Carbon fiber composite material bearing rod and manufacturing method thereof

Abstract

The present invention relates to the technical field of aerostat load-bearing structure equipment, and discloses a carbon fiber composite material load-bearing rod and a manufacturing method thereof, wherein the carbon fiber composite material load-bearing rod comprises a base shaft and two embedded pipe joints, the outer side wall of the base shaft is provided with a first fiber bundle winding layer; the base shaft comprises a middle section and connecting sections at both ends, the embedded pipe joint is sleeved on the outside of the first fiber bundle winding layer corresponding to the connecting section, and a second fiber bundle winding layer is further provided outside the first fiber bundle winding layer corresponding to the middle section; the outer surface of the second fiber bundle winding layer and the outer surface of the embedded pipe joint are jointly covered with a third fiber bundle winding layer. The carbon fiber composite material load-bearing rod effectively converts in-plane failure stress into normal extrusion failure stress by providing a fiber winding layer and an embedded pipe joint, greatly improving the bearing strength of the load-bearing rod, and has excellent tensile, compression, torsion, fatigue and impact resistance.

Description

Technical Field

[0001] The invention relates to the technical field of aerostat load-bearing structures, and in particular to a carbon fiber composite material load-bearing rod and a manufacturing method thereof. Background Art

[0002] The lightweight application of the main load-bearing structure of aerostat is in its infancy. Carbon fiber composite materials have excellent mechanical properties, especially in terms of specific strength and specific stiffness. Therefore, it is an inevitable trend to consider carbon fiber composite circular tubes as the main load-bearing structure of aerostat. On the one hand, it can achieve lightweight, and on the other hand, it can meet the requirements of heavy-load bearing capacity.

[0003] Composite structural parts are mainly connected by bonding, bolting, riveting and mixed connection. So far, the connection methods of composite circular tubes for main load-bearing structural parts mainly use high-strength adhesive bonding and bolting modes. For adhesive connection, the interface performance of the adhesive and composite circular tube will be weakened under the action of complex external forces, making the bonding interface a weak link. Similarly, under the action of high and low temperature cycles, due to the mismatch of thermal expansion coefficients between fiber and metal and between different fibers, the mechanical properties of the bonding interface will be weakened, thereby reducing the overall bearing strength of the composite circular tube. For bolt connection, it is usually considered to connect two composite structural parts or metal parts with composite structural parts by perforation. Under load conditions, the structure often has relatively large stress concentration and distortion at the position of the threaded hole, which is obviously limited in application for the main load-bearing structure that bears large loads. In actual use, there is also a type of co-curing connection of metal embedded parts and composite circular tube parts, but often the metal embedded parts are not specially designed and processed, and their bearing capacity is also greatly limited. Summary of the invention

[0004] The embodiment of the present invention provides a carbon fiber composite material bearing rod and a manufacturing method thereof, which are used to solve the problems of weakened connection interface performance and limited bearing capacity caused by the existing connection method between composite material structural parts.

[0005] An embodiment of the present invention provides a carbon fiber composite material bearing rod, comprising a base shaft and two embedded pipe joints, wherein the outer wall of the base shaft is provided with a first fiber bundle winding layer; the base shaft comprises a middle section and connecting sections at both ends, the embedded pipe joint is sleeved on the outside of the first fiber bundle winding layer corresponding to the connecting section, and a second fiber bundle winding layer is further provided on the outside of the first fiber bundle winding layer corresponding to the middle section; the outer surface of the second fiber bundle winding layer and the outer surface of the embedded pipe joint are jointly covered with a third fiber bundle winding layer.

[0006] Among them, the outer surface of the embedded pipe joint is constructed with a plurality of annular grooves in the axial direction and a plurality of longitudinal grooves in the circumferential direction; the third fiber bundle winding layer corresponding to the outer surface of the embedded pipe joint includes a plurality of first longitudinal fiber bundle sublayers and a plurality of annular fiber bundle sublayers alternately stacked from the inside to the outside, the first longitudinal fiber bundle sublayer is arranged in the longitudinal groove, and the annular fiber bundle sublayer is arranged in the annular groove.

[0007] The third fiber bundle winding layer corresponding to the outer surface of the second fiber bundle winding layer includes a plurality of second longitudinal fiber bundle sublayers stacked sequentially from the inside to the outside, and the first longitudinal fiber bundle sublayer is connected to the second longitudinal fiber bundle sublayer.

[0008] The winding angle of the fiber bundles of the first longitudinal fiber bundle sublayer is 0° to 40°; the winding angle of the fiber bundles of the circumferential fiber bundle sublayer is 80° to 90°.

[0009] Wherein, the outer edge diameter of the end portion of the embedded pipe joint facing the base shaft is greater than the outer edge diameter of the end portion of the embedded pipe joint facing away from the base shaft.

[0010] Wherein, a taper angle between an outer edge of an end portion of the embedded pipe joint facing the base shaft and an outer edge of an end portion of the embedded pipe joint away from the base shaft is 0.4° to 0.6°.

[0011] The thickness of the third fiber bundle winding layer corresponding to the outer surface of the embedded pipe joint gradually increases from the end toward the base shaft to the end away from the base shaft, so that the outer diameter of the third fiber bundle winding layer is uniform.

[0012] The embodiment of the present invention further provides a method for manufacturing the carbon fiber composite material bearing rod as described above, comprising:

[0013] Helically and reciprocatingly winding a fiber bundle on the outer surface of the base shaft along the axis of the base shaft to form a first fiber bundle winding layer;

[0014] A pre-buried pipe joint is respectively sleeved on the connecting sections at both ends of the base shaft, and the inner surface of the pre-buried pipe joint is glued to the outer surface of the first fiber bundle winding layer;

[0015] Helically and reciprocatingly winding a fiber bundle along the axis of the base shaft in the middle section of the base shaft to form a second fiber bundle winding layer, until the outer diameter of the second fiber bundle winding layer is equal to the outer edge diameter of the end of the embedded pipe joint facing the base shaft;

[0016] Fiber bundles are spirally and reciprocally wound on the outer surface of the second fiber bundle winding layer and the outer surface of the embedded pipe joint along the axis of the base shaft to form a third fiber bundle winding layer.

[0017] Wherein, the outer surface of the second fiber bundle winding layer and the outer surface of the embedded pipe joint are spirally wound with fiber bundles along the axis of the base shaft to form a third fiber bundle winding layer, further comprising:

[0018] The fiber bundle is spirally and reciprocatingly wound on the outer surface of the second fiber bundle winding layer and in the longitudinal groove of the embedded pipe joint along the axis of the base shaft until the number of layers of the first longitudinal fiber bundle sublayer reaches a first preset number of layers, and the fiber bundle is wound circumferentially in the annular groove of the embedded pipe joint along the embedded pipe joint until the number of layers of the annular fiber bundle sublayer reaches a second preset number of layers, and the annular fiber bundle sublayer is tightened.

[0019] Wherein, after the fiber bundle is spirally and reciprocatingly wound around the middle section of the base shaft along the axis of the base shaft, and before the fiber bundle is spirally wound around the outer surface of the second fiber bundle winding layer and the outer surface of the embedded pipe joint along the axis of the base shaft, the method further comprises:

[0020] The longitudinal groove and the annular groove of the embedded pipe joint are sandblasted and an adhesive is injected;

[0021] After the fiber bundles are spirally and reciprocatingly wound around the outer surface of the second fiber bundle winding layer and the outer surface of the embedded pipe joint along the axis of the base shaft, a glue suction treatment is performed and an upper cloth bag co-curing operation is performed.

[0022] The carbon fiber composite material bearing rod and its manufacturing method provided by the embodiment of the present invention, wherein the carbon fiber composite material bearing rod includes a base shaft and two embedded pipe joints, firstly, the entire outer wall of the base shaft is provided with a first fiber bundle winding layer, and then the embedded pipe joints are sleeved at both ends of the base shaft to increase the connection tightness between the base shaft and the embedded pipe joints. Then, a second fiber bundle winding layer is provided outside the first fiber bundle winding layer in the middle section of the base shaft to make it flush with the outer surface of the embedded pipe joint, and then a third fiber bundle winding layer is jointly covered on the outer surface of the second fiber bundle winding layer and the outer surface of the embedded pipe joint, and finally the base shaft and the embedded pipe joint are tightly connected, so that the carbon fiber composite material base shaft can be connected to the external structural parts of other materials through the embedded pipe joint. The carbon fiber composite material bearing rod effectively converts the in-plane failure stress into the normal extrusion failure stress by providing the fiber winding layer and the embedded pipe joint, greatly improving the bearing strength of the bearing rod, and having excellent tensile, compression, torsion, fatigue and impact resistance. The manufacturing method of the load-bearing rod provides a new way to connect carbon fiber composite material load-bearing parts and embedded pipe joints. Compared with traditional adhesive connection and mechanical connection, this connection method greatly improves the bearing strength of the load-bearing rod, and achieves a breakthrough in the heavy-load connection technology of composite materials as the main load-bearing structure, effectively promoting the application of carbon fiber composite material heavy-load connection technology in the field of aerostats. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 is a structural schematic diagram of a carbon fiber composite material bearing rod in an embodiment of the present invention;

[0025] Figure 2 yes Figure 1 An enlarged schematic diagram of the connection between the embedded pipe joint and the base shaft;

[0026] Figure 3 It is a structural schematic diagram of a pre-buried pipe joint in an embodiment of the present invention;

[0027] Figure 4 yes Figure 3 A side view of the embedded pipe joint in FIG.

[0028] Figure 5 is a schematic flow chart of a method for manufacturing a carbon fiber composite material bearing rod in an embodiment of the present invention;

[0029] Figure 6 is a tensile load-displacement curve of a carbon fiber composite material bearing rod in an embodiment of the present invention;

[0030] Description of reference numerals:

[0031] 1. Base shaft; 11. Middle section; 12. Connecting section;

[0032] 2. Embedded pipe joint; 21. Circumferential groove; 22. Longitudinal groove;

[0033] 23. Root of the joint; 24. Head of the joint; 25. Internal thread of the joint;

[0034] 3. The first fiber bundle winding layer; 4. The second fiber bundle winding layer; 5. The third fiber bundle winding layer;

[0035] 51. a first longitudinal fiber bundle sublayer; 52. a circumferential fiber bundle sublayer;

[0036] 53. Second longitudinal fiber bundle sublayer. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "first", "second" and "third" are for the purpose of clearly describing the numbering of product components and do not represent any substantial difference. "Up", "down", "left" and "right" are only used to indicate relative position relationships. When the absolute position of the described object changes, the relative position relationship may also change accordingly. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0039] It should be noted that, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense, for example, it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the invention can be understood in specific circumstances.

[0040] like Figure 1 to Figure 2 As shown, a carbon fiber composite material bearing rod provided by an embodiment of the present invention includes a base shaft 1 and two embedded pipe joints 2, and the outer wall of the base shaft 1 is provided with a first fiber bundle winding layer 3. The base shaft 1 includes a middle section 11 and connecting sections 12 at both ends, and the embedded pipe joint 2 is sleeved on the outside of the first fiber bundle winding layer 3 corresponding to the connecting section 12, and a second fiber bundle winding layer 4 is further provided on the outside of the first fiber bundle winding layer 3 corresponding to the middle section 11. The outer surface of the second fiber bundle winding layer 4 and the outer surface of the embedded pipe joint 2 are jointly covered with a third fiber bundle winding layer 5.

[0041] Specifically, the base shaft 1 may be a solid shaft or a round tube made of carbon fiber composite material, and the entire outer side wall of the base shaft 1 is provided with a first fiber bundle winding layer 3, and the thickness of the first fiber bundle winding layer 3 may be 0.8 mm to 1.5 mm. In this embodiment, a 1 mm thick first fiber bundle winding layer 3 is used as an example for explanation. The first fiber bundle winding layer 3 may be formed by spirally winding the fiber bundle along the axial direction of the base shaft 1 on the outer side wall of the entire base shaft 1, and the winding angle may be 0° to 90°, and the fiber winding bundle layer may be formed by circumferential winding, spiral winding, or longitudinal winding. Among them, circumferential winding refers to the uniform rotation of the mandrel around its own axis, and the wire guide head of the winding machine moves in a direction parallel to the axis of the mandrel. For every rotation of the mandrel, the wire guide head moves a yarn bundle width, and the winding angle is usually 70°~90°; spiral winding refers to the uniform rotation of the mandrel around its own axis, and the wire guide head reciprocates along the axis of the mandrel at a specific speed, and the winding angle is generally 12°~70°; longitudinal winding refers to the slow rotation of the mandrel around its own axis, and the wire guide head of the winding machine makes uniform circular motion in a fixed plane. For every rotation of the wire guide head, the mandrel rotates a small angle, which is equivalent to a yarn bundle width on the surface of the mandrel, and the winding angle is generally 0°~25°.

[0042] The embedded pipe joint 2 can be made of titanium alloy, which has high strength and low density, good mechanical properties, and good toughness and corrosion resistance. It can be used as a transition part between the carbon fiber composite material base shaft and the external metal connector, and can effectively prevent corrosion between the metal and the carbon fiber composite material. The inner diameter of the embedded pipe joint 2 is slightly larger than the outer diameter of the base shaft 1, so it can be sleeved on the outer side of the base shaft 1.

[0043] The base shaft 1 is divided into three sections from left to right, namely the left connecting section, the middle section and the right connecting section. The first fiber bundle winding layer 3 corresponding to the connecting section 12 can be bonded to the inner surface of the embedded pipe joint 2 by an adhesive, and the adhesive can be a high-strength and low-temperature resistant adhesive. The first fiber bundle winding layer 3 corresponding to the middle section 11 can be sleeved with a second fiber bundle winding layer 4. The second fiber bundle winding layer 4 can be formed by spirally winding the fiber bundle reciprocatingly along the axial direction of the base shaft 1 on the outside of the first fiber bundle winding layer 3 corresponding to the middle section 11, and the winding angle can be ±α, and α can be 8° to 35°. The outer diameter of the second fiber bundle winding layer 4 is equivalent to the outer edge diameter of the embedded pipe joint 2.

[0044] A third fiber bundle winding layer 5 is wound around the outer surface of the second fiber bundle winding layer 4 and the outer surface of the embedded pipe joint 2 to further strengthen the connection between the base shaft 1 and the embedded pipe joint 2 .

[0045] A carbon fiber composite material bearing rod provided in this embodiment includes a base shaft and two embedded pipe joints. A first fiber bundle winding layer is firstly arranged on the entire outer wall of the base shaft, and then the embedded pipe joints are sleeved on both ends of the base shaft to increase the connection tightness between the base shaft and the embedded pipe joints. Then, a second fiber bundle winding layer is arranged outside the first fiber bundle winding layer in the middle section of the base shaft to make it flush with the outer surface of the embedded pipe joint, and then a third fiber bundle winding layer is arranged on the outer surface of the second fiber bundle winding layer and the outer surface of the embedded pipe joint, and finally the base shaft and the embedded pipe joint are tightly connected, so that the carbon fiber composite material base shaft can be connected to external structural parts of other materials through the embedded pipe joints. The carbon fiber composite material bearing rod effectively converts the in-plane failure stress into the normal extrusion failure stress by arranging the fiber winding layer and the embedded pipe joint, greatly improving the bearing strength of the bearing rod, and having excellent tensile, compression, torsion, fatigue and impact resistance.

[0046] Furthermore, if Figures 1 to 4 As shown, the outer surface of the embedded pipe joint 2 is configured with a plurality of parallel and spaced annular grooves 21 in the axial direction, and a plurality of longitudinal grooves 22 in the circumferential direction. The third fiber bundle winding layer 5 corresponding to the outer surface of the embedded pipe joint 2 includes a plurality of first longitudinal fiber bundle sublayers 51 and a plurality of annular fiber bundle sublayers 52 alternately stacked from the inside to the outside, the first longitudinal fiber bundle sublayer 51 is arranged in the longitudinal groove 22, and the annular fiber bundle sublayer 52 is arranged in the annular groove 21.

[0047] Specifically, the annular groove 21 is a circle of circular grooves opened along the circumference of the embedded pipe joint 2, and the longitudinal groove 22 can be a strip groove opened along the axial direction of the embedded pipe joint 2, in which case a plurality of rectangular protrusions are formed on the outer wall surface of the embedded pipe joint 2. Alternatively, the longitudinal groove 22 can also be an oblique groove opened around the outer wall surface of the embedded pipe joint 2, that is, the extension line of the groove is set at an acute angle to the axis of the base shaft 1, in which case a plurality of oblique parallelogram protrusions are formed on the outer wall surface of the embedded pipe joint 2.

[0048] The first longitudinal fiber bundle sublayer 51 is arranged in the longitudinal groove 22, and can be wound in a spiral manner, and the winding angle can be ±α, where α can be 0° to 40°. The circumferential fiber bundle sublayer 52 is arranged in the circumferential groove 21, and can be wound in a circumferential manner, and the winding angle can be 80° to 90°. In a specific embodiment, the winding angle α of the first longitudinal fiber bundle sublayer 51 can be 8° to 35°, and the winding angle of the circumferential fiber bundle sublayer 52 is 90°. Multiple first longitudinal fiber bundle sublayers 51 and multiple circumferential fiber bundle sublayers 52 are alternately stacked in sequence, which means that n first longitudinal fiber bundle sublayers 51 are first stacked in the longitudinal groove 22 of the embedded pipe joint 2, and then on this basis, m circumferential fiber bundle sublayers 52 are stacked in the circumferential groove 21 of the embedded pipe joint 2, and then the cycle is repeated in sequence. In this embodiment, n is 5 and m is 1, that is, after winding 5 layers of the first longitudinal fiber bundle sublayer 51, one layer of the circumferential fiber bundle sublayer 52 is wound, and at the same time, a 90-degree yarn tightening operation can be performed on the circumferential fiber bundle sublayer 52.

[0049] In a specific embodiment, Figure 3 and Figure 4 As shown, the depths of the annular groove 21 and the longitudinal groove 22 of the embedded pipe joint 2 are both between 2 mm and 3 mm. Eight rows of longitudinal grooves 22 are evenly distributed in the circumferential direction of the embedded pipe joint 2, and five rows of annular grooves 21 are evenly distributed in the axial direction of the embedded pipe joint 2. The width of the longitudinal groove 22 is designed to be 3 mm, and the width of the annular groove 21 is designed to be 5 mm. For a base shaft 1 with an outer diameter greater than 35 mm, the number of grooves of the embedded pipe joint 2 can be appropriately increased, and the angle distribution of the grooves can be adjusted.

[0050] Furthermore, if Figure 1 to Figure 2 As shown, the third fiber bundle winding layer 5 corresponding to the outer surface of the second fiber bundle winding layer 4 includes a plurality of second longitudinal fiber bundle sublayers 53 stacked sequentially from the inside to the outside, and the first longitudinal fiber bundle sublayer 51 is connected to the second longitudinal fiber bundle sublayer 53. That is, the first longitudinal fiber bundle sublayer 51 and the second longitudinal fiber bundle sublayer 53 can be wound together.

[0051] Furthermore, if Figures 1 to 3 As shown, the outer diameter of the end of the embedded pipe joint 2 facing the base shaft 1 (i.e., the joint root 23) is larger than the outer diameter of the end of the embedded pipe joint 2 away from the base shaft 1 (i.e., the joint head 24). That is, the outer surface of the embedded pipe joint 2 is a frustum, and gradually decreases from the joint root 23 to the joint head 24. The size of the cone angle β of the embedded pipe joint 2 can be adjusted according to the load use requirements.

[0052] Furthermore, the taper angle β between the outer edge of the end of the embedded pipe joint 2 facing the base shaft 1 (i.e. the joint root 23) and the outer edge of the end of the embedded pipe joint 2 away from the base shaft 1 (i.e. the joint head 24) is 0.4° to 0.6°.

[0053] Furthermore, the thickness of the third fiber bundle winding layer 5 corresponding to the outer surface of the embedded pipe joint 2 gradually increases from the end facing the base shaft 1 to the end away from the base shaft 1, so that the outer diameter of the third fiber bundle winding layer 5 is uniform, that is, the thickness of the third fiber bundle winding layer 5 corresponding to the outer surface of the embedded pipe joint 2 gradually increases from the joint root 23 to the joint head 24. Since the outer surface of the embedded pipe joint 2 is a frustum, the embedded pipe joint 2 connected to the right side of the base shaft 1 is used as an example for explanation. The outer diameter of the embedded pipe joint 2 decreases from left to right. In order to ensure that the outer diameter of the entire bearing rod is consistent, the thickness of the third fiber bundle winding layer 5 corresponding to the outer surface of the embedded pipe joint 2 on the right side increases from left to right. The increase in thickness can be achieved by increasing the number of layers of the annular fiber bundle sublayer 52 in the annular groove 21 of the embedded pipe joint 2.

[0054] In actual use, such as Figure 1 As shown, the embedded pipe joint 2 is provided with a joint internal thread 25 on the inner wall surface at the joint head 24, which can realize a quick and detachable connection between the carbon fiber bearing rod and other connecting parts. If the outer diameter of the bearing rod is small, the embedded pipe joint 2 can be extended outward by one end, and then the connecting thread is transferred to the outer wall surface of the embedded pipe joint 2. When the bearing rod and other connecting parts are connected together, since the thickness of the third fiber bundle winding layer 5 corresponding to the outer surface of the embedded pipe joint 2 increases successively, the force distribution at the embedded pipe joint 2 is more reasonable, which greatly improves the overall connection performance.

[0055] like Figure 5 As shown, an embodiment of the present invention further provides a method for manufacturing the carbon fiber composite material bearing rod as described above, comprising:

[0056] Step S1: spirally and reciprocatingly wind a fiber bundle on the outer surface of a base shaft 1 along the axis of the base shaft 1 to form a first fiber bundle winding layer 3 .

[0057] Specifically, the first fiber bundle winding layer 3 can be wound in a circumferential winding, spiral winding or longitudinal winding mode, and can be wet wound in a pre-tensioned manner. The thickness of the first fiber bundle winding layer 3 can be 0.8 mm to 1.5 mm, and 1 mm is used as an example in this embodiment.

[0058] Step S2: A pre-buried pipe joint 2 is respectively sleeved on the connecting sections 12 at both ends of the base shaft 1 , and the inner surface of the pre-buried pipe joint 2 is glued to the outer surface of the first fiber bundle winding layer 3 .

[0059] Specifically, the bonding may be performed using a high-strength and low-temperature resistant adhesive, which may enhance the bonding performance of the contact interface between the carbon fiber and the metal embedded pipe joint 2 .

[0060] Step S3: spirally and reciprocatingly wind the fiber bundle along the axis of the base shaft 1 in the middle section 11 of the base shaft 1 to form a second fiber bundle winding layer 4 until the outer diameter of the second fiber bundle winding layer 4 is equal to the outer edge diameter of the end of the embedded pipe joint 2 facing the base shaft 1 (i.e., the joint root 23).

[0061] Specifically, the second fiber bundle winding layer 4 can adopt a winding mode of spiral winding or longitudinal winding, and the winding angle can be ±α, α can be 8° to 35°, that is, when the spiral winding is from left to right, the winding angle is +α, and when the spiral winding is from right to left, the winding angle is -α. The second fiber bundle winding layer 4 can also be wet-wound in a pre-tensioned manner.

[0062] Step S4: spirally and reciprocatingly winding fiber bundles on the outer surface of the second fiber bundle winding layer 4 and the outer surface of the embedded pipe joint 2 along the axis of the base shaft 1 to form a third fiber bundle winding layer 5 .

[0063] Specifically, the third fiber bundle winding layer 5 can adopt a comprehensive winding mode of hoop winding, spiral winding and / or longitudinal winding, and simultaneously adopt a pre-tensioning method to perform wet winding.

[0064] Furthermore, step S4 further comprises:

[0065] The fiber bundle is wound spirally and reciprocatingly along the axis of the base shaft 1 on the outer surface of the second fiber bundle winding layer 4 and in the longitudinal groove 22 of the embedded pipe joint 2. At this time, the first longitudinal fiber bundle sublayer 51 and the second longitudinal fiber bundle sublayer 53 are wound together, and the number of layers is the same. After the number of layers of the first longitudinal fiber bundle sublayer 51 reaches the first preset number of layers, the fiber bundle is wound in the annular groove 21 of the embedded pipe joint 2 along the circumference of the embedded pipe joint 2 until the number of layers of the annular fiber bundle sublayer 52 reaches the second preset number of layers, and the annular fiber bundle sublayer 52 is tightened.

[0066] Specifically, the first preset number of layers is 5 layers, and the second preset number of layers is 1 layer. The thickness of each fiber winding layer is 0.15 mm, and after winding 5 layers of the first longitudinal fiber bundle sublayer 51, winding 1 layer of the circumferential fiber bundle sublayer 52 is performed, and the circumferential fiber bundle sublayer 52 is tightened by 90 degrees.

[0067] Furthermore, after step S3 and before step S4, the method further includes:

[0068] The longitudinal groove 22 and the annular groove 21 of the embedded pipe joint 2 are sandblasted and injected with adhesive. The adhesive is a high-strength and low-temperature resistant adhesive. On the one hand, the bonding performance of the contact interface between the carbon fiber and the metal embedded pipe joint 2 is enhanced. On the other hand, the cohesive failure of the outer surface of the groove is effectively converted into the fiber tearing failure inside the carbon fiber bearing rod, so that the destructive strength of the bearing rod is no longer dependent on the bonding strength, but the bonding strength is converted into the fiber failure strength of the entire bearing rod.

[0069] After step S4, the load-bearing rod is subjected to a glue absorption treatment, and a cloth bag co-curing operation is performed to complete the final forming of the load-bearing rod.

[0070] Figure 6 The tensile load-displacement curve of the carbon fiber composite material bearing rod in this embodiment is shown. The experimental test results show that the bearing capacity of the bearing rod made by the pre-embedded winding connection method proposed in the present invention is greatly enhanced. Compared with the traditional adhesive connection method, the bearing strength is increased by more than 5 times. The existing adhesive connection can only withstand a maximum load of 20kN. Therefore, the bearing rod provided in this embodiment can realize the actual engineering application of lightweight and heavy-load carbon fiber composite materials for airships.

[0071] The pre-embedded winding connection method (i.e., the manufacturing method of the load-bearing rod) proposed by the present invention has the following advantages compared with the traditional adhesive connection and bolt connection methods:

[0072] 1) This connection method combines the advantages of mechanical connection, adhesive connection and embedded connection, greatly enhancing the bearing capacity of the carbon fiber composite base shaft as the main load-bearing structure;

[0073] 2) Effectively convert the in-plane failure stress into normal extrusion failure stress, which greatly improves the bearing strength of the carbon fiber composite base shaft;

[0074] 3) Effectively convert the cohesive failure of the outer surface of the groove into the fiber tearing failure inside the carbon fiber composite material base shaft, and optimize the winding thickness, winding angle and joint parameters according to different use environment requirements to obtain the optimal load-bearing mechanical properties;

[0075] 4) During the fiber winding process, the hoop yarn is tightened and a high-strength and low-temperature resistant adhesive is injected. On the one hand, the bonding performance of the fiber and metal contact interface is enhanced. On the other hand, the base shaft failure strength is no longer dependent on the bonding strength, but the bonding strength is converted into the overall fiber failure strength of the circular tube.

[0076] It can be seen from the above embodiments that the carbon fiber composite material bearing rod and its manufacturing method provided by the present invention, wherein the carbon fiber composite material bearing rod includes a base shaft and two embedded pipe joints, the first fiber bundle winding layer is firstly arranged on the entire outer side wall of the base shaft, and then the embedded pipe joints are sleeved at both ends of the base shaft to increase the connection tightness between the base shaft and the embedded pipe joints. Then, a second fiber bundle winding layer is arranged outside the first fiber bundle winding layer in the middle section of the base shaft to make it flush with the outer surface of the embedded pipe joint, and then a third fiber bundle winding layer is arranged on the outer surface of the second fiber bundle winding layer and the outer surface of the embedded pipe joint, and finally the base shaft and the embedded pipe joint are tightly connected, so that the carbon fiber composite material base shaft can be connected to the external structural parts of other materials through the embedded pipe joint. The carbon fiber composite material bearing rod effectively converts the in-plane failure stress into the normal extrusion failure stress by arranging the fiber winding layer and the embedded pipe joint, greatly improves the bearing strength of the bearing rod, and has excellent tensile, compression, torsion, fatigue and impact resistance. The manufacturing method of the load-bearing rod provides a new way to connect carbon fiber composite material load-bearing parts and embedded pipe joints. Compared with traditional adhesive connection and mechanical connection, this connection method greatly improves the bearing strength of the load-bearing rod, and achieves a breakthrough in the heavy-load connection technology of composite materials as the main load-bearing structure, effectively promoting the application of carbon fiber composite material heavy-load connection technology in the field of aerostats.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A carbon fiber composite material bearing rod, characterized in that: It comprises a base shaft and two embedded pipe joints, wherein the outer side wall of the base shaft is provided with a first fiber bundle winding layer; the base shaft comprises a middle section and connecting sections at both ends, the embedded pipe joint is sleeved on the outside of the first fiber bundle winding layer corresponding to the connecting section, and a second fiber bundle winding layer is further provided on the outside of the first fiber bundle winding layer corresponding to the middle section; the outer surface of the second fiber bundle winding layer and the outer surface of the embedded pipe joint are jointly covered with a third fiber bundle winding layer.

2. The carbon fiber composite material bearing rod according to claim 1, characterized in that: The outer surface of the embedded pipe joint is constructed with a plurality of annular grooves in the axial direction and a plurality of longitudinal grooves in the circumferential direction; the third fiber bundle winding layer corresponding to the outer surface of the embedded pipe joint includes a plurality of first longitudinal fiber bundle sublayers and a plurality of annular fiber bundle sublayers alternately stacked from the inside to the outside, the first longitudinal fiber bundle sublayer is arranged in the longitudinal groove, and the annular fiber bundle sublayer is arranged in the annular groove.

3. The carbon fiber composite material bearing rod according to claim 2, characterized in that: The third fiber bundle winding layer corresponding to the outer surface of the second fiber bundle winding layer includes a plurality of second longitudinal fiber bundle sublayers stacked sequentially from the inside to the outside, and the first longitudinal fiber bundle sublayer is connected to the second longitudinal fiber bundle sublayer.

4. The carbon fiber composite material bearing rod according to claim 2, characterized in that: The winding angle of the fiber bundles of the first longitudinal fiber bundle sublayer is 0° to 40°; the winding angle of the fiber bundles of the circumferential fiber bundle sublayer is 80° to 90°.

5. The carbon fiber composite material bearing rod according to claim 2, characterized in that: The outer edge diameter of the end portion of the embedded pipe joint facing the base shaft is greater than the outer edge diameter of the end portion of the embedded pipe joint facing away from the base shaft.

6. The carbon fiber composite material bearing rod according to claim 5, characterized in that: A taper angle between an outer edge of an end portion of the embedded pipe joint facing the base shaft and an outer edge of an end portion of the embedded pipe joint away from the base shaft is 0.4° to 0.6°.

7. The carbon fiber composite material bearing rod according to claim 5, characterized in that: The thickness of the third fiber bundle winding layer corresponding to the outer surface of the embedded pipe joint gradually increases from the end toward the base shaft to the end away from the base shaft, so that the outer diameter of the third fiber bundle winding layer is uniform.

8. A method for manufacturing a carbon fiber composite material bearing rod according to any one of claims 1 to 7, characterized in that: include: Helically and reciprocatingly winding a fiber bundle on the outer surface of the base shaft along the axis of the base shaft to form a first fiber bundle winding layer; A pre-buried pipe joint is respectively sleeved on the connecting sections at both ends of the base shaft, and the inner surface of the pre-buried pipe joint is glued to the outer surface of the first fiber bundle winding layer; Helically and reciprocatingly winding a fiber bundle along the axis of the base shaft in the middle section of the base shaft to form a second fiber bundle winding layer, until the outer diameter of the second fiber bundle winding layer is equal to the outer edge diameter of the end of the embedded pipe joint facing the base shaft; Fiber bundles are spirally and reciprocally wound on the outer surface of the second fiber bundle winding layer and the outer surface of the embedded pipe joint along the axis of the base shaft to form a third fiber bundle winding layer.

9. The manufacturing method according to claim 8, characterized in that: The method of spirally winding fiber bundles on the outer surface of the second fiber bundle winding layer and the outer surface of the embedded pipe joint along the axis of the base shaft to form a third fiber bundle winding layer further includes: The fiber bundle is spirally and reciprocatingly wound on the outer surface of the second fiber bundle winding layer and in the longitudinal groove of the embedded pipe joint along the axis of the base shaft until the number of layers of the first longitudinal fiber bundle sublayer reaches a first preset number of layers, and the fiber bundle is wound circumferentially in the annular groove of the embedded pipe joint along the embedded pipe joint until the number of layers of the annular fiber bundle sublayer reaches a second preset number of layers, and the annular fiber bundle sublayer is tightened.

10. The manufacturing method according to claim 8, characterized in that: After the fiber bundle is spirally and reciprocatingly wound around the middle section of the base shaft along the axis of the base shaft, and before the fiber bundle is spirally wound around the outer surface of the second fiber bundle winding layer and the outer surface of the embedded pipe joint along the axis of the base shaft, the method further comprises: The longitudinal groove and the annular groove of the embedded pipe joint are subjected to sandblasting treatment, and adhesive is injected; After the fiber bundles are spirally and reciprocatingly wound around the outer surface of the second fiber bundle winding layer and the outer surface of the embedded pipe joint along the axis of the base shaft, a glue suction treatment is performed and an upper cloth bag co-curing operation is performed.

Images