CN113104210B

CN113104210B - Rotor blade integrally formed by three-dimensional woven composite material and manufacturing method

Info

Publication number: CN113104210B
Application number: CN202110546706.8A
Authority: CN
Inventors: 王财政; 苏丹丹; 谢之峰; 周明
Original assignee: Tsinghua University
Current assignee: Tsinghua University
Priority date: 2021-05-19
Filing date: 2021-05-19
Publication date: 2022-02-01
Anticipated expiration: 2041-05-19
Also published as: CN113104210A

Abstract

The application provides a rotor blade integrally formed by a three-dimensional woven composite material and a manufacturing method, wherein the rotor blade integrally formed by the three-dimensional woven composite material comprises the following components: the root connector is provided with a tow connecting hole; and the blade body comprises a three-dimensional woven composite material woven by tows, and the blade body is connected to the root connecting head through the tow connecting hole by at least partially penetrating the tows.

Description

Rotor blade integrally formed by three-dimensional woven composite material and manufacturing method

Technical Field

The application relates to a rotor blade integrally formed by a three-dimensional woven composite material and a manufacturing method.

Background

The rotor blade used by the existing unmanned helicopter comprises an upper wing surface, a lower wing surface and a bearing girder, wherein the upper wing surface, the lower wing surface and the bearing girder are all formed by firstly adopting an independent mould to lay carbon fiber unidirectional cloth or woven cloth for preforming and then finally forming in a bonding or co-curing mode. The process for manufacturing the paddle by adopting the process mode is complex, the laying of the carbon fiber cloth depends on manual experience, the production efficiency is low, and the uniformity of different paddles is difficult to ensure. In addition, the upper airfoil surface, the lower airfoil surface and the crossbeam of the paddle are bonded together only through resin, so that the integrity is poor, the interlayer strength is low, the delamination damage is easy to occur when the paddle is subjected to a large load or external impact, and the performance advantage of the carbon fiber material cannot be fully exerted.

Disclosure of Invention

The application aims to provide the rotor blade integrally formed by the three-dimensional woven composite material, so that the rotor blade integrally has higher strength.

The application also provides a manufacturing method of the rotor blade integrally formed by the three-dimensional woven composite material

The application provides a rotor blade of three-dimensional machine weaving combined material integrated into one piece, rotor blade of three-dimensional machine weaving combined material integrated into one piece includes:

the root connector is provided with a tow connecting hole; and

a blade body comprising a three-dimensional woven composite material woven from tows, the blade body being connected to the root connector by at least part of the tows passing through the tow connection holes.

Preferably, the blade body comprises:

the bearing beam is provided with a cavity, and a beam core is filled in the cavity;

a first filler located at a rear side of the load beam;

a trailing edge strip located on a trailing side of the first filler;

covering the upper airfoil surface; and

a lower airfoil skin, the upper and lower airfoil skins wrapping the load beam, the first filler, and the trailing edge strip,

wherein the carrier bar, the upper airfoil skin, the lower airfoil skin and the trailing edge strip are three-dimensional woven structures integrally formed by three-dimensional weaving.

Preferably, the beam core comprises a second filler, a unidirectional fiber tape, a weight and a fiber cloth wrapping layer,

the fiber cloth wrapping layer wraps the second filler, the unidirectional fiber tape and the counterweight,

the unidirectional fiber tape is located at the front side of the cavity, the second filler is located at the rear side of the cavity, the unidirectional fiber tape wraps the weight, and the weight is located at the front side of the second filler.

Preferably, the load beam is a shell having a multi-layer structure, and the modulus of the fibers forming the middle layer of the shell is less than the modulus of the fibers forming the inner and outer layers of the shell.

Preferably, the load-bearing beam comprises a shell front edge, a first region ring layer, a second region ring layer and a third region ring layer, the shell front edge is located on the front side of the load-bearing beam, the wall thickness of the shell front edge is smaller as the shell front edge extends backwards, the shell front edge comprises tough fibers, the first region ring layer wraps the second region ring layer, and the second region ring layer wraps the third region ring layer.

Preferably, the tough fibers comprise at least one of glass fibers, quartz fibers, or aramid fibers.

Preferably, the three-dimensional woven structure comprises angle interlocking structures, angle interlocking structures with warp inserts, angle interlocking structures with weft inserts, angle interlocking structures with warp inserts and weft inserts, and angle interlocking structures with bias yarns.

Preferably, the blade body is cured by a resin transfer molding process, a high pressure resin transfer molding process or a high pressure compression resin transfer molding process.

The application also provides a manufacturing method of the rotor blade integrally formed by the three-dimensional woven composite material, and the manufacturing method of the rotor blade integrally formed by the three-dimensional woven composite material comprises the following steps:

providing a root connector;

providing a beam core and a first filler;

penetrating partial axial yarns through tow connecting holes of a root connector, wherein the tow connecting holes are used as initial positions of the partial axial yarns of the integral weaving structure, integrally weaving and forming an upper wing surface skin, a lower wing surface skin, a bearing beam and a rear edge strip, filling a first filler in a cavity between the upper wing surface skin and the lower wing surface skin and filling a beam core in the bearing beam;

and curing and forming the rotor blade integrally formed by the three-dimensional woven composite material through a resin transfer molding process, a high-pressure resin transfer molding process or a high-pressure compression resin transfer molding process.

Preferably, the providing the beam core comprises:

and paving a unidirectional fiber belt in a die for manufacturing the beam core, placing a balance weight and a second filler in the die, wrapping fiber cloth to form a fiber cloth wrapping layer, and then carrying out compression molding.

By adopting the technical scheme, at least one of the following beneficial effects can be obtained.

(1) The paddle formed by the three-dimensional woven structure can have various fibers, the performance parameters such as frequency, gravity center, rigidity and the like of the paddle can be adjusted by adjusting the distribution and proportion of different fibers, and meanwhile, the hybrid toughening property of the three-dimensional woven composite material can be utilized, so that the structural strength, toughness and impact resistance are improved, and the problem of sudden failure of the pure carbon fiber composite material structure is avoided.

(2) The weaving process has the characteristic of shape modification, and the requirement of a blade topological structure is easily met.

(3) The complex paddle structure can be manufactured through a three-dimensional weaving process, secondary bonding and machining are not needed, and the problem that the traditional laminated composite material is easy to delaminate is solved. The blade of the application has higher fatigue resistance and damage tolerance.

Drawings

Fig. 1 illustrates a schematic structural view of a three-dimensional woven composite integrally formed rotor blade according to an embodiment of the present application.

Figure 2 illustrates a schematic structural view of a root attachment of a three-dimensional woven composite integrally formed rotor blade according to an embodiment of the present application.

Figure 3 illustrates a cross-sectional view of a three-dimensional woven composite integrally formed rotor blade according to an embodiment of the present application.

Figure 4 illustrates a cross-sectional view of a three-dimensional woven molded portion of a three-dimensional woven composite integrally molded rotor blade according to an embodiment of the present application.

Fig. 5 shows a partial enlarged view of the carrier beam in fig. 4.

Figure 6 illustrates a cross-sectional view of a spar core of a three-dimensional woven composite integrally formed rotor blade according to an embodiment of the present application.

Fig. 7 shows a cross-sectional view along line a-a in fig. 6.

Figure 8 illustrates a schematic view of a spar core of a three-dimensional woven composite integrally formed rotor blade according to an embodiment of the present application.

Figure 9 shows a schematic view of a corner interlock arrangement with bushings.

Description of the reference numerals

1 root connector 11 tow connecting hole 12 propeller hub mounting hole

2 blade body

21 loadbeam 211 shell leading edge 212 first zone ring 213 second zone ring 214 third zone ring 215 cavity 216 beam core

2161A second filler 2162 a unidirectional fiber tape 2163 a weighted 2164 fibrous web wrap

22 upper airfoil skin

23 lower airfoil skin

24 first filler

25 trailing edge strip

100 angle interlocking structure 101 inlay warp yarn 102 weft yarn 103 binding warp yarn

200 axial yarns.

Detailed Description

In order to more clearly illustrate the above objects, features and advantages of the present application, a detailed description of the present application is provided in this section in conjunction with the accompanying drawings. This application is capable of embodiments in addition to those described herein, and is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this application pertains and which fall within the limits of the appended claims. The protection scope of the present application shall be subject to the claims.

As shown in fig. 1 to 9, the present application proposes a three-dimensional woven composite integrally molded rotor blade (hereinafter sometimes simply referred to as a blade) including a root connector 1 and a blade main body 2.

(root connecting head)

As shown in fig. 1 and 2, the root connector 1 is provided with a tow connecting hole 11 and a hub mounting hole 12, and the root connector 1 may be made of an aluminum alloy material, so that the weight of the root connector 1 is light. The root connection 1 may be made by machining. The tow attachment hole 11 is used to allow a part of the yarn tow (axial yarn 200) to pass through, and the tow attachment hole 11 may serve as a starting position of at least a part of the axial yarn 200 of the paddle body 2.

The hub mounting hole 12 is used for mounting the blade to the hub, and a bushing can be arranged in the hub mounting hole 12 and can be made of alloy steel or titanium alloy, and the alloy steel or the titanium alloy has better wear resistance. The position and the dimensional tolerance of the central hole of the blade can be ensured through the assembly position of the positioning bush and a curing and forming die which is described later.

(blade body)

As shown in fig. 3 to 9, the blade body 2 includes a carrier bar 21, an upper airfoil skin 22, a lower airfoil skin 23, a first filler 24 and a trailing edge strip 25.

The blade body 2 comprises a three-dimensional woven (also known as 2.5D angle interlock woven) composite material, in particular, the carrier beam 21, the upper airfoil skin 22, the lower airfoil skin 23 and the trailing strip 25 are three-dimensional woven structures integrally formed by three-dimensional weaving. The fiber yarn bundles forming the load beam 21, the upper airfoil skin 22, the lower airfoil skin 23 and the trailing strip 25 are continuous during the three-dimensional weaving process.

The load beam 21 is hollow, the load beam 21 is formed with a cavity 215, and the housing of the load beam 21 has a multi-layered structure. The cross-section of the load beam 21 may be D-shaped, so the load beam 21 is also called a D-beam. The arc side of the D-shaped cross section is the front side of the load beam 21, and the straight side of the D-shaped cross section is the rear side of the load beam 21. When the blade rotates, the windward side of the blade is the front side.

The first filler 24 may be located at the rear side of the carrier bar 21, the upper and lower airfoil skins 22, 23 wrapping the carrier bar 21, the first filler 24 and the trailing strip 25, the carrier bar 21, the first filler 24 and the trailing strip 25 forming the blade body 2 into a three-dimensional solid shape.

As shown in fig. 5, the shell of the loadbeam 21 includes a shell leading edge 211, a first zone ring layer 212, a second zone ring layer 213, and a third zone ring layer 214.

The shell front edge 211 is located on the front side of the load beam 21, the first region ring layer 212 wraps the second region ring layer 213, and the second region ring layer 213 wraps the third region ring layer 214. The wall thickness may be uniform throughout the first, second, and third regional ring layers 212, 213, and 214. The wall thickness of the shell leading edge 211 may be varied and non-uniform, for example, the front wall thickness of the shell leading edge 211 may be greater and the wall thickness of the shell leading edge 211 may be less as it extends further rearward until the shell leading edge 211 gradually disappears at the side of the load beam 21. The shell leading edge 211 may be made of a tough fiber, for example, a tough fiber including at least one of a glass fiber, a quartz fiber, or a high performance aramid fiber, which may include kevlar fiber, aramid III fiber, or the like. The shell leading edge 211 of ductile fiber makes the blade lighter in weight and more suitable for use in small aircraft.

The first regional ring layer 212 may be made of carbon fiber with high strength and high modulus. The second regional ring layer 213 can be made of aramid fiber with a medium modulus. The third zone annulus 214 may be formed from a high strength, high modulus carbon fiber. The shell of the load-bearing beam 21 formed by overlapping and wrapping can achieve the purpose of adjusting the performance of the blade by adjusting the wall thickness of each layer, such as adjusting the distribution of the center of gravity of the section, adjusting the integral rigidity and the like.

As shown in fig. 3, 6 and 7, the cavity 215 of the load beam 21 is provided with a beam core 216. The beam core 216 includes a secondary filler 2161, a unidirectional fiber tape 2162, a weight 2163, and a fiber cloth wrapping 2164.

The unidirectional fiber tape 2162 extends along the length of the blade, the unidirectional fiber tape 2162 is located at the front side of the cavity 215, the second filler 2161 is located at the rear side of the cavity 215, the unidirectional fiber tape 2162 wraps the weight 2163, the weight 2163 may be tubular, the weight 2163 extends along the length of the blade, and the weight 2163 may be made of lead or steel.

As shown in fig. 6 and 7, weights 2163 may be located at the tip region of the blade remote from the root.

First filler 24 and second filler 2161 may be pre-compressed polymethacrylimide foam (PMI foam).

As shown in fig. 7 and 8, a second filler 2161, unidirectional fiber tape 2162, and weight 2163 are wrapped by a fiber cloth wrapping layer 2164. The fiber cloth wrapping layer 2164 may have two sets of diagonal fibers perpendicular to each other, so that the fiber cloth wrapping layer 2164 has a net structure.

Three-dimensional woven structures include, but are not limited to, corner interlocking structures with warp inserts, corner interlocking structures with weft inserts, corner interlocking structures with warp inserts and weft inserts, and corner interlocking structures with bias yarns.

The angle interlock structure includes a binder warp yarn and a weft yarn or a binder weft yarn and a warp yarn; the angle interlocking structure with the lining warp comprises lining warp yarns, binding warp yarns and weft yarns or lining warp yarns, binding weft yarns and warp yarns; the angle interlocking structure with weft insertion comprises weft insertion yarns, binding warp yarns and weft yarns or weft insertion yarns, binding weft yarns and warp yarns; the angle interlocking structure of the warp and weft insertion with the lining comprises lining warp yarns, weft insertion yarns, binding warp yarns and weft yarns or the lining warp yarns, the weft insertion yarns, the binding weft yarns and the warp yarns; the angle interlocking structure with oblique yarns comprises oblique yarns, binding warp yarns and weft yarns or oblique yarns, binding weft yarns and warp yarns. The binder yarns may be either warp or weft binders depending on the differences in the weaving process.

Figure 9 shows an angle interlock structure 100 with warp inserts (a three-dimensional woven structure) comprising insert warp yarns 101, binder warp yarns 103 and weft yarns 102, the weft yarns 102 and the insert warp yarns 101 crossing each other, the binder warp yarns 103 being warp, the binder warp yarns 103 coupling the weft yarns 102 of two adjacent layers. In other possible embodiments, the binder warp yarns may couple the weft yarns of the barrier layers to form a three-dimensional woven structure.

The weft yarns, the weft insertion yarns and the warp insertion yarns in the three-dimensional woven structure can be made of carbon fibers, glass fibers or aramid fibers. The carbon fiber material can adopt high-strength carbon fiber with grade above T700 or high-modulus carbon fiber with grade above M55, such as T700 fiber, T800 fiber or T1000 fiber. The binder yarns may be made of glass or aramid fibers. The titer of the binder yarn is less than the titer of the weft yarn, the weft inserted yarn and the warp inserted yarn, for example, the titer of the binder yarn can be 20-60% of the titer of the weft yarn, the weft inserted yarn and the warp inserted yarn.

The rotor blade integrally formed by the three-dimensional woven composite material has the following beneficial effects.

(1) The paddle formed by the three-dimensional woven structure can have various fibers, the performance parameters such as frequency, gravity center, rigidity and the like of the paddle can be adjusted by adjusting the distribution and proportion of the unnecessary fibers, and meanwhile, the hybrid toughening characteristic of the three-dimensional woven composite material can be utilized, so that the structural strength, toughness and impact resistance are improved, and the problem of sudden failure of the pure carbon fiber composite material structure is avoided.

The application also provides a manufacturing method of the rotor blade integrally formed by the three-dimensional woven composite material.

Step 1: and designing the appearance of the blade.

According to the design working condition of the blade, on the basis of carrying out optimization design such as pneumatics, aeroelastic, rotor dynamics and stability, the appropriate airfoil combination and the span-wise chord length change of the blade are determined, and the structure of the blade and a corresponding mould are designed on the basis of the airfoil combination and the span-wise chord length change. The above process may require multiple iterations to meet the design requirements.

Step 2: and designing a weaving process of the blade.

Determining the weaving process of different parts of the paddle according to the load form, the geometric structure and the like of the paddle, designing the fiber yarn bundle trend and different weaving processes in the weaving process, and determining the weaving process of the paddle.

And step 3: preparing a fiber yarn bundle required by weaving, and designing a mechanical loom.

The type of the required fiber yarn bundle is selected according to the weaving process of the paddle, and the required length of different fiber yarn bundles is estimated according to the weaving path of the fiber yarn bundle. The mechanical loom procedure of each weaving process is designed according to the topological section shape and the weaving mode of the woven component.

And 4, step 4: the root connector 1, the beam core 216 and the first filler 24 are manufactured.

The root connector 1 is made by machining.

The beam core 216 is pre-molded by laying a unidirectional fiber tape 2162 pre-impregnated with resin in a mold for manufacturing the beam core 216, placing a weight 2163 in the mold near the tip of the blade, placing a second filler 2161, wrapping a layer of fiber cloth to form a fiber cloth wrapping layer 2164, and then performing compression molding to manufacture the beam core 216.

The first filler 24 is machined to the desired shape.

And 5: the three-dimensional weaving structures of the blade, such as an upper airfoil surface skin 22, a lower airfoil surface skin 23, a carrier beam 21, a trailing edge strip 25 and the like, are integrally woven and molded.

Part of the axial yarns penetrate through the tow connecting holes 11 of the root connector 1, the tow connecting holes 11 serve as starting positions of the part of the axial yarns of the integral woven structure, the upper airfoil skin 22, the lower airfoil skin 23, the load-bearing beam 21 and the trailing edge strip 25 are integrally woven and molded, and a cavity between the upper airfoil skin 22 and the lower airfoil skin 23 is filled with a first filler 24 and the load-bearing beam 21 is filled with a beam core 216.

Step 6: and integrally molding, curing and forming the blade.

The three-dimensional woven structure is placed in a mold, and Resin is injected by using an injection Molding technique such as a Resin Transfer Molding technique (RTM), a High Pressure Resin Transfer Molding technique (HP-RTM), or a High Pressure Compression Resin Transfer Molding technique (HP-CRTM). And (3) obtaining a composite blade blank finished product through resin flowing mold filling, impregnation, curing and demolding.

And 7: and (5) grinding, polishing and spraying paint on the outer surface of the blade.

And (4) after the demoulded blade is inspected, grinding, polishing and spraying paint to the demoulded blade to form a final finished product.

While the present application has been described in detail with reference to the above embodiments, it will be apparent to those skilled in the art that the present application is not limited to the embodiments described in the present specification. The present application can be modified and implemented as a modified embodiment without departing from the spirit and scope of the present application defined by the claims. Therefore, the description in this specification is for illustrative purposes and does not have any limiting meaning for the present application.

Claims

1. A three-dimensional woven composite integrally formed rotor blade, said three-dimensional woven composite integrally formed rotor blade comprising:

the root connector (1), the root connector (1) is provided with a tow connecting hole (11); and

a blade body (2), the blade body (2) comprising a three-dimensional woven composite material woven from tows, the blade body (2) being connected to the root connector (1) by at least part of the tows passing through the tow connection holes (11),

the blade body (2) comprises:

a load beam (21), wherein the load beam (21) is provided with a cavity (215), and a beam core (216) is filled in the cavity (215); and

a first filler (24), the first filler (24) being located at a rear side of the load beam (21),

the beam core (216) comprises a second filler (2161), a unidirectional fiber tape (2162), a weight (2163), and a fiber cloth wrapping layer (2164),

the fiber cloth wrapping layer (2164) wraps the second filler (2161), the unidirectional fiber tape (2162), and the weight (2163),

the unidirectional fiber tape (2162) is located at a front side of the cavity (215), the second filler (2161) is located at a rear side of the cavity (215), the unidirectional fiber tape (2162) wraps the weight (2163), and the weight (2163) is located at a front side of the second filler (2161).

2. The three-dimensional woven composite integrally formed rotor blade according to claim 1, wherein said blade body (2) comprises:

a trailing edge strip (25), the trailing edge strip (25) being located on a rear side of the first filler (24);

an upper airfoil skin (22); and

a lower airfoil skin (23), the upper airfoil skin (22) and the lower airfoil skin (23) wrapping the load beam (21), the first filler (24) and the trailing edge strip (25),

wherein the carrier bar (21), the upper airfoil skin (22), the lower airfoil skin (23) and the trailing edge strip (25) are a three-dimensional woven structure integrally formed by three-dimensional weaving.

3. A three-dimensional woven composite integrally formed rotor blade according to claim 2, wherein said load beam (21) is a shell having a multi-layer structure, the modulus of the fibers forming the middle layer of the shell being less than the modulus of the fibers forming the inner and outer layers of the shell.

4. The three-dimensional woven composite integrally formed rotor blade according to claim 2, wherein said carrier bar (21) comprises a leading shell edge (211), a first regional ring layer (212), a second regional ring layer (213) and a third regional ring layer (214), said leading shell edge (211) is located at the front side of said carrier bar (21), said leading shell edge (211) extends backward and has a smaller wall thickness, said leading shell edge (211) comprises ductile fibers, said first regional ring layer (212) wraps said second regional ring layer (213), and said second regional ring layer (213) wraps said third regional ring layer (214).

5. A three-dimensional woven composite integrally formed rotor blade according to claim 4, wherein said tough fibers comprise at least one of glass fibers, quartz fibers, or aramid fibers.

6. A three-dimensional woven composite integrally formed rotor blade according to claim 2, wherein said three-dimensional woven structure comprises warp-backed corner interlocking structures, weft-backed corner interlocking structures, warp-backed weft-backed corner interlocking structures, and diagonal yarn-backed corner interlocking structures.

7. The three-dimensional woven composite integrally formed rotor blade according to claim 2, wherein said blade body (2) is cured and formed by a resin transfer molding process.

8. The three-dimensional woven composite integrally formed rotor blade according to claim 2, wherein said blade body (2) is cured and formed by a high pressure resin transfer molding process.

9. The three-dimensional woven composite integrally formed rotor blade according to claim 2, wherein said blade body (2) is cured and formed by a high pressure compression resin transfer molding process.

10. A method for manufacturing a rotor blade integrally formed by a three-dimensional woven composite material is characterized by comprising the following steps of:

providing a root connector (1);

providing a beam core (216) and a first filler (24), the providing a beam core (216) comprising: laying a unidirectional fiber tape (2162) in a die for manufacturing the beam core (216), placing a weight (2163) and a second filler (2161) in the die, wrapping fiber cloth to form a fiber cloth wrapping layer (2164), and then carrying out compression molding;

penetrating partial axial yarns through a tow connecting hole (11) of a root connector (1), wherein the tow connecting hole (11) is used as a starting position of the partial axial yarns (200) of an integral woven structure, integrally weaving and forming an upper airfoil skin (22), a lower airfoil skin (23), a load-bearing beam (21) and a trailing edge strip (25), and filling a cavity between the upper airfoil skin (22) and the lower airfoil skin (23) with a first filler (24) and filling the load-bearing beam (21) with a beam core (216);