U.S. patent application number 13/432928 was filed with the patent office on 2013-03-28 for geometric connecting assembly and method for braced frame connections.
The applicant listed for this patent is Ian David Aiken, Daniel Merle Andreason, Cameron John Black, Junichi Yazawa. Invention is credited to Ian David Aiken, Daniel Merle Andreason, Cameron John Black, Junichi Yazawa.
Application Number | 20130074440 13/432928 |
Document ID | / |
Family ID | 47909694 |
Filed Date | 2013-03-28 |
United States Patent
Application |
20130074440 |
Kind Code |
A1 |
Black; Cameron John ; et
al. |
March 28, 2013 |
GEOMETRIC CONNECTING ASSEMBLY AND METHOD FOR BRACED FRAME
CONNECTIONS
Abstract
The present invention is directed towards improved apparatuses
and methods for connecting a structural bracing system having a
first geometry to a structure or structural component having a
second geometry.
Inventors: |
Black; Cameron John;
(Berkeley, CA) ; Aiken; Ian David; (Oakland,
CA) ; Andreason; Daniel Merle; (Sparks, NV) ;
Yazawa; Junichi; (Tokyo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Black; Cameron John
Aiken; Ian David
Andreason; Daniel Merle
Yazawa; Junichi |
Berkeley
Oakland
Sparks
Tokyo |
CA
CA
NV |
US
US
US
JP |
|
|
Family ID: |
47909694 |
Appl. No.: |
13/432928 |
Filed: |
March 28, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61468949 |
Mar 29, 2011 |
|
|
|
Current U.S.
Class: |
52/704 ;
52/745.21 |
Current CPC
Class: |
E04B 1/38 20130101; E04B
1/54 20130101; E04H 9/028 20130101; E04B 2001/2496 20130101; E04H
9/02 20130101; E04H 9/0237 20200501 |
Class at
Publication: |
52/704 ;
52/745.21 |
International
Class: |
E04B 1/38 20060101
E04B001/38 |
Claims
1. A method for connecting a structural brace to a building frame
comprising the steps of: providing a brace having an end comprising
a geometric mating surface; providing a connector comprising a
first end comprising a mating component, said mating component
having a geometric shape that is substantially complementary to the
geometric mating surface of the brace end such that the geometric
mating surface of the brace end is insertable and receivable into
the substantially complementary geometric shape of the connector
mating component, and a second end pre-selected and dimensioned to
engage a frame; providing a frame support connected to the frame,
said frame support comprising a surface dimensioned to engage the
second end of the connector; attaching the connector to the frame
support; and attaching the brace to the connector.
2. The method of claim 1, wherein the connector comprises a
plurality of components.
3. The method of claim 1, wherein the geometric shape of the
connector mating component is selected from the group consisting
of: curved, linear, box-shaped, cruciform-shaped, I-shaped, x- or
star-shaped, intersecting diagonals, and "arrow-shaped", continuous
or interrupted geometries, and combinations thereof.
4. The method of claim 1, wherein the geometric shape of the
connector mating component is configured to receive a substantially
cruciform shape.
5. The method of claim 1, wherein the brace is made from a material
selected from the group consisting of: steel, steel alloys,
aluminum, aluminum alloys, and combinations thereof.
6. The method of claim 1, wherein the connector is made from a
material selected from the group consisting of: ASTM Grade A500,
A501, A53, A36, A572, A913, A992, A1043, A958, and combinations
thereof.
7. The method of claim 1, wherein the frame support is made from a
material selected from the group consisting of steel, steel alloys,
aluminum, aluminum alloys, and combinations thereof.
8. The method of claim 1, wherein the frame support comprises a
gusset.
9. The method of claim 1, wherein the connector is attached to the
frame support according to method selected from the group
consisting of: welding, bolting, riveting, and combinations
thereof.
10. The method of claim 1, wherein the brace is attached to the
connector according to method selected from the group consisting
of: welding, bolting, riveting, and combinations thereof.
11. An apparatus for connecting a structural brace to a frame
comprising a connector comprising a first connector end having a
mating component, said mating component having a geometric shape
that is substantially complementary to a geometric mating surface
of a brace end such that the geometric mating surface of the brace
end is insertable and receivable into the substantially
complementary geometric shape of the connector mating component,
and a second connector end pre-selected and dimensioned to engage a
frame.
12. The apparatus of claim 11, wherein the connector comprises a
plurality of components.
13. The apparatus of claim 11, wherein the geometric shape of the
connector mating component is selected from the group consisting
of: curved, linear, box-shaped, cruciform-shaped, I-shaped, x- or
star-shaped, intersecting diagonals, "arrow-shaped", and
combinations thereof.
14. The apparatus of claim 11, wherein the geometric shape of the
connector mating component is configured to receive a substantially
cruciform shape.
15. The apparatus of claim 11, wherein the brace is made from a
material selected from the group consisting of: steel, aluminum,
and combinations thereof.
16. The apparatus of claim 11, wherein the connector is made from a
material selected from the group consisting of: ASTM Grade A500,
A501, A53, A36, A572, A913, A992, A1043, A958, and combinations
thereof.
17. The apparatus of claim 11, wherein the frame comprises a frame
support, said support made from a material selected from the group
consisting of: steel, steel alloys, aluminum, aluminum alloys, and
combinations thereof.
18. A structure comprising the apparatus of claim 11.
19. The structure of claim 18, wherein the structure is a
building.
20. The structure of claim 18, wherein the structure is a
bridge.
21. The structure of claim 18, wherein the structure is an
industrial structure.
Description
CROSS-REFERENCE
[0001] This application claims the benefit of the priority of
presently pending Provisional U.S. application No. 61/468,949,
filed Mar. 29, 2011, entitled "Geometric Connecting Assembly and
Method for Braced Frame Connections", and is incorporated by
reference herein in its entirety.
FIELD OF THE INVENTION
[0002] The present invention is directed towards improved
apparatuses and methods for the connection of a structural bracing
system to a structure.
BACKGROUND
[0003] Braces of many types, including, but not limited to
budding-restrained braces are used as part of lateral
load-resisting systems for earthquake and wind resistance of
structures (buildings, bridges or other types of structures). They
are most commonly used in diagonal configurations between building
stories, however, other configurations/orientations are possible.
Braces for building structures may be used in many different forms,
such as, for example, braces used in concentric and non-concentric
bracing systems. Braces used in structural construction are often
square or rectangular tube, or round pipe sections. Other types of
braces use rolled sections (I-shapes or angles). Many types of
structural brace elements are known. For example,
buckling-restrained braces may have an outer steel shell and an
inner steel component with a material such as a concrete, cement,
or other material of varying elasticity interposed between the two
steel components. In the case of braces comprising tube or pipe
outer sections, the connection between the brace element and the
frame structure of, for example a building or bridge, etc., is
usually made by slotting the end of the tube (or pipe) to allow it
to fit over a gusset plate, and then connecting the tube to the
gusset to complete the connection.
[0004] A gusset plate is a flat plate located at the intersection
of a frame of a structure, such as, for example, a beam and/or
column. The gusset plate may be welded along its edge at the beam
and column. The primary function of the gusset plate is to provide
a connection point to the structural framing system and is commonly
used for diagonal bracing systems. However, the end of a brace may
often comprise a multi-planar geometry, such as, for example, a
cruciform cross-section, and the gusset plate on the main structure
to which the brace attaches is typically a flat plate occurring in
a substantially singular plane. In the past, according to known
configurations, bolted connections between a cruciform
cross-section brace and a gusset plate have required the addition
of a series of separate rib plates connected to the gusset plate to
create a cruciform cross-section on the gusset, substantially
similar in shape to the brace end. Additional splice plates are
then bolted onto the gusset and onto the brace to establish the
connection therebetween.
[0005] Many types of connections between cruciform brace ends and
gusset plates with rib plates are known. One such connection
comprises groove-welding in the interface between the brace end and
the gusset. This type of welding is difficult to perform in the
field, and combined with the angular installation of the brace, and
considering required tolerances for this special type of weld, such
a connection is time-consuming, difficult, requires additional
multiple parts such as wing, or side plates to build-up the gusset,
and is otherwise not preferred for use in practice. Another type or
connection comprises the presence of a slot in the gusset plate,
with one horizontal leg of the brace cruciform end placed in the
gusset slot until the vertical legs of the cruciform adjoin the
gusset plate. Weld metal is then placed around the edges of the
vertical surface of the brace cruciform end to connect it to the
gusset. This configuration is also a time-consuming, difficult to
perform, and involves a number of structural compromises that are
undesirable. Another type of known welding comprises the welding of
multiple plates or angle sections between the cruciform brace end
and the cruciform cross-section on the gusset. This configuration
is also time-consuming, difficult to perform, and involves a number
of structural compromises that are undesirable. Additionally, such
joining of brace elements to a structural frame in the field is
labor-intensive and requires maintaining a large inventory of
custom fittings uniquely identified to the type of brace being
used. A cost-effective and less labor-intensive method of joining
braces and brace elements to structural frames that is also more
universal or standardized would be particularly advantageous.
SUMMARY OF THE INVENTION
[0006] Embodiments of the present invention are directed to methods
for connecting a structural brace to a building frame comprising
the steps of providing a brace having an end comprising a geometric
mating surface, and providing a connector for one or multiple
parts, such as a geometric connecting assembly (GCA), comprising a
first end having a mating component comprising a geometric shape
that is substantially complementary to the geometric mating surface
of the brace, such that the geometric mating surface of the brace
end is insertable and receivable into the substantially
complementary geometric shape of the connector mating component.
The connector has a second end pre-selected and dimensioned to
engage a frame support. A frame support is provided comprising a
surface dimensioned to engage the second end of the connector. The
connector is then connected to the frame support, and the brace is
connected to the connector.
[0007] The geometric shape of the connector mating component may be
any desired geometric shape, but is preferably selected from the
group consisting of: curved, linear, box-shaped, I-shaped, x-shaped
or star-shaped, intersecting diagonals, and "arrow-shaped",
continuous or interrupted geometries, and combinations thereof,
with a geometry suited to receive a cruciform shape being
particularly preferred. It is understood that the term "cruciform"
encompasses all cross-shaped geometries including those where the
intersecting lines are and are not equidistant, and the
intersecting lines may intersect each other at angles that create
angles at their intersection of more than, less than or equal to
about 90.degree..
[0008] According to further embodiments, the present invention is
directed to an apparatus for connecting a structural brace to a
building frame comprising a brace having an end comprising a
geometric mating surface and a connector comprising a first end
having a mating component comprising a geometric shape that is
substantially complementary to a geometric mating surface of a
brace, such that the geometric mating surface of the brace end is
insertable and receivable into the substantially complementary
geometric shape of the connector mating component. The connector
has a second end pre-selected and dimensioned to engage a frame
support.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The objects and advantages of the embodiments of the
invention will become more readily apparent to those of ordinary
skill in the field after reviewing the following detailed
description and accompanying drawings wherein:
[0010] FIG. 1 is a perspective close-up view of one embodiment of
the invention showing a cruciform-ended brace connected by a GCA to
the gusset plate;
[0011] FIG. 2 shows a second view of the embodiment of FIG. 1;
[0012] FIG. 3 shows a further variation of the embodiment of FIG.
1, wherein the GCA end closest to structural frame is tapered and
closed, and the GCA end closest to the brace end is open;
[0013] FIG. 4 shows a variation of the embodiment of FIG. 3,
wherein the GCA end closest to the structural frame is tapered and
closed, and the GCA end closest to the brace end is closed;
[0014] FIG. 5 is a further perspective close-up view of another
embodiment of the invention showing a brace of cruciform
cross-section connected by a GCA to the gusset plate;
[0015] FIG. 6 is an exploded view of the assembly shown in FIG. 5;
and
[0016] FIGS. 7a and 7c-7g show illustrative configurations for the
geometric shapes of GCA alternative to the box-shape of FIG. 7b and
illustrated in FIGS. 1-6.
DETAILED DESCRIPTION OF THE INVENTION
[0017] Embodiments of the GCA of the present invention are
significant improvements over known structural connection concepts,
namely, the slotting of a closed prismatic section, by using a
selectively dimensioned segment or segment, preferably "built-up
from two component parts, to facilitate the attachment of a brace
to a structural frame, such as, for example, a gusset plate. The
built-up section or sections form an adapter that is specifically
dimensioned to universally connect the brace having a first
geometric configuration (typically in multiple planes) to a
building support structure having a second geometric configuration
different from the first configuration (typically in one plane).
According to preferred embodiments of the present invention braces
with cruciform cross-sections are connected to a gusset plate at
each end of the brace using the GCA of the present invention to
transfer the force from the brace to the building frame.
[0018] According to still further embodiments of the present
invention, one function of the current invention is to connect a
bracing member to a structural frame. It is understood that the
structural frame is one that may be found in any structure such as,
for example, buildings, bridges, open structures such as a hangars,
and any industrial structure that may or may not be designed for
occupancy. For cruciform cross-section braces, the GCA provides
greatly enhanced stability against in- or out-of-plane bending or
buckling for brace compression loads, such as, for example, those
that occur under earthquake or wind lateral loading on a structure,
both for the end of the brace and for the gusset plate itself. For
a brace with a GCA connection, compared to, for example, the known
cruciform brace connection types described above, the bending
moment of inertia of the connection region is of the order of about
3 to about 5 times greater.
[0019] FIG. 1 shows one embodiment of the present invention. A
connection assembly 10 is shown. Gusset plate 12 is connected to or
is an integral part of building support 14. A GCA 16 is connected
to gusset plate 12. Brace 18 has cruciform connecting end 20
engaging and connected to GCA 16. FIG. 2 is a reverse angle view of
FIG. 1.
[0020] FIG. 3 shows an embodiment of the present invention where
GCA 16 comprises a tapered end 22 engaging gusset plate 12. In
FIGS. 1-3, GCA 16 has an open end 24. FIG. 4 shows an embodiment
where GCA 16 has a top plate 26 having a negative cruciform cut
into top plate 26 and into which brace cruciform connecting end 20
is inserted. It is understood that top plate 26 may be constructed
from numerous separate plates joined together to form the top plate
26. As such, it is understood that end 20 is secured at top plate
26, including scenarios where end 20 is brought to a particular
orientation first, and top plate 26 is built-up around end 20.
[0021] According to one embodiment of the present invention, as
shown in FIG. 5, an end of a cruciform-ended brace 50, which may
include a buckling-restrained brace (not shown), is shown in
position engaging the geometric (in this instance, box-shape,
configured to receive a cruciform shape) end of the GCA 52 of the
present invention. The end of the brace 50 that engages the GCA 52
is configured to mate with the substantially complementary
geometric shape of the GCA 52. In this way, a length of the
cruciform end of the brace 50 is inserted into, and otherwise
engages the GCA 52 in a mating orientation. The mating end of the
brace 50 and the GCA 52, therefore, have cruciform and negative
cruciform cross-sections, respectively.
[0022] FIG. 6 is an exploded view of the structure shown in FIG. 5.
As shown in FIGS. 5-6, according to one embodiment of the present
invention, in the case of a cruciform cross-section brace, the slot
in the brace end of the GCA is adjoined to the cruciform end of the
brace and the GCA and brace are connected together by welding. FIG.
6 shows the two C-shaped components of the GCA, 52a and 52b. When
components 52a and 52b are positioned relative to each other to
form a negative geometric opening at end 58 that is preselected to
substantially match the dimension and geometry of the gusset plate
54 into which the GCA will fit. The GCA components 52a and 52b are
then preferably connected to the gusset 54 by welding. In addition,
when components 52a and 52b are positioned relative to each other
to form a negative geometric opening at end 56 that is preselected
to substantially match the dimension and geometry of the brace end
60 allowing the brace end 60 to engage the GCA component.
[0023] According to one preferred embodiment, to connect the GCA
components 52a and 52b to the brace end 60, edges A of 52a' and 52b
are adjoined to edge A' of brace end 60. Slots B of 52a and 52b are
positioned over edge B' of brace end 60 and edges C of 52a and 52b
are adjoined to edge C' of brace end 60. Further, the GCA
components 52a and 52b are adjoined to the gusset plate 54 by
adjoining edges D of 52a and 52b to regions D' of gusset plate 54
(region D' is on both sides of gusset plate 54) and similarly by
adjoining edges E of 52a and 52b to region E' of gusset plate 54
(region E' is on both sides of gusset plate 54).
[0024] It is further understood that the presence of the two
"C-shaped components" 52a and 52b may be obviated by providing a
singular GCA component, or more than two components that have been
designed and dimensioned to receive the brace, in geometric, and
substantially complementary fashion, while also fitting onto the
gusset of a structural frame, or the structural frame itself.
[0025] It is also understood that any geometry may be used, in
addition to cruciform, that is structurally advantageous in terms
of resistance to in- and out-of-plane bending, load/force transfer,
etc., or that may be desired for ease of assembly or architectural
reasons. Other embodiments are further contemplated by the present
invention, including the use of GCAs having a geometry
complementary with braces having cross-sections such as, for
example, curved, linear, box-shaped, I-shaped, x- or star-shaped,
intersecting diagonals or "arrow-shaped", continuous or interrupted
geometries, etc. Non-limiting, illustrative geometries are shown in
FIGS. 7a-7g. As mentioned above, in these embodiments, and
alternatively, also for the case of a cruciform cross-section
brace, the GCA may comprise a single tube section, rather than
multiple components that can be oriented together to best join a
brace end to a structural frame. For example, as shown in FIG. 6,
two "C-shaped" components, with appropriate slots provided are
dimensioned to accept the geometric form of the brace cross-section
at one end of the GCA, and the gusset section at the other end of
the GCA.
[0026] Therefore, according to one embodiment, the GCA has a
slotted end opposite the cruciform end for engaging with a frame
structure component, such as, for example, a gusset plate. Though
not shown, it is understood that the gusset plate represents the
feature by which the brace is connected to the structure to be
supported via the GCA. Therefore, embodiments of the present
invention further contemplate attachment of braces via the GCA
directly to the structural frame, even in the absence of a specific
gusset.
[0027] Further, embodiments of the present invention allow for
significantly larger forces to be transferred from a
cruciform-ended brace to the building frame as compared to other
known welded connection configurations. For lower-force braces, the
present invention further contemplates that the tube portions of
the GCA can be made, for example, from split hollow steel sections,
and for larger-force braces the tube portions of the GCA can be
fabricated from steel plate pieces to form a built-up section.
Embodiments of the present invention also allow for the casting of
the GCA to achieve desired geometric connecting pieces and
architectural details. The GCA can be fabricated from any steel, or
metallic alloy, that provides sufficient strength and stiffness
properties for the application, such as, for example, ASTM Grade
A500, A501 and A53, etc., with ASTM Grade A 500 being particularly
preferred for a GCA comprising hollow steel sections; and also ASTM
A36, A572, A913, A992 and A1043 for GCA built-up sections, with
ASTM A36 and A572 being particularly preferred; and ASTM A958 being
particularly preferred for GCAs comprising cast shapes.
[0028] According to one embodiment of the present invention, as
shown in FIGS. 5 and 6, an end of a cruciform-ended brace, which
may include, for example, a buckling-restrained brace, is shown in
position engaging the geometric (in this instance, box-shape,
configured to receive a cruciform shape) end of the GCA of the
present invention. The end of the brace that engages the GCA is
configured to mate with the substantially complementary geometric
shape of the GCA. In this way, a length of the cruciform end of the
brace is inserted into, and otherwise engages the GCA in a mating
orientation. The mating end of the brace and the GCA, therefore,
has cruciform and negative cruciform cross-sections, respectively.
It is further understood that any geometry may be used, in addition
to cruciform, that is structurally advantageous in terms of
resistance to in- and out-of-plane bending, load/force transfer,
etc., or that may be desired for ease of assembly or architectural
reasons. Such alternative geometries are illustrated in FIGS. 7a-7g
for non-limiting and non-comprehensive purposes.
[0029] There are various possible methods that may be used to
connect (e.g. attach, etc.) the GCA component, or components, to
the brace end and to the gusset plate. For example, the GCA
component, or components, may be attached to the brace ends by
welding, at a location remote from the building construction site.
The brace, with GCA components attached, may be subsequently welded
to, for example, the gusset plate at the building construction
site, etc.
[0030] No specific welding technique is required according to the
present invention, and the methods employed may depend only on the
structural building code having jurisdiction in the region of
intended use. Useful non-limiting welding techniques may include,
for example, GMAW, SMAW, FCAW, SAW, EGW and ESW, as would be
readily understood by one skilled in the welding field.
[0031] To facilitate welding of the brace and GCA to the gusset
plate at the building site, various temporary support features may
be provided on the brace, gusset and on the GCA, or any combination
thereof, to facilitate positioning of the GCA before welding it to
the gusset plate and brace. These may include features, such as,
for example, holes or temporary support seats, etc.
[0032] It is further understood, and further embodiments of the
present invention contemplate, that the GCA may be designed to
connect any brace element, especially a brace element end having
multi-planar geometry to a support frame element, such as for
example, a gusset having single- or multi-planar geometry. The
desired connecting method comprises not only welding, but any
attaching or connecting means that will suitably join a brace
element to a support structure of a building, such as, for example,
a building frame. Such connecting means include bolting, riveting,
or use of any suitable fastening means designed to provide the
required strength, stability and resistance to in-and out-of-plane
bending of the brace end, connection region and gusset plate, while
allowing control of the cross-sectional dimensions of the
connection region in the design process, to meet architectural
design requirements, local building standards and codes, etc.
[0033] Therefore, embodiments of the present invention contemplate
many unique features of the GCA such as, for example facilitating
attachment of a brace member having a multi-planed end to a flat
(single-planed) frame or multi-planed support feature, such as, for
example, a gusset plate. In a preferred embodiment the multi-planed
end of the brace is cruciform in shape.
[0034] Still further, embodiments of the present invention
contemplate facilitating the connection of brace and gusset plate
parts of dissimilar thickness, dimension and/or geometry. This is
accomplished by, for example, varying of the width of the slots
along the longitudinal length of the GCA, and varying the geometry
on each end of the GCA. According to one embodiment, the present
invention obviates the need for bolts or pins, as the components
are preferably welded.
[0035] If desired, all welds for the attachment of the GCA to the
brace, and the GCA to the gusset plate, can be fillet welds; among
the easiest and most economical weld used in building structure
construction. A fillet weld is understood to be a weld used to join
two parts of steel with surfaces to be welded often oriented at
approximately right angles to each other, to make lap joints,
corner joints, or T-joints. Other types of welds may be used,
including groove-welds of the partial or full penetration type.
[0036] As mentioned above, the GCA configurations of the present
invention therefore provide high-strength and a high-bending
stiffness for superior stability and resistance to in- and
out-of-plane bending of the brace end, connection region and gusset
plate, while allowing control of the cross-sectional dimensions of
the connection region in the design process, to meet architectural
design requirements. This is possible because the GCA does not
necessarily comprise a single pre-defined cross-sectional shape.
Rather, the size, shape and thickness of the GCA component parts
can be selectively designed and dimensioned to achieve strength,
stiffness and architectural design objectives. As a result, the GCA
configuration allows greater flexibility in the cross-sectional
dimensions of the brace cruciform end (than with conventional known
connections), to meet architectural design requirements. One
example of this flexibility is that the dimension of the cross
section of the cruciform is not dictated by dimensions previously
required, such as, for example, bolting. In addition, according to
still further embodiments of the present invention, the GCAs are
understood to facilitate connecting braces to structural frames,
including frames that may or may not have structural connecting
features, such as, for example, gussets. In this way, the GCAs of
the present invention also contemplate connecting braces and brace
assemblies directly to structural frames.
[0037] As stated above, the present invention allows many
variations in the geometric shape and form of the connection (such
as tapers, and closed forms), and thus provides for greater
architectural design opportunity, such as, for example, greater
variations in the geometric shape and form of the brace tube and
the tube connection portion when built-up sections are used. This
allows greater architectural design opportunities, different weld
configurations, and consequently more manufacturing options. Some
illustrative configurations are shown in FIGS. 7a-7g.
[0038] Numerous other aspects of embodiments, embodiments,
features, and advantages of the present invention will appear from
the following detailed description and the accompanying drawings.
In the description and/or the accompanying drawings, reference is
made to exemplary aspects of embodiments and/or embodiments of the
invention which can be applied individually or combined in any way
with each other. Such aspects of embodiments and/or embodiments do
not represent the full scope of the invention. Reference should
therefore be made to the claims herein for interpreting the full
scope of the invention.
* * * * *