CN113719519B - Rod piece structure for connecting composite material and metal joint - Google Patents

Abstract

The invention provides a rod piece structure for connecting a composite material and a metal joint, which comprises: the linkage rod is used for connecting the engine; the fixed joints are used for fixedly connecting the wings and are arranged at two ends of the linkage rod; the connecting bolt is used for connecting the linkage rod and the fixed joint; the invention relates to a fringe anti-instability piece which is used for fixing a fringe on a linkage rod, and the fringe anti-instability piece is arranged on the periphery of the linkage rod.

Description

Rod piece structure for connecting composite material and metal joint

[ technical field ] A method for producing a semiconductor device

The invention relates to the technical field of airplane structure design, in particular to a rod piece structure for connecting a composite material and a metal joint.

[ background of the invention ]

The design of aircraft airframe components requires structural lightweighting with limited weight allowed. With the improvement of the technical maturity of advanced composite materials, the wide application of the composite materials on airplanes is greatly promoted. The application of the composite material on the airplane follows the rule from small to large from a secondary bearing structure to a main bearing structure. Although the configuration of the current civil aircraft is not changed greatly, the fiber reinforced composite material obtains a large amount of application of replacing metal in situ in the main and secondary load-bearing structures of the modern aviation aircraft due to the excellent specific rigidity and specific strength of the fiber reinforced composite material. The aircraft engine hanger is a main force bearing part of an aircraft, wherein a lower connecting rod which is one of core parts connected with the hyperstatic hanger and the wings is mainly used for transmitting engine thrust and only bears tension/compression load. Compared with the traditional all-metal hollow hanging connecting rod structure (adopted by B737, B777 and C919 airplanes), the composite material is reasonably designed, the rod structure formed by connecting the novel composite material and the metal joint can realize obvious weight reduction effect, and a good using effect is obtained, for example, the lower connecting rod of the B787 airplane hanging adopts a composite rod to be connected with the titanium alloy joint.

Aiming at the existing composite material connecting rod piece, the design difficulty is how to ensure that the composite material and metal joint connecting structure is safe and reliable, easy to maintain and low in cost. Many designers have conducted a great deal of research on connection forms, joint designs, linkage rod members and ply optimization. For example, the connection form adopts gluing, screwing, sewing, bolting and the like; the joint design adopts a hybrid joint, a spindle joint and the like; the linkage rod piece mainly adopts a hollow cylindrical layer or a winding linkage rod. As shown in fig. 6. Among the prior art schemes, there are 6 most similar schemes as proposed in the present application, which are shown as 7-12.

FIG. 7 is from the Composite base structure and end fastening joint and method patent application No. 4,469,730. The scheme converts tensile load between the composite rod and the metal joint into hop load, namely 90-degree carbon fiber tension load, and the compressive load is transmitted through the contact surface of the composite rod and the metal. According to the scheme, the original metal rod piece is partially replaced by the composite material in situ, the load is transferred through gluing and inclined surface contact, and the ageing and the failure of the gluing surface are easily caused by heat and wet environments.

FIG. 8 is from the patent "Method for manufacturing a draft of a gas-turbine engine, in a partial radial draft or a draft arrangement at an angle to the turbine axis", application No. US 2014130964. The scheme provides a connection scheme of a composite material turbine shaft and a metal joint. According to the scheme, the inner metal joint and the outer metal joint in a spline form are designed, the composite material prepreg is laid on the inner metal joint, and then the outer metal joint is connected to compact the composite material into the spline, so that torque is transmitted. The scheme is a torque transmission shaft design, and the tension and compression load transmission capacity is insufficient.

FIG. 9 is derived from the patent "Structure and method for enhancing shear Strength of composite pipe joints with composite slender rods" application No. CN 101509582B. The scheme is similar to the scheme of fig. 8, and provides a connection scheme of a composite material hollow rod and a metal joint, and in order to increase the load transmission efficiency and the shearing strength of the structure, the contact area is increased by adopting sawtooth-shaped threads.

Fig. 10 is from the patent "a connection structure of a composite hollow rod and a metal joint", application No. CN 2017211110.1. The scheme provides a connection scheme of a composite material hollow rod and a metal joint, and spindle type joints are connected through threads. The metal joint is divided into a main joint and an auxiliary joint. But the structure transmits tensile and compressive loads through inclined surface contact, and compared with an all-metal structure, the metal joint structure has an insignificant weight reduction effect.

Figure 11 is from the patent "composite structure with composite-to-metal joint and method of making the same" application No. CN 103068565B. The scheme provides a connection scheme of a composite material laminate and a metal joint, and a laminated scheme is adopted for connection. The metal sheet and the edge of the composite material are connected after cross curing. Although the scheme increases the adhesive area, the efficiency of transferring larger tension and compression load is not high.

FIG. 12 is from the patent "a composite and metal bonded connecting rod structure", application No. 201811332440.1. The proposal provides a connecting rod structure combining composite materials and metal, wherein a composite material cylinder body is of an inner and outer double-cylinder structure; the tail ends of the metal connecting structures of the two metal joints are respectively connected with the two end parts of the composite material barrel inner cylinder; and winding the metal connecting structures of the two metal connectors and the inner cylinder of the composite material cylinder body together by using a composite material along the axial direction of the connecting rod, and forming an outer cylinder of the composite material cylinder body on the outer surfaces of the inner cylinder and the metal connecting structures.

According to the retrieval result of the patent database, the hanging lower connecting rod mainly replaces a metal round pipe with a composite round pipe in situ; the composite round pipe is mostly wound by a winding process; because the circular pipe is difficult to connect the circumference by adopting the bolt, the connection mode mainly adopts the glue joint or the inclined plane connection. But the structure or the joint of the scheme has heavy weight, low fiber bearing efficiency or high repair and maintenance cost due to complex connection.

For example, patent 1 "Composite base structure and end fitting joint and Method" and patent 2 "Method for manufacturing a draft of a gas-turbine engine, in a Composite draft or a draft arrangement at an angle to the turbine axis" are structures that typically replace metal tubing in situ and are joined by adhesive bonding. Patent 3 'structure and method for reinforcing shear strength of composite material pipeline joint by composite material slender rod' and patent 'connection structure of composite material hollow rod and metal joint' both relate to connection of composite material pipe fittings through threads or inclined planes, and do not relate to bolt connection form. Patent 5 "composite structure with composite-metal joint and method of making the same" and patent "connecting rod structure with composite bonded to metal" propose a solution to increase the bonding area to improve the joint strength. Although the technical schemes are related to the connection structure of the airplane rod piece, the structure is complex, the safety of the connection structure of the composite material and the metal joint can be further improved, and the maintenance cost is high.

Accordingly, there is a need to develop a rod structure of composite material connected with metal joints to address the deficiencies of the prior art and to solve or alleviate one or more of the problems described above.

[ summary of the invention ]

In view of the above, the invention provides a rod structure for connecting a composite material and a metal joint, which is characterized in that a stringer preparation process commonly used for composite material airplanes is matched with a double-shear bolt connection joint, the structure is designed based on tension and compression stress and composite material anisotropy characteristics, the rod is simple to manufacture, the laying design is strong, the connection strength is reliable, the safety is high, and the maintenance is easy.

In one aspect, the present invention provides a rod structure for connecting a composite material to a metal joint, the rod structure comprising:

the linkage rod is used for connecting the engine;

the fixed joints are used for fixedly connecting the wings and are arranged at two ends of the linkage rod;

the connecting bolt is used for connecting the linkage rod and the fixed joint;

the bead instability preventing piece is used for fixing a bead on the linkage rod and is arranged on the periphery of the linkage rod.

The above-described aspects and any possible implementations further provide an implementation in which the linkage rod includes a twill strip and four L-shaped profile composite materials, the four L-shaped profile composite materials are four unidirectional tapes having identical plies, the twill strip is a center-filled unidirectional tape having four identical paving, and the four L-shaped profile composite materials are integrally laid on the four identical paving of the twill strip in a cross shape.

The above-described aspects and any possible implementations further provide for an implementation in which the bead stiffeners are composite bead stiffeners or composite bead stiffener assemblies.

The above aspects and any possible implementations further provide an implementation, in which the composite bead reinforcement is a circular metal piece, and the interior of the composite bead reinforcement is a cross-shaped hollow structure matched with the linkage rod in shape.

The above aspects and any possible implementations further provide an implementation in which the composite bead reinforcement assembly includes a fixed foam, a composite gusset disposed on the fixed foam, and a composite round tube simultaneously encasing the fixed foam and the composite gusset, the composite gusset having an arc equal to 1/4 round composite tube.

The above-mentioned aspects and any possible implementation manner further provide an implementation manner, and two of the fixed joints are symmetrically arranged at two ends of the linkage rod respectively.

The above aspects and any possible implementations further provide an implementation, where each fixed joint includes a double-shear tab joint, a joint body, and a connection angle piece, where the double-shear tab joint includes two tabs, the two tabs are symmetrically and parallel arranged to form a double-shear structure, and the double-shear tab joint is connected to the connection angle piece through the joint body.

The above aspects and any possible implementation manners further provide an implementation manner, a cross cavity is arranged inside the connecting angle piece along the direction of the linkage rod, and the linkage rod is fixed in the cross cavity.

The above aspect and any possible implementation manner further provide an implementation manner, wherein the rod structure further includes an excessive fillet, and the excessive fillet is disposed outside the cross-shaped cavity and fixedly connects the connecting corner piece and the joint body.

The above aspect and any possible implementation manner further provide an implementation manner, wherein the connecting bolt is a high-strength bolt, and the connecting bolt is used for fixedly connecting two adjacent L-shaped section composite materials.

Compared with the prior art, the invention can obtain the following technical effects:

1): for the plane hanging connection area, the lower connecting rod is used as a main bearing structure and made of composite materials, and the structure is lightened by utilizing the high specific strength, specific stiffness and designability of the lower connecting rod;

2): based on the advanced manufacturing process of the composite material, the sectional dimension and the layering angle of the composite material L-shaped rod piece can be designed in a modularized mode, the composite material L-shaped rod piece and the layering angle are integrally formed through co-curing, the design efficiency is improved, meanwhile, the assembly is simple, and the cost can be further reduced;

3): the composite material is mechanically connected by the fastener, so that the structure form is simple, the analysis technology is mature, and the safety is high;

4): the invention has strong designability, simple assembly and easy disassembly; the safety and the maintenance performance of the airplane are improved by adopting the bolt connection.

Of course, it is not necessary for any product to achieve all of the above-described technical effects simultaneously in the practice of the invention.

[ description of the drawings ]

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1(a) is a block diagram of a rod assembly for connecting a composite material to a metal joint according to one embodiment of the present invention (the bead instability prevention member is a composite bead reinforcement assembly);

FIG. 1(b) is a block diagram of a rod connected to a metal joint using composite material (the bead destabilizing prevention member is a composite bead reinforcement member) according to one embodiment of the present invention;

FIG. 2(a) is an elevation view of a fixed joint provided by one embodiment of the present invention;

FIG. 2(b) is a top view of a fixed joint provided by one embodiment of the present invention;

FIG. 2(c) is a left side view of a fixed joint provided by one embodiment of the present invention;

FIG. 3 is an isometric view of a linkage member provided in accordance with one embodiment of the present invention;

FIG. 4 is a structural view of a composite bead reinforcement provided in accordance with one embodiment of the present invention;

FIG. 5 is a high strength bolt construction provided in accordance with one embodiment of the present invention;

FIG. 6 is a schematic view of a prior art composite connecting rod and fixed joint mechanical connection scheme in the background of the invention;

FIG. 7 is a block diagram of a Composite base structure and end fitting joint and method according to the background of the present invention;

FIG. 8 is a structural diagram of a "Method for manufacturing a draft of a gas-turbine engine, in a radial draft or a draft arrangement at an angle to the turbine engine axis" in the background of the present invention;

FIG. 9 is a structure diagram of the structure and method for enhancing the shear strength of a composite material pipe joint by a composite material slender rod in the background art of the present invention;

FIG. 10 is a view of a structure of a connection structure of a hollow rod and a fixed joint made of a composite material according to the background of the invention;

FIG. 11 is a diagram of a composite structure with composite-anchor joints and a method of making the same according to the background of the invention;

FIG. 12 is a block diagram of the prior art "connecting rod structure of composite material and metal" in the background of the invention.

Wherein, the joint 1 is fixed in the figure; a linkage rod 2; a connecting bolt 3; a bead instability prevention member 4; a tab 11; a joint body 12; a connecting corner piece 13; an L-shaped section composite material 21; twill strips 22; a fixing foam 41; composite corner pieces 42; a composite circular tube 43; a composite bead reinforcement 44; an over-rounding 5.

[ detailed description ] embodiments

For better understanding of the technical solutions of the present invention, the following detailed descriptions of the embodiments of the present invention are provided with reference to the accompanying drawings.

It should be understood that the described embodiments are only some embodiments of the invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The terminology used in the embodiments of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the examples of the present invention and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

The invention relates to a rod piece structure connected by a composite material and a metal joint, which comprises fixed joints, a linkage rod, a connecting bolt and a fringe instability preventing piece, wherein the fixed joints are arranged at two ends of the linkage rod and connected with the linkage rod through the connecting bolt, the fringe instability preventing piece is arranged on the periphery of the linkage rod, the fixed joints are made of a metal material, and the linkage rod is made of a composite material.

The linkage rod comprises a twister strip and four L-shaped profile composite materials, the four L-shaped profile composite materials are four unidirectional tapes with the same paving layer, the twister strip is a center filling unidirectional tape with four same paving layers, and the four L-shaped profile composite materials are integrally paved on the four same paving layers of the twister strip in a cross shape. The bead destabilizing prevention member is a composite bead reinforcement or a composite bead reinforcement assembly. The composite edge strip reinforcing piece is a circular metal piece, and the interior of the composite edge strip reinforcing piece is of a cross-shaped hollow structure matched with the linkage rod in shape.

The composite material edge strip reinforcing assembly comprises fixed foam, composite material corner pieces and composite material round tubes, wherein the fixed foam is foam placed by clinging to four L-shaped section composite materials, the composite material corner pieces are arranged on the fixed foam, the composite material round tubes are simultaneously wrapped with the fixed foam and the composite material corner pieces, the radian of each composite material corner piece is equal to 1/4 composite material round tubes, the foam is used for fixing the positions of the composite material corner pieces so as to improve the instability resistance of the edge strip, the composite material round tubes are used for protecting the structural integrity of a rod piece and further improving the instability resistance of the rod piece, the number of the fixed joints is two, the two fixed joints are respectively and symmetrically arranged at two ends of a linkage rod, each fixed joint comprises a double-shear lug joint, a joint body and a connecting corner piece, the double-shear lug joints comprise two lugs, the two lugs are symmetrically and parallelly arranged to form a double-shear structure, the double-shear lug joint is connected with the connecting angle piece through the joint body, a cross cavity is arranged inside the connecting angle piece along the direction of the linkage rod, and the linkage rod is fixed in the cross cavity. The rod piece structure further comprises an excessive fillet, wherein the excessive fillet is arranged outside the cross cavity body and fixedly connected with the connecting angle piece and the joint body. The connecting bolts are high-strength bolts and are fixedly connected with two adjacent L-shaped profile composite materials.

The two fixed joints can be symmetrical or asymmetrical and are connected with a connected piece such as a wing or an engine, the single metal structure is characterized by two symmetrical lug plates, a joint body and a bolt connecting end, and the connecting end is of a double-shear structure.

The fixed joint is manufactured in one piece. The body of the linkage rod is of a composite material laminated plate structure, and is manufactured by adopting 4L-shaped sections and filling unidirectional composite material twill strips in the middle through co-curing. The linkage rod body and the metal structure are in a double-shear mode and are connected through multiple rows and multiple columns of high-strength bolts, and the designed load and the connection strength of the rod can be obtained through the strength evaluation of the fastening piece. The composite material has the characteristic that the tensile strength is far greater than the compressive strength, and a circular anti-instability structure is arranged at a certain interval for improving the compressive strength and preventing the instability damage of the L-shaped edge strip. The rod piece structure is mechanically connected by a fastener, combines the characteristics of composite materials, bears tensile load and bears smaller sectional area, bears compressive load and bears larger sectional area, and the connecting structure is in a detachable design so as to ensure the assembly, the detectability and the maintainability of a butt joint area.

As a specific embodiment, the rod structure of the present invention includes two fixed joints 1, a linkage rod 2 composed of 4 "L" section composite materials through co-curing, a connecting bolt 3 and a bead instability prevention member 4, wherein the fixed joint 1 includes a lug 11, a joint body 12 and a connecting angle piece 13; the linkage rod 2 comprises an L-shaped section composite material 21 and a twisting strip 22; the bead destabilizing prevention member 4 and the bolt 3 are plural.

As a specific example, as shown in fig. 1(a) and fig. 1(b), the rod structure anti-destabilization structure of the composite material connected with the metal joint can have two structures, one of which is that in fig. 1(a), the linkage rod 2 is divided by using the fixed foam 41 and the composite material angle piece 42, and the outer layer is wound by the composite material circular tube 43; the other is shown in fig. 1(b), the anti-destabilization structure 44 shown in fig. 4 is directly added by a metal machine, and the anti-destabilization structure 44 is fixed before the rod and the structure are assembled.

As a specific example, as shown in fig. 2(a), 2(b) and 2(c), the fixed joint 1 is formed by casting, the two lugs 11 have a smaller cross section than the fixed joint body 12, and the connecting corner piece 13 and the fixed joint body 12 have a transition fillet 5 to prevent fatigue failure caused by stress concentration; the fillet thickness of the transition fillets 5 may be determined by design loading.

As a specific example, as shown in fig. 3, the link rod 2 is formed by co-curing 4 unidirectional tapes with the same ply L section 21 and a twisted strip 22 of unidirectional composite material filled in the center, and the preparation process is similar to that of a T-shaped stringer made of composite material; firstly, preparing a plane structure (plane paving and pasting) by a wire laying or tape laying machine, then transferring to a thermal diaphragm machine tool for L-section molding, assembling 4L-section composite unidirectional tapes 21 and twill strips 22 which are laid in the same layer, vacuumizing, and then putting into an autoclave for curing molding. As an embodiment, as shown in fig. 5, the linkage rod and the fixed joint connection rod are mechanically connected by bolts 3, and are detachably designed to ensure assemblability, detectability and maintainability of the butt-joint area.

As an embodiment, as shown in fig. 5, the linkage rod and the fixed joint connection rod are mechanically connected by bolts 3, and are detachably designed to ensure assemblability, detectability and maintainability of the butt-joint area.

The invention relates to a rod piece structure for connecting a composite material and a metal joint, which is an important component of an airplane hanger and is used for connecting an engine and wings and transmitting the load of the engine to an airplane body, and has the following characteristics: the fixed joint has the advantages of light weight, high load transmission efficiency, high safety of connection between the fixed joint and the composite material, strong manufacturability and simple assembly. The proposed linkage rod can be divided into 4 identical L-shaped structures and formed by co-curing; the connection adopts a bolt double-shear structure to improve the connection strength. The hanging lower connecting rod is used as one of main paths for transferring load between the engine and the wing, the requirements on safety reliability and easiness in maintenance are high, general design conservation is high, and weight reduction space is large. The rod piece structure connected with the metal joint by the composite material is connected with the metal lug piece by taking the composite material as the rod piece structure so as to achieve the purpose of reducing weight; the rod piece mainly comprises a double-shear lug piece joint, a connecting bolt, a linkage rod piece and an edge strip instability prevention reinforcing piece.

The rod structure of the composite material and metal joint connection provided by the embodiments of the present application is described in detail above. The above description of the embodiments is only for the purpose of helping to understand the method of the present application and its core ideas; meanwhile, for a person skilled in the art, according to the idea of the present application, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present application.

As used in the specification and claims, certain terms are used to refer to particular components. As one skilled in the art will appreciate, manufacturers may refer to a component by different names. This specification and claims do not intend to distinguish between components that differ in name but not function. In the following description and in the claims, the terms "include" and "comprise" are used in an open-ended fashion, and thus should be interpreted to mean "include, but not limited to. "substantially" means within an acceptable error range, and a person skilled in the art can solve the technical problem within a certain error range to substantially achieve the technical effect. The description which follows is a preferred embodiment of the present application, but is made for the purpose of illustrating the general principles of the application and not for the purpose of limiting the scope of the application. The protection scope of the present application shall be subject to the definitions of the appended claims.

It is also noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a good or system that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such good or system. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of additional like elements in the article of commerce or system in which the element is comprised.

It should be understood that the term "and/or" as used herein is merely a relationship that describes an associated object, meaning that three relationships may exist, e.g., a and/or B, may represent: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

The foregoing description shows and describes several preferred embodiments of the present application, but as aforementioned, it is to be understood that the application is not limited to the forms disclosed herein, but is not to be construed as excluding other embodiments and is capable of use in various other combinations, modifications, and environments and is capable of changes within the scope of the application as described herein, commensurate with the above teachings, or the skill or knowledge of the relevant art. And that modifications and variations may be effected by those skilled in the art without departing from the spirit and scope of the application, which is to be protected by the claims appended hereto.

Claims (7)

1. A rod structure of composite material connected to a metal joint, said rod structure comprising:

the linkage rod is used for connecting an engine;

the fixed joints are used for fixedly connecting the wings and are arranged at two ends of the linkage rod;

the connecting bolt is used for connecting the linkage rod and the fixed joint;

the bead instability preventing piece is used for fixing a bead on the linkage rod and is arranged on the periphery of the linkage rod;

the linkage rod comprises a twister strip and four L-shaped profile composite materials, the four L-shaped profile composite materials are four unidirectional tapes with the same paving layer, the twister strip is a center filling unidirectional tape with four same paving layers, and the four L-shaped profile composite materials are integrally paved on the four same paving layers of the twister strip in a cross shape;

the bead instability-preventing part is a composite bead reinforcing part or a composite bead reinforcing assembly;

the sub-assembly is strengthened to combined material bead includes fixed foam, combined material angle piece and combined material pipe, the foam that four L shape section combined materials placed is hugged closely to fixed foam, the combined material angle piece sets up on fixed foam, fixed foam and combined material angle piece are wrapped simultaneously to the combined material pipe, the radian of combined material angle piece equals 1/4 combined material pipe.

2. The rod structure of claim 1 wherein the composite bead reinforcement is a circular metal piece with an interior cross-shaped hollow structure that is form-fit to the linkage rod.

3. The rod structure of claim 1, wherein there are two of the fixed joints symmetrically disposed at two ends of the linkage rod.

4. The rod structure of claim 3 wherein each fixed joint comprises a double shear tab joint, a joint body and a connecting angle piece, wherein the double shear tab joint comprises two tabs, the two tabs are symmetrically and parallel arranged to form a double shear structure, and the double shear tab joint is connected with the connecting angle piece through the joint body.

5. The bar structure of claim 4, wherein the connecting angle pieces are provided with cross cavities inside along the direction of the linkage bars, and the linkage bars are fixed in the cross cavities.

6. The rod structure of claim 5 further comprising an over-fillet disposed outside the cross-shaped cavity fixedly connecting the connection gusset and the fitting body.

7. The rod structure according to claim 1, wherein the connecting bolt is a high-strength bolt fixedly connecting two adjacent L-shaped section composite materials.

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