U.S. patent application number 10/875713 was filed with the patent office on 2005-12-29 for multi-purpose laminate beam.
Invention is credited to Lardizabal, Brian Aiken, Schneider, William C..
Application Number | 20050284085 10/875713 |
Document ID | / |
Family ID | 35504019 |
Filed Date | 2005-12-29 |
United States Patent
Application |
20050284085 |
Kind Code |
A1 |
Schneider, William C. ; et
al. |
December 29, 2005 |
Multi-purpose laminate beam
Abstract
A multi-purpose laminate beam for providing structural support
to a spacecraft and to contain a pressurized gas, or pressure
vessel. The inside of the beam has a metal layer that is over
wrapped with at least one laminae. Disposed within the beam is a
pair of dividers that allow for a pressurized volume or a least one
pressure vessel. There is an access port through the beam for
accessing the pressure vessel. The composite nature of the beam
allows the beam to be relatively lightweight, but strong enough to
support a load. By having the pressure vessel inside the beam,
space is optimized. Furthermore the beam provides a measure of
protection for the pressure vessel and any inhabitants of the
spacecraft should the pressure vessel leak or explode.
Inventors: |
Schneider, William C.;
(Houston, TX) ; Lardizabal, Brian Aiken; (Las
Vegas, NV) |
Correspondence
Address: |
Mr. Franklin E. Gibbs, Esq.
Bigelow Aerospace
1899 W. Brooks Ave.
North Las Vegas
NV
89032
US
|
Family ID: |
35504019 |
Appl. No.: |
10/875713 |
Filed: |
June 24, 2004 |
Current U.S.
Class: |
52/834 |
Current CPC
Class: |
E04C 3/29 20130101 |
Class at
Publication: |
052/738.1 |
International
Class: |
E04C 003/30 |
Claims
What is claimed is:
1. A multi-purpose laminate beam for use with a structure
comprising: an elongated tubular like metallic layer having a
generally circular cross section, an outer surface, and a length;
at least one lamina over wrapping the outer surface of the
elongated tubular like metallic layer and extending substantially
the length of the elongated tubular like metallic layer; and at
least one pressure vessel having at least one valve and the
pressure vessel and valve being disposed within the elongated
tubular like metallic layer.
2. The multi-purpose composite beam as in claim 1, further
comprising a wall and at least one access port, wherein the access
port extends through the wall for allowing access to the valve.
3. The multi-purpose composite beam as in claim 2, wherein the
elongated tubular like metallic layer has a generally circular
cross section.
4. The multi-purpose composite beam as in claim 2, wherein the
elongated tubular like metallic layer has a generally oval cross
section.
5. A multi-purpose composite beam for use with a structure
comprising: an elongated tubular like metallic layer having a
generally circular cross section, an outer surface, an inner
surface, and a length; at least one lamina over wrapping the outer
surface of the elongated tubular like metallic layer and extending
substantially the length of the elongated tubular like metallic
layer; opposing dividers disposed within the elongated tubular like
metallic layer and along the length of the elongated tubular like
metallic layer, and the opposing dividers being fixedly attached to
the inner surface thereby forming a cavity between the dividers,
and at least one lamina over wrapping, and reinforcing the
dividers, and at least one divider having a valve; and the cavity
between the opposing dividers forming a pressure vessel for
containing a pressurized gas.
6. The multi-purpose laminate beam according to claim 5 further
comprising a wall and at least one access port extending through
the wall for allowing access to the valve.
7. The multi-purpose composite beam as in claim 6, wherein the
elongated tubular like metallic layer has a generally circular
cross section.
8. The multi-purpose composite beam as in claim 6, wherein the
elongated tubular like metallic layer has a generally oval cross
section.
9. A method for using a plurality of multi-purpose laminate beams
in conjunction with opposing bulkheads in a spacecraft comprising:
securing at least one multi-purpose laminate beam as in claim 3
between opposing bulkheads; securing at least one multi-purpose
laminate beam as in claim 4 between opposing bulkheads; securing at
least one multi-purpose laminate beam as in claim 7 between
opposing bulkheads; and securing at least one multi-purpose
laminate beam as in claim 8 between opposing bulkheads.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to a multi-purpose laminate beam for
use in a space environment to support a human habitat module or
other space structure. The multi-purpose laminate beam functions to
provide structural support for the module and storage of
pressurized gases such as oxygen and nitrogen.
[0003] 2. Description of the Prior Art
[0004] Structural supports are well known in the building trade and
have been used in a number of earth bound applications. This has
carried over to the use of structural beams in the construction of
space related crafts. In a space environment, the beam can take a
number of forms. One such form is that of a longeron.
[0005] A longeron is a framing member that runs fore and aft on a
structure such as a space based human habitat module. In
application, there are usually a number of longerons that are at
the structural core of modular space habitats.
[0006] Another application of the beam is as a cross member
attached to longerons, or as structural support to other elements
of the habitat. The use of beams in such situations deals with the
forces on a structure.
[0007] In space applications such as a modular human habitat, the
module experiences significant stresses from a number of sources.
For example, load stresses from the module being launched into
space. Also, internal forces due to the pressurization in the case
of an inflatable modular habitat. Further, externally applied loads
such as those experienced during docking maneuvers or linear
attachment of other modules.
[0008] The aforementioned loads identify the need for a rigid
structure. A framework of rigid beams can accomplish this task. In
the case of a modular habitat, a structural member is part of the
framework that provides a substantially rigid foundation. This can
be, for example, part of the metallic structural core, or a
translation tube, in the case of an inflatable module.
[0009] While the use of beams is critical to the construction of a
module in space, there is an overriding consideration that severely
restricts widespread application of beams in that environment; the
weight associated with structural beams.
[0010] The cost to place a structure in space is extremely high.
This cost rises in relation to the increase in the mass of the
structure launched. Since metallic beams provide structural
support, they tend to be heavy and this weight increases the cost
associated with a launch of the beams, and the overall space
module, into space.
[0011] An alternative to using of metal beams is to utilize
composite materials. The terms related to composite and laminate
materials used herein are given their ordinary and customary
definitions as known in the field.
[0012] It is important at this point to define a few terms used in
the field of composites. A lamina is a single ply or layer, which
can be comprised of, for example, carbon fibers and epoxy. A
composite is a combination of at least two materials that, on a
macroscale, have differing properties. The composite is essentially
nonhomogenous such that the constituents do not merge completely
into each other and the constituents can be physically identified.
Since the lamina has two elements in this case, that are not merged
completely, it would also qualify as a composite material. A
plurality of lamina is referred to as laminae and, when multiple
lamina are combined, they form a laminate. Again, the laminate
would also qualify as a composite material as it has at least two
constituents and the lamina constituents would be the carbon fibers
and epoxy.
[0013] These terms, and other composite related terms, are to be
interpreted in accordance with the definitions of terms in
MIL-HDBK-17-1E as of Jan. 23, 1997, Chapter 1, Section 1.7
"Definitions" and those definitions are controlling over other
sources such as Webster's Dictionary.
[0014] While recent advances have been made in the use of
composites comprised of non-metal materials that are lighter in
weight and still provide structural support, they too have
drawbacks. For example, it is not uncommon for non-metal composites
to be very expensive. Another drawback is that many non-metal
composites may work well in one structural application and not in
another. Further, some non-metal composites are not as easy to work
with as traditional structural materials such as aluminum. For
example, it is easier to drill holes in aluminum as opposed to many
composites, which tend to splinter and fracture.
[0015] Thus, metal beams have certain advantages, as do composite
beams comprised of, for example, a number of lamina containing
carbon fiber filler in an epoxy matrix where the filler in each
lamina may be oriented in directions that are different from other
lamina. The present invention proposes combining metal and
non-metal materials, such as carbon fiber fillers in an epoxy
matrix, to overcome a number of the aforementioned drawbacks. This
results in laminae formed into a laminate beam that has desirable
characteristics of metal and non-metal constituents and at the same
time is lighter than a solid metal beam and would be more versatile
than the individual components.
[0016] The thickness of the metal in a composite beam is a variable
that can give rise to a number of uses based upon various
characteristics of the metal. In one application, the metal can be
sufficiently thick to lend structural support to the laminate. In
another application, the metal may be too thin to lend structural
support, but still be useful in providing a non-porous barrier to
prevent the escape of an enclosed gas.
[0017] A laminated beam would be comprised of a metal core, which
can be a hollow metal type tube, externally covered by a number of
lamina thus forming an outer laminate. Since a cross section of the
metal and lamina would yield distinct layers on a macro-scale, the
laminated tube could also be classified as a composite
material.
[0018] In this way, the laminated, or composite, beam could exhibit
the preferable characteristics of a non-metallic composite material
and that of a metal beam while being lighter than an equivalent all
metal beam.
[0019] While the use of a composite material utilizing metal and
non-metal constituents solves a number of structural problems for a
space craft, there are still other issues that remain. For one,
there is a limited space within a craft to store critical materials
such as compressed gases like nitrogen and oxygen. A laminated beam
can be of use in this area.
[0020] While composite pressurized gas tanks are well known in the
art as evidenced by U.S. Pat. No. 5,822,838 to Seal et al and U.S.
Pat. No. 6,401,963 to Seal et al, they are directed to containing
the gas and not performing a structural function as, for example, a
longeron. In the present invention the laminated beam performs a
structural function and the hollow volume can be compartmentalized
to contain a compressed gas, or pressure vessel.
[0021] In another embodiment, the hollow beam could enclose a
compressed gas container. Not only does this make use of a space
that otherwise might not be utilized it also provides an extra
level of safety. Should the compressed gas container suffer a
catastrophic failure, the laminated beam would absorb and could
potentially redirect a certain amount of the force transferred by
the escaping gas. While the beam may be damaged by such an event, a
multiplicity of beams would make it unlikely that any such damage
would be structurally catastrophic for a module. Further, the extra
shielding provided by the beam could reduce the amount, and
velocity of, debris produced by an exploding container.
[0022] Accordingly, the present invention is directed to a lighter
and more versatile structural beam that can be used to store
compressed gases or compressed gas containers.
SUMMARY OF THE INVENTION
[0023] The multi-purpose laminate beam has an elongated tubular
like metallic layer having a generally circular cross section, an
external surface, and a length. There is at least one lamina over
wrapping, and reinforcing, the external surface of the elongated
tubular like metallic layer and extending substantially the length
of the elongated tubular like metallic layer. There is also at
least one pressure vessel having at least one valve and the
pressure vessel and valve are disposed within the elongated tubular
like metallic layer. The multi-purpose laminate beam is adapted for
use in the construction of an inflatable modular structure.
[0024] In an alternate embodiment, opposing dividers are fixedly
attached within the elongated tubular like metallic layer and
attached to the metallic layer so as to provide a cavity for
containing gases. A valve for accessing the cavity is on one
divider.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 is a cross-sectional view of a multi-purpose
composite beam;
[0026] FIG. 2 is an isometric view of a lamina;
[0027] FIG. 3 is a top view of a plain weave pattern;
[0028] FIG. 4 is an isometric view of a lamina;
[0029] FIG. 5 is an isometric view of a laminate;
[0030] FIG. 6 is a longitudinal cross sectional view of a
multi-purpose laminate beam;
[0031] FIG. 7 is a longitudinal cross sectional view multi-purpose
laminate beam with a gas container;
[0032] FIG. 8 is a longitudinal cross sectional view multi-purpose
laminate beam with dividers; and
[0033] FIG. 9 is a longitudinal cross sectional view of a
spacecraft core.
DETAILED DESCRIPTION OF THE DRAWINGS
[0034] The present invention may best be understood by reference to
the following description taken in conjunction with the
accompanying drawings.
[0035] FIG. 1 is a cross-sectional view of a multi-purpose laminate
beam 10. There is a metallic inner layer 12 covered by a laminate
14. While the cross-sectional view illustrates a generally circular
geometry, as would be used in the preferred embodiment, the
invention is not limited to such a cross-section. A substantially
oval cross-section could be used in an alternate embodiment.
[0036] A beam formed using a single lamina over wrapping an
elongated tubular like metallic layer is referred to as a laminate
beam. Strictly speaking, in this case, there are not laminae
involved and thus not a laminate in the technical sense, however
the choice of using the term "multi-purpose laminate beam" is
intended to encompass single and multiple bonded lamina cases for
simplicity.
[0037] Turning to FIG. 2, each lamina 16 is comprised of a matrix
18 and filler 20. The matrix 18 is essentially a homogenous
material and, in the prime embodiment, consists of an epoxy type
polymer that acts as a binder. In the preferred embodiment, the
filler 20, which is the material that is impregnated in the matrix
that lends desirable properties to the finished material, is a
graphite type material. In alternate embodiments, the filler could
be a synthetic fiber such as KEVLAR.RTM.. In this figure, the
filler 20 is comprised of long continuous fibers.
[0038] While FIG. 2 identifies the filler as being fibers that run
parallel to one-another, as in the preferred embodiment, the
invention is not restricted to this configuration.
[0039] FIG. 3 identifies a plain weave 22 of fibers 20 as an
alternate embodiment. Further embodiments could include weaves well
known in the art including a basket, twill, leno, unidirectional,
and long-shaft satin weaves. In the preferred embodiment, the
fibers are long fibers. However, alternate embodiments can utilize
short fibers. These terms are well known in the art and are related
to the fiber's length to diameter ratio.
[0040] FIG. 4 displays a lamina with a chopped fiber filler 24
within the matrix 18. An alternate embodiment would include a
mixture of a chopped fiber filler and a weave. Such a combination
is referred to as a hybrid laminate.
[0041] FIG. 5 is a laminate having three layers of individual
lamina 16. The fibers 20 in each layer have a fiber axis 28. Each
layer may have a different fiber axis 28 in relation to the other
layers. The orientation of the fiber axis of each layer is chosen
for achieving particular desired results.
[0042] FIG. 6 is a longitudinal cross-sectional view of the
multi-purpose laminate beam 10. There is a laminate 14 over
wrapping an elongated tubular like metal layer 12. In the preferred
embodiment, the reinforcing composite 14 is adhered to the metal
layer 12. In an alternate embodiment, the composite 14 is not
adhered to the metal layer 12.
[0043] The elongated tubular like metallic layer 12 can be thin and
even so thin as to be a liner and have virtually no structural
properties apart from the lamina. For example, the metallic layer
could serve primarily to as a relatively non-porous barrier to
prevent gas leakage.
[0044] In the preferred embodiment, the metallic layer 12 is made
of aluminum. Metals which may be utilized to form the metallic
layer are preferably selected from the group consisting of steel,
aluminum, stainless steel, titanium and various combinations and
alloys thereof.
[0045] The laminate 14 of FIG. 6 is comprised of a number of lamina
and the orientation of the fibers of each lamina are chosen for
optimal distribution of the forces as dictated by the chosen
situation. The laminate 14 exhibits excellent in-plane properties
and as such serves to reinforce the metal layer 12.
[0046] The number of lamina used, orientation of the fibers, and
thickness of the metallic layer are chosen to meet the requirements
of a given set of operational conditions. Where metallic strength
is not a prime factor, the laminate itself would be designed to
accommodate large axial loads and pressure. In the case where
weight is a factor along with a variety of forces being applied
from different directions, a metallic inner layer might be
desirable to buttress the laminate. The choice of laminates, number
of layers, orientation of fibers, and type as well as thickness of
metal for an inner layer, are all variables that can be designated
by known processes and those skilled in the art.
[0047] Turning now to FIG. 7, a gas container 30 is disposed within
the metal layer 12. There is an access port 32 that runs through
the multi-purpose laminate beam 10 to allow access to a valve 34 by
way of a hose 36. In this way, the contents of the container 30 are
made available external to the multi-purpose laminate beam 10. In
an alternate embodiment, the hose could run from the container to a
valve that is external to the composite beam. The gas container 30
is made of metal in the preferred embodiment. However, the gas
container 3 may be made of a composite material over wrapping a
metal liner, or a metal alloy. The gas container 3 is supported in
place by a brace 37.
[0048] The container 3 of FIG. 7 is shorter than the length of the
beam 10. This is the preferred embodiment, however the container 3
can extend to encompass substantially the length of the beam 3.
[0049] Drilling is not a preferred method of making a hole in a
composite structure. The structural characteristics of many
composites are damaged by the drilling operation. For this reason,
the access port 32 is formed during the process of adding lamina to
develop the laminate 14. This can be accomplished by a number of
well know techniques in the field.
[0050] In the preferred embodiment, the container 30 is inserted
into a pre-formed multi-purpose laminate beam 10 and held in place
with end caps 37 that are fixedly attached to the metal layer 12.
The container 30 may be a composite structure or metal. To
facilitate a tight fit within the beam, spacers or buffers may be
placed between the container 30 and the metal layer 12.
[0051] In an alternate embodiment, the metal layer 12 and laminate
14 are formed around the container 30. In this manner, the
container 30 is permanently attached to the beam 10.
[0052] Referring now to FIG. 8, the elongated tubular like metallic
layer 12 is of sufficient thickness to bond with the opposing
dividers 38. The thickness of the metallic layer 12 and dividers 38
are chosen such that the cavity 40 can retain a pressurized gas.
The amount of pressure in the cavity 40 would be chosen such that
it is not great enough to damage the bond between the dividers 38
and the metal layer 12. While the figure illustrates a section of
the cavity 40, the length of such a section could extend
substantially the length of the cavity 40.
[0053] In the preferred embodiment, the metallic layer 12 and the
dividers 38 would be aluminum and the bond would be a weld. In
alternate embodiments, the materials would be chosen from metals or
metal alloys that could be welded together. The shape of the
dividers 38 are dome-like to facilitate an even distribution of the
forces resulting from the pressurized gas.
[0054] Referring now to FIG. 9, a spacecraft core 42 is
illustrated. The core 42 has opposing bulkheads 44 and at least two
laminated beams 10 acting as longerons and separating the bulkheads
44. Two types of braces 46 and 48 are shown. In the preferred
embodiment, a brace 46 fits securedly around the outside ends of
the beam 10 and each brace 46 is further secured to a bulkhead.
These braces 46 are formed with the beam 10 and in this way secured
in place with the beam 10. In another embodiment, the braces 48 can
be inserted into a finished beam 10 and secured in place with well
know methods in the art including the use of epoxy based materials.
In the preferred embodiment, the braces 46, 48 are made of metal
and are secured to the beam 10, again, by well know methods in the
art including the use of epoxy based materials. In an alternate
embodiment, the braces 46, 48 are secured to the bulkheads 44 by
the use of bolts or other means equally well known in the art.
[0055] There has thus been described a novel multi-purpose laminate
beam. It is important to note that many configurations can be
constructed from the ideas presented. Thus, nothing in the
specification should be construed to limit the scope of the
claims.
* * * * *