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.

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 μm and 40 μm, and the thickness of each of the interlayers is between 6 μm and 35 μm.

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

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 μm and 40 μm, 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 μm and 35 μm; 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