U.S. patent application number 15/287778 was filed with the patent office on 2017-10-05 for composite structural element and method of producing the same.
The applicant listed for this patent is TAIYOI Graphite Co., Ltd., TYKO Tech Co., Ltd.. Invention is credited to Chih-Hsiao CHIEN, Wen-Bin HSIEH.
Application Number | 20170284099 15/287778 |
Document ID | / |
Family ID | 57708149 |
Filed Date | 2017-10-05 |
United States Patent
Application |
20170284099 |
Kind Code |
A1 |
CHIEN; Chih-Hsiao ; et
al. |
October 5, 2017 |
COMPOSITE STRUCTURAL ELEMENT AND METHOD OF PRODUCING THE SAME
Abstract
The present invention provides a composite structural element
and a method of producing the same, which includes taking a tape
formed by alternatively laminating composite layers made of a
non-isotropic composite material and interlayers made of an
isotropic material as a major component of the structural element,
molding into a structural element of a fixed shape for use in
industry, and optionally, directly drilling holes on the laminate
of the composite layers and the interlayers for connection.
Inventors: |
CHIEN; Chih-Hsiao; (New
Taipei City, TW) ; HSIEH; Wen-Bin; (Zhubei City,
TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TAIYOI Graphite Co., Ltd.
TYKO Tech Co., Ltd. |
Zhubei City
New Taipei City |
|
TW
TW |
|
|
Family ID: |
57708149 |
Appl. No.: |
15/287778 |
Filed: |
October 7, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E04C 3/29 20130101 |
International
Class: |
E04C 3/29 20060101
E04C003/29 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 1, 2016 |
TW |
105204660 |
Aug 24, 2016 |
TW |
105212899 |
Claims
1. A composite structural element, comprising: an outer portion,
comprising a plurality of composite layers and a plurality of
interlayers laminated with each other, wherein each of the
composite layers has unidirectionally aligned fiber reinforcing
materials and a polymeric base material wrapping each of the fiber
reinforcing materials, and each of the interlayers is made of an
isotropic material being aluminum and is located between any two
adjacent ones of the composite layers; and a plurality of fixing
holes respectively passing through each of the composite layers and
each of the interlayers; wherein the thickness of each of the
composite layers is between 10 .mu.m and 40 .mu.m, and the
thickness of each of the interlayers is between 6 .mu.m and 35
.mu.m.
2. The composite structural element according to claim 1, further
comprising an inner portion having a section with an I-shape, an
L-shape, a C-shape, or other geometric shapes, located within the
outer portion.
3. The composite structural element according to claim 2, wherein
the inner portion is a tangible article or a space.
4. The composite structural element according to claim 1, wherein
each of the composite layers and each of the interlayers are
sequentially alternatively laminated with each other.
5-6. (canceled)
7. The composite structural element according to claim 2, wherein
each of the composite layers and each of the interlayers are
sequentially alternatively laminated with each other.
8-9. (canceled)
10. The composite structural element according to claim 3, wherein
each of the composite layers and each of the interlayers are
sequentially alternatively laminated with each other.
11-12. (canceled)
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001] The present invention relates to a structural element, and
more particularly, to a composite structural element and a method
of producing the same.
2. Description of the Related Art
[0002] A method of producing a composite structural element
disclosed in U.S. Pat. No. 7,357,726 is a conventional pultrusion
method that is commonly used for continuously producing a
special-shaped product, which enables the cross section of the
molded structural element to have an I-shape, a C-shape, an
L-shape, or an annular shape, and so on through a molding space
provided by a specific mould, for use in construction, automotive,
and other industries.
[0003] Microscopically, in the composite structural element, a
desired arrangement direction of reinforcing materials such as
fiber must be maintained by means of a base material such as resin,
and a closed protection film is formed at the periphery of the
fiber to provide a lateral support, so as to avoid stress
concentration caused by the damage of the fiber due to the mutual
friction, thereby affecting the strength and structure of the
structural element itself. Moreover, in order to facilitate the
combination of the composite material with other components, it is
still necessary to adopt the technical means of drilling holes on
the structural element for the combination by combining components.
However, once holes are drilled on the structural element,
breakpoints are generated in the continuity of the fiber to become
the parts having concentrated stress, resulting in the damage that
affects the structural strength such as delamination or cracks,
which is contrary to the purpose of providing reinforcement by the
reinforcing materials.
[0004] Therefore, in order to avoid the deficiency derived from the
drilling on the composite material, the prior art discloses that on
the premise that the integrity of fiber in the composite material
is maintained, the structural element is combined with other
components by adhering. Although such technologies can avoid the
damage on the fiber so as to ensure the strength of the composite
structural element, due to the limited adhesion of the combination
sites, the application of the composite structural element is
limited. For example, a vehicle transmission shaft made of carbon
fiber can only be combined with metal joints on both ends by means
of gluing, and the deterioration degree of the adhesive and the
fatigue tolerance of the metal interfaces are unpredictable and
thus have become potential dangerous factors for the driving
security.
[0005] Thus, although the composite material has been widely used
in various technical fields, the combination thereof with other
components is still limited in technology. For drilling holes, good
combination strength can be provided by means of the combining
components such as bolts, but the concentration of stress will
result in the damage on the composite structural element itself;
and for the adhesive gluing means, the integrity of the composite
structural element can be maintained, thereby avoiding the
occurrence of stress concentration, but due to the deterioration of
the adhesive that cannot be avoided, the combination strength is
less than that of the bolts. Both means are imperfect.
SUMMARY OF THE INVENTION
[0006] In view of the above, the major objective of the present
invention is to provide a composite structural element and a method
of producing the same, which can avoid the damage on the structural
element due to the stress concentration caused by the damage of the
structural element at local structures such as drilled holes during
the combination between the structural element and the external
components.
[0007] Therefore, in order to achieve the above objective, the
present invention provides a composite structural element, obtained
by taking a tape formed by alternatively laminating composite
layers made of a non-isotropic composite material and interlayers
made of an isotropic material as a major component of the
structural element, molding into a structural element of a fixed
shape for use in industry, and optionally, directly drilling holes
on the laminate of the composite layers and the interlayers.
[0008] Each of the composite layers has unidirectionally aligned
fiber reinforcing materials and a polymeric base material wrapping
each of the fiber reinforcing materials, and each of the
interlayers is made of an isotropic material, and is located
between any two adjacent ones of the composite layers.
[0009] To achieve a specific shape for the structural element, the
composite structural element further includes an inner portion
having a specific shape, and each of the composite layers and each
of the interlayers wrap the external side of the inner portion, so
as to forma profile having the same contour as that of the inner
portion.
[0010] The shape of the inner portion may be an I-shape, an
L-shape, a C-shape, or other geometric shapes, and the inner
portion may be a non-physical space in addition to a physical
article.
[0011] In order to properly distribute the stress transmission by
means of the interlayers and avoid the damage on the fiber
reinforcing materials of the composite layers, the interlayers are
evenly distributed among the composite layers such that they are
sequentially alternatively laminated with each other. Also, in
order to further strengthen the mechanical strength of the
structural element, the individual thickness of the composite
layers is made between 10 .mu.m and 40 .mu.m, and the individual
thickness of the interlayers is made between 6 .mu.m and 35
.mu.m.
[0012] When the interlayers are made of aluminum or alloy materials
thereof, surface treatment such as anodizing treatment should be
performed on the interlayers, so as to avoid galvanic
corrosion.
[0013] In addition, the method of producing a composite structural
element provided by the present invention includes forming a
laminate by laminating the composite layers with the interlayers as
described above, winding the laminate into a tubular outer portion,
then taking a core having a specific shape to pass through the
inner space of the outer portion as a mould, and exerting an
external force such as an air pressure, such that the outer portion
is contracted and attached to the periphery of the core, and then
curing.
[0014] During the curing of the outer portion, the core may be
formed integrally with the outer portion, such that the core serves
as the inner portion of the structural element. In this case, for
the purpose of lightweight, foamed plastics or other lightweight
materials can be used to produce the core.
[0015] In contrast, after the curing of the outer portion, the core
may also be drawn off, such that the space where the core is
originally located becomes a non-physical space, so as to form the
inner portion with a non-physical space.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a perspective view of a structural element
according to a preferred embodiment of the present invention.
[0017] FIG. 2 is a schematic view of a laminate of composite layers
and interlayers alternatively laminated with each other according
to a preferred embodiment of the present invention.
[0018] FIG. 3 is a cross-sectional view of a preferred embodiment
of the present invention.
[0019] FIG. 4 is a schematic view of a producing process according
to a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] First of all, as shown in FIG. 1 to FIG. 3, a composite
structural element (10) provided in a preferred embodiment the
present invention has an I-shape, which can be used as a substitute
of an I-shaped steel beam in building materials or a component of a
vehicle, and of course, it may also has other different shapes or
structures for use in other different industries. In other words,
the so-called structural element in the present invention is not
limited to the so-called structural element in the building
technology, and in terms of the structure, the composite structural
element (10) mainly comprises an outer portion (20) and an inner
portion (30).
[0021] The outer portion (20) is a laminate formed by laminating a
plurality of single layers respectively made of a composite
material and an isotropic material with each other, and includes a
plurality of composite layers (21) and a plurality of interlayers
(22), wherein the composite layers (21) are respectively structured
as a fiber tape and not a fiber cloth, and each have
unidirectionally aligned fiber reinforcing materials and a
polymeric base material wrapping on each of the fiber reinforcing
materials. The thickness of the single layer is preferably between
10 .mu.m and 40 .mu.m, and may be a material such as a glass fiber,
a graphite fiber, a Keviar fiber, a carbon nanotube, or a
substitute or surrogate thereof;
[0022] each of the interlayers (22) is made of an isotropic
material including metals such as aluminum or other non-metals, and
the thickness of a single layer thereof is preferably between 6
.mu.m and 35 .mu.m; and
[0023] each of the composite layers (21) and each of the
interlayers (22) are sequentially alternatively laminated with each
other, such that the interlayers (22) can be uniformly distributed
in the whole laminate, whereby the interlayers (22) can uniformly
distribute the received force inside the laminate, thereby avoiding
the damage derived from the local concentration of stress.
[0024] The inner portion (30) serves to give a specific shape as a
whole of the structural element (10) and achieve the effect of
increasing the volume of the structural element and reducing the
usage amount of the outer portion (20, and thus may be a
lightweight material such as foam or foamed plastics, such that the
outer portion (20) is wrapped onto the inner portion (30).
[0025] Through the constitution of the components above, the
composite structural element (10) can provide a good mechanical
strength by means of the outer portion (20), and also, a plurality
of fixing holes (11) may be directly drilled on the outer portion
(20) and the inner portion (30) to respectively pass through each
of the composite layers (21) and each of the interlayers (22).
Hereby, when the combining components such as bolts are fixed in
the fixing holes (11) to combine the composite structural element
(10) with another composite structural element or an external
component, although the fiber continuity of the fiber reinforcing
materials is damaged by the fixing holes (11), so that the force
fails to be further transmitted and focuses at breakpoint sites, by
means of the interlayers (22), the force that is not transmitted by
the fiber may be further transmitted to the fiber with the isotropy
of the material of the interlayers (22), so as to avoid stress
concentration, thereby achieving the purpose of enhancing the
mechanical strength of the combination sites of the composite
structural element (10) and making the composite structural element
(10) have a wider application range. In addition, because the
interlayers (22) are uniformly distributed in the laminate and have
a very small thickness, the uniform distribution of force can be
ensured and the delamination can be avoided, so as to maintain the
structural stability of the composite structural element (10).
[0026] Further, referring to FIG. 4, in order to manufacture the
composite structural element (10), the following steps may be
carried out:
[0027] a. taking a laminate formed by laminating each of the
composite layers (21) with each of the interlayers (22) and winding
to form a tubular outer portion (20);
[0028] b. taking an elongated core (41) to coaxially pass through
the inner space of the outer portion (20);
[0029] c. exerting an external forces such as an air pressure to
the external side of the outer portion (20), such that the outer
portion is contracted and attached to the periphery of the core
(41); and
[0030] d. wrapping the outer portion (20) onto the core (41) and
curing.
[0031] When the step d is carried out, if the outer portion (20) is
integrally formed with the core (41), so that the core (41) cannot
be separated from the outer portion after molding, the core (41)
becomes the inner portion (30) of the composite structural element
(10) as shown in (a) of FIG. 4. For this reason, a lightweight
material such as foams or other foamed plastics is preferably used
as the material of the core, so as to achieve the purpose and
effect of lightweight.
[0032] In contrast, if after the step d is carried out, it is
necessary to separate the core (41) from the cured outer portion
(20), when the step d is carried out, a possibility of separating
the outer portion (20) from the core (41) should be provided, for
example, a release agent is applied on the surface of the core (41)
in advance, such that after the step d is carried out, the core
(41) is drawn away, and as shown in (b) of FIG. 4, the space after
the core (41) is drawn away forms the inner portion (30) of the
composite structural element (10).
[0033] Regardless of a physical core or a non-physical space which
constitutes the inner portion (30) of the composite structural
element (10), the efficacy of avoiding the stress concentration
achieved by the outer portion (20) is not affected, and also, in
order to obtain a specific shape of the composite structural
element (10), in addition to the I-shape, the sectional shape of
the core may be a C-shape, an L-shape, or other geometric shapes,
such that the shape of the composite structural element (10) can
satisfy different requirements.
DESCRIPTION OF REFERENCE NUMERALS
[0034] (10) composite structural element (11) fixing hole (20)
outer portion
[0035] (21) composite layer (22) interlayer (30) inner portion
[0036] (41) core
* * * * *