Composite turbine engine component comprising a core surrounded by two 3D woven fiber preforms

Abstract

The invention relates to a turbine engine component (1) comprising a central core (2) made of a rigid cellular material, said central core comprising a first face and a second face opposite to said first face, characterized in that said central core (2) is first surrounded by a first outer skin (3) located on the first face of said central core (2), said first outer skin being made of a composite material comprising a first fibrous reinforcement (31) woven according to a three-dimensional weaving, and secondly surrounded by a second outer skin (4) located on the second face of said central core (2), said second outer skin being made of a composite material comprising a second fibrous reinforcement (41) woven according to a three-dimensional weaving.

Description

Technical Field

[0001] This invention relates to the general field of composite material turbine engine components, which are formed from a central core surrounded by an outer skin.

[0002] This invention is particularly applicable to the field of turbine engine blades, such as diffuser blades. Background Technology

[0003] It is well known that composite material parts are manufactured by forming a central core surrounded by an outer skin, which provides mechanical properties to the part, while the core makes it possible to reduce weight.

[0004] This composite material design is advantageous for components subjected to bending stress.

[0005] The use of 3D braided fiber preforms in the manufacture of such composite material components is also known.

[0006] To manufacture parts with fine edges, it is known to produce 3D-woven fiber preforms that form a sheath, with the core inserted inside the sheath. However, this solution can lead to defects, such as the strands getting caught or snagged when the central core is inserted into the sheath formed from the fiber preform. Furthermore, the fact that the 3D-woven fiber preform is the sheath imposes weaving limitations; for example, the total number of layers is the same across the entire height of the sheath, thus limiting design choices for the part. Summary of the Invention

[0007] Therefore, the main objective of this invention is to provide a solution to the above-mentioned problems.

[0008] According to a first aspect, the present invention relates to a turbine engine component, the component comprising a central core having a first surface and a second surface opposite to the first surface, characterized in that the central core is first surrounded by a first outer skin located on the first surface of the central core, the first outer skin being made of a composite material comprising a first fiber-reinforced fabric woven according to a three-dimensional weave, and secondly surrounded by a second outer skin located on the second surface of the central core, the second outer skin being made of a composite material comprising a second fiber-reinforced fabric woven according to a three-dimensional weave.

[0009] Such components can locally adapt the fiber reinforcement to the localized stress of the component. Furthermore, such components can be manufactured with fine edges.

[0010] Depending on the possible characteristics, the first fiber reinforcement and the second fiber reinforcement have different weaving patterns.

[0011] Depending on the possible characteristics, the first fiber reinforcement and the second fiber reinforcement have different strand sizes.

[0012] Depending on the possible characteristics, the first fiber reinforcement and the second fiber reinforcement have different numbers of layers.

[0013] According to one possible feature, at least one of the first fiber reinforcement and the second fiber reinforcement includes a first portion having a first strand size and a second portion having a second strand size.

[0014] According to one possible feature, the component includes a platform formed by at least one debonded region formed on a first fiber reinforcement or a second fiber reinforcement, the debonded region being bent backward to protrude from the component.

[0015] According to one possible feature, the reinforcing ply is located on at least one of the first outer skin and the second outer skin, and the reinforcing ply is a ply woven by two-dimensional weaving, or a ply woven by three-dimensional weaving, or a unidirectional fiber sheet.

[0016] According to one possible feature, the component is an irregularly shaped component, including a suction side, a pressure side, a leading edge and a trailing edge, with a first outer skin arranged on the pressure side and a second outer skin arranged on the suction side.

[0017] According to one possible feature, the first outer skin and the second outer skin are joined at the leading and trailing edges.

[0018] According to one possible feature, at least one of the first outer skin and the second outer skin has a thickness that decreases at the leading edge, and at least one of the first outer skin and the second outer skin has a thickness that decreases at the trailing edge.

[0019] According to one possible feature, the first fiber reinforcement includes at least one of the following:

[0020] - A weave pattern different from the weave pattern of the second fiber reinforcement;

[0021] - A strand larger than the strand of the second fiber reinforcement;

[0022] - A higher number of layers than the second fiber reinforcement;

[0023] - A lower warp / weft ratio than the second fiber reinforcement.

[0024] According to a second aspect, the present invention relates to a method for manufacturing a component according to any possible characteristics, comprising the following steps:

[0025] - The first and second fiber reinforcements are manufactured by three-dimensional weaving;

[0026] - The first fiber reinforcement and the second fiber reinforcement are placed around the central core to surround the central core, the first fiber reinforcement is disposed against the first surface of the central core, and the second fiber reinforcement is disposed against the second surface of the central core;

[0027] - Densify the first fiber reinforcement and the second fiber reinforcement to form the first outer skin and the second outer skin. Attached Figure Description

[0028] Other features and advantages of the invention will become apparent from the description given below, with reference to the accompanying drawings, which illustrate exemplary embodiments but are by no means limiting.

[0029] Figure 1 A turbine engine component according to a possible embodiment of the present invention is illustrated schematically.

[0030] Figure 2 A cross-sectional view of a turbine engine irregular component according to a possible embodiment of the present invention is shown schematically.

[0031] Figure 3A , 3B And 3C schematically shown Figure 1 An exemplary embodiment of the prefabricated components in the process.

[0032] Figure 4 The various steps of a method for manufacturing a component according to a possible embodiment of the present invention are illustrated schematically. Detailed Implementation

[0033] like Figure 1 As shown, the turbine engine section 1 includes a central core 2, which is surrounded by a first outer skin 3 and a second outer skin 4. The first outer skin 3 includes a first fiber reinforcement 31 densified with a matrix, and the second outer skin 4 includes a second fiber reinforcement 41 densified with a matrix. The first outer skin 3 and the second outer skin 4 are disposed on either side of the central core, so that the first outer skin 3 is located on a first surface of the central core 2, and the second outer skin 4 is located on a second surface of the central core 2 opposite to the first surface of the central core 2.

[0034] like Figure 2 As shown, turbine engine component 1 can be a component with an irregular cross-section, which has a pressure side 11, a suction side 12, a leading edge 13, and a trailing edge 14. In fact, the invention is particularly suitable for stresses encountered by blades. This component can be, in particular, a rotor blade or a stator blade, such as a diffuser blade (also known as an "outlet guide vane," OGV). In fact, the composite structure of the invention is particularly suitable for diffuser blades.

[0035] The first outer skin 3 and the second outer skin 4 are made of composite materials, each comprising a fiber-reinforced fabric woven according to a three-dimensional weave, the fiber-reinforced fabric being densified by a matrix, such as filled or unfilled resin. More precisely, the first outer skin 3 is formed by a first fiber reinforcement 31 densified by a matrix, and the second outer skin 4 is formed by a second fiber reinforcement 41 densified by a matrix.

[0036] Here, the term "three-dimensional weaving" or "3D weaving" refers to weaving where warp yarns intersect with multiple layers of weft yarns, or weft yarns intersect with multiple layers of warp yarns.

[0037] Such a composite component 1 can reduce its weight by using a core made of a lightweight material, while providing mechanical properties that enable it to withstand the service stresses of the component 1 caused by the outer skins 3 and 4 with 3D braided fiber reinforcements. More specifically, the central core 2 is made of a rigid porous material; in other words, a low-density material, such as a foam structure or a honeycomb structure. The central core can be produced by molding or machining a block of rigid porous material. The core preferably does not contain a composite material comprising fiber reinforcements woven according to three-dimensional braiding, which are densified by matrix densification to minimize the overall mass of the component.

[0038] Furthermore, the fact that the first outer skin 3 and the second outer skin 4 are different makes it possible to adapt the features of the two outer skins 3 and 4 to the stress encountered by each surface of the component 1.

[0039] Therefore, the first fiber reinforcement 31 and the second fiber reinforcement 41 can have different weave patterns, so that the weave patterns can be adapted to the local stress encountered by the surface of the component 1.

[0040] The first fiber reinforcement 31 and the second fiber reinforcement 41 may also have strands of different sizes, thereby locally increasing the strength of component 1 while limiting the increase in the mass of component 1. Here, the strand size refers to the thickness of the strands of the yarn constituting the fiber preforms 31 and 41.

[0041] The first fiber reinforcement 31 and the second fiber reinforcement 41 may also have different warp / weft ratios, thereby allowing for local adaptation to the mechanical properties of component 1. Here, the warp / weft ratio refers to the ratio between the number of warp yarns and the number of weft yarns in each fiber reinforcement 31, 41.

[0042] The first fiber reinforcement 31 and the second fiber reinforcement 41 may also have different numbers of layers, which can locally increase the strength of component 1 while limiting the increase in the mass of component 1. Here, the number of layers refers to the number of layers of weft yarns or warp yarns.

[0043] Furthermore, the first fiber reinforcement 31 and / or the second fiber reinforcement 41 may include a first portion having a first strand size and a second portion having a second strand size different from the first strand size. Both portions are 3D woven. A greater number of portions is also possible. Fiber reinforcement may also be used in only one portion.

[0044] Figures 3A to 3C The formation of the preform used to produce component 1 is shown. More precisely, Figure 3A and Figure 3C Exemplary embodiments of the first fiber reinforcement 31 and the second fiber reinforcement 41 before molding and resin impregnation are shown respectively. Figure 3B The assembly of the first fiber reinforcement 31 and the second fiber reinforcement 41 on the central core 2 and their forming are shown to form the preform 100 of component 1.

[0045] exist Figures 3A to 3C In the exemplary embodiment shown, the first fiber reinforcement 31 includes a first portion 31a having a first strand size and a second portion 31b having a second strand size, wherein the first strand size is larger than the second strand size. Additionally, the second fiber reinforcement 41 also includes a first portion 41a and a second portion 41b, however, both portions 41a and 41b have strands of the same size. The use of a fiber preform made of two parts makes it particularly possible to form a platform on component 1, as will be described in detail below.

[0046] like Figure 1 As shown, component 1 may include one or more platforms 5 formed on the first outer skin 3 and / or the second outer skin 4. The one or more platforms 5 may be used, for example, to attach component 1 to a turbine engine or to restrict airflow in the turbine engine.

[0047] like Figures 3A to 3C As shown, platform 5 can be formed from debonding regions 51 of fiber reinforcements 31 and 41, these debonding regions being obtained by forming debonding regions 52 between the first and second portions of the fiber reinforcements. Furthermore, when the debonding regions 51 are formed on the fiber reinforcements, the fiber reinforcements also include drop regions 53 formed solely of warp yarns, which are then cut to release one or more debonding regions initially attached to the drop regions 53. Once one or more debonding regions 51 are released, and once the fiber reinforcements have been impregnated with matrix precursor resin, one or more debonding regions 51 are folded outwards from component 1 to form platform 5. Figure 1 and Figure 2 The debonding region 51 can be formed specifically using molds for dense fiber reinforcements 31, 41.

[0048] In addition, such as Figure 3BAs shown, the reinforcing fabric layer 6 can be deposited on the first outer skin 3 or the second outer skin 4, or simultaneously deposited on the first fiber reinforcement 31 and / or the second fiber reinforcement 41. Figure 3B (Not shown in the image). The reinforcing cord layer 6 can locally improve the mechanical properties of component 1. The reinforcing cord layer 6 can also increase the corrosion resistance of component 1. According to a first possible alternative, the reinforcing cord layer 6 is formed of a cord layer woven by three-dimensional weaving.

[0049] According to the second possible alternative, the reinforcing fabric layer 6 is formed by a fabric layer woven by two-dimensional weaving. Here, "two-dimensional weaving" is a traditional weaving pattern in which each weft yarn passes from one side of a single warp layer to the other, and vice versa.

[0050] According to a third possible alternative, the reinforcing fabric layer 6 is formed from unidirectional fiber (UD) sheets, which can be obtained by automated fiber placement (AFP) or by filament winding. The fiber orientation is adjusted according to the mechanical properties of the component 1 to be reinforced.

[0051] like Figure 2 As shown, the first outer skin 3 is disposed on the pressure side 11, and the second outer skin 4 is disposed on the suction side 12. According to an advantageous feature, the reinforcing strength of the first outer skin 3 is stronger than that of the second outer skin 4. The first outer skin 3 and the second outer skin 4 are joined at the leading edge 13 and the trailing edge 14, thereby completely surrounding the central core 2.

[0052] Therefore, the first fiber reinforcement 31 of the first outer skin 3 may include strands larger than those of the second fiber reinforcement 41 of the second outer skin 4. The first fiber reinforcement 31 of the first outer skin 3 may also include more layers than the second fiber reinforcement 41 of the second outer skin 4, and is therefore thicker.

[0053] The warp / weft ratio of the first fiber reinforcement 31 of the first outer skin 3 is lower than that of the warp / weft ratio of the second fiber reinforcement 41 of the second outer skin 4.

[0054] Furthermore, in order to form the fine edges of the blade, namely the leading edge 13 and the trailing edge 14, the thickness of the first outer skin 3 and / or the second outer skin 4 decreases at the leading edge 13, and the thickness of the first outer skin 3 and / or the second outer skin 4 decreases at the trailing edge 14. Figure 2 In the alternative shown, the thickness of both the first outer skin 3 and the second outer skin 4 is reduced so that the leading edge 13 and trailing edge 14 of the blade are thinned.

[0055] like Figure 4 As shown, component 1 is manufactured according to the following method:

[0056] -100: The first fiber reinforcement 31 and the second fiber reinforcement 41 are manufactured by three-dimensional weaving. During this manufacturing step 100 of the fiber reinforcements 31 and 41, if it is necessary to form a platform 5, a debonded region 52 may be generated.

[0057] -200: A first fiber reinforcement 31 and a second fiber reinforcement 41 are placed around a central core 2 to surround the central core 2. The first fiber reinforcement 31 is disposed and shaped against a first surface of the central core 2, and the second fiber reinforcement 41 is disposed and shaped against a second surface of the central core 2. The first fiber reinforcement 31 and the second fiber reinforcement 41 may, for example, be glued to the central core 2.

[0058] -300: Densify the first fiber reinforcement 31 and the second fiber reinforcement 41 to form the first outer skin 3 and the second outer skin 4. Densify the first fiber reinforcement 31 and the second fiber reinforcement 41 by injecting a matrix precursor material, such as filled or unfilled resin, into the pores of the fiber reinforcement and then polymerizing the precursor material.

Claims

1. A turbine engine component comprising a central core made of a rigid honeycomb material, the central core including a first surface and a second surface opposite to the first surface, characterized in that, The central core does not contain a composite material including fiber reinforcements woven according to three-dimensional weaving and densified by a matrix. The first surface of the central core is covered by a first outer skin, which is made of a composite material including a first fiber reinforcement woven according to three-dimensional weaving. The second surface of the central core is covered by a second outer skin, which is made of a composite material including a second fiber reinforcement woven according to three-dimensional weaving. The first outer skin and the second outer skin are independent of each other, and the first woven fiber reinforcement of the first outer skin and the second woven fiber reinforcement of the second outer skin are respectively disposed on the first surface and the second surface of the central core, and there is no woven connection between them.

2. The component according to claim 1, wherein the first fiber reinforcement and the second fiber reinforcement have different weave patterns.

3. The component according to claim 1, wherein the first fiber reinforcement and the second fiber reinforcement have different strand sizes.

4. The component according to claim 1, wherein the first fiber reinforcement and the second fiber reinforcement have different numbers of layers.

5. The component according to claim 1, wherein at least one of the first fiber reinforcement and the second fiber reinforcement comprises a first portion having a first strand size and a second portion having a second strand size.

6. The component of claim 1, wherein the component includes a platform formed by at least one debonding region formed on the first fiber reinforcement or the second fiber reinforcement, the debonding region being bent rearward to protrude from the component.

7. The component according to claim 1, wherein the reinforcing fabric layer is located on at least one of the first outer skin and the second outer skin, the reinforcing fabric layer being a fabric layer woven by two-dimensional weaving, or a fabric layer woven by three-dimensional weaving, or a unidirectional fiber sheet.

8. The component according to claim 1, wherein the component is an irregularly shaped component, including a pressure side, a suction side, a leading edge and a trailing edge, wherein the first outer skin is disposed on the pressure side and the second outer skin is disposed on the suction side.

9. The component according to claim 8, wherein the first outer skin and the second outer skin are joined at the leading edge and the trailing edge.

10. The component of claim 9, wherein at least one of the first outer skin and the second outer skin has a reduced thickness at the leading edge, and at least one of the first outer skin and the second outer skin has a reduced thickness at the trailing edge.

11. The component according to any one of claims 8 to 10, wherein the first fiber reinforcement comprises at least one of the following: - A weave pattern different from the weave pattern of the second fiber reinforcement; - Larger strands than the strands of the second fiber reinforcement. - A higher number of layers than the second fiber reinforcement. - A lower warp / weft ratio than the second fiber reinforcement.

12. A method for manufacturing a component according to any one of claims 1 to 11, comprising the following steps: - (100): The first fiber reinforcement and the second fiber reinforcement are manufactured by three-dimensional weaving; - (200): The first fiber reinforcement and the second fiber reinforcement are arranged around a central core made of rigid honeycomb material to surround the central core, the first fiber reinforcement is disposed against a first surface of the central core, and the second fiber reinforcement is disposed against a second surface of the central core; - (300): Densify the first fiber reinforcement and the second fiber reinforcement to form the first outer skin and the second outer skin.

Images