CN117087252A - Composite fan blade and paving method - Google Patents

Abstract

The invention provides a composite fan blade, comprising a composite body, wherein the laying sequence of a fiber structure of the composite body is circulated according to the laying angles of 0 DEG, 45 DEG, 0 DEG and-45 DEG, and the fiber structure comprises a plurality of first layers with the laying angles of 0 deg. The lay-up angle varies at least partially from 0 ° to 90 ° in at least part of the first lay-up 5 layers of the plurality of first lay-ups. The invention also provides a paving method. The composite fan blade can improve the foreign object damage resistance of the composite fan blade.

Description

Composite fan blade and paving method

Technical Field

The invention relates to a composite fan blade, and also relates to a paving method for paving a fiber structure of a composite body of the composite fan blade.

Background

The aeroengine is provided with two working blades, namely a rotor type working blade and a stator type working blade, and the blades do work in the working process. The fan blade is positioned at the forefront end of the air inlet channel, plays roles in air entraining and thrust generation through high-speed rotation, and mainly consists of tenons and blade bodies. Under normal working conditions, the fan blades mainly bear pneumatic load and centrifugal load, and the tenons transmit the load to the fan disc.

Modern turbofan aeroengines are continuously developing towards large duct ratio, large thrust, low oil consumption, low noise, high safety, high reliability and the like. In order to increase the aero-engine bypass ratio, large-sized fan blades have become a necessary choice for various turbofan aero-engine manufacturers, which has resulted in a continual increase in the weight of the engine fan over the weight of the total engine.

To meet the high thrust-to-weight ratio requirements, metallic fan blades are increasingly being replaced. In the 60 s of the 20 th century, composite materials enter the sight of people as a new material, and the composite materials are rapidly growing up due to the advantages of high specific strength and specific modulus, designable performance, easiness in integral molding and the like, and become an aerospace four-structure material together with aluminum alloy, titanium alloy and alloy steel. At present, composite material fan blades, namely composite material fan blades, are well applied to foreign mature turbofan aeroengines. At present, no mature composite fan blade is applied to an aeroengine at home.

The inventors have analyzed that attempts may be made to improve the resistance of composite fan blades to foreign object damage based on the designable characteristics of the composite material properties.

Disclosure of Invention

The invention aims to provide a composite fan blade, which can improve the damage resistance of the composite fan blade to foreign objects.

Another object of the present invention is to provide a method for laying a fiber structure of a composite body of a composite fan blade, which can improve the resistance of the obtained composite fan blade against damage by foreign objects.

The invention provides a composite fan blade, comprising a composite body, wherein the laying sequence of a fiber structure of the composite body is circulated according to the laying angles of 0 DEG, 45 DEG, 0 DEG and-45 DEG, and the fiber structure comprises a plurality of first layers with the laying angles of 0 deg. The lay-up angle varies at least partially from 0 ° to 90 ° in at least part of the first plies of the plurality of first plies.

In one embodiment, only a portion of the plurality of first plies has a variation in the lay angle.

In one embodiment, the angle of lay-up varies only in localized areas in the at least part of the first ply.

In one embodiment, the localized area covers at least a portion of the leading edge of the composite body.

In one embodiment, the localized area covers at least a portion of the tip of the composite body.

In one embodiment, the localized area covers only a portion of the leading edge and a portion of the blade tip of the composite body.

In one embodiment, the localized area has a first boundary and a second boundary. The first boundary extends from the tip of the composite body toward the root of the blade, thereby having a first end point on the underside of the tip. The second boundary extends from the first end of the first boundary to a leading edge of the composite body.

In one embodiment, the first boundary is disposed at a pitch line of a first order torsional mode of the composite fan blade.

In one embodiment, the second boundary is disposed above a middle portion of the composite fan blade.

The invention also provides a method for laying a fibre structure of a composite body of a composite fan blade, the fibre structure being cyclically laid at laying angles of 0 °, 45 °, 0 °, -45 ° in the order of laying, whereby the fibre structure comprises a plurality of first plies with laying angles of 0 °. In the laying method, the laying angle is changed from 0 ° to 90 ° at least partially in at least part of the first plies of the plurality of first plies.

According to the composite fan blade and the composite fan blade obtained by the paving method, based on the designable characteristic of the performance of the composite material, at least part of the first paving layer with the original paving angle of 0 DEG is changed into 90 DEG at least partially, so that the chordwise stiffness of the composite fan blade can be improved, the strength performance of the composite fan blade is optimized, and particularly the capability of resisting foreign object impact 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 is a schematic structural view of an exemplary composite fan blade.

Fig. 2 is a schematic diagram schematically illustrating a ply structure.

Fig. 3 is a schematic diagram exemplarily showing a position of a local area.

Fig. 4 is a schematic view exemplarily showing a torsional vibration mode of a composite fan blade.

Fig. 5 is a schematic diagram illustrating a lay-up structure of a composite fan blade.

Detailed Description

The present invention will be further described with reference to the following detailed description and the accompanying drawings, in which more details are set forth in order to provide a thorough understanding of the present invention, but it will be apparent that the present invention can be embodied in many other forms than described herein, and that those skilled in the art may make similar generalizations and deductions depending on the actual application without departing from the spirit of the present invention, and therefore should not be limited in scope by the context of this detailed description.

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 are formed between the first and second features, such that no direct contact between the first and second features is possible. 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.

The fan blade is positioned at the forefront end of an air inlet channel of the aero-engine and is an engine front end part, and the main functions of the fan blade are compressed gas and energy transfer. The air flow enters the fan after passing through the air inlet channel, the tangential velocity of the air flow is increased by the fan blades rotating at high speed, and the speed is converted into static pressure rise by the expansion channels formed among the blades. The high-energy air flow passing through the fan blades is divided into two parts, namely an external culvert and an internal culvert. The external air flow is finally converted into engine thrust through parts such as a fan outlet guide vane, a tail nozzle and the like.

The working environment of the fan blades and the loads applied to the fan blades are complex and severe, and meanwhile, the thrust of the aero-engine is mainly provided by the fan blades. The strength and dynamics of the fan blade not only determine the working performance of the fan blade, but also have important influence on the overall performance of the aero-engine. Practice proves that the novel composite material technology has wide application prospect in the turbofan aero-engine, and can effectively improve the performance of the aero-engine.

Composite materials generally include a matrix and fibers. For example, the matrix may be a resin and the fibers may be carbon fibers, for example. Taking resin-based composite materials as an example, the composite materials mainly comprise fibers, a matrix and an interface layer, so that the single composition of the resin-based composite materials different from metals is determined, and the composite structure and the manufacturing process of various components lead to the composite materials having different material characteristics from those of the metal materials, and the load transmission path, the failure mechanism and the design mechanism of the composite materials are greatly different from those of the metal structures. The composite fan blade manufactured by the resin matrix composite material can realize effective weight reduction, and can also effectively reduce the impact degree of the broken blade on the fan casing.

The invention aims to develop the design of the local layering structure of the fan blade in a targeted way based on the designable characteristic of the performance of the composite material, the dynamic response characteristic of the fan blade under the impact of foreign objects and the damage mechanism of the fan blade. In the case of a certain fan blade configuration, the local rigidity distribution of the fan blade is adjusted so as to improve the damage resistance of the fan blade to foreign objects.

Fig. 1 shows an example configuration of a composite fan blade 10. The composite fan blade 10 comprises a composite body 1. It is to be understood that the drawings are by way of example only and are not drawn to scale and should not be construed to limit the true scope of the invention.

As shown in fig. 2, the lay-up sequence of the fibre structure 2 of the composite body 1 is cycled through lay-up angles of 0 °, 45 °, 0 °, -45 °, whereby the fibre structure 2 comprises a plurality of first plies 31 with lay-up angles of 0 °.

As shown in fig. 3, the composite fan blade 10 provided by the present invention has a laying angle that varies at least partially from 0 ° to 90 ° in at least a part of the first plies 31a of the plurality of first plies 31.

The composite fan blade 10, i.e., the majority of the volume, uses composite material as the fan blade for the load bearing structure. The composite body 1, i.e. the body part of the composite fan blade 10, is made of a composite material. For example, as shown in FIG. 1, the composite fan blade 10 may also include a metallic reinforcing rim 20 and a cover layer 30. Wherein the cover layer 30 may be located on the blade body surface above the flow path line SL. The cover layer 30 is mainly used for protecting the composite body 1, and the composite body 1 and the metal reinforcing edge 20 can be bonded through an adhesive film.

The fiber structure 2 is a composite material constituting the composite body 1, and includes a structural portion made of individual fibers except a matrix. The fibrous structure 2 may comprise a plurality of layers of unidirectional tape prepreg, each layer of prepreg may also be referred to as each ply.

The lay-up sequence of the fibre structure 2 is cycled through lay-up angles of 0 °, 45 °, i.e. the lay-up angle sequence is designed as [0 °/45 °/0 °/-45 °] _N . Typically, the suction side outermost layer of the composite fan blade 10 may be a 0 ° ply (i.e., the first ply 31). The radial direction (or the spanwise direction C0) of the composite fan blade 10 is 0 °, and the axial positive direction is from the leading edge L0 to the trailing edge T0 of the composite fan blade 10. It will be appreciated that the textA range of tolerances, for example + -5 deg., may be permitted for the particular angle of (c). Whereas a lay-up angle of 45 ° means, for example, inclined toward the trailing edge T0 in comparison to the 0 ° direction with the root R0 of the composite fan blade 10, for example, a certain point of the tenon, as the origin; a laying angle of-45 ° means that, starting from this origin, it is inclined towards the leading edge L0 compared to the 0 ° direction; a 90 ° lay angle means substantially along the axial direction (or chordwise direction X0) of the composite fan blade 10. It is to be understood that reference herein to two directions being "coincident", "parallel" or "along" a direction, etc. does not require that the mathematically strict angular requirements be met, but rather that certain tolerance ranges are tolerated, e.g. within 5 ° of the mathematically required angle.

In at least part of the first plies 31a of the aforementioned plurality of first plies 31, the laying angle varies at least partially from 0 ° to 90 °, meaning that the laying angle of some or all of the 0 ° plies varies partially or globally from 0 ° to 90 °. It should be understood that the expression "from 0 ° to 90 °" used herein for the composite fan blade 10 and the subsequent coating method is merely for convenience of expression and is not limited to the action of this variation. That is, it is not required that the specific area is first spread at a spread angle of 0 ° and then the spread angle is corrected from 0 ° to 90 °. Instead, the laying angle of the specific region may be designed to be 90 ° directly at the time of design, that is, the corresponding 0 ° ply is laid at 0 ° except for the specific region, and the laying is performed directly at 90 ° in the specific region.

It is understood that "plurality" herein means more than two, including two, three, four, five, etc. It will be further understood that the terms "first," "second," and the like, as used herein, are merely intended to facilitate distinguishing between corresponding features, and unless otherwise indicated, and are not intended to limit the scope of the invention in any way. For example, the aforementioned first ply 31 is intended to mean a 0 ° ply, intended to be distinguished from 45 ° -45 ° plies.

The inventor analysis believes that the composite body 1 of the composite fan blade 10Part of the load transmission path is mainly determined by the lay-up direction of the prepreg, i.e. the fibrous structure 2, i.e. by the stiffness distribution of the composite body 1. The inventors have further found that [ 0/45/0/45 °and that] _N The lay-up angle of (c) results in the spanwise stiffness of the composite fan blade 10 being significantly higher than the chordwise stiffness of the composite fan blade 10.

In the composite fan blade 1, the chordwise stiffness of the composite fan blade 1 can be improved by designing at least a part of the 0 ° ply at least partially from 0 ° to 90 °.

The composite fan blade 1 is based on the designability of the composite material, and at least partial 0 DEG layering is designed to be 90 DEG from 0 DEG at least partially, so that at least partial strength performance of the composite fan blade 1, particularly the capability of resisting foreign object impact, can be improved.

In the illustrated embodiment, as shown in fig. 3, only a part of the first mat 31a of the plurality of first mats 31 changes in the laying angle. That is, not all 0 ° plies have at least a partial angular change, and some 0 ° plies have no change in the laying angle. In this way, the overall performance of the composite fan blade 1 may be facilitated.

It is to be understood that the use of specific words to describe embodiments of the invention, such as "one embodiment," "another embodiment," and/or "some embodiments" means that a particular feature, structure, or characteristic is associated with at least one embodiment of the invention. Thus, it should be emphasized and should be appreciated that two or more references to "one embodiment" or "another embodiment" in this specification at different positions are not necessarily referring to the same embodiment. Furthermore, certain features, structures, or characteristics of one or more embodiments of the invention may be combined as suitable.

Fig. 3 schematically illustrates the local stiffness optimization of the composite fan blade 10. In the illustrated embodiment, as shown in fig. 2 and 3, the laying angle changes only in the partial area A1 in the aforementioned at least partial first ply 31 a. That is, a 0 ° ply having a variation in the ply angle does not have a variation in the ply angle over the entire area of the 0 ° ply, but only partially to 90 °, and some areas still maintain the ply angle of 0 °. In this way, the overall performance of the composite fan blade 1 may be facilitated.

In fig. 3, the partial area A1 may cover at least part of the leading edge L1 of the composite body 1. It will be appreciated that L1 is used herein to represent the leading edge of the composite body 1, unlike the leading edge L0 of the composite fan blade 10, because the leading edge L0 of the illustrated composite fan blade 10 is provided by the metal reinforcing rim 20. In another embodiment, the leading edge L1 of the composite body 1 may also directly constitute the leading edge L0 of the composite fan blade 10.

During the operation of the fan blade, the front edge part of the blade can bear more foreign object impact, and even needs to bear very severe foreign object impact loads such as bird strike and the like. Taking the composite fan blade 10 shown in fig. 1 as an example, the front edge metal reinforcing edge 20 increases the capability of the composite fan blade 10 to resist the impact of foreign objects, and at the same time, the metal reinforcing edge 20 transmits the impact load to the composite body 1, wherein a part of the load is transmitted along the spanwise direction C0 (radial direction), and a part of the load is transmitted along the chordwise direction X0 (front edge to tail edge direction), so as to further excite the composite fan blade 10 to generate a power response.

The chordwise stiffness of the leading edge of the composite fan blade 10 can be improved by designing the leading edge portion of the partial ply 31 of the composite fan blade 10 at least partially from 0 ° to 90 °.

In fig. 3, the partial area A1 may also cover at least part of the blade tip J0 of the composite body 1.

In fig. 3, the partial area A1 covers only a part of the leading edge L1 and a part of the blade tip J0 of the composite body 1. That is, not all of the leading edge L1 and all of the blade tips J0 are covered by the localized area A1. The front edge and the blade tip of the partial layer 31 of the composite fan blade 10 are partially designed to be 90 degrees from 0 degrees, so that the local strength performance of the composite fan blade 10 can be improved.

In fig. 3, the partial region A1 may have a first boundary B1. The first boundary B1 extends from the tip J0 of the composite body 1 toward the root R0 so as to have a first end point P1 located on the bottom side of the tip J0. For example, the extending direction of the first boundary B1 may substantially coincide with the spanwise direction C0 or the 0 ° direction. The first boundary B1 may also be referred to as a chordwise boundary.

The partial area A1 may have a second boundary B2. The second boundary B2 may extend from the first end point P1 of the first boundary B1 to the front edge L1 of the composite body 1. For example, the extending direction of the second boundary B2 may substantially coincide with the chordwise direction X0 or the 90 ° direction. The second boundary B2 may also be referred to as a spanwise boundary.

Fig. 4 shows the first order torsional mode of the composite fan blade 10 calculated by simulation. Referring to fig. 3 and 4, the first boundary B1 may be disposed at a pitch line LZ of the first-order torsional mode of the composite fan blade 10, as shown in fig. 4.

Referring to fig. 3, the second boundary B2 may be disposed above the middle of the composite fan blade 10. That is, the second boundary B2 may be disposed on a side of the spanwise centerline LC near the tip J0. The spanwise centerline LC may be the centerline of the entire composite fan blade 10 in the spanwise direction C0.

The chord-wise boundary first boundary B1 of the partial 90 ° ply is set at the pitch line LZ of the 1 st order torsional vibration mode of the fan blade (shown by the boundary line of the darkest region in fig. 4), and the second boundary B2 of the partial 90 ° ply is set above the middle of the blade, which is an optimal design based on the dynamic response characteristics of the composite blade under the impact load of foreign objects and the corresponding damage mechanism.

The invention also provides a cladding method for cladding the fibrous structure 2 of the composite body 1 of the composite fan blade 10. The laying sequence of the fibre structure 2 is cycled through the laying angles 0 °, 45 °, 0 °, -45 °, whereby the fibre structure 2 comprises a plurality of first plies 31 with a laying angle of 0 °. In the laying method according to the present invention, the laying angle is changed from 0 ° to 90 ° at least partially in at least part of the first plies 31a of the plurality of first plies 31.

By the above-described laying method, the aforementioned stiffness-optimized composite fan blade 1 can be obtained. Specific arrangements in the above-described laying method may be described with reference to the structure of the composite fan blade 1 described above.

As an example, in actual operation, the laying angle of the partial area A1 of the partial lay-up of the composite fan blade 1 may be designed from 0 ° to 90 ° at the design stage, and as shown in fig. 3, the design origin O1 of the 90 ° partial lay-up may be located substantially at the center of the 90 ° partial lay-up. And then laying according to the design. The lay-up structure of the actual laid up composite fan blade 10 is shown in fig. 5, with each curve in fig. 5 representing the boundary of each layer of prepreg (i.e., lay-up) and multiple curves representing different boundaries of prepreg at different thickness locations. The part of the composite body 1 of the composite fan blade 10 can be covered and overlapped with the prepreg sequentially at a certain angle by taking resin as a matrix, and the boundary B3 of each layer of prepreg needs to adapt to the thickness space distribution of the composite fan blade 10. The fan blades 10 are sequentially laid from the suction side to the pressure side in the order of the designed laying angle (or lay angle).

According to the composite fan blade and the paving method, based on the characteristic that the performance of the composite material can be designed, the dynamic characteristics of the composite fan blade are subjected to targeted design by combining the corresponding damage mechanism and failure mode, and the process is easy to realize.

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 (10)

1. Composite fan blade comprising a composite body, the lay-up sequence of the fibrous structure of which is cycled through lay-up angles of 0 °, 45 °, 0 °, -45 °, whereby the fibrous structure comprises a plurality of first plies with lay-up angles of 0 °,

the lay-up angle varies at least partially from 0 ° to 90 ° in at least part of the first plies of the plurality of first plies.

2. The composite fan blade of claim 1, wherein only a portion of the plurality of first plies have a variation in lay-up angle.

3. The composite fan blade of claim 1, wherein the lay-up angle varies only in localized areas in the at least a portion of the first lay-up.

4. A composite fan blade according to claim 3, wherein the localized area covers at least part of the leading edge of the composite body.

5. The composite fan blade of claim 4, wherein the localized area covers at least a portion of the tip of the composite body.

6. The composite fan blade of claim 5, wherein the localized area covers only a portion of the leading edge and a portion of the blade tip of the composite body.

7. The composite fan blade of claim 6, wherein the localized area has:

a first boundary extending from the tip of the composite body toward the root of the blade, thereby having a first end point located on the underside of the tip; and

a second boundary extends from the first end of the first boundary to a leading edge of the composite body.

8. The composite fan blade of claim 7 wherein,

the first boundary is disposed at a pitch line of a first order torsional mode of the composite fan blade.

9. The composite fan blade of claim 7 wherein,

the second boundary is arranged above the middle of the composite fan blade.

10. A method for laying a fibre structure of a composite body of a composite fan blade, the fibre structure being laid in a sequence of laying angles of 0 °, 45 °, whereby the fibre structure comprises a plurality of first plies having a laying angle of 0%,

in the laying method, the laying angle is changed from 0 ° to 90 ° at least partially in at least part of the first plies of the plurality of first plies.