Patent Publication Number: US-11649632-B2

Title: Buckling-restrained braces and frames including the same

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a U.S. nationalization of PCT International Application No. PCT/US2019/028040 filed on 18 Apr. 2019, which claims priority to U.S. Provisional Application No. 62/660,478 filed on 20 Apr. 2018, the disclosure of each of the foregoing applications is incorporated herein, in its entirety, by this reference. 
    
    
     BACKGROUND 
     Buckling restrained braces (“BRBs”) are structural braces that are often used in buildings and other structures. BRBs are configured to withstand cyclical loading caused, for example, by earthquakes. Typically BRBs are most effective when they can resist equal or substantially equal magnitudes of tensile axial forces and compressive axial forces. 
     Generally, conventional BRBs include a core and a casing. The core may resist large tensile and compression axial forces. When in compression, the core is restricted from buckling by the casing. In an example, a convention BRB may include one or more cementitious materials (e.g., cement, grout, etc.) that at least substantially fill any gap between the core and the casing. However, the cementitious materials significantly increase the weight of the conventional BRB which in turn impacts fabrication, shipping, and installation costs. 
     In an example, some BRBs have been disclosed but not seen widespread use, that may include one or more protrusions extending therefrom or attached to the casing that extend between the core and the casing thereby eliminating the need for the BRB to include the cementitious materials. However, the protrusions can greatly increase the difficulty in manufacturing the conventional BRB. For instance, it may be necessary to form the casing from two or more pieces which are then attached together to allow the protrusions to be attached to a middle section of the casing which increases the time and energy required to form the conventional BRB. 
     In an example, a conventional BRB may increase the cross-sectional size of the core relative to the casing thereby significantly decreasing the gap between the core and the casing and eliminating the need for the BRB to include the cementitious materials. However, in such an example, increasing the cross-sectional size of the core relative to the case also increases the ability of the core to resist tensile axial forces. Increasing the ability of the core to resist tensile axial forces creates a dilemma since the cross-sectional size of the casing likewise needs to be increased such that the ability of the conventional BRB to resist tensile and compressive axial forces should be substantially equal. However, the increased cross-sectional size of the casing then requires the cross-sectional size of the core to be increased which starts the whole cycle of increasing cross-sectional sizes of the core and casing again. 
     As such, users and producers of BRBs continue to seek new and improved BRBs. 
     SUMMARY 
     In an embodiment, a BRB is disclosed. The BRB includes a casing exhibiting a hollow cross-sectional shape defining an interior region. The casing exhibits a first length. The BRB also includes a core disposed in the interior region of the casing. The core exhibits a generally I cross-sectional shape. The core exhibits a second length that is greater than the first length. The core is separated from the casing by an minimum gap distance along at least a portion of the first length of the casing and a corresponding portion of the second length of the core. 
     In an embodiment, a BRB is disclosed. The BRB includes a casing exhibiting a hollow cross-sectional shape defining an interior region. The casing exhibits a first length. The BRB also includes a core disposed in the interior region of the casing. The core exhibits a second length that is greater than the first length. The core is separate from the casing along at least a portion of the first length of the casing and a corresponding portion of the second length of the core by an minimum gap distance. The minimum gap distance is about 2% to about 49% of at least one outer dimension of the casing. 
     In an embodiment, a BRB is disclosed. The BRB includes a casing exhibiting a hollow cross-sectional shape defining an interior region. The casing exhibits a first length. The BRB also includes a core disposed in the interior region of the casing. The core exhibits a second length that is greater than the first length. The BRB further includes a plurality of bridge plates that each extend substantially between the core and the casing. The core is separated from the casing by an minimum gap distance along at least a portion of the first length of the casing and a corresponding portion of the second length of the core. 
     Features from any of the disclosed embodiments may be used in combination with one another, without limitation. In addition, other features and advantages of the present disclosure will become apparent to those of ordinary skill in the art through consideration of the following detailed description and the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawings illustrate several embodiments of the present disclosure, wherein identical reference numerals refer to identical or similar elements or features in different views or embodiments shown in the drawings. 
         FIG.  1 A  is a partial cross-sectional view of a BRB, according to an embodiment. 
         FIG.  1 B  is a cross-sectional view of the BRB taken along line  1 B- 1 B shown in  FIG.  1 A , according to an embodiment. 
         FIG.  1 C  is a cross-sectional view of a BRB, according to an embodiment. 
         FIGS.  1 D- 1 I  are cross-sectional views of different BRBs, according to different embodiments 
         FIG.  2 A  is a partial cross-sectional view of a BRB that includes a plurality of bridge plates, according to an embodiment. 
         FIG.  2 B  is a cross-sectional view of the BRB taken along line  2 B- 2 B shown in  FIG.  2 A , according to an embodiment. 
         FIG.  2 C  is a cross-sectional view of a BRB that includes a core that is an I-beam, according to an embodiment. 
         FIG.  3    is a schematic illustration of a frame, according to an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments disclosed herein are directed towards BRBs and frames including BRBs. An example BRB includes a casing exhibiting a hollow cross-sectional shape defining an interior region. The BRB also includes a core and at least a portion of the core is disposed in the interior region of the casing. For example, the casing may exhibit a first length and the core may exhibit a second length that is greater than the first length such that a portion of the core extends from the casing. The core is separated from the casing by an minimum gap distance along at least a portion of the first length of the casing and a corresponding portion of the second length of the core. 
     The minimum gap distance is the distance between the core and the casing. The minimum gap distance is measured perpendicularly to a longitudinal axis of the casing and/or the core. Generally, any gap between the core and the casing is unoccupied space (e.g., occupied by air). When discussing the minimum gap distance, any protrusions extending from or attached to the casing are considered part of the casing and any protrusions extending from or attached to the core are considered part of the core. 
       FIG.  1 A  is a partial cross-sectional view of a BRB  100 , according to an embodiment.  FIG.  1 B  is a cross-sectional view of the BRB  100  taken along line  1 B- 1 B shown in  FIG.  1 A , according to an embodiment. The BRB  100  includes a casing  102  and a core  104  disposed in the casing  102 . For example, the casing  102  exhibits a generally hollow cross-sectional shape that allows the casing  102  to define an interior region  106 . A portion of the core  104  is positioned within the interior region  106 . The BRB  100  includes an minimum gap distance “g” between the casing  102  and the core  104 . 
     The casing  102  may include any suitable casing. In an example, the casing  102  may include any suitable material. Generally, the casing  102  is formed from steel. However, the casing  102  may be formed from other materials, such as aluminum, without limitation. In an example, the casing  102  is formed from a single piece (e.g., is unitary), such as when the casing  102  is extruded or cold formed. However, the casing  102  may be formed from a plurality of pieces, such as a plurality of pieces that are welded together prior to forming the BRB  100 . 
     The casing  102  exhibits a first length. In an embodiment, the casing  102  may exhibit a first length that is similar to a common length for casings of conventional BRBs. In such an embodiment, the casing  102  may exhibit a first length that is greater than 3 m, such as greater than about 6 m, greater than about 9 m, greater than about 12 m, or in ranges of 3 m to about 6 m, about 4.5 m to 7.5 m, about 6 m to about 9 m, about 7.5 m to about 10.5 m, or about 9 m to about 12 m. In an embodiment, the casing  102  may exhibit a first length that is less than a common length of casings of conventional BRBs. For example, the casing  102  may exhibit a length that is less than 3 m, such as less than about 2.5 m, less than about 2 m, less than about 1.5 m, less than about 1 m, or in ranges of about 1 m to about 2 m, about 1.5 m to about 2.5 m, or about 2 m to 3 m. It is currently believed that the minimum gap distance “g” between the casing  102  and the core  104  allows the casing  102  to exhibit a first length that is less than the common length of casings of conventional BRBs because the minimum gap distance “g” (e.g., the absence of cementitious material) allows for scaling down of the BRB  100 . 
     The first length of the casing  102  may be selected based on a number of factors. In an example, the first length of the casing  102  may be selected based on the second length of the core  104 . For example, the second length of the core  104  is selected to be greater than the first length of the casing  102  which allows the core  104  to protrude from the casing  102 . The portions of the core  104  that protrude from both sides of the casing  102  allows the core  104  to be coupled to the rest of a frame (e.g., beams  322  and/or columns  324  of  FIG.  3   ) while the casing  102  is only indirectly coupled to the frame via the core  104 . In an example, the first length of the casing  102  may be selected based on needed ability of the casing  102  to resist compressive axial forces since the ability of the casing  102  to resist compressive axial forces is directly proportional to the inverse of the first length. It is noted that the needed ability of the casing  102  to resist compressive axial forces depends on the strength of the core  104  in tension (e.g., the yield strength of the ultimate tensile strength of the core  104 ) and the cross-sectional area of the core  104 . In an example, the first length of the casing  102  may be selected based on the application of the BRB  100 . For instance, when the BRB  100  is used in a frame for a building, the casing  102  may exhibit a first length that is the same or similar to the common lengths of conventional BRBs. However, the BRB  100  may be used in other applications (e.g., pallet racks or other large shelving, other general bracing of equipment such as. braces for piping or ducting feature) due to the reduced weight thereof compared to conventional BRBs exhibiting the same length and because the casing  102  can exhibit a length that is less than the common length of casings used in conventional BRBs. For instance, the casing  102  may exhibit a length of about 1 m to about 2.5 m when the BRB  100  is used in a pallet rack or other large shelving. 
     The casing  102  may exhibit a first outer casing dimension D 1Ca  and a second outer casing dimension D 2Ca . The first and second outer casing dimensions D 1Ca  and D 2Ca  are measured perpendicularly to a longitudinal axis of the casing  102  and the second outer casing dimension D 2Ca  is measured perpendicularly to the first outer casing dimension D 1Ca . In an embodiment, the first outer casing dimension D 1Ca  and the second outer casing dimension D 2Ca  are the same, such as when the casing  102  exhibits a hollow generally square cross-sectional shape or a hollow generally circular cross-sectional shape. In an embodiment, the first outer casing dimension D 1Ca  is different (e.g., greater) than the second outer casing dimension D 2Ca . 
     In an embodiment, the first outer casing dimension D 1Ca  and the second outer casing dimension D 2Ca  may be the same or substantially similar to a common outer casing dimensions of conventional BRBs. For example, the first outer casing dimension D 1Ca  and the second outer casing dimension D 2Ca  may be greater than 12.5 cm, greater than about 15 cm, greater than about 20 cm, greater than about 30 cm, greater than about 40 cm, or in ranges of 12.5 cm to about 20 cm, about 15 cm to about 30 cm, or about 20 cm to about 40 cm. However, in an embodiment, at least one of the first outer casing dimension D 1Ca  or the second outer casing dimension D 2Ca  may be less than a common outer casing dimension of conventional BRBs. For example, at least one of the first outer casing dimension D 1Ca  or the second outer casing dimension D 2Ca  may be less than about 12 cm, less than about 10 cm, less than about 7.5 cm, less than about 5 cm, less than about 2.5 cm, or in ranges of about 2.5 cm to about 7.5 cm, about 5 cm to about 10 cm, or about 7.5 cm to about 12 cm. At least one of the first outer casing dimension D 1Ca  or the second outer casing dimension D 2Ca  may be less that a common outer dimension of conventional BRBs due to the minimum gap distance “g” between the casing  102  and the core  104 . For example, the minimum gap distance “g” may decrease the weight of the BRB  100  compared to conventional BRBs thereby allowing the BRB  100  to exhibit the relatively small first and/or second outer casing dimensions D 1Ca  and D 2Ca . Further, as previously discussed, the minimum gap distance “g” may allow the casing  102  to exhibit a relatively small first length. The relatively small first length increases the casing&#39;s  102  ability to resist compressive axial forces thereby decreasing the need to have a large outer cross-sectional dimension (e.g., the casing&#39;s  102  ability to resist compressive axial forces may proportional to the outer casing dimension). 
     The interior region  106  may exhibit a first interior region dimension D 1IR  and a second interior region dimension D 2IR . The first interior region dimension D 1IR  and the second interior region dimension D 2IR  may be measured perpendicularly to the first outer casing dimension D 1Ca  and the second outer casing dimension D 2Ca , respectively. In an embodiment, as shown, the first interior region dimension D 1IR  and the second interior region dimension D 2IR  are the same, such as when the casing  102  exhibits a hollow generally square cross-sectional shape or a hollow generally circular cross-sectional shape. In an embodiment, the first interior region dimension D 1IR  is different (e.g., greater) than the second interior region dimension D 2IR . 
     The first interior region dimension D 1IR  and the second interior region dimension D 2IR  may be less than the first outer casing dimension D 1Ca  and the second outer casing dimension D 2Ca , respectively, by at least about 2 mm, at least about 5 mm, at least about 7.5 mm, at least about 1 cm, at least about 1.5 cm, at least about 2 cm, at least about 3 cm, at least about 5 cm, or in ranges of about 2 mm to about 7.5 mm, about 5 mm to about 1 cm, about 7.5 mm to about 1.5 cm, about 1 cm to about 2 cm, about 1.5 cm to about 3 cm, or about 2 cm to about 5 cm. The difference between the first and second interior region dimensions D 1IR , D 2IR  and the first and second outer casing dimensions D 1Ca , D 2Ca , respectively, may be selected based on the needed ability of the casing  102  to resist compressive axial forces such that the BRB  100  resists both tensile and compressive axial forces equally or substantially equally. 
     As previously discussed, the core  104  exhibits a second length that is typically greater than the first length of the casing  102 . In an embodiment, the second length of the core  104  is the similar to a common length for cores of conventional BRBs. For example, the second length of the core  104  may be greater than 3.05 m, such as greater than about 6 m, greater than about 9 m, greater than about 12 m, or in ranges of 3.05 m to about 6 m, about 4.5 m to 7.5 m, about 6 m to about 9 m, about 7.5 m to about 10.5 m, or about 9 m to about 12 m. In an embodiment, the core  104  may exhibit a second length that is less than about a common length of casing of conventional BRBs. For example, the casing  102  may exhibit a length that is less than about 3 m, such as less than about 2.5 m, less than about 2 m, less than about 1.5 m, less than about 1 m, or in ranges of about 1 m to about 2 m, about 1.5 m to about 2.5 m, or about 2 m to about 3 m. It is currently believed that the minimum gap distance between the casing  102  and the core  104  allows the core  104  to exhibit a second length that is less than the common length of cores of conventional BRBs. 
     The second length of the core  104  may be selected based on a number of factors. In an example, as previously discussed, the second length of the core  104  may be selected based on the first length of the casing  102 . In an example, the first length of the core  104  may be selected based on the needed ability of the core  104  to resist compressive axial forces since the ability of the core  104  to resist compressive axial forces is dependent on the inverse of the second length squared. In an example, the second length of the core  104  may be selected based on the application of the BRB  100 . For instance, when the BRB  100  is used in a frame for a building, the core  104  may exhibit a second length that is the same or similar to the common lengths of cores of conventional BRBs. However, the BRB  100  may be used in other applications due to the reduced weight thereof compared to conventional BRBs exhibiting the same length and because the BRB  100  can exhibit a length that is less than conventional BRBs. For instance, the core  104  may exhibit a second length of about 1 meter to about 2.6 m when the BRB  100  is used in a pallet rack or other large shelving. 
     As previously discussed, the second length of the core  104  may be greater than the first length of the casing  102 . For example, the second length of the core  104  may be greater than the first length of the casing  102  by at least about 2.5 cm, at least about 5 cm, at least about 7.5 cm, at least about 10 cm, at least about 15 cm, at least about 20 cm, at least about 30 cm, at least about 40 cm, at least about 50 cm, at least about 75 cm, at least about 1 m, at least about 1.5 m, at least about 2 m, at least about 2.5 m, at least about 3 m, or in ranges of about 2.5 cm to about 7.5 cm, about 5 cm to about 10 cm, about 7.5 cm to about 15 cm, about 10 cm to about 20 cm, about 15 cm to about 30 cm, about 20 cm to about 40 cm, about 30 cm to about 50 cm, about 40 cm to about 75 cm, about 50 cm to about 1 m, about 75 cm to about 1.5 m, about 1 m to about 2 m, or about 1.5 m to about 3 m. The difference between the first length of the casing  102  and the second length of the core  104  may be selected based on the length of the core  104  required to attach BRB  100  to a frame. 
     Referring to  FIG.  1 B , in an embodiment, the core  104  may include a hollow structural section, such as a tube (e.g., steel tube) having a hollow generally circular cross-sectional shape. The hollow generally circular cross-sectional shape of the core  104  exhibits a high moment of inertia relative to certain types of cores, such as a substantially similar solid generally circular cross-sectional shape and plates. The high moment of inertia of the core  104  makes the core  104  more resistant to buckling which, in turn, may allow the BRB  100  to include a smaller casing  102  than if the core  104  exhibited another shape exhibiting a lower moment of inertia. 
     However, it is noted that the core  104  used in the BRB  100  may exhibit other cross-sectional shapes.  FIG.  1 C  is a cross-sectional view of a BRB  100   c  that, except as otherwise disclosed herein, is the same as or substantially similar to the BRB  100  of  FIGS.  1 A and  1 B , according to an embodiment. For example, the BRB  100   c  includes a core  104   c  that is a rolled I-beam. The core  104   c  exhibits a high moment of inertia. The high moment of inertia of the core  104   c  allows the core  104   c  to exhibit may of the same properties as the core  104  shown in  FIG.  1 B . 
     Some conventional BRBs include cruciform or double cruciform beams that exhibit a moment of inertia that is comparable to the core  104   c . However, the cruciform or double cruciform beams require a significant amount of welding to form which may require a significant amount of time required to form the cruciform or double cruciform beams. However, the rolled I-beam that forms the core  104   c  does not require welding to form and may be readily available. As such, the BRB  100   c  may be formed much quicker, more efficiently, and cheaper than the conventional BRBs that include cruciform or double cruciform beams. 
     It is noted that any of the BRBs disclosed herein may include a casing and/or core exhibiting a different cross-sectional shape than the cross-sectional shapes shown in  FIGS.  1 B and  1 C . For example, FIGS. D- 1 I are cross-sectional views of different BRBs, according to different embodiments. Except as otherwise disclosed herein, the BRBs shown in  FIGS.  1 D- 1 I  are the same or substantially similar to any of the BRBs disclosed herein.  FIG.  1 D  illustrates a BRB  100   d  including a casing  102   d  that is the same or substantially similar to the casing  102  of  FIG.  1 B . However, the BRB  100   d  including a core  104   d  exhibiting a generally rectangular cross-sectional shape, such as a hollow generally rectangular cross-sectional shape (e.g., the core  104   d  is a hollow structural section).  FIG.  1 E  illustrates a BRB  100   e  including a casing  102   e  that is the same or substantially similar to the casing  102  of  FIG.  1 B . However, the BRB  100   e  may include a core  104   e  that is a double I-beam core.  FIG.  1 F  illustrates a BRB  100   f  including a casing  102   f  exhibiting a hollow generally circular cross-sectional shape. The BRB  100   f  also includes a core  104   f  that is the same or substantially similar to the core  104  of  FIG.  1 B .  FIG.  1 G  illustrates a BRB  100   g  including a casing  102   g  that is the same or substantially similar to the casing  102   f  of  FIG.  1 F . Also, the BRB  100   g  includes a core  104   g  that is the same or substantially similar to the core  104   c  of  FIG.  1 C .  FIG.  1 H  illustrates a BRB  100   h  including a casing  102   h  that is the same or substantially similar to the casing  102   f  of  FIG.  1 F . Also, the BRB  100   h  includes a core  104   h  that is the same or substantially similar to the core  104   d  of  FIG.  1 D .  FIG.  1 I  illustrates a BRB  100   i  including a casing  102   i  that is the same or substantially similar to the casing  102   f  of  FIG.  1 F . Also, the BRB  100   i  includes a core  104   i  that is the same or substantially similar to the core  104   e  of  FIG.  1 E . It is noted that the BRBs may include casings and/or cores exhibiting a different cross-sectional shape other than the cross-sectional shapes shown in  FIGS.  1 B- 1 I . For example, the casings of the BRBs disclosed herein may exhibit any suitable hollow cross-sectional shape and/or the cores of the BRBs disclosed herein may include a solid generally circular shape, one or more plates, cruciform or double cruciform beams, or any other suitable core. 
     Referring back to  FIG.  1 B , the core  104  may exhibit a first core dimension D 1Co  and a second outer core dimension D 2Co . The first and second core dimensions D 1Co  and D 2Co  are measured perpendicularly to a longitudinal axis of the core  104  and the second core dimension D 2Co  is measured perpendicularly to the first core dimension D 1Co . In an embodiment, as shown in  FIG.  1 B , the first core dimension D 1Co  and the second core dimension D 2Co  are the same. In an embodiment, as shown in  FIG.  1 C , the first core dimension D 1Co  is different (e.g., greater) than the second core dimension D 2Co . 
     The first core dimension D 1Co  and the second core dimension D 2Co  may be at least about 1 mm, at least about 2 mm, at least about 3 mm, at least about 4 mm, at least about 5 mm, at least about 7.5 mm, at least about 1 cm, at least about 1.5 cm, at least about 2 cm, at least about 3 cm, at least about 4 cm, at least about 5 cm, at least about 7.5 cm, at least about 10 cm, at least about 15 cm, at least about 20 cm, at least about 25 cm, at least about 30 cm, at least about 40 cm, at least about 50 cm, or in ranges of about 1 mm to about 3 mm, about 2 mm to about 4 mm, about 3 mm to about 5 mm, about 4 mm to about 7.5 mm, about 5 mm to about 1 cm, about 7.5 mm to about 1.5 cm, about 1 cm to about 2 cm, about 1.5 cm to about 3 cm, about 2 cm to about 4 cm, about 3 cm to about 5 cm, about 4 cm to about 7.5 cm, about 5 cm to about 10 cm, about 7.5 cm to about 15 cm, about 10 cm to about 20 cm, about 15 cm to about 25 cm, about 20 cm to about 30 cm, about 25 cm to about 40 cm, or about 30 cm to about 50 cm. The first core dimension D 1Co  and the second core dimension D 2Co  may be selected based on a number of factors. In an example, the first core dimension D 1Co  and the second core dimension D 2Co  may be selected based on the desired maximum tensile load that the core  104  is designed to withstand. For instance, increasing the first core dimension D 1Co  and the second core dimension D 2Co  increases the tensile load that the core  104  can resist with plastically deforming or otherwise failing. In an example, the first core dimension D 1Co  and the second core dimension D 2Co  may be selected based on the desired compressive axial force that the core  104  can withstand without buckling or otherwise failing. In an example, the first core dimension D 1Co  and the second core dimension D 2Co  may be selected based on the desired minimum gap distance “g” between the casing  102  and the core  104 . 
     Referring back to  FIG.  1 B , in an embodiment, the core  104  may be disposed at or substantially near the middle of the interior region  106 . In an embodiment, the core  104  may be asymmetrically disposed in the interior region  106  such that the core  104  is closer to one edge of the casing  102  than an opposing edge of the casing  102 . 
     The BRB  100  exhibits an minimum gap distance “g” between the casing  102  and the core  104  (the minimum gap distance “g” is also shown in  FIG.  1 C ). As previously discussed, the minimum gap distance “g” is the minimum distance between the casing  102  and the core  104  when the core  104  is disposed in the middle of the interior region  106  of the casing  102 . The minimum gap distance “g” allows the BRB  100  to exhibit the desirable property of being able to resist equal or substantially equal compressive and tensile axial forces while minimizing (e.g., eliminating) the amount of cementitious material used in the BRB  100 . 
     The size of the minimum gap distance “g” may depend on the size of the casing  102  and/or the size of the core  104 . For example, the minimum gap distance “g” increases or decreases as the size of the casing  102  and/or core  104  increase or decrease, respectively. In an embodiment, the minimum gap distance “g” may be about 2% to about 49% of at least one of the first outer casing dimension D 1Ca  or the second outer casing dimension D 2Ca , such as in ranges of about 2% to about 4%, 3% to about 5%, about 4% to about 6%, about 5% to about 7%, about 6% to about 8%, about 7% to about 9%, about 8% to about 10%, about 9% to about 11%, about 10% to about 12%, about 11% to about 13%, about 12% to about 14%, about 13% to about 15%, about 14% to about 17%, about 16% to about 20%, about 18% to about 22%, about 20% to about 25%, about 23% to about 28%, about 25% to about 30%, about 28% to about 33%, about 30% to about 35%, about 33% to about 38%, about 35% to about 40%, about 38% to about 43%, about 40% to about 45%, or about 43% to about 49%. 
     In an embodiment, the minimum gap distance “g” may be at least about 2.54 cm, at least about 3 cm, at least about 3.5 cm, at least about 4 cm, at least about 4.5 cm, at least about 5 cm, at least about 6 cm, at least about 7 cm, at least about 8 cm, at least about 9 cm, at least about 10 cm, at least about 12 cm, at least about 15 cm, or in ranges of about 2.5 cm to about 3.5 cm, about 3 cm to about 4 cm, about 3.5 cm to about 4.5 cm, about 4 cm to about 5 cm, about 4.5 cm to about 6 cm, about 5 cm to about 7 cm, about 6 cm to about 8 cm, about 7 cm to about 9 cm, about 8 cm to about 12 cm, about 10 cm to about 15 cm, about 10 cm to about 17 cm, or about 15 cm to about 20 cm. 
     The size of the minimum gap distance “g” may depend on a number of factors. In an example, as previously discussed, the size of the minimum gap distance “g” may depend on the size of the casing  102  and/or the size of the core  104 . In an example, the minimum gap distance “g” may depend on the maximum tensile axial force that the core  104  can resist without plastically yielding or otherwise failing since increasing the maximum tensile load of the core  104  may require an increased size in the casing  102 . In an example, the minimum gap distance “g” may depend on the moment of inertia of the core  104  because increasing the moment of inertia of the core  104  may allow the BRB  100  to include a casing  102  exhibiting a small cross-sectional area. In an example, the minimum gap distance “g” may depend on the length of the casing  102  and/or the core  104  since the ability of the casing  102  and the core  104  to resist buckling is directly proportional to the inverse of the length thereof squared. 
     As previously discussed, the BRB  100  is configured to minimize the amount of cementitious material that is used therein compared to a substantially similar conventional BRB. In an embodiment, the BRB  100  may be substantially free of cementitious material. As used herein, substantially free of cementitious material means that the BRB  100  includes structurally insignificant amount of cementitious material and/or the BRB  100  only include inadvertent contamination of cementitious material caused, for example, by the BRB  100  be manufactured, shipped, stored, and/or used in locations were cementitious materials are used. In an embodiment, the BRB  100  may include some amount of cementitious material. For example, the cementitious material may form two of the caps formed of cementitious material as discussed below or may be used to form a rust and/or thermal insulating layer on one or more components of the BRB  100 . However, when the BRB  100  includes some cementitious material, the cementitious material occupies at most about 50% of the volume between the casing  102  and the core  104 , and more preferable occupies at most about 25% and even more preferable occupies at most 10% of the volume between the casing  102  and the core  104 . 
     In the illustrated embodiment, the BRB  100  does not include any structure that supports and/or suspends (hereafter simply referred to as “support”) the core  104  in the interior region  106  casing  102 . As such, the casing  102  may rest on and directly contact the core  104 . However, resting the casing  102  on the core  104  may at least one of affect how the core  104  buckles or increase the likelihood that the core  104  buckles. As such, in an embodiment, the BRB  100  may include a support structure (not shown) that supports the core  104  in the interior region  106  which may at least partially alleviate some of the problems associated with resting the casing  102  on the core  104 . The support structure may include any suitable support structure. 
     In an embodiment, the support structure that suspends the core  104  in the interior region  106  may include two caps at and/or near each terminal end  108  of the casing  102 . The two caps may be attached to the casing  102  and may extend between the casing  102  and the core  104  thereby supporting the core  104  in the interior region  106 . The caps may also be attached to the core  104 , weakly attached to the core  104  such that the attachment fails when the core  104  buckles, or may not be attached to the core  104  thereby allowing the core  104  to freely move relative to the caps. The caps may be formed from any suitable material. For example, the caps may be metal plates or cementitious material. The caps may be simple to form compared to other support structures commonly found in conventional BRB since the caps are only located at and/or near the terminal ends  108  of the casing  102 . The caps also allow the BRB to include the minimum gap distance “g” along at least a portion (e.g., a majority) of the first length of the casing  102 . 
     In an embodiment, the support structure includes a plurality of protrusions attached to or integrally formed with the casing  102  located at and/or near the terminal ends  108  of the casing  102 . Similar to the caps, the plurality of protrusions extend between the casing  102  and the core  104  thereby supporting the core  104  in the interior region  106 . Generally, the plurality of protrusions are not attached or are only weakly attached to the core  104 . The protrusions only extend along a portion of the first length of the casing  102  that is at and/or near the terminal ends  108  of the casing  102 . Extending the protrusions along only a portion of the first length makes the protrusions significantly easier to attach to the casing  102  than if the protrusions extends along all of the first length. Also, extending the protrusions along only a portion of the first length allow the BRB to include the minimum gap distance “g” along at least a portion (e.g., a majority) of the first length of the casing  102 . 
     In an embodiment, the support structure may include a plurality of bridge plates. For example,  FIG.  2 A  is a partial cross-sectional view of a BRB  200  that includes a plurality of bridge plates  210 , according to an embodiment.  FIG.  2 B  is a cross-sectional view of the BRB  200  taken along line  2 B- 2 B shown in  FIG.  2 A , according to an embodiment. Except as otherwise disclosed herein, the BRB  200  is the same or substantially similar to any of the BRBs disclosed herein. For example, the BRB  200  includes a casing  202  having a first length, a core  204  having a second length, and an minimum gap distance “g” along at least a portion of the first length of the casing  202 . 
     Each of the plurality of bridge plates  210  are configured to extend between the casing  202  and the core  204  when the core  204  is disposed in the interior region  206  such that the bridge plates  210  support the core  204  in the interior region  206 . Each of the bridge plates  210  may be configured to fit in the interior region  206  of the casing  202 . As such, as illustrated, an outer periphery  214  the bridge plates  210  may exhibit a shape that generally corresponds to a shape formed by at least one interior surface  212  of the casing  202 . The bridge plates  210  also define an opening  216  therein that is configured to have the core  204  positioned therethrough. The opening  216  allows the core  204  to be positioned through each of the bridge plates  210 . The opening  216  may exhibit a shape that at least generally corresponds to the cross-sectional shape of the core  204  which allows the core  204  to be positioned therethrough. At least some (e.g., each) of the bridge plates  210  are longitudinally spaced from each other along the longitudinal axis of the casing  202  and/or the longitudinal axis of the core  204 . 
     In an embodiment, the BRB  200  is formed by positioning the bridge plates  210  around the core  204  at different locations along the core  204 . To facilitate positioning the bridge plates  210  around the core  204 , the opening  216  may be slightly larger than a cross-sectional shape of the core  204 . For example, the opening  216  may exhibit a dimension (not shown) that is larger than a corresponding dimension (e.g., at least one of the first core dimension or the second core dimension) by at most about 15 mm, at most about 10 mm, at most about 7.5 mm, at most about 6 mm, at most about 5 mm, at most about 4 mm, at most about 3 mm, at most about 2 mm, at most about 1 mm, or in ranges of about 1 mm to about 3 mm, about 2 mm to about 4 mm, about 3 mm to about 5 mm, about 4 mm to about 6 mm, about 5 mm to about 7.5 mm, about 6 mm to about 10 mm, or about 7.5 mm to about 15 mm. The above differences in the dimension of the opening  216  and the corresponding dimension of the core  204  allows the bridge plates  210  to be easily positioned along the core  204  while preventing the core  204  from significantly moving in a direction that is perpendicular to a longitudinal axis thereof from a desired location within the interior region  206 . The difference between the dimension of the opening  216  and the corresponding dimension of the core  204  may be selected based on the size of the corresponding dimension of the core  204  and the thickness of the bridge plate  210 , wherein increasing the corresponding dimension of the core  204  and/or the thickness of the bridge plate  210  may require an increase in the dimension of the opening  216  relative to the corresponding dimension of the core  204 . It is noted that the corresponding dimension of the core  204  is the dimension that overlaps and is parallel to the dimension of the opening  216  when the core  204  is disposed in the center of the opening  216  and the core  204  is not rotated relative to the opening  216  (e.g., any gap between the core  204  and the opening  216  is as uniform as possible). 
     In  FIG.  2 B , the cross-sectional shape of the core  204  and the shape of the opening  216  are both circular. However, as previously discussed, the core  204  may exhibit cross-sectional shapes other than a circular cross-sectional shape. For example,  FIG.  2 C  is a cross-sectional view of a BRB  200 ′ that includes a core  204 ′ that is an I-beam, according to an embodiment. Except as otherwise disclosed herein, the BRB  200 ′ is the same as or substantially similar to the BRB  200  of  FIGS.  2 A and  2 B . Since the core  204 ′ exhibits a generally I cross-sectional shape, the opening  216 ′ of the bridge plate  210 ′ also exhibits a generally I cross-sectional shape that is slightly larger than the generally I cross-sectional shape of the core  204 ′. 
     Referring back to  FIGS.  2 A and  2 B , it is generally desirable that the core  204  be allowed to move relative to the bridge plates  210  when the core  204  buckles. Otherwise, buckling of the core  204  may cause the bridge plates  210  to move relative to the casing  202  which may cause the bridge plates  210  to gouge or otherwise weaken the casing  202 . In an embodiment, the core  204  may not be attached to the bridge plates  210  thereby allowing the core  204  to move relative to the bridge plates  210  when the core  204  buckles. However, the bridge plates  210  may be positioned adjacent to a selected portion of the core  204  and not attaching the core  204  to the bridge plates  210  may make maintaining the bridge plates  210  adjacent to the selected portion of the core  204  during assembly and handling of the BRB  200  difficult. As such, the bridge plates  210  may be attached to the core  204 . In an example, as shown, a weld  218  is formed between corresponding first portions of the core  204  and the opening  216  while corresponding second portions of the core  204  and the opening  216  are not attached together with the weld  218 . The second portions of the core  204  and the opening  216  may be significantly larger than the first portion of the core  204  and the opening  216  such that the weld  218  is sufficient to maintain the position of the bridge plate  210  relative to the core  204  during assembly and handling. The weld  218  may or may not fail when the core  204  buckles. In an example, at least substantially all of the outer periphery of the core  204  is welded to corresponding portions of the opening  216 . In an example, a polymer is positioned between the core  204  and the opening  216  and maintains the position of the bridge plate  210  relative to the core  204 . The polymer may or may not fail or otherwise become detached from at least one of the core  204  or the bridge plate  210  when the core  204  buckles. 
     In an embodiment, the BRB  200  is formed by positioning the core  204  with the bridge plates  210  positioned thereabout in the interior region  206 . To facilitate positioning the core  204  and the bridge plates  210  in the interior region  206 , each of the bridge plates  210  may be slightly smaller than a cross-sectional shape of the interior region  206  as defined by the interior surface  212  of the casing  202 . For example, each bridge plate  210  may exhibit a dimension (not shown) that is smaller than a corresponding dimension of the interior region  206  (e.g., at least one of the first interior region dimension or the second interior region dimension) by at most about 25 mm, at most about 20 mm, at most about 15 mm, at most about 10 mm, at most about 7.5 mm, at most about 6 mm, at most about 5 mm, at most about 4 mm, at most about 3 mm, at most about 2 mm, at most about 1 mm, or in ranges of about 1 mm to about 3 mm, about 2 mm to about 4 mm, about 3 mm to about 5 mm, about 4 mm to about 6 mm, about 5 mm to about 7.5 mm, about 6 mm to about 10 mm, about 7.5 mm to about 15 mm, about 10 mm to about 20 mm, or about 15 mm to about 25 mm. The above differences in the dimension of the bridge plate  210  and the corresponding dimension of the interior region  206  allows the bridge plates  210  to be easily positioned within the interior region  206  while preventing the bridge plates  210  from gouging or becoming stuck during assembly. The difference between the dimension of the bridge plates  210  and the corresponding dimension of the interior region  206  may be selected based on the size of the corresponding dimension of the interior region  206  and the thickness of the bridge plate  210 , wherein increasing the corresponding dimension of the interior region  206  and/or the thickness of the bridge plate  210  may require an increase in the dimension of the bridge plate  210  relative to the corresponding dimension of the interior region  206 . It is noted that the corresponding dimension of the interior region  206  is the dimension that overlaps and is parallel to the dimension of the bridge plate  210  when the bridge plate  210  is disposed in the center of the interior region  206  and the bridge plate  210  is not rotated relative to the interior region  206  (e.g., any gap between the bridge plate  210  and the interior surface  212  defining the interior region  206  is as uniform as possible). 
     In an embodiment, each of the plurality of bridge plates  210  are not attached to the casing  202 . In such an embodiment, not attaching the bridge plates  210  to the casing  202  may facilitate movement of the core  204  relative to the casing  202  when the core  204  buckles since the core  204  can move relative to the casing  202  even when the core  204  gets stuck to one of the bridge plates  210 . Further, it may be difficult to attach the bridge plates  210  that are spaced from the terminal ends  208  of the casing  202 . 
     In an embodiment, one or more of the plurality of bridge plates  210  are attached to the casing  202 . For example, the ones of the plurality of bridge plates  210  that are at or nearest the terminal ends  208  may be attached to the casing  202 . Attaching the ones of the plurality of bridge plates  210  that are at or nearest the terminal ends  208  may be significantly easier to attach to the casing  202  that other ones of the plurality of bridge plates  210 . Also, attaching the ones of the plurality of bridge plates  210  that are at or nearest the terminal ends  208  may maintain the other ones of the bridge plates  210  within the interior region  206  even when the other ones of the bridge plates  210  move. 
     In an embodiment, the bridge plates  210  may define one or more cutouts  219 . The cutouts  219  are variations in the shape of the bridge plates  210  relative to the cross-sectional shape of the interior region  206 . In an example, the cutouts  219  may blunt or remove sharp corners from the bridge plate  210 , as shown in  FIG.  2 B . For example, sharp corners are more likely to contact and become stuck against the casing  202  when the bridge plate  210  is positioned within the interior region  206 . However, cutouts  219  that blunt or remove the sharp corners minimize such contact. As such, the cutouts  219  facilitate forming the BRB  200 . In an example, the cutouts  219  may decrease the weight of the bridge plate  210  thereby decreasing the overall weight of the BRB  200 . 
     The BRB  200  may include any suitable number of bridge plates  210 . For example, the BRB  200  may include at least 2, at least 3, at least 4, at least 5, at least 6, at least 7, at least 8, at least 9, at least 10, at least 12, at least 15, at least 20, at least 30, at least 40, at least 50, at least 60, at least 70, at least 80, at least 90, or at least 100 bridge plates  210 , such as in ranges of 2 to 4 bridge plates  210 , 3 to 5 bridge plates  210 , 4 to 6 bridge plates  210 , 5 to 7 bridge plates  210 , 6 to 8 bridge plates  210 , 7 to 9 bridge plates  210 , 8 to 10 bridge plates  210 , 9 to 12 bridge plates  210 , 10 to 15 bridge plates  210 , 12 to 20 bridge plates  210 , 15 to 25 bridge plates  210 , 20 to 30 bridge plates  210 , 25 to 40 bridge plates  210 , 30 to 50 bridge plates  210 , 40 to 50 bridge plates  210 , 40 to 60 bridge plates  210 , 50 to 70 bridge plates  210 , 60 to 80 bridge plates  210 , 70 to 90 bridge plates  210 , 80 to 100 bridge plates  210 , 90 to 150 bridge plates  210 , or 120 to 200 bridge plates  210 . The number of bridge plates  210  that are present in the BRB  200  affect the average spacing between the bridge plates  210 . For example, increasing the number of bridge plates  210  in the BRB  200  decreases the average spacing between bridge plates  210  and decreasing the number of bridge plates  210  in the BRB  200  increase the average spacing between the bridge plates  210 . Also, increasing the first length of the casing  202  increases the average spacing between the number of bridge plates  210  and, as such, the number of bridge plates  210  that are present in the BRB  200  may depend on the first length of the casing  202 . 
     The average spacing between the bridge plates  210  may have a significant effect on the ability of the core  204  to resist buckling. For example, the ability of the core  204  to resist buckling is inversely proportional to the length of the core  204  squared. As such, increasing the length of the core  204  drastically decreases the ability of the core  204  to resist buckling. However, the bridge plates  210  may increase the ability of the core  204  to resist buckling by effectively breaking the core  204  into a plurality of portions and the length of the plurality of portions determines the ability of the core  204  to resist buckling. As such, the bridge plates  210  may drastically increase the ability of the core  204  to resist buckling. Increasing the ability of the core  204  to resist buckling due to the presence of the bridge plates  210  may have a cascading effect on the design of the BRB  200 . For example, the increased ability of the core  204  to resist buckling increases the ability of the BRB  200  to resist compressive axial forces. Thus, the bridge plates  210  may allow the casing  202  to be smaller while still allowing the BRB  200  to resist an equal or substantially equal magnitude in the compressive and tensile axial forces. 
     In an embodiment, the bridge plates  210  are equidistantly spaced apart such that the average distant between adjacent ones of the bridge plates  210  is the same as the actual distance between equal pair of adjacent bridge plates  210 . In such an embodiment, the core  204  resists buckling to the same or substantially the same degree along the entire second length of the core  204 . In an embodiment, the bridge plates  210  are not equidistantly spaced apart. For example, the bridge plates  210  may include at least one first pair of adjacent bridge plates and at least one second pair of adjacent bridge plates. The first pair of adjacent bridge plates may have a first spacing therebetween and the second pair of adjacent bridge plates may have a second spacing therebetween that is less than the first spacing. As such, the portion of the core  204  between the first pair of adjacent bridge plates is more likely to buckle than the portion of the core  204  between the second pair of adjacent bridge plates. As such, the first and second pair of adjacent bridge plates may be used to select which portion of the core  204  buckles initially which, in some embodiments, may be beneficial. In an example, it may be beneficial for the core  204  to buckle at a location at or near at least one of the terminal ends  208  of the casing  202 . In such an example, the first pair of adjacent bridge plates may be at or near at least one of the terminal ends  208  while the second pair of adjacent bridge plates may be spaced from at least one of the terminal ends  208 . In an example, it may be beneficial for the core  204  to buckle at a location that is spaced from the terminal ends  208  since avoiding buckling near the terminal ends  208  may decrease demands on the connection between the BRB  200  and a frame (e.g., frame  320  of  FIG.  3   ). In such an example, the first pair of adjacent bridge plates may be spaced from the terminal ends  208  while the second pair of adjacent bridge plates may be at or near the terminal ends  208 . 
     As previously discussed, the BRBs disclosed herein may be used in a frame.  FIG.  3    is a schematic illustration of a frame  320 , according to an embodiment. The frame  320  may include one or more horizontally oriented beams  322  connected to and extending between opposing vertical columns  324 . Each beam  322  may be connected to one of the columns  324  using any suitable connection. The frame  320  also includes one or more BRBs  300  that is the same or substantially similar to any of the BRBs disclosed herein. The BRBs  300  extend diagonally between the vertical columns  324  and/or the horizontally oriented beams  322 . The BRBs  300  may be connected to the vertical columns  324  and/or the horizontally oriented beams  322  using any suitable connection. 
     In an embodiment, application of a force to the frame  320 , for example during a seismic event, may produce movement (e.g., bending, twisting, and/or tilting) of the frame  320 . The movement of the frame  320  may apply a compressive axial force, a tensile axial force, or alternating compressive and tensile axial forces to the BRBs  300 . For instance, tilting the frame  320  shown in  FIG.  3    to the side may apply a compressive axial force to one of the BRBs  300  shown in  FIG.  3    and a tensile axial force to the other BRB  300  shown in  FIG.  3   . However, since the BRBs  300  are able to resist an equal or substantially equal magnitude of compressive and tensile axial forces, the BRBs  300  are able to withstand both the compressive and tensile axial forces. 
     While various aspects and embodiments have been disclosed herein, other aspects and embodiments are contemplated. The various aspects and embodiment disclosed herein are for purposes of illustration and are not intended to be limiting. Also, terms of degree (e.g., about) indicate structurally insignificant variations or variations of at most ±10% or at most ±5%.