U.S. patent application number 13/870723 was filed with the patent office on 2014-10-30 for structural member with x-web.
This patent application is currently assigned to Wetzel Engineering, Inc.. The applicant listed for this patent is Ryan Michael Barnhart, Kyle K. Wetzel. Invention is credited to Ryan Michael Barnhart, Kyle K. Wetzel.
Application Number | 20140322025 13/870723 |
Document ID | / |
Family ID | 51789392 |
Filed Date | 2014-10-30 |
United States Patent
Application |
20140322025 |
Kind Code |
A1 |
Barnhart; Ryan Michael ; et
al. |
October 30, 2014 |
Structural Member with X-Web
Abstract
Disclosed is a structure that may include a first flange, a
second flange, and a web connecting the first flange to the second
flange. In example embodiments, the web may include at least one
end with at least two angled members attaching to one of the first
flange and the second flange and another end connecting to the
other of the first flange and the second flange. Disclosed also is
a wind turbine blade that includes the structure.
Inventors: |
Barnhart; Ryan Michael;
(Lenexa, KS) ; Wetzel; Kyle K.; (Lawrence,
KS) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Barnhart; Ryan Michael
Wetzel; Kyle K. |
Lenexa
Lawrence |
KS
KS |
US
US |
|
|
Assignee: |
Wetzel Engineering, Inc.
Lawrence
KS
|
Family ID: |
51789392 |
Appl. No.: |
13/870723 |
Filed: |
April 25, 2013 |
Current U.S.
Class: |
416/241R ;
428/172 |
Current CPC
Class: |
F01D 5/147 20130101;
Y02E 10/72 20130101; F03D 1/0675 20130101; Y02B 10/30 20130101;
Y10T 428/24612 20150115; F05D 2230/51 20130101; Y02E 10/721
20130101 |
Class at
Publication: |
416/241.R ;
428/172 |
International
Class: |
F01D 5/14 20060101
F01D005/14 |
Claims
1. A structure comprised of: a first flange; a second flange; and a
web connecting the first flange to the second flange, wherein the
web includes at least one end with at least two angled members
attaching to one of the first flange and the second flange and
another end connecting to the other of the first flange and the
second flange.
2. The structure according to claim 1, wherein the web is comprised
of a core sandwiched between a first layer and a second layer.
3. The structure according to claim 2, wherein the core includes
one of an X-shaped core and a V-shaped core.
4. The structure according to claim 1, wherein the web has a
substantially X-shape and the at least one end with at least two
angled members attaching to one of the first flange and the second
flange includes two angled members attaching to the first
flange.
5. The structure of claim 4, wherein the another end connecting to
the other of the first flange and the second flange includes two
angled members attaching the second flange.
6. A wind turbine blade including the structure of claim 1.
7. The wind turbine blade according to claim 6, wherein the web has
a substantially X-shape and at least one end with at least two
angled members attaching to one of the first flange and the second
flange includes two angled members attaching to the first
flange.
8. The wind turbine blade according to claim 7, wherein the another
end connecting to the other of the first flange and the second
flange includes two angled members attaching the second flange.
9. The wind turbine blade according to claim 7, further comprising:
a shell enclosing the web.
10. The wind turbine blade according to claim 6, wherein the web
has one of an X shape, a Y shape, a double Y shape, and a
.PSI.-shape.
11. The wind turbine blade according to claim 6, wherein the web
runs along a substantial length of the blade.
Description
BACKGROUND
[0001] 1. Field
[0002] Example embodiments relate to a structure having a web
comprised of angled members. A non-limiting example of a structure
using the web comprised of angled members is a wind turbine
blade.
[0003] 2. Description of the Related Art
[0004] FIGS. 1A and 1B illustrate a perspective view and a
cross-section view of a conventional I beam 10 as is well known in
the art. FIGS. 2A and 2B illustrate a modification of the
conventional I beam 10. In the first embodiment, the I beam 10
includes a web 12 connecting a first flange 14 to a second flange
16. Similarly, the modified I beam 20 includes a web 22 also
connecting a first flange 24 to a second flange 26. As is obvious
in the drawings, the first and second flanges 24 and 26 of the
modified I beam 20 are curved members whereas the first and second
flanges 14 and 16 of the conventional I beam 10 are flat members.
In either case, however, the webs 12 and 22 of the I beams 10 and
20 are rectangular shaped members. Such beams have found use in
various structures such as buildings and machines.
[0005] FIG. 3 illustrates a cross-section of a conventional wind
turbine blade 50. As shown in FIG. 3, the conventional wind turbine
blade 50 includes a shell 70 which encloses a spar member 60. The
spar member 60, like the conventional I-beam 10 and the modified
I-beam 20, includes a shear web 62 and two flanges 64 and 66
(referred to as spar caps) arranged at ends of the shear web 62.
The spar member 60 generally runs along a length of the wind
turbine blade 50 and acts as a primary load bearing member. In use,
the wind turbine blade 50 is subject to various loads such as
shear, bending, and torsion loads and the spar member 60 must be
designed to withstand each of these loads. As is well known in the
art, because the spar 60 may be subject to relatively high shear
loads, the web 62 is susceptible to buckling. Buckling of the web
62, however, may be prevented by increasing a thickness of the web
62 or by adding various reinforcing structures to the web 62.
However, each approach adds weight to a wind turbine blade which is
undesirable.
SUMMARY
[0006] Example embodiments relate to a structure having a web
comprised of angled members. A non-limiting example of a structure
using the web comprised of angled members is a wind turbine
blade.
[0007] Example embodiments disclose a structure that may include a
first flange, a second flange, and a web connecting the first
flange to the second flange. In example embodiments, the web may
include at least one end with at least two angled members attaching
to one of the first flange and the second flange and another end
connecting to the other of the first flange and the second flange.
Disclosed also is a wind turbine blade that includes the
structure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Example embodiments are described in detail below with
reference to the attached drawing figures, wherein:
[0009] FIGS. 1A and 1B are views of a conventional I-beam;
[0010] FIGS. 2A and 2B are views of a modified I-beam;
[0011] FIG. 3 is a cross-section view of a conventional wind
turbine blade;
[0012] FIGS. 4A and 4B are views of a structure in accordance with
example embodiments;
[0013] FIGS. 5A and 5B are views of a structure in accordance with
example embodiments;
[0014] FIGS. 6A-6C are views of a structure in accordance with
example embodiments;
[0015] FIGS. 7A-7D are cross section views of structures in
accordance with example embodiments
[0016] FIG. 8 is a cross-section view of a wind turbine blade in
accordance with example embodiments;
[0017] FIG. 9 is a cross-section view of a conventional wind
turbine blade showing a shear flow pattern;
[0018] FIG. 10 is a cross-section view of a wind turbine blade in
accordance with example embodiments showing a shear flow
pattern;
[0019] FIGS. 11A-11C are cross section views of wind turbine blades
in accordance with example embodiments; and
[0020] FIGS. 12A-12C are section views of conventional wind turbine
blades.
DETAILED DESCRIPTION
[0021] Example embodiments will now be described more fully with
reference to the accompanying drawings. Example embodiments are not
intended to limit the invention since the invention may be embodied
in different forms. Rather, example embodiments are provided so
that this disclosure will be thorough and complete, and will fully
convey the scope of the invention to those skilled in the art. In
the drawings, the sizes of components may be exaggerated for
clarity.
[0022] In this application, when an element is referred to as being
"on," "attached to," "connected to," or "coupled to" another
element, the element may be directly on, directly attached to,
directly connected to, or directly coupled to the other element or
may be on, attached to, connected to, or coupled to any intervening
elements that may be present. However, when an element is referred
to as being "directly on," "directly attached to," "directly
connected to," or "directly coupled to" another element or layer,
there are no intervening elements present. In this application, the
term "and/or" includes any and all combinations of one or more of
the associated listed items.
[0023] In this application, the terms first, second, etc. are used
to describe various elements and components. However, these terms
are only used to distinguish one element and/or component from
another element and/or component. Thus, a first element or
component, as discussed below, could be termed a second element or
component.
[0024] In this application, terms, such as "beneath," "below,"
"lower," "above," "upper," are used to spatially describe one
element or feature's relationship to another element or feature as
illustrated in the figures. However, in this application, it is
understood that the spatially relative terms are intended to
encompass different orientations of the structure. For example, if
the structure in the figures is turned over, elements described as
"below" or "beneath" other elements would then be oriented "above"
the other elements or features. Thus, the term "below" is meant to
encompass both an orientation of above and below. The structure may
be otherwise oriented (rotated 90 degrees or at other orientations)
and the spatially relative descriptors used herein interpreted
accordingly.
[0025] Example embodiments are illustrated by way of ideal
schematic views. However, example embodiments are not intended to
be limited by the ideal schematic views since example embodiments
may be modified in accordance with manufacturing technologies
and/or tolerances.
[0026] The subject matter of example embodiments, as disclosed
herein, is described with specificity to meet statutory
requirements. However, the description itself is not intended to
limit the scope of this patent. Rather, the inventors have
contemplated that the claimed subject matter might also be embodied
in other ways, to include different features or combinations of
features similar to the ones described in this document, in
conjunction with other technologies. Generally, example embodiments
relate to a structure having a web comprised of angled members. A
non-limiting example of a structure using the web comprised of
angled members is a wind turbine blade.
[0027] FIGS. 4A and 4B represent a perspective view and a cross
section view of a structure 100 in accordance with example
embodiments. Like a conventional I beam, the structure 100 may
include a first flange 110 and a second flange 120. However, unlike
the conventional I beam, which uses a rectangular shaped web to
connect a first flange to a second flange, the structure 100
includes a web having members angled with respect to the first and
second flanges 110 and 120. In this particular nonlimiting example,
the angled members form an X-shaped web 130 connecting the first
flange 110 to the second flange 120. In example embodiments, the
first and second flanges 110 and 120 may be substantially plate
shaped members. For example, each of the first and second flanges
110 and 120 may resemble rectangular plates having substantially
the same dimensions.
[0028] FIGS. 5A and 5B represent a perspective view and a cross
section view of a structure 200 in accordance with example
embodiments. Like a conventional I beam, the structure 200 may
include a first flange 210 and a second flange 220. However, unlike
the conventional I beam which uses a rectangular shaped web to
connect a first flange to a second flange, the structure 200
includes angled members to connect the first flange 210 to the
second flange 220. In this particular nonlimiting example, the
angled members form an X-shaped web 230 connecting the first flange
210 to the second flange 220. In example embodiments, the first and
second flanges 210 and 220 may be substantially plate shaped
members. However, unlike the flat plate shaped flanges 110 and 120
of structure 100, the first and second flanges 210 and 220 may
resemble curved plates or shells.
[0029] In example embodiments, the structures 100 and 200 are
illustrated as structures have substantially constant cross
sections. However, this aspect of example embodiments is not
intended to limit the invention. For example, FIG. 6A illustrates
another example of a structure 300 in accordance with example
embodiments. In example embodiments, the cross-section of the
structure 300 changes along a length L of the structure 300. As in
the previous examples, the structure 300 includes a substantially
X-shaped web 330 that connects a first flange 310 to a second
flange 320. FIG. 6B is a section view of the structure 300 taken
near a first end 6B of the structure 300 and FIG. 6C is a view of
the structure 300 taken near a second end 6C of the structure 300.
As shown in FIGS. 6B and 6C the dimensions of the flanges 310 and
320 as well as the dimensions and configuration of the web 330 of
the structure 300 may change along a length of the beam.
[0030] It is understood that the structures 100, 200, and 300 are
exemplary structures only and are not intended to limit example
embodiments. For example, in structures 100 and 200 the flanges are
illustrated as being substantially identical to each other. For
example, in structure 100 the first flange 110 and the second
flange 120 are both substantially rectangular plate shaped members
having substantially the same dimensions. Similarly, in structure
200, the first flange 210 and the second flange 220 are both
substantially curved plate shaped members having substantially the
same dimensions. However, example embodiments also include
structures having an X-web wherein the structure has a first flange
of a first shape, for example, a flat rectangular plate such as
flange 110, and a second flange of a second shape, for example, a
curved plate such as flange 220. Furthermore, the sizes of the
flanges may be different. For example, example embodiments also
include structures having an X-web and a first and second flange
wherein the first and second flanges have different thicknesses,
widths, and/or shapes.
[0031] In example embodiments, each of the components of the
structures 100, 200, and 300 may be made from an isotropic
material, for example, metal; or an orthotropic or anisotropic
material, such as a laminated composite material, or a combination
thereof. For example, each of the webs and flanges may be made from
laminated composite materials wherein a core member, such as balsa,
is sandwiched between glass layers.
[0032] FIGS. 7A-7D illustrate various non-limiting examples of
structures in accordance with example embodiments. In FIG. 7A, for
example, the structure 400 is comprised of a first flange 410, a
second flange 420, and an X-web 430 connecting the first flange 410
to the second flange 420. In example embodiments the X-web 430 is
comprised of a first V-shaped member 440 and a second V-shaped
member 450 connected together by an adhesive 460. As shown in FIG.
7A, the first V-shaped member 440 may be comprised of a first core
442 sandwiched between a first layer 444 and a second layer 446.
Similarly, the second V-shaped member 450 may be comprised of a
second core 452 sandwiched between a third layer 454 and a fourth
layer 456. In example embodiments, either of the cores 442 and 452
may be made from materials such as end grain balsa, cork, styrene
acrylonitrile (SAN) foam, polyvinyl chloride (PVC) foam,
polyethylene terephthalate (PET) foam, and/or a combination
thereof. The first, second, third, and fourth layers 444, 446, 454,
and 456 may be made from materials such as plastic reinforced by
glass, carbon, high-modulus aromatic polyamide (i.e. aramid),
basalt, and/or a combination thereof. These materials are provided
as nonlimiting examples and should not be construed as a limitation
on the invention. In example embodiments, the first and second
flanges 410 and 420 may likewise be made from a laminated composite
material. In this particular nonlimiting example embodiment, the
first V-shaped member 440 and the second V-shaped member 450 may be
manufactured separately and then joined together by the adhesive
460.
[0033] FIG. 7B illustrates another example of a structure 500 in
accordance with example embodiments. As shown in FIG. 7B, the
structure 500 may be comprised of a first flange 510, a second
flange 520, and an X-web 530 connecting the first flange 510 to the
second flange 520. In example embodiments the X-web 530 may be
comprised of a X-shaped core 540. As shown in FIG. 7B, surfaces of
the X-shaped core 540 may be covered by a layer or layers of
materials. For example, the X-shaped core 540 may be covered by a
first layer 541, a second layer 542, a third layer 543, and a
fourth layer 544. In example embodiments, the core 540 may be made
from materials such as end grain balsa, cork, styrene acrylonitrile
(SAN) foam, polyvinyl chloride (PVC) foam, polyethylene
terephthalate (PET) foam, and/or a combination thereof. The first,
second, third, and fourth layers 541, 542, 543, and 544 may be made
from materials such as plastic reinforced by glass, carbon,
high-modulus aromatic polyamide (i.e. aramid), basalt, and/or a
combination thereof. In example embodiments, the first and second
flanges 510 and 520 may likewise be made from a laminated composite
material. These materials are provided as nonlimiting examples and
should not be construed as a limitation on the invention.
[0034] FIG. 7C illustrates another example of a structure 600 in
accordance with example embodiments. As shown in FIG. 7C, the
structure 600 may be comprised of a first flange 610, a second
flange 620, and an X-web 630 connecting the first flange 610 to the
second flange 620. In example embodiments the X-web 630 may be
comprised of a first rectangular shaped core 640 to which a second
rectangular shaped core 660 and a third rectangular shaped core 670
are attached. In example embodiments, the first, second, and third
rectangular shaped cores 640, 660, and 670 may be attached to one
another, for example, by an adhesive or another fastening means,
and then covered by first layer 671, a second layer 672, a third
layer 673, and a fourth layer 674. In example embodiments, the
first, second, and third cores 640, 660, and 670 may be made from
materials such as end grain balsa, cork, styrene acrylonitrile
(SAN) foam, polyvinyl chloride (PVC) foam, polyethylene
terephthalate (PET) foam, and/or a combination thereof. The first,
second, third, and fourth layers 671, 672, 673, and 674 may be may
be made from materials such as plastic reinforced by glass, carbon,
high-modulus aromatic polyamide (i.e. aramid), basalt, and/or a
combination thereof. In example embodiments, the first and second
flanges 610 and 620 may likewise be made from a laminated composite
material. These materials are provided as nonlimiting examples and
should not be construed as a limitation on the invention.
[0035] FIG. 7D illustrates another example of a structure 700 in
accordance with example embodiments. As shown in FIG. 7D, the
structure 700 may be comprised of a first flange 710, a second
flange 720, and an X-web 730 connecting the first flange 710 to the
second flange 720. In example embodiments the X-web 730 may be
comprised of a first V-shaped core 740 and a second V-shaped core
750 connected together by an adhesive 760. In example embodiments,
the structure 700 may further include a first layer 751, a second
layer 752, a third layer 753, and a fourth layer 754 covering the
V-shaped cores 740 and 750 as well as the adhesive 760. In example
embodiments, the first and second V-shaped cores 740 and 750 may be
made from materials such as end grain balsa, cork, styrene
acrylonitrile (SAN) foam, polyvinyl chloride (PVC) foam,
polyethylene terephthalate (PET) foam, and/or a combination
thereof. The first, second, third, and fourth layers 751, 752, 753,
and 754 may be made from materials such as plastic reinforced by
glass, carbon, high-modulus aromatic polyamide (i.e. aramid),
basalt, and/or a combination thereof. In example embodiments, the
first and second flanges 710 and 720 may likewise be made from a
laminated composite material. In this particular nonlimiting
example embodiment, the first core 740 and the second core 750 may
be manufactured separately and then joined together by the adhesive
460. These materials are provided as nonlimiting examples and
should not be construed as a limitation on the invention.
[0036] It is understood that the structures 400, 500, 600, and 700
are for purposes of illustration only and are not intended to limit
the invention. For example, although each of the structures 400,
500, 600, and 700 are illustrated as having flanges with a
rectangular cross-section having substantially the same dimensions,
the flanges may assume another configuration such as, but not
limited to, a curved flange or an irregular shaped flange.
Furthermore, the pairs of flanges provided in each of the
structures 400, 500, 600, and 700 are not required to have the same
configuration or dimension. For example, the first flange 410 may
have a rectangular cross-section as shown in FIG. 7A and the second
flange 420 may have a curved cross-section, for example, as shown
in FIG. 5A. In addition, the X-webs 430, 530, 630, and 730 are for
purposes of illustration only since the X-webs are not required to
be comprised of a core sandwiched between layers. For example, the
X-webs 430, 530, 630, and 730 may alternatively be made from a
metal, for example, aluminum. Furthermore, the dimensions
illustrated in the figures are for purposes of illustration and are
not intended to limit example embodiments. For example, the X-web
530 of structure 500 appears to be a substantially symmetric
structure, however, none of the X-webs are required to have the
degree of symmetry provided in the figures.
[0037] In example embodiments, the aforementioned structures are
well suited for use in various structures. For example, FIG. 8
illustrates a cross section of a wind turbine blade 1000 which
includes angled members in accordance with example embodiments. In
this particular nonlimiting example embodiment, the angled members
form an X-web. As shown in FIG. 8, the example wind turbine blade
1000 includes a shell 1170 which encloses a spar member 1160. The
spar member 1160, includes an X-web 1162 (an example of the angled
members) and two flanges 1164 and 1166 (sometimes referred to as
spar caps) arranged at ends of the X-web 1162. In example
embodiments, the spar member 1160 may have a cross-section that is
substantially similar to the previously described structure 200. As
in the conventional art, the spar member 1160 generally runs along
a length of the wind turbine blade 1000 and acts as the primary
load bearing structure.
[0038] FIGS. 9 and 10 illustrate shear flow through the
conventional wind turbine blade 50 and the wind turbine blade 1000
in accordance with example embodiments. As shown in FIG. 10, the
shear flow through the web of the conventional wind turbine blade
50 may be relatively high. Accordingly, a width or thickness of the
web of the conventional wind turbine blade 50 may be relatively
large to accommodate the relatively significant shear stress. The
straight web, as illustrated in FIG. 9, is essentially an
unsupported column which, when subject to this shear stress, could
have the tendency to buckle. This requires additional width or
thickness of core material in order to stabilize the column. In the
wind turbine blade 1000 according to example embodiments, the X-web
members may be designed with a reduced thickness in the core and/or
face sheet(s) (compared to the conventional art) due to the
redirection of the shear flow path. Furthermore, the angled members
of the X-web tend to stabilize the web against buckling. Thus, a
thickness of the components associated with the X-web may be
substantially thinner than a thickness of the components of the web
of the conventional turbine blade. As such, a reduction in the
material required for the web may lead to reduced material costs
leading to significant cost savings for the blade.
[0039] Example embodiments are directed to a structure which uses
angled members (for example, an X-web) as a method of transferring
shear from two spar flanges. When incorporated in a wind turbine
blade, the angled members transfer shear between the flanges on
each side of the spar (pressure and suction) of the wind turbine
blade. In example embodiments, the angled members may be
constructed from one member or several members.
[0040] In example embodiments, the angled members have been
illustrated as an X-web that may be attached to two flanges.
However, the inventive concepts are not limited thereto. For
example, FIG. 11A illustrates another example of a structure 4000
(for example, a wind turbine blade) in accordance with example
embodiments. In this latter example, the angled members form a
Y-shape rather than an X-shape. FIG. 12B illustrates another
example of a structure 5000 (for example, a wind turbine blade) in
accordance with example embodiments. In this latter example, the
main support member is configured to provide four points of contact
and resembles a .PSI.. FIG. 12C illustrates another example of a
wind turbine blade 6000 in accordance with example embodiments. In
this latter example, the main support member is configured to
provide four points of contact and resembles two Y's connected end
to end. In example embodiments, the Y-shaped web, the .PSI.-shape
web, and the double Y shaped webs provide multiple points of
contact while providing support against buckling.
[0041] Example embodiments have particular advantages over the
prior art. For example, when employed in a wind turbine blade, the
angled members reduce the requirements for core on the flanges,
reduce the propensity for buckling of the webs by providing a more
favorable closed-section shear flow path in bending, and eliminate
some of the traditional straight vertical components of shear webs
in order to form a more favorable closed-section shear flow path in
torsion, that is, a more torsionally stiff blade.
[0042] Example embodiments have additional advantages over the
prior art. For example, FIG. 12A illustrates another example of a
cross-section of a conventional wind turbine blade 7000. In FIG.
12A, the wind turbine blade 7000 includes a pair of webs 7100 and
7200 (also known as spars) which act to transfer shear from a
suction side of the of the wind turbine blade 7000 to a pressure
side of the wind turbine blade 7000. This type of configuration
forms what is called a "box" profile. Symbol C in FIG. 12A
illustrates transverse shear forces that are induced by various
loadings on the blade 7000 due to various types of loadings (for
example, wind loads WF in a flapwise direction of the blade, wind
loads WE along an edgewise direction of the blade, and torsional
loads WT exerted on the blade). As shown in FIG. 12B, the
transverse shear forces C cause the section of the blade to distort
which has an adverse effect on the blade's ultimate strength.
Furthermore, if the transverse shear distortion exceeds a certain
limit (which depends on the geometry of the blade and material of
the blade), the blade's resistance to a crushing pressure is
reduced and a sudden collapse of the blade can occur. As is well
known in the art, the crushing pressure is caused by the flapwise
loads and occurs in a box due to its longitudinal curvature. This
effect is also referred to as the Brazier effect.
[0043] Some artisans have sought to reduce the shear distortions in
conventional wind turbine blades by using various stiffeners and/or
reinforcing members. For example, as shown in FIG. 12C, some
artisans have sought to reduce shear distortions by introducing
X-shaped reinforcing members 7300 to reinforce the flanges of the
box beam. However, while the reinforcing members 7300 do reduce
torsional distortion of the blade 7000, they do very little to
prevent flange buckling of the blade 7000.
[0044] Unlike the prior art, the X-web according to example
embodiments alleviates many of the aforementioned problems. For
example, in the embodiment of FIG. 10, a transverse distortion of
the wind turbine load due to transverse shear forces results in
loads which are substantially along a length of the legs of the
X-web. Thus, while the axial loads of the legs may increase, the
bending loads of the legs of the X-web are lower than the bending
loads seen in the webs of the conventional art. Furthermore, and as
alluded to earlier, because the legs of the X-web are joined
together, each leg reinforces the other against buckling. This
allows for a thinner web design compared to the conventional art
and thus allows for a wind turbine blade with less core material.
In addition, the X-web also reinforces the flanges by spreading
shear forces along a chordwise direction of the wind turbine blade
(for example, compared to an I-beam configuration as in FIG. 3).
Furthermore, because a section of a wind turbine blade using the
X-web according to example embodiments is inherently stiffer than
either a conventional box-type configuration or a I-type
configuration, distortion of the flange is reduced further
reinforcing the shell of the wind turbine blade and reducing its
tendency to buckle under transverse loading.
[0045] When implemented in a wind turbine blade, the angled members
may be placed in various locations. For example, the angled members
may be placed on a wind turbine's main flanges (as shown in at
least FIG. 8), across a dual flange configuration with flanges
positioned with nonzero chordwise separation, between dual flanges
positioned with nonzero chordwise separation, fore of a main flange
(i.e. towards a leading edge of wind turbine blade), or aft the
main flange (i.e. towards a trailing edge of the wind turbine
blade).
[0046] In example embodiments, the material from which the angled
members may be made are not limited to sandwich composite materials
and may include, but are not limited to, metals, unreinforced
plastics, and composite plastic without sandwich core reinforced
with fibers that might include, but are not limited to, glass,
carbon, boron, or an aramid.
[0047] It is understood that fabrication processes can include, but
are not limited to, 1, 2, 3, and 4 or more individual pieces, which
are then bonded, welded, etc. (based on the material) together to
form the desired shape. It is also noted that the final component
does not necessarily have to be bonded into the shell as one piece.
For example, the bonding surfaces may be laminated between the
inner and outer skins of the shell prior to the bonding application
of the angled structures.
[0048] In example embodiments, the example structures include a
first flange, a second flange and a web connecting the first flange
to the second flange. In example embodiments, the web may have at
least one end with at least two angled members. For example, in the
event the web is X-shaped, each end of the web is includes two
angled members, in the event the web is Y-shaped, only one end of
the web includes two angled members, in the event the web is
.PSI.-shaped, only one end of the web includes angled members, in
the event the web is double Y-shaped, both ends of the web include
angled members. The angled members allow for forces to be spread
across a larger area thereby reducing shear at the points of
contact.
[0049] Example embodiments of the invention have been described in
an illustrative manner. It is to be understood that the terminology
that has been used is intended to be in the nature of words of
description rather than of limitation. Many modifications and
variations of example embodiments are possible in light of the
above teachings. Therefore, within the scope of the appended
claims, the present invention may be practiced otherwise than as
specifically described.
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