destroy the braced frame itself.

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