Reinforced structure that has elements reinforced with continuous fibers and the method of production thereof.

Abstract

Reinforced structures consisting of elements reinforced with continuous fibers and their production method are described. These structures are composed of reinforced elements that have continuous fibers embedded in a matrix material. The reinforced elements are combined in a matrix material to form a desired reinforced structure shape.

Description

1 / 19 Descriptive Report of the Invention Patent for: "REINFORCED STRUCTURE HAVING ELEMENTS REINFORCED WITH CONTINUOUS FIBERS AND METHOD OF PRODUCING THE SAME" FUNDAMENTALS Area

[001] The invention relates to a thermoplastic structure that has a profile that is reinforced with continuous fiber reinforcing filaments. Related Technique

[002] The use of highly resilient fiber composite materials, for example, with carbon, glass, aramid, ceramic or basalt fibers, as well as a matrix, for example, made of thermoset or thermoplastic, elastomer, carbon, graphite or ceramic and related materials, requires the use of appropriate constructions for the proper transmission of force to the material. Related to the material means that the anisotropy of the material with respect to the different mechanical properties in the direction of the fibers and through them is used in a targeted manner.

[003] Connecting rods made of fiber composite material for power transmission are mainly used for mechanical guidance and storage, for support, for tying, or for connection. Connecting rods made of material Petition 870220110416, dated 11 / 29 / 2022, page 26 / 60 2 / 19 fiber composites have been known for many years. Such connecting rods are preferably, but not exclusively, used in aircraft or spacecraft. Connecting rods in aircraft and spacecraft, for example, airplanes, rotary-wing aircraft, airships, unmanned aerial systems, rockets or satellites, are mainly subjected to axial loads from both compressive and tensile forces.

[004] Increasing demands for weight and cost savings are pushing the limits of the potential of known designs for struts with tubular bodies made of thermoset fiber composite materials.

[005] The thermoplastic structure can be used for connecting rods or for tension and compression struts, in which a strut with large external dimensions can be obtained within a predetermined installation space.

[006] When using fiber-reinforced tubes and profiles on a thermoset matrix base, there is often a fundamental problem of keeping the level of impact damage to the laminate as low as possible. Modified and high-cost resin systems are often used for problematic impact damage. In contrast, the use of a thermoplastic matrix material has a positive effect on impact behavior. Petition 870220110416, dated 11 / 29 / 2022, page 27 / 60 3 / 19

[007] Production costs for fiber-reinforced profiles are very high, and the profile geometry is still very limited. Profiles made with a thermoset matrix cannot be reshaped after completion, and thermosets have inferior impact behavior compared to thermoplastics. Furthermore, only a limited number of thermosets have FST (fire smoke and toxicity) approval and can be used in certain environments, including the aviation sector. SUMMARY OF DESCRIPTION

[008] The present technique can provide a thermoplastic structure that has a profile that is reinforced with continuous fiber reinforcing filaments. This profile can form the basis for tension and compression struts and other support structures.

[009] One embodiment of the description includes a reinforced structure having a cross-sectional profile that has continuous fiber reinforcing filaments and a first matrix material. The continuous fiber reinforcing filaments are embedded along a longitudinal axis of a fiber-reinforced element in the first matrix material to form continuous fiber reinforced elements.

[0010] In some modalities, the reinforced structure Petition 870220110416, dated 11 / 29 / 2022, page 28 / 60 4 / 19 additionally comprises a second matrix material. The continuous fiber reinforced elements are embedded into the second matrix material to form the cross-sectional profile.

[0011] In one variation, the material of the first die and the material of the second die are different materials. In another variation, the material of the first die and the material of the second die are the same material.

[0012] In one aspect, the cross-sectional profile of the reinforced structure may have a shape selected from the group consisting of triangular, circular, rectangular, and T-shaped. In one implementation, the cross-sectional profile has an outer contour that surrounds a hollow area with a shape selected from the group consisting of triangular, circular, and rectangular.

[0013] In another aspect, the cross-sectional profile of continuous fiber reinforced elements can have a shape selected from the group consisting of triangular, circular, rectangular, trapezoidal, and hexagonal. In a particular aspect, continuous fiber reinforced elements have a circular cross-sectional shape with a diameter of 0.4 mm or greater.

[0014] In yet another aspect, the reinforced structure Petition 870220110416, dated 11 / 29 / 2022, page 29 / 60 5 / 19 includes continuous fiber reinforced elements that have an outer contour for interlocking or interlacing with other continuous fiber reinforced elements.

[0015] The reinforced structure may have a volume fraction of continuous fiber-reinforced element fibers of at least 35%.

[0016] In a particular embodiment, the reinforced structure has a tubular cross-sectional profile. The continuous fiber reinforced elements may have a cross-sectional shape selected from the group consisting of triangular, circular, rectangular, trapezoidal, and hexagonal. In one implementation, the continuous fiber reinforced elements have a circular cross-sectional shape with a diameter of 0.4 mm or greater. In any of the tubular reinforced structures, the fiber volume fraction of the continuous fiber reinforced element may be at least 35%.

[0017] In one aspect of the reinforced structure that has a tubular cross-sectional profile, the fiber-reinforced elements may have a cross-sectional shape that is an arc segment of a diameter (D) of the tubular cross-section. The fiber-reinforced elements form a tubular arrangement of the reinforced structure. A unidirectional reinforced tape wrapping layer may be wrapped around and over Petition 870220110416, dated 11 / 29 / 2022, page 30 / 60 6 / 19 an outer surface of the tubular arrangement of arc segments.

[0018] In another aspect of the reinforced structure that has a tubular cross-sectional profile, the fiber-reinforced elements may have a cross-sectional shape that is an arc segment of a diameter (D) of the tubular cross-section. The arc segments form the tubular arrangement of the reinforced structure which has gaps between the edges of the fiber-reinforced elements. A matrix material may surround an outer surface of the tubular arrangement and fill the gaps. A layer of unidirectional reinforced thermoplastic tape wrapping may be wrapped around and over an outer surface of the matrix material.

[0019] One embodiment of the description is a method for forming the reinforced structure with the tubular cross-section profile that includes forming at least two of the arc segments of a diameter (D) of the tubular cross-section and forming a tubular arrangement of the reinforced structure with the at least two arc segments. This may include wrapping a layer around and over an outer surface of the formed tubular arrangement.

[0020] In one aspect of the method for forming the reinforced structure, the edges of adjacent arch segments are in contact and adhered to each other at points of contact. In Petition 870220110416, dated 11 / 29 / 2022, page 31 / 60 7 / 19 In a specific implementation, the arc segments are interlocking elements that adhere to each other.

[0021] In another aspect of the method for forming the reinforced structure, there is a gap between the edges of the adjacent arch segments that form the tubular arrangement and that applies a matrix material over an outer surface of the arch segments, the matrix material filling the gaps.

[0022] In any aspect of the method for forming the reinforced structure having a tubular arrangement, the layer wrapped over the outer surface may be one-way reinforced thermoplastic tape. Alternatively, the layer is one-way reinforced thermoset tape. In either of these aspects, the method includes wrapping the layer under a pre-tension with a defined winding feed width and rotating and heating the layer to fuse a tape matrix and the tubular arrangement to aid in bonding. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 illustrates a cross-sectional profile of a fiber-reinforced element that has a circular cross-section.

[0024] Figure 2 illustrates a cross-sectional profile of a fiber-reinforced element that has a Petition 870220110416, dated 11 / 29 / 2022, page 32 / 60 8 / 19 rectangular cross-section.

[0025] Figure 3 illustrates a cross-section of an element reinforced with woven fibers.

[0026] Figures 4A to 4D illustrate examples of cross-sectional shapes of structural elements composed of fiber-reinforced elements.

[0027] Figure 5 illustrates a cross-sectional profile of a continuous fiber-reinforced interlocking element.

[0028] Figure 6 illustrates a detail of a cross-sectional shape of a structural tubular element that includes at least two fiber-reinforced interlocking elements of Figure 5.

[0029] Figure 7 illustrates a cross-section of a fiber-reinforced element that has an arc segment profile.

[0030] Figure 8 illustrates a cross-sectional profile of a first reinforced tubular structure that uses the elements of Figure 7 in combination with a reinforcement layer.

[0031] Figure 9 illustrates a cross-sectional profile of a second reinforced tubular structure that uses the elements of Figure 7 in combination with a layer of Petition 870220110416, dated 11 / 29 / 2022, page 33 / 60 9 / 19 reinforcement.

[0032] Figures 10A to 10B illustrate a mechanism for applying a ring layer to secure various fiber-reinforced elements that have an arc segment profile to obtain a reinforced tubular structure. DETAILED DESCRIPTION

[0033] The terms “comprising” and “comprising” in this description may mean “includes,” “includes,” or “has,” or may have the meaning commonly given to the term “comprising” or “comprising” in the U.S. Patent Law. The terms “essentially consisting of” or “essentially consisting of,” if used in the claims, have the meaning ascribed to them in the U.S. Patent Law. Other aspects of the invention are described or become apparent from (and within the scope of the invention) the following description.

[0034] The terms lines, fibers, filaments, and yarns are used interchangeably in the following description. Lines, fibers, filaments, and yarns, as used herein, may refer to monofilaments, multifilament yarns, twisted yarns, multifilament cables, textured yarns, braided yarns, coated yarns, bicomponent yarns, as well as yarns made of any known material. Petition 870220110416, dated 11 / 29 / 2022, page 34 / 60 10 / 19 specialists in the technique. The threads can be made of carbon, fiberglass, cotton, aramid, polyamide, polyester, metal, polyethylene and / or other materials that exhibit desired physical, thermal, chemical or other properties.

[0035] The terms embedded, embedded, encapsulated and encapsulated” are used interchangeably.

[0036] Fiber-reinforced structures as described can be distinguished by the fact that the cross-section of the profile is filled with continuous fiber-reinforced elements to improve mechanical properties such as strength and stiffness. In a particular application, such fiber-reinforced structures can provide a cross-sectional profile for supporting members such as tension and compression struts or rods, in which a rod with the largest possible external dimensions can be achieved within a predetermined installation space.

[0037] Figure 1 illustrates a cross-sectional profile of a fiber-reinforced element 100. A circular cross-sectional shape is shown, but other cross-sectional shapes are contemplated, including but not limited to rectangular, triangular, trapezoidal, hexagonal, etc. Continuous fiber-reinforced elements Petition 870220110416, dated 11 / 29 / 2022, pp. 35 / 60 11 / 19 may have a fiber volume content of at least 35%. The fiber-reinforced element includes continuous fiber-reinforced filaments 105 embedded in a matrix 104, which are continuous along the length of the fiber-reinforced element 100 and distributed throughout the cross-sectional profile. The continuous fiber-reinforced elements 100 may have a diameter of at least 0.40 mm.

[0038] Fiber-reinforced filaments are composed of materials that include, but are not limited to, textiles, carbon, glass, basalt, plastic, ceramic, aramid, polyester, nylon, and rayon. Matrix material includes, but is not limited to, Polypropylene (PP), Polyamide (PA), Acrylonitrile butadiene styrene (ABS), Polyethylene Imine (PEI), Polyphthalamide (PPA), Polyphenylene Sulfide (PPS), Polyaryletherketone (PAEK), Polyetherketoneacetone (PEKK), or Polyetheretherketone (PEEK). Textiles include single-fiber filaments or continuous strands made of glass, carbon, basalt, ceramic, and / or plastic to form woven fabrics, braids, knitted fabrics, and nonwoven fabrics.

[0039] A thermoplastic element reinforced with continuous fibers can be produced, for example, by a pultrusion process into which continuous fiber reinforcing filaments are fed. Petition 870220110416, dated 11 / 29 / 2022, page 36 / 60 12 / 19

[0040] Figure 2 illustrates a fiber-reinforced element 200 of continuous fiber-reinforced full profile with a rectangular cross-section and having fiber-reinforced filaments 205 embedded in the matrix material 204. The dimensions of the fiber-reinforced element may be equal to or greater than 0.5 inch (12.7 mm) wide by 0.008 inch (0.2 mm) thick.

[0041] Figure 3 illustrates a cross-section of a woven fiber-reinforced element 300, comprising matrix material 304 and textile reinforcing filaments 307 interwoven with fibers 310. Using semi-finished textile products, additional reinforcement can be achieved transversely to the longitudinal axis of the element 300 with fibers 310. The element 300 is illustrated as having a rectangular cross-sectional shape for convenience, as any shape is contemplated. The textile reinforcing filaments 307 are illustrated as having an oval cross-section, but other shapes are contemplated. Furthermore, the shape of the textile reinforcing filaments 307 can be altered when subjected to compressive forces.

[0042] Woven fiber reinforced elements 300 can be combined to form reinforced structures having any desired cross-sectional profile, as shown here. Petition 870220110416, dated 11 / 29 / 2022, pp. 37 / 60 13 / 19 described.

[0043] Figures 4A to 4D illustrate non-limiting examples of cross-sectional shapes of structural elements that may be composed of fiber-reinforced elements described above. Circular fiber-reinforced elements are shown for convenience, although other shapes are contemplated. The cross-sectional shapes of Figures 4A to 4C are external contours that are perimeters of the shapes. That is, the perimeters of the structural elements encircle a hollow area H.

[0044] Figure 4A illustrates a circular structural element 400 composed of fiber-reinforced elements 410 embedded in a matrix material 430. The matrix material 430, discussed above, may be the same as or different from the matrix material in the fiber-reinforced element 410. Figure 4B illustrates a rectangular structural element 404 composed of fiber-reinforced elements 410 embedded in the matrix material 430. Figure 4C illustrates a triangular structural element 406 composed of fiber-reinforced elements 410 embedded in the matrix material 430. Figure 4D illustrates a T-shaped structural element 408 composed of fiber-reinforced elements 410 embedded in the matrix material 430. Figures 4A-D illustrate examples of element shapes. Petition 870220110416, dated 11 / 29 / 2022, pp. 38 / 60 14 / 19 structural elements that can be formed from fiber-reinforced elements. Other shapes of structural elements are also considered.

[0045] Figure 5 illustrates a section of a continuous fiber reinforced interlocking element 500 in connection with continuous fiber reinforcing filaments 510. The fiber reinforcing filaments may be similar to those described above in relation to Figure 1. The fiber reinforcing filaments may be unidirectional along the length of the element 500 and may be embedded in a matrix material 540.

[0046] The continuous fiber reinforcing elements 500 can interlock or interlock as a result of the functional outer contour 502. The interlocking element 500 illustrates a possible functional outer contour of interlocking 502 that has a head portion 504 and a tail portion 506. The head portion 504 is shaped to interlock or interlock with the tail portion 506 as illustrated in Figure 6. Other interlocking functional outer contours known to those skilled in the art are contemplated without departing from the inventive concept of the technique, which will be described shortly.

[0047] Figure 6 illustrates an implementation of a Petition 870220110416, dated 11 / 29 / 2022, pp. 39 / 60 15 / 19 reinforced structure 600 which includes at least two fiber-reinforced interlocking elements 500. The fiber-reinforced structure 600 may have any desired external shape, which may be formed by interlocking at least two fiber-reinforced elements 500 in the matrix material 640, which may be the same as or different from the matrix material 540 of the fiber-reinforced interlocking elements, to form a desired external shape 602.

[0048] Figure 7 illustrates a cross-section of another implementation of a fiber-reinforced element 702 composed of fiber-reinforced filaments 705 embedded in the matrix material 706. The fiber-reinforced elements 702 can be an arc segment of a circle. A thickness W of the element 702 can be 1 mm, but any desired thickness can be formed.

[0049] Figure 8 illustrates a cross-section of a reinforced tubular structure 801 formed from fiber-reinforced elements 802, 804, 806, 808. Each of the fiber-reinforced elements 802, 804, 806, 808 can be an arc segment of a circle formed as discussed above in relation to Figure 7. Elements 802, 804, 806, 808 form a circle having a diameter D that can be encircled and contacted on the outside of elements 802, 804, 806, 808 by a layer Petition 870220110416, dated 11 / 29 / 2022, pp. 40 / 60 16 / 19 winding 803. As illustrated, each fiber-reinforced element 802, 804, 806, 808 is a quarter-angle (90-degree) arc segment. The illustration in Figure 8 is for convenience of explanation, as there may be two or more fiber-reinforced elements. Furthermore, these elements can have any arc degree value, not necessarily having the same arc degree value.

[0050] Elements 802, 804, 806, 808 can be assembled at contact points 810 to form a tubular structure. Elements 802, 804, 806, 808 can be bonded to each other at contact points 810 by any mechanism known to those skilled in the art. Alternatively, the arc segments can be pre-fixed to a mandrel with adhesive points or similar, on an inner surface of the arc segments. Furthermore, elements 802, 804, 806, 808 can be bonded to each other by being interlocking elements as discussed above in relation to Figure 5. A winding layer 803 can be formed using one-way reinforced thermoplastic tape wrapped around the formed tubular structure, as will be described later.

[0051] Figure 9 illustrates a cross-section of a reinforced tubular structure 901 formed from elements Petition 870220110416, dated 11 / 29 / 2022, page 41 / 60 17 / 19 fiber-reinforced elements 902, 904, 906, 908. Each of the fiber-reinforced elements 902, 904, 906, 908 can be an arc segment of a circle formed as discussed above in relation to Figure 7. Elements 902, 904, 906, 908 form a circle with gaps 910 between the arc segments. A matrix material 914 can fill gaps 910 and also surround and make contact with the elements on its exterior, which can be accomplished by a co-extrusion process or other known means. A winding layer 903 can surround and make contact with the outer part of the matrix material 914. The winding layer 903 can be formed using unidirectional reinforced thermoplastic or thermoset tape wrapped around the formed tubular structure, as will be described later. The illustration in Figure 9 is for convenience of explanation, as there may be two or more elements reinforced with fibers.Furthermore, these elements can have any value of arc degrees, not necessarily having an equal value of arc degrees.

[0052] Figure 10A illustrates a first stage of the process in which arc segment elements 1002, which can be arc segment elements 802, 804, 806, 808, are positioned in a mandrel 1007.

[0053] Figure 10B illustrates a second stage of Petition 870220110416, dated 11 / 29 / 2022, pp. 42 / 60 18 / 19 process in which the arc segment elements 1002 positioned on the mandrel 1007 are reinforced by a winding layer 1003 made of unidirectional reinforced thermoplastic tape 1012. The winding layer 1003 is shown as a hoop winding produced, for example, by thermoplastic winding in which a heat source 1008 melts the tape matrix 1012 and is wound under pre-tension 1010 and with a defined winding feed width 1011 and rotation 1009. By the hoop winding, the arc segment elements are fixed and consolidated in the tube body. The winding layer can also be cross-winding layers. With cross-winding layers, the winding layers deviate from a hoop winding angle of about 90° relative to the longitudinal axis of the arc segments. For example, the cross-wound tape layer can be wound at ±45° relative to the longitudinal axis of the arc segments.Other winding angles are also considered. The winding layer can be one or more than one layer.

[0054] The winding process can be discontinuous or continuous. In the case of continuous winding, the arc segment elements can be pre-fixed by co-extrusion. Alternatively, the arc segment of the tubular structure can Petition 870220110416, dated 11 / 29 / 2022, pp. 43 / 60 19 / 19 can be pultruded directly without an intermediate manufacturing step for fiber-reinforced elements. Furthermore, in contrast to discontinuous winding, the winder would rotate, not the component. In the case of continuous winding, pre-feeding may be sufficient to eliminate a mandrel.

[0055] Other implementations are within the scope of the following claims. Petition 870220110416, dated 11 / 29 / 2022, pp. 44 / 60

Claims

1 / 5 CLAIMS 1.Reinforced structure having a tubular cross-section profile (400, 404, 406, 408, 600, 801, 901) comprising: continuous fiber reinforcement filaments (105, 205, 307, 510, 705); and a first matrix material (104, 204, 304, 540, 706), characterized in that continuous fiber reinforcement filaments are embedded along a longitudinal axis of a fiber-reinforced element in the first matrix material to form continuous fiber-reinforced elements (100, 200, 300, 500, 702), wherein the fiber-reinforced elements (702, 802, 804, 806, 808, 902, 904, 906, 908) have a cross-sectional shape that is an arc segment of a diameter (D) of a tubular cross-section, wherein the fiber-reinforced elements (802, 804, 806, 808) form a tubular arrangement of the reinforced structure and, wherein a winding layer (803) of unidirectional reinforced tape is wound around and over an outer surface of the tubular arrangement.

2. Reinforced structure, according to claim 1, characterized in that it comprises: a second matrix material (430, 640), Petition 870250010994, dated 10 / 02 / 2025, page 12 / 19 2 / 5 in which continuous fiber reinforced elements are embedded in the second matrix material to form the cross-sectional profile.

3. Reinforced structure, according to claim 2, characterized in that the material of the first die and the material of the second die are different materials.

4. Reinforced structure, according to claim 2, characterized in that the material of the first die and the material of the second die are the same material.

5. Reinforced structure, according to any one of claims 1 to 4, characterized in that the continuous fiber reinforced elements have an outer contour for interlocking or interlacing with other continuous fiber reinforced elements.

6. Reinforced structure, according to any one of claims 1 to 5, characterized in that the fiber-reinforced elements are interlocked with each other and embedded in a second matrix material.

7. Reinforced structure, according to claim 1, characterized in that the continuous fiber reinforced elements have a cross-sectional shape selected from the group consisting of triangular, circular, rectangular, trapezoidal and hexagonal.

8. Reinforced structure, according to claim 7, characterized in that the reinforced elements Petition 870250010994, dated 10 / 02 / 2025, page 13 / 19 3 / 5 with continuous fibers have a circular cross-sectional shape with a diameter of 0.4 mm or greater.

9. Reinforced structure, according to any one of claims 1, 7 and 8, characterized in that the volume fraction of fibers in the continuous fiber-reinforced element is at least 35%.

10. Reinforced structure according to claim 1, characterized in that it comprises: fiber-reinforced elements (902, 904, 906, 908) forming a tubular arrangement of the reinforced structure having gaps (910) between the edges of the fiber-reinforced elements; a second matrix material (914) surrounding an outer surface of the tubular arrangement and filling the gaps; and a winding layer (903) of one-way reinforced thermoplastic tape wrapped around and over an outer surface of the second matrix material.

11. Method for forming the reinforced structure with the tubular cross-section profile, as defined in claim 1, characterized in that it comprises: forming at least two arc segments of a diameter (D) of the tubular cross-section; forming a tubular arrangement of the reinforced structure with at least two arc segments; and wrapping a layer of unidirectional reinforced tape around and over an outer surface of the formed tubular arrangement.

12. Method for forming the reinforced structure, according to claim 11, characterized in that the edges of adjacent arc segments are in contact and adhered to each other at points of contact.

13. Method for forming the reinforced structure, according to claim 11, characterized in that the arch segments are interlocking elements for adhering to each other.

14. Method for forming the reinforced structure, according to claim 11, characterized in that there is a gap between the edges of adjacent arc segments that form the tubular arrangement and application of a matrix material on an outer surface of the arc segments, filling the gaps with the matrix material.

15. Method for forming the reinforced structure, according to any one of claims 11 to 14, characterized in that the winding layer is one-way reinforced thermoplastic tape.

16. Method for forming the reinforced structure, according to any one of claims 11 to 14, characterized in that the winding layer is unidirectional reinforced thermoset tape. Petition 870250010994, dated 10 / 02 / 2025, page 15 / 19 5 / 5 17. Method for forming the reinforced structure, according to any one of claims 15 or 16, characterized in that it comprises: winding the winding layer under a pre-tension with a defined winding feed width and rotation; and heating the winding layer to fuse a tape matrix and heat the tubular arrangement. Petition 870250010994, dated 10 / 02 / 2025, pp. 16 / 19

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