CN109210003B

CN109210003B - Fan containing casing and preparation method thereof

Info

Publication number: CN109210003B
Application number: CN201710527600.7A
Authority: CN
Inventors: 陈云永; 陈巍; 秦文; 陈璐璐; 廖连芳
Original assignee: AECC Commercial Aircraft Engine Co Ltd
Current assignee: AECC Commercial Aircraft Engine Co Ltd
Priority date: 2017-06-30
Filing date: 2017-06-30
Publication date: 2022-02-08
Anticipated expiration: 2037-06-30
Also published as: CN109210003A

Abstract

The invention provides a fan containing casing which is surrounded around a fan of an aeroengine and comprises a main frame, wherein the main frame comprises a cylindrical side wall and flange edges positioned at two ends of the side wall, the main frame is made of a carbon fiber resin matrix composite material, the side wall of the main frame axially comprises a containing area and non-containing areas positioned at two sides of the containing area along the casing, a containing layer distributed along the circumferential direction of the casing is arranged in the containing area on the inner side of the side wall of the main frame, and the containing layer is made of a resin matrix composite material formed by mixing and weaving carbon fibers and aramid fibers.

Description

Fan containing casing and preparation method thereof

Technical Field

The invention relates to the field of design of composite material fan casings of aircraft engines, in particular to a fan containing casing with a mixed structure and composite materials and a preparation method thereof.

Background

The fan containing casing is an important part of an aeroengine and has the function of containing fallen fan blades or fragments when the fan blades are accidentally fallen off or damaged so as to prevent the fan blades from further damaging the engine and the airplane structure.

The design requirement of the fan-containing casing ensures sufficient rigidity and has excellent containing capacity, which puts very high requirements on the design of the fan-containing casing. An aircraft engine generally adopts the following modes to realize the containment design of a fan casing:

1. most of traditional aircraft engines are made of all-metal materials (high-strength steel, titanium alloy and aluminum alloy), and in order to ensure that the overall rigidity of a thin-wall structure casing meets requirements, annular reinforcing ribs are designed on the outer side of the thin-wall casing to improve the overall rigidity of the thin-wall structure casing and reduce the weight of the thin-wall structure casing.

2. The second casing structure mostly adopts a casing with an aramid fiber winding structure, and the design concept of the casing is to reduce the weight of the casing as much as possible on the basis of meeting the inclusion, so Kevlar and other light materials are adopted, the structural metal material of the casing is used as a main casing of the casing, but aluminum alloy or titanium alloy is milled into a thin-wall structure, in order to improve the inclusion, aluminum honeycomb and aramid fiber cloth are wrapped outside the aluminum alloy or titanium alloy casing, and in order to meet the inclusion, the aramid fiber cloth is usually wrapped by dozens of layers or even dozens of layers.

3. The third type of case adopts a carbon fiber reinforced full composite material structure, the case of the structure is woven by two-dimensional and three-dimensional carbon fibers into cloth, then the cloth is wound around the engine shaft to the required thickness, and then epoxy resin is injected by adopting an RTM (resin transfer molding) process. On the other hand, in order to realize structural optimization, the casing can be designed to have the characteristic of non-uniform thickness distribution, the thickness of a contained area is larger than that of a non-contained area, but the non-uniform thickness characteristic of the casing is difficult to realize due to the fact that the casing adopts a winding process. More importantly, the casings can only be applied to realize the containment of the composite material fan blade.

Therefore, a new hybrid structure/material fan containing casing is needed, which uses light materials on the premise of meeting the requirement of aeroengine containment, and can reduce weight and also can contain composite material fan blades and metal fan blades.

Disclosure of Invention

The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

According to one aspect of the invention, a fan-containing casing is provided for surrounding a fan of an aircraft engine, the fan-containing casing comprising a main frame, the main frame comprising a cylindrical side wall and flange edges at both ends of the side wall, the main frame being made of a carbon fiber resin-based composite material, the side wall of the main frame comprising a containing region and non-containing regions at both sides of the containing region along the axial direction of the casing, the containing region inside the side wall of the main frame being provided with a containing layer distributed along the circumferential direction of the casing, the containing layer being made of a resin-based composite material in which carbon fibers and aramid fibers are co-woven.

In one example, the containment layer includes a plurality of reinforcing blocks distributed circumferentially along the barrel.

In one example, the thickness of the sidewall of the containing region of the main frame is larger than that of the sidewall of the non-containing region.

In one embodiment, the minimum thickness of the side wall of the main frame is not less than 20mm, and the thickness of the side wall of the containing area is between 25 and 35 mm.

In one example, the side wall and the flange of the main frame are formed in one step by using an automatic wire laying or automatic tape laying process.

In one example, the volume content ratio of the carbon fiber to the aramid fiber mixed and woven with the containing layer is 2: 1.

In one example, a plurality of reinforcing brackets are uniformly distributed on the outer side of the side wall of the main frame along the circumferential direction of the casing, and each reinforcing bracket is axially fixed on the flange edges of the front edge and the rear edge of the main frame along the axial direction of the casing.

In one example, the reinforcing brackets are titanium alloy pipes, and each reinforcing bracket is fixed on the flange edges of the front edge and the rear edge of the main frame in a bolt connection mode.

In one example, a gap is left between the reinforcing bracket and the side wall of the main frame.

In one example, the gap is between 8-12 mm.

In one example, the fan containing casing further comprises a reinforcing layer formed by winding the reinforcing supports and covering the reinforcing supports, wherein the reinforcing layer is made of a resin-based composite material formed by co-weaving carbon fibers and aramid fibers.

In one example, the containment zone reinforcement thickness of the reinforcement layer is greater than the non-containment zone reinforcement thickness.

In one example, the thickness of the containing-region reinforcing layer of the reinforcing layer is not less than 30mm, and the thickness of the non-containing-region reinforcing layer is between 10 and 15 mm.

In one example, a protective layer is wrapped around the outside of the reinforcement layer.

In one example, the protective layer includes a polyurethane polymer material layer and a hydrophobic coating applied over the polyurethane polymer material layer.

According to another aspect of the invention, a method for preparing a fan-containing case for enclosing around a fan of an aircraft engine, the method comprising:

the forming method comprises the following steps of finishing forming of a main frame of a laying layer structure by adopting a carbon fiber resin matrix composite material through a manual laying or automatic tape laying or automatic wire laying process, wherein the main frame comprises a cylindrical side wall and flange edges positioned at two ends of the side wall, the flange edges are formed at one time by adopting an integral flanging process, and the side wall of the main frame axially comprises a containing area and non-containing areas positioned at two sides of the containing area along a casing;

mixing carbon fibers and aramid fibers, three-dimensionally weaving and compounding with resin to obtain a containing layer; and

the containing layer is arranged in the containing area on the inner side of the side wall of the main frame so as to lead the containing layer and the main frame to be connected into a whole in a secondary co-curing mode.

In one example, the volume content ratio of the carbon fiber to the aramid fiber for weaving the containing layer is 2: 1.

In one example, the fan containment case further includes a flange that uniformly secures a plurality of reinforcing brackets to the front and rear edges of the main frame along a circumferential direction of the case outside the side walls of the main frame.

In one example, the gap is between 8-12 mm.

In one example, the method further comprises winding the hybrid satin fabric of the carbon fiber and the aramid fiber on the reinforcing bracket slowly and uniformly under the control of a certain tension, and compounding the hybrid satin fabric with the resin to form the reinforcing layer.

In one example, after winding is complete, the interface region is adhesively encapsulated with an epoxy resin having high shear strength.

In one example, the method further comprises wrapping a protective layer outside the reinforcing layer.

In one example, the wrapping a protective layer outside the reinforcing layer includes wrapping a polyurethane film outside the reinforcing layer; and spraying a hydrophobic coating on the polyurethane film layer.

Drawings

The above features and advantages of the present disclosure will be better understood upon reading the detailed description of embodiments of the disclosure in conjunction with the following drawings. In the drawings, components are not necessarily drawn to scale, and components having similar relative characteristics or features may have the same or similar reference numerals.

FIG. 1 illustrates a schematic view of a hybrid construction/material fan containment case for an aircraft engine according to an aspect of the present invention;

FIG. 2 illustrates a cross-sectional schematic view of a hybrid construction/material fan containment case for an aircraft engine according to an aspect of the present invention;

FIG. 3 illustrates a schematic representation of stiffeners along a case frame of a hybrid structural/material aero-engine fan containment case according to an aspect of the present invention;

FIG. 4 illustrates an example cross-sectional schematic view of a hybrid construction/material fan containment case for an aircraft engine according to an aspect of the present invention; and

FIG. 5 illustrates a schematic view of a hybrid construction/material fan containment case mounting reinforcement bracket for an aircraft engine according to an aspect of the present invention.

Detailed Description

The invention is described in detail below with reference to the figures and specific embodiments. It is noted that the aspects described below in connection with the figures and the specific embodiments are only exemplary and should not be construed as imposing any limitation on the scope of the present invention.

The present invention provides a hybrid structure/material aero-engine fan containment case 100 that provides sufficient stiffness and containment while minimizing its weight. FIG. 1 illustrates a schematic view of a hybrid construction/material fan containment case 100 for an aircraft engine according to an aspect of the present invention.

As shown in fig. 1, the fan containment case 100 is generally cylindrical and surrounds a fan of an aircraft engine. The fan containment case 100 of FIG. 1 is partially cut away to illustrate a cross-sectional view of FIG. 2.

FIG. 2 illustrates a schematic view of a cross-section through a case axis of a hybrid structural/material fan containment case 100 for an aircraft engine according to an aspect of the present invention.

As shown in fig. 2, the fan containment case 100 may include a main frame 10. The main frame 10 includes a cylindrical side wall 11 and two flange sides 12 at both ends of the side wall. The sidewall of the main frame 10 may be divided into two regions along the axial direction of the casing, namely a containing region a and non-containing regions B and C located at both sides of the containing region a.

In the example shown in fig. 2, in the containing region a, a containing layer 20 is disposed inside the sidewall of the main frame 10 and distributed along the circumferential direction of the casing to enhance the containing effect. Since the accommodating layer 20 is only disposed in the accommodating area a, the weight of the fan casing is reduced as much as possible while enhancing the accommodating effect.

Of course, in other examples, containment layer 20 may be provided in the non-containment region.

In the present invention, the main frame 10 may be made of a carbon fiber resin-based composite material, and the containing layer 20 may be made of a resin-based composite material in which carbon fibers and aramid fibers are co-woven.

The carbon fiber composite material with the small thickness and the same thickness is used as the main frame, and compared with a metal material, the carbon fiber composite material has the advantage of large weight reduction. The inner side of the main frame 10 is provided with a containing layer which is formed by blending carbon fibers and aramid fibers by a 3-dimensional weaving process, the containing layer is uniformly distributed on the inner side of the main frame 10, the characteristics of high strength, high modulus and good toughness of the aramid fibers of the carbon fiber material are fully utilized, and the main function of the containing layer is to bear impact load and realize containing.

Compared with the characteristic that the wall thickness of the full composite material casing is not uniformly distributed, the design of the containing layer improves the process realizability and maintainability.

In particular practice, the main frame 10 of the fan case is made of a high-strength medium-modulus (e.g., T800) carbon fiber reinforced resin matrix composite material, and the side walls 11 of the main frame 10 of the case are the main body portion of the fan containment case 100. In order to ensure the rigidity of the main frame of the casing, the minimum thickness of the side wall 11 is not less than 20mm, and the thickness of the containing area is controlled between 25 mm and 35 mm.

Bolt holes are uniformly distributed on the flange edge 12 on the casing main frame 10, and the side wall 11 and the flange edge 12 of the fan casing main frame 10 are formed in one step by adopting an automatic wire laying or automatic belt laying process.

In one example, the containment layer 20 includes a plurality of reinforcing blocks 21 distributed circumferentially along the barrel. As an example, inside the side wall of the casing main frame 10, 6 reinforcing blocks 21 (shown in fig. 3) are uniformly distributed along the casing circumferential direction, and the reinforcing blocks 21 are made of a mixed fiber reinforced composite material in which aramid fibers and T800 fibers are mixed. The reinforcing block 21 serves to locally reinforce the θ angle region most affected by the impact.

This boss 21 has adopted aramid fiber and carbon fiber's 3 dimension to mix to weave the structure, and the volume content ratio of aramid fiber and carbon fiber is 2: 1. therefore, the reinforcing block is guaranteed to have high strength and modulus and good toughness, and when a foreign object impacts the area, the impact damage resistance of the casing to the foreign object can be effectively improved.

In one example, a plurality of reinforcing brackets 30 are uniformly distributed along the circumferential direction of the casing outside the side wall of the main frame 10, and each reinforcing bracket 30 is axially fixed to the flange 12 of the front and rear edges of the main frame 10 along the casing. FIG. 5 illustrates a schematic view of a hybrid construction/material fan containment case 100 mounting reinforcement bracket for an aircraft engine according to an aspect of the present invention.

As shown in fig. 5, a plurality of reinforcing brackets 30 are uniformly distributed along the circumferential direction of the casing outside the side wall 11 of the main frame 10, and each reinforcing bracket 30 is fixed to the flange 12 of the front and rear edges of the main frame 10 along the axial direction of the casing.

In one example, 8-12 titanium alloy metal reinforcing brackets 30 are uniformly distributed on the outer layer of the fan case main frame 10. To reduce weight, the titanium alloy metal reinforcing bracket 30 may be a high strength titanium alloy tube.

The titanium alloy metal reinforcing bracket 30 is fixed on the flange 12 at the front and rear edges of the main frame 10 of the fan case by means of bolts. In order to ensure the maintainability and the installability, a space 40 of 8-12mm is left between the metal reinforcing bracket 30 and the side wall 11 of the casing main frame 10.

The metal reinforcing bracket 30 may not only improve the overall rigidity of the casing main frame 10, but also effectively absorb impact energy when the casing main frame 10 is impacted by a foreign object, improve stress distribution of the casing main frame 10, and also provide support for an outer reinforcing layer 50 (described below) as shown in fig. 2.

The space 40 between the metal reinforcing bracket 30 and the sidewall 11 of the casing main frame 10 as shown in the figure can effectively improve the maintainability and assemblability of the fan housing casing 100, and when the outer reinforcing layer 50 is damaged due to rain corrosion, the outer reinforcing layer can be conveniently removed and maintained, and meanwhile, the casing body cannot be corroded due to direct contact with the casing main frame 10.

Compared with the integral metal casing with annular reinforcing ribs, the casing with the high-strength titanium alloy support frame can not only increase the rigidity of the whole main frame, but also effectively absorb energy when the main frame bears impact load, and reduce deformation of the casing.

As shown in fig. 2, the fan-housing case 100 may further include a reinforcing layer 50 wound around the reinforcing brackets 30 to cover the outer sides of the plurality of reinforcing brackets 30. The reinforcing layer 50 may be made of a resin-based composite material in which carbon fibers and aramid fibers are mixed.

In one example, the reinforcing brace 30 may be covered with a 10-30mm thick carbon/aramid fiber hybrid reinforced composite. The thickness distribution of the reinforcement layer 50 is discontinuous, e.g., the containment zone reinforcement layer thickness is greater than the non-containment zone reinforcement layer thickness.

Specifically, the thickness of the outer reinforcement layer 50 of the fan case non-containment region B, C is 10-15 mm; the thickness of the outer reinforcing layer of the fan casing containing area A is not less than 30 mm. But the actual thickness should be determined according to the simulation analysis or test result of the fan casing. It should be noted that the angle θ corresponding to the accommodation region a is different for different models of engines.

The main function of the outer reinforcement layer 50 is to further catch the fan blades or debris flying out in case of fan blade falling and breaking through the casing main frame 10, so as to ensure the safety of the engine and the airplane.

Finally, a layer of polyurethane polymer material may be coated on the outer side of the outer reinforcing layer 50, and a hydrophobic coating may be coated on the outer side of the polyurethane polymer material, which is collectively referred to as a protective layer 60. The hydrophobic coating in the protective layer 60 is used for reducing the contact between rainwater and the casing as much as possible, and the polyurethane material is used for preventing the contact between the casing and the rainwater so as to prevent the rainwater from corroding the composite material under the condition of long-term service.

FIG. 4 illustrates an example cross-sectional schematic view of a hybrid structural/material fan containment case for an aircraft engine according to an aspect of the present invention.

The carbon fiber and aramid fiber composite material reinforcing layer is arranged on the outer side of the main frame, and the auxiliary containing effect is mainly achieved, so that compared with an aramid fiber winding reinforcing casing, the reinforcing layer is small in thickness and does not need to be provided with a honeycomb structure. In order to reduce the corrosion of rainwater to the composite material, a protective layer is finally arranged on the outer side of the casing, and a hydrophobic coating is coated on the protective layer, so that the contact between the rainwater and the casing is reduced as much as possible.

The fan containing casing 100 can be made of carbon fiber resin matrix composite materials, titanium alloy, high-toughness aramid fiber and the like, and the characteristics of the three materials are exerted through a specific structural form, so that the coordination and unification of the rigidity, the containing performance and the weight reduction of the casing are realized, the metal and composite blades are contained, and the weight is light.

An example of a method of making a fan containment case is described below.

Step 1: the forming of the carbon fiber composite material casing main frame with the layer structure is completed by adopting a manual laying or automatic tape laying or automatic filament laying process according to a design drawing.

The side wall and the flange edge of the main frame of the casing are integrally formed by a flanging process.

Step 2: according to the size of a casing, adopting a 3-dimensional mixed weaving process, and mixing aramid fiber and carbon fiber according to the volume content of 2:1, carrying out mixed three-dimensional weaving, and compounding with high-toughness resin to obtain the inner side containing layer.

And step 3: the inner side containing layer and the casing main frame can be connected into a whole in a secondary co-curing mode.

And 4, step 4: a plurality of (for example, 12) titanium alloy pipes can be fixedly supported with the casing main frame in a bolt connection mode to form the titanium alloy metal reinforcing support.

The casing with the reinforcing brackets mounted thereon is shown in fig. 5.

Step 6: the carbon fiber/aramid fiber hybrid satin fabric can be slowly and uniformly wound on the titanium alloy metal reinforcing bracket under the control of a certain tension force and is compounded with resin to form an outer reinforcing layer.

And after winding is finished, bonding and packaging the interface region by using epoxy resin with high shear strength.

And 7: a polyurethane film of a certain thickness (for example, 0.2 to 0.4mm) is used, and winding is performed outside the outer reinforcing layer.

After winding is completed, the interface area is bonded and encapsulated by using epoxy resin with high shear strength.

And finally, spraying a hydrophobic coating with the thickness not more than 0.5-0.8mm on the outer side of the polyurethane film.

While, for purposes of simplicity of explanation, the methodologies are shown and described as a series of acts, it is to be understood and appreciated that the methodologies are not limited by the order of acts, as some acts may, in accordance with one or more embodiments, occur in different orders and/or concurrently with other acts from that shown and described herein or not shown and described herein, as would be understood by one skilled in the art.

The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A fan containing casing surrounds a fan of an aircraft engine and comprises a main frame, wherein the main frame comprises a cylindrical side wall and flange edges positioned at two ends of the side wall, the main frame is made of a carbon fiber resin matrix composite material, the side wall of the main frame comprises a containing area and non-containing areas positioned at two sides of the containing area along the axial direction of the casing, a containing layer distributed along the circumferential direction of the casing is arranged in the containing area on the inner side of the side wall of the main frame, the containing layer is made of a resin matrix composite material formed by mixing carbon fibers and aramid fibers, the volume content ratio of the carbon fibers and the aramid fibers in the containing layer is 2:1, a plurality of reinforcing supports and reinforcing layers formed by winding the reinforcing supports on the plurality of reinforcing supports are uniformly distributed on the outer side of the side wall of the main frame along the circumferential direction of the casing, each reinforcing support is axially fixed on the flange edge of the front edge and the rear edge of the main frame along the casing, and a gap is reserved between each reinforcing support and the side wall of the main frame.

2. A fan containment case according to claim 1, wherein the containment layer comprises a plurality of reinforcing blocks distributed circumferentially of the case.

3. A fan containment case according to claim 1, wherein the containment region sidewall thickness of the primary frame is greater than the non-containment region sidewall thickness.

4. A fan containment case according to claim 3, wherein the minimum thickness of the sidewalls of said main frame is no less than 20mm, and the containment zone sidewall thickness is between 25-35 mm.

5. A fan containment case according to claim 1, wherein said side walls and said flanged edges of said main frame are formed in one piece using an automated wire or tape laying process.

6. The fan containment case of claim 1, wherein the reinforcing brackets are titanium alloy tubing, each reinforcing bracket being bolted to the flange at the front and rear edges of the main frame.

7. A fan containment case according to claim 1, wherein said gap is between 8-12 mm.

8. The fan containment case of claim 1, wherein the containment zone reinforcement layer thickness of the reinforcement layer is greater than the non-containment zone reinforcement layer thickness.

9. The fan containment case of claim 8, wherein the containment zone reinforcement layer thickness of the reinforcement layer is not less than 30mm and the non-containment zone reinforcement layer thickness is between 10-15 mm.

10. The fan containment case of claim 1, wherein a protective layer is wrapped around the outside of said reinforcement layer.

11. The fan containment case of claim 10, wherein the protective layer comprises a polyurethane polymer material layer and a hydrophobic coating applied over the polyurethane polymer material layer.

12. A method for preparing a fan-containing case for enclosing around a fan of an aircraft engine, the method comprising:

the forming method comprises the following steps of finishing forming of a main frame of a laying structure by adopting a process of manually laying or automatically laying a belt or automatically laying a wire on a carbon fiber resin-based composite material, wherein the main frame comprises a cylindrical side wall and flange edges positioned at two ends of the side wall, the flange edges are formed in one step by adopting an integral flanging process, the side wall of the main frame comprises a containing area and non-containing areas positioned at two sides of the containing area along the axial direction of a casing, a plurality of reinforcing supports are uniformly fixed on the flange edges of the front and rear edges of the main frame along the circumferential direction of the casing at the outer side of the side wall of the main frame, and a gap is reserved between each reinforcing support and the side wall of the main frame;

mixing carbon fibers and aramid fibers, carrying out three-dimensional weaving, and compounding the carbon fibers and the aramid fibers with resin to obtain a containing layer, wherein the volume content ratio of the carbon fibers to the aramid fibers in the mixed weaving of the containing layer is 2: 1; and

the containing layer is arranged in the containing area on the inner side of the side wall of the main frame so as to lead the containing layer and the main frame to be connected into a whole in a secondary co-curing way,

the method also comprises the steps of winding the mixed-woven satin fabric of the carbon fiber and the aramid fiber on the reinforcing support slowly and uniformly under the control of a certain tension force, and compounding the mixed-woven satin fabric with resin to form a reinforcing layer.

13. The method of claim 12, wherein the containment zone sidewall thickness of the primary frame is greater than the non-containment zone sidewall thickness.

14. The method of claim 13, wherein the minimum thickness of the side walls of the main frame is not less than 20mm and the thickness of the side walls of the containment region is between 25 mm and 35 mm.

15. The method of claim 12, wherein the reinforcing brackets are titanium alloy tubes, and each reinforcing bracket is bolted to the flange of the front and rear edges of the main frame.

16. The method of claim 12, wherein the gap is between 8-12 mm.

17. The method of claim 12, wherein the containment zone reinforcement layer thickness of the reinforcement layer is greater than the non-containment zone reinforcement layer thickness.

18. The method of claim 17, wherein the containment zone reinforcement layer thickness of the reinforcement layer is not less than 30mm and the non-containment zone reinforcement layer thickness is between 10-15 mm.

19. The method of claim 12, wherein the interface region is adhesively encapsulated with a high shear strength epoxy after winding is complete.

20. The method of claim 12, further comprising:

and a protective layer is wrapped on the outer side of the reinforced layer.

21. The method of claim 20, wherein wrapping a protective layer outside the reinforcing layer comprises:

winding a polyurethane film layer on the outer side of the enhancement layer; and

and spraying a hydrophobic coating on the polyurethane film layer.

22. The method of claim 21, wherein after winding, the interface region is adhesively encapsulated with an epoxy resin having high shear strength.