CN112855616B

CN112855616B - Containing casing and preparation method thereof

Info

Publication number: CN112855616B
Application number: CN201911170941.9A
Authority: CN
Inventors: 孔维夷; 李向前; 张璇
Original assignee: AECC Commercial Aircraft Engine Co Ltd
Current assignee: AECC Commercial Aircraft Engine Co Ltd
Priority date: 2019-11-26
Filing date: 2019-11-26
Publication date: 2023-05-09
Anticipated expiration: 2039-11-26
Also published as: CN112855616A

Abstract

An object of the present invention is to provide a housing case which can have better housing. Another object of the present invention is to provide a method for preparing a containment casing as described above. The composite material body further comprises a linear reinforcing material, wherein the reinforcing material is implanted to the thickness direction of the prefabricated body along the circumferential direction of the casing for at least two circles of prefabricated bodies so as to be connected with at least one interlayer interface, and the implantation depth of the reinforcing material is smaller than the thickness of the prefabricated body corresponding to the connected at least one interlayer interface.

Description

Containing casing and preparation method thereof

Technical Field

The invention relates to a containing casing and a preparation method thereof.

Background

There are a large number of blades rotating at high speed in aeroengines and gas turbines, and in the case of foreign object impacts, process defects, etc., the rotating blades may come off. Therefore, the engine casing is required to have good inclusion, wherein the inclusion means that the casing can ensure that high-speed and high-energy fragments do not penetrate the casing, and damage is caused to equipment and personnel. The presence of a large unbalanced load on the engine rotor after blade flying can cause the engine to vibrate continuously before stopping, during which time the casing is required to maintain a certain structural integrity without disassembly.

Meanwhile, the engine case is large in size, and the weight of the engine case can obviously influence the total weight of the engine, so that the efficiency of the engine is further influenced. Carbon fiber composite materials are commonly used for low-temperature end cases in new-generation commercial engines. As proposed in patent application publication EP1674244, a triaxial woven preform is used, and a resin liquid forming process is used to manufacture fan containment cases of equal thickness. A variable thickness fan containment casing is proposed in the publication EP1674671, the reinforcement phase of the casing composite core being a circumferentially aligned, multi-layered superimposed braid, the additional composite layers being obtained from a helically wound braid. The patent application with publication number of US8322971B2 proposes a composite material containing casing, firstly adopting a three-dimensional weaving method to process a variable-thickness fiber preform, then laminating and winding on a mandrel to obtain a casing preform, and then forming by resin liquid to obtain the casing.

FIG. 1 shows a schematic diagram of a prior art aircraft gas turbine engine including a fan section 91, a core 93, a low pressure turbine 94, and a tail vane 95. The fan section 91 of the engine has a fan housing case 910 on the outer peripheral side thereof, and fan blades 92 are provided on the inner side thereof. Fig. 2 shows a schematic cross-sectional view of a prior art containing case comprising a composite body formed by winding a preform 930 at least three times, it being understood that in the embodiment shown in fig. 2, the number of turns of the preform 930 is three, and in other embodiments different from the one shown, the number of turns of the preform 930 may be more. Wherein the preform 930 may be made by multi-layer three-dimensional weaving.

However, the inventors found that the containment casing was prepared by winding the preform as in fig. 1 to 2, and that the interface 931 of the different preform layers were joined by a matrix material. Upon being subjected to a blade-shedding load, the matrix material at interface 931 fails under the action of the interlaminar stress, causing the interface to debond and the different layers to begin to separate. After the blades are detached, the engine can vibrate violently for a period of time, so that the influence range of interface failure and debonding is increased continuously, the rigidity of the casing is reduced seriously, and even the casing is disassembled, so that great threat is caused to man-machine safety.

Disclosure of Invention

An object of the present invention is to provide a housing case which can have better housing.

Another object of the present invention is to provide a method for preparing a containment casing as described above.

The composite material body further comprises a linear reinforcing material, wherein the reinforcing material is implanted to the thickness direction of the prefabricated body along the circumferential direction of the casing for at least two circles of prefabricated bodies so as to be connected with at least one interlayer interface, and the implantation depth of the reinforcing material is smaller than the thickness of the prefabricated body corresponding to the connected at least one interlayer interface.

In one or more embodiments, the reinforcement material maintains the connection of the at least one interlayer interface by friction of the reinforcement material with the preform.

In one or more embodiments, the casing includes a containment region, a transition region, and an equal thickness region in a width direction, at least one set of the reinforcing materials being implanted in each of the containment region, the transition region, and the equal thickness region.

In one or more embodiments, the reinforcement material is implanted into the thickness direction of the preform for every two turns of the preform.

In one or more embodiments, the reinforcement material is implanted in the thickness direction of the preform for two or more turns of the preform.

In one or more embodiments, the reinforcement material is implanted in the thickness direction of the preform for all turns of the preform.

In one or more embodiments, the reinforcement materials implanted in the preform corresponding to different turns are respectively spaced apart by a distance in a width direction of the receiver.

In one or more embodiments, the reinforcement material is distributed 360 ° along the casing periphery.

In one or more embodiments, the reinforcement material is implanted into the preform at least 50% of the thickness of the preform at the innermost ring.

In one or more embodiments, the preform includes a start region and a stop region at both ends thereof in a length direction, and an inner wall region, an outer wall region, and an intermediate region are sequentially disposed from the start region to the stop region;

wherein the thicknesses of the start region and the end region are gradually reduced toward the end portion respectively.

In one or more embodiments, the reinforcing material is a continuous yarn made of one or more of carbon fiber, glass fiber, aramid fiber, ultra-high density polyethylene fiber, polyimide fiber, basalt fiber, or filaments made of steel, titanium.

To achieve the other object, a method for manufacturing a housing case includes:

a. winding the preform on a mandrel;

b. after more than one circle of the prefabricated body is wound on the core mould, reinforcing materials are arranged on the outer sides of the prefabricated bodies positioned opposite to the outer ring;

c. the reinforced material is sequentially implanted into the prefabricated body along the circumferential direction of the casing by using a thimble mechanism;

d. casting the preform with resin and curing and forming.

The gain effect of the invention is as follows: by implanting the reinforcing material into the prefabricated body containing the casing, the prefabricated bodies of all layers are limited by the reinforcing material if the prefabricated bodies are separated by debonding, so that the containing property of the casing is improved.

Drawings

The above and other features, properties and advantages of the present invention will become more apparent from the following description in conjunction with the accompanying drawings and embodiments, in which:

FIG. 1 shows a schematic view of a prior art aircraft gas turbine engine;

FIG. 2 shows a schematic cross-sectional view of a prior art containing case;

FIG. 3 illustrates a schematic cross-sectional view of one embodiment of the present containment case;

FIG. 4 shows a schematic perspective view of a preform in an expanded state;

FIG. 5 shows a schematic cross-sectional view of a first embodiment of a containing case;

FIG. 6 shows a schematic cross-sectional view of a second embodiment of a containing case;

FIG. 7 shows a schematic cross-sectional view of a third embodiment of a containment case;

fig. 8 to 11 show schematic views of the process of preparing the containing case.

Detailed Description

The following discloses a number of different embodiments or examples of implementing the subject technology. Specific examples of components and arrangements are described below for purposes of simplifying the disclosure, and are, of course, merely examples and are not intended to limit the scope of the present application. For example, a first feature described later in this specification may be formed above or on a second feature, and may include embodiments in which the first and second features are formed in direct contact, as well as embodiments in which additional features may be formed between the first and second features, such that no direct contact may be made between the first and second features. In addition, the disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. Further, where a first element is described as being coupled or combined with a second element, the description includes embodiments in which the first and second elements are directly coupled or combined with each other, and also includes embodiments in which one or more other intervening elements are added to indirectly couple or combine the first and second elements with each other.

It should be noted that where used, the description of upper, lower, left, right, front, rear, top, bottom, forward, reverse, clockwise and counterclockwise are used for convenience only and do not imply any particular orientation of securement. In fact, they are used to reflect the relative position and/or orientation between the various parts of the object.

For the avoidance of doubt, reference numerals in the embodiments described below are independent of the labelling system of figures 1 to 2 in the background.

Fig. 3 shows a schematic cross-sectional view of an embodiment of the present containment case, and fig. 4 shows a schematic perspective view of the preform in an expanded state. The containment casing 1 is a composite body 10 formed by winding a strip-shaped preform 2 at least three times, the composite body 10 further comprising a wire-shaped reinforcing material 3, the reinforcing material 3 being implanted in the thickness direction a of the preform 2 for at least two turns of the preform 2 along the casing circumferential direction so as to connect at least one interlayer interface 20. Wherein the implantation depth of the reinforcement material 3 is smaller than the thickness of the preform corresponding to the interface between the layers to be joined. It is understood that the interlayer interface 20 refers to the interface between two adjacent layers of preforms.

The reinforcement material 3 maintains the connection of at least one interlayer interface 20 by its friction with the preform 2. When the casing is loaded, the interlayer interface 20 between the adjacent preforms 2 is easily debonded due to stress concentration. After the debonding and expansion encounters the obstruction of the reinforcement material 3 across the interface, either along the reinforcement material 3, causing a substantial increase in the path of expansion; or continue to expand after destroying the reinforcing material 3, increasing the energy consumed for expansion. In addition, the expansion of the interfacial debonding also overcomes the friction force when the reinforcing material 3 is pulled out, and when the reinforcing material 3 is made of a material with stronger friction effect, a large amount of energy is dissipated in the pulling-out process. This means that a greater driving force is required to debond the expansion interface, or in other words the difficulty of debonding and expansion is significantly increased. Thus, interfacial debonding will be inhibited locally, protecting the casing from extensive debonding and consequent performance degradation. Specifically, in one or more embodiments, the reinforcing material 3 is a continuous yarn made of one or more of carbon fiber, glass fiber, aramid fiber, ultra-high density polyethylene fiber, polyimide fiber, basalt fiber, and filaments made of steel and titanium. The reinforcing material 3 may also be made of any other fiber or metal that has a strong friction with the preform 2.

With continued reference to fig. 3, in one embodiment of a containment casing, the casing 1 includes a containment region 11, a transition region 12, and an equal thickness region 13 in the width direction b, with at least one set of reinforcing materials 3 being implanted into the containment region 11, the transition region 12, and the equal thickness region 13, respectively. Specifically, as shown in fig. 4, the preform 2 is flattened to be approximately rectangular, and its width is equal to or larger than the width of the casing 1. The width direction includes a region 21 corresponding to the casing accommodating region 11, a region 22 corresponding to the transition region 12, and a region 23 corresponding to the equal thickness region 13. The equal-thickness region 13 comprises a region corresponding to the flange 14 of the casing, a flange is formed at the flange 14 in a region 23 corresponding to the equal-thickness region 13 in the prefabricated body 2, the casing 1 is connected with the engine through bolts, the surrounding is not easy to be layered due to the bolt fastening action, part of the casing outside the bolt fastening action region still exists, and the inclusion of the casing is further improved through implanting reinforcing materials 3 in each region. It will be appreciated that the direction of implantation of the reinforcement material 3 at the corresponding casing flange 14 is horizontal as shown in the figures. Wherein the width direction of the preform 2 is the weft direction of the weave.

Please continue to refer to fig. 3. The preform 2 includes a start region 24 and a finish region 25 in the longitudinal direction, and further includes an inner wall region 26 corresponding to the inner wall of the casing, an outer wall region 27 corresponding to the outer wall of the casing, and an intermediate region 28. The starting region 24 and the terminating region 25 are positioned at two ends of the preform 2, and the respective lengths are not smaller than the arc length of 10 DEG of the outer diameter of the casing, the thickness gradually decreases towards the end part, and the step height of the end part is reduced, so that the possibility of interface failure caused by stress concentration in the place is reduced. The inner wall region 26, the middle region 28 and the outer wall region 27 are arranged in sequence from the initial region 24 to the final region 25, and the length of the prefabricated body 2 is such that the number of turns of the wound casing prefabricated body is more than or equal to 3 and less than or equal to 20. For softer preform materials, reducing the number of windings can improve production efficiency. However, the number of windings of the preform with higher rigidity needs to be increased, so that the preform region 23 corresponding to the equal-thickness region 13 still has a certain deformability, and flanging of the preform to form a flange edge can be realized. However, too many winding turns and too thin a single-layer preform thickness are also required to be avoided, and too many resin-rich regions on the surface of the preform after molding are avoided. The thickness of each area of the preform is changed as required by adjusting the number of layers of yarns during weaving, so that the copying preform imitating the contour and thickness distribution of the case is realized. It will be appreciated that fig. 3 is only a schematic drawing, and that the lengths of the start zone 24, the end zone 25, the inner wall zone 26, the intermediate zone 28, and the outer wall zone 27 shown in the drawing are only examples, and that the actual lengths should not be limited to those shown in the drawing.

In one embodiment of the containment casing, the reinforcement material 3 is distributed 360 ° along the casing periphery, further enhancing the overall containment of the casing.

In one embodiment of the containment casing, the reinforcement material 3 is implanted to a depth of at least 50% of the thickness of the ring of preforms relative to the innermost ring of preforms to ensure that the reinforcement material 3 in the connected interlayer interface 20 is implanted to a sufficient depth that a significant amount of energy will be dissipated during extraction, thereby enhancing the containment of the casing.

The following description is directed to a specific implantation form of the reinforcement material 3 in various embodiments of the containment casing 1.

Embodiment one

Fig. 5 shows a schematic cross-sectional view of a first embodiment of the containment casing, wherein the reinforcement material 3 'is implanted in the thickness direction of the preform 2' for every two turns. Specifically, the second set of reinforcing materials 3a 'is implanted into the adjacent two turns of the preform 2a' and 2b 'located on the opposite outer side, and the first set of reinforcing materials 3b' is implanted into the adjacent two turns of the preform 2b 'and 2c' located on the opposite inner side. Wherein the second set of reinforcement materials 3a 'and the first set of reinforcement materials 3b' implanted corresponding to different circles are respectively separated by a distance along the width direction of the casing (i.e. the direction perpendicular to the paper surface) so as to avoid overlapping of the two sets of reinforcement materials 3a 'and 3 b'. The implantation depth h1 of the reinforcement material 3' is smaller than the thickness b1 of the preforms 2a ' and 2b ' corresponding to the interface between the layers to be joined. In some embodiments, different from the illustration, the reinforcing material may be multiple sets.

Second embodiment

Fig. 6 shows a schematic cross-sectional view of a second embodiment of the containment casing, wherein the reinforcement material 3 "is implanted in the thickness direction of the preform 2" for every three turns. In particular, the second set of reinforcing materials 3a "is implanted in the adjacent three turns of preform 2a", 2b ", 2c" located on the opposite outer side, and the first set of reinforcing materials 3b "is implanted in the adjacent three turns of preform 2c", 2d ", 2e" located on the opposite inner side. The second set of reinforcement materials 3a "and the first set of reinforcement materials 3b" implanted in correspondence with different circles are respectively spaced apart from each other by a distance along the width direction of the casing (i.e., the direction perpendicular to the paper surface) so as to avoid overlapping of the two sets of reinforcement materials 3a "and 3b". The implantation depth h2 of the reinforcement material 3 "is smaller than the thickness b2 of the corresponding preforms 2a", 2b ", 2c" of the interface between the layers to be joined. In some embodiments, different from the illustration, the reinforcing material may be multiple sets, with each set having greater than three turns of the reinforcing material implanted.

Embodiment III

Fig. 7 shows a schematic cross-sectional view of a third embodiment of the containment case, in which the reinforcement material 3 '"is implanted for the entire number of turns of the preform 2'" in the thickness direction thereof. Specifically, the number of turns of the preform 2 '"may be three or more turns as shown, and the preform 2'" passes through an interlayer interface formed between the preforms of all turns and is implanted into the preform of the innermost turn. The implantation depth h3 of the reinforcement material 3 '"is smaller than the thickness b3 of the preform 2'" corresponding to the interface between the layers to be joined.

The following describes a method of preparing a containment case in one or more embodiments described above.

Schematic diagrams of the process of preparing the containment case are shown in fig. 8 to 11.

Step a: winding the preform on a mandrel.

As shown in fig. 8, the preform 2 is wound around the core mold 50. The mandrel 50 is rigid and has a hollow cylindrical shape with an outer surface having a step that matches the starting region 24 of the preform 2. The core die is connected to a driving mechanism at the hollowed-out portion 51 so that the core die can rotate around the rotation axis. The outer wall 52 of the mandrel is sufficiently thick to ensure rigidity of the mandrel. Starting from the start zone 24, the mandrel 50 is rotated to wind the preform 2 onto the mandrel 50. During winding, the portion of the preform 2 corresponding to the flange edge in the equal-thickness region 23 is turned over.

Step b: after the preform is wound more than one turn around the mandrel, reinforcing material is disposed outside the preform at the opposite outer turn.

Specifically: after the preform 2 is wound one turn and covers the starting region 24 as shown in fig. 8, the reinforcing material 3 is disposed from the outside of the preform 2 covering the starting region 24. The preform wound this turn corresponds to the inner wall region 26 in the preform.

Step c: and utilizing a thimble mechanism to implant the reinforcing material into the preform ring along the circumferential direction of the casing in sequence.

Specifically: as shown in fig. 9, a set of reinforcing materials 3 are sequentially inserted into the casing preform 2 at equal intervals along the casing circumferential direction using a thimble mechanism in the region where the starting region 24 is stacked with the first-turn preform. The distance between the individual reinforcement materials 3 being pierced is greater than 5mm and less than 200mm, and the extent of the piercing does not exceed the stacked preforms 2. The part of the reinforcing material 3 is sent into the prefabricated body 2 in the penetrating process, and when the thimble mechanism is pulled out, the reinforcing material 3 is remained in the prefabricated body 2, so that the implantation of the reinforcing material is achieved. In addition, since the reinforcing material 3 is in the form of a wire, a portion connecting the reinforcing materials is left outside the preform. The implantation process is repeated so that the casing is formed in the width direction in regions corresponding to the containment region 11, the transition region 12 and the equal thickness region 13, each of which is implanted with at least one set of reinforcing material 3. The region of the equal thickness region 13 corresponding to the flange edge is now not implanted with reinforcing material. The implantation is such that the reinforcement material 3 completely penetrates the first-turn wound preform and is buried for a certain length in the initiation region 24. This length is at least equal to the smaller of 70% and 2mm of the minimum thickness, avoiding the ejector pin structure colliding with the core 50. Wherein, at the thicker position of the initial region or the position where the thimble is not easy to collide, the implantation depth is at least 70% of the thickness of the position, and at this time, the reinforcement material 3 of the initial region 24 is implanted completely.

When the preform 2 is wound more than once around the outside of the mandrel 50 as shown in fig. 10, the reinforcement material 3 is further implanted, concretely as follows:

for the first embodiment shown in fig. 5, after the reinforcement material 3 is partially implanted in the initiation region 24, the winding of the preform 2 is continued until one more turn is completed, at which point a portion of the intermediate region 28 on the preform is wound onto the mandrel 50 and the first turn of preform. Then, a group of reinforcing materials 3' are equidistantly implanted in the circumferential 360-degree range of the casing by using the thimble mechanism. The depth of implantation should extend through the freshly wound preform and be at least 50% of the thickness of the first turn of preform. The distance between the implanted individual reinforcement materials 3' is greater than 10mm and less than 200mm. The implantation process is repeated so that the casing is formed in the width direction in regions corresponding to the containment region 11, the transition region 12 and the equal thickness region 13, each of which is implanted with at least one set of reinforcing material 3'. The spacing between the reinforcing materials 3' of each group should be greater than 10mm and less than 200mm, and the actual distance is determined according to the design of the casing.

For the second embodiment shown in fig. 6, after the reinforcement material 3 is implanted in the initial region 24, the reinforcement material 3 is wound by more integer turns. In this case, it should be ensured that the implanted reinforcement material 3″ penetrates all the wound preforms and at least 50% of the thickness of the preform relative to the innermost ring. For example, after two complete turns of the preform are wound as shown in the figure, the first set of reinforcement materials 3 b) are equidistantly implanted within 360 ° of the casing circumference using a thimble mechanism. Then two more complete turns of the preform are wound and the second set of reinforcement materials 3 a) are implanted. The above operation is repeated until a sufficient number of turns of the reinforcing material 3 "are wound.

For the third embodiment shown in fig. 7, after the reinforcement material 3 is implanted in the initial region 24 until the winding of the preform 2 '"of the last turn is completed, the reinforcement material 3'" is implanted so as to penetrate the preform 2 '"of the opposite innermost turn and at least reach 50% of the thickness of the preform 2'" of the opposite innermost turn.

As in the previous embodiments one to three, after winding a single layer or several layers, the reinforcement material 3 is implanted until the winding of the end turn preform 2 and the reinforcement material implantation are completed. The reinforcement materials 3 passing through the preforms of the different layers should be staggered by at least 20mm to avoid mutual influence.

Subsequently, as shown in fig. 11, winding of the termination region 24 is completed, and the reinforcing material 3 is implanted in the region where the termination region 24 overlaps with the end turn preform 3. The implantation should be such that the reinforcement material 3 completely penetrates the preform of the termination region 24 and amounts to at least 50% of the thickness of the end turn preform 3.

Subsequently, in areas other than the flange-side bolting action. The reinforcement material 3 is implanted equidistantly in the thickness direction of the flange edge, the implantation being such that the reinforcement material 3 passes through all preform layers 2 up to at least 50% of the thickness of the end turn preform.

Step d: casting the preform with resin and curing and forming.

Specifically, a rigid outer mold or a flexible material is used to wrap the outer surface of the wound casing preform 2, a cavity required by liquid molding is formed with the core mold 50, a proper liquid molding process is used to introduce liquid resin into the cavity, the resin is solidified by adopting a heating, pressurizing, vacuumizing or other proper process methods, and the solidified casing is demolded to finish the subsequent processing.

While the invention has been described in terms of preferred embodiments, it is not intended to be limiting, but rather to the invention, as will occur to those skilled in the art, without departing from the spirit and scope of the invention. Therefore, any modification, equivalent variation and modification of the above embodiments according to the technical substance of the present invention fall within the protection scope defined by the claims of the present invention.

Claims

1. A containment casing comprising a composite body formed by winding a strip-shaped preform for at least three turns, characterized in that the composite body further comprises a continuous linear reinforcing material, the reinforcing material is implanted to the thickness direction of the preform along the circumferential direction of the casing for at least two turns of the preform so as to connect at least one interlayer interface, and the implantation depth of the reinforcing material is smaller than the thickness of the preform corresponding to the connected at least one interlayer interface;

the reinforcing materials implanted into the preform corresponding to different rings are respectively spaced apart by a distance along the width direction of the casing.

2. The containment casing of claim 1, wherein the reinforcement material maintains the connection of the at least one interlayer interface by friction of the reinforcement material with the preform.

3. The containment case of claim 1, wherein the case comprises a containment region, a transition region, and an equal thickness region in a width direction, at least one set of the reinforcing materials being implanted in each of the containment region, the transition region, and the equal thickness region.

4. The containment casing of claim 1, wherein the reinforcement material is implanted into the thickness direction of the preform for every two turns of the preform.

5. The containment case of claim 1, wherein the reinforcement material is implanted in a thickness direction of the preform for two or more turns of the preform.

6. A containment casing according to claim 1, wherein the reinforcement material is distributed 360 ° along the casing periphery.

7. A containment casing according to claim 1, wherein the reinforcement material is implanted into the preform at the innermost ring to a depth of at least 50% of the thickness of the ring of preforms.

8. The containment casing according to claim 1, wherein the preform includes a start region and a stop region at both ends thereof in a length direction, and an inner wall region, an outer wall region and an intermediate region are provided in this order from the start region to the stop region;

9. The containment case of claim 1, wherein the reinforcing material is a continuous yarn made of one or more of carbon fiber, glass fiber, aramid fiber, ultra-high density polyethylene fiber, polyimide fiber, basalt fiber, or filaments made of steel, titanium.

10. A method of manufacturing a containment casing according to any one of claims 1 to 9, comprising:

a. winding the preform on a mandrel;

d. casting the preform with resin and curing and forming.