Carbon fiber wavelike beam guardrail and preparation method thereof

Abstract

The application discloses a carbon fiber wave-shaped beam guardrail and a preparation method thereof, and mainly relates to the field of road engineering. The method comprises the following steps: S1, determining a first curvature area and a second curvature area with opposite curvature directions and a curvature reversing area between the first curvature area and the second curvature area according to a target wave-shaped section of the carbon fiber wave-shaped beam guardrail; and selecting a reference yarn bundle continuously passing through the first curvature area, the curvature reversing area and the second curvature area. The application has the beneficial effect that part of the main yarn bundle has a limited position adjustment space in the wave forming process, so that the path length change in different curvature areas during the formation of the wave crest and the wave trough can be redistributed, the problem of excessive tension of local yarn bundles or yarn bundle aggregation caused by the fixed position of the yarn bundle in the forming process of the traditional three-dimensional locking structure is avoided, and the adaptability of the carbon fiber preform to the target wave-shaped section is improved.

Description

Technical Field

[0001] This application relates to the field of road engineering, specifically a carbon fiber corrugated beam guardrail and its preparation method. Background Technology

[0002] Corrugated beam guardrails are typically installed on the roadside or median strip of highways. When a vehicle veers off course and collides with the guardrail, the corrugated beam absorbs the impact energy through bending, stretching, and the gradual unfolding of its corrugated cross-section, thus guiding the vehicle. Current corrugated beam guardrails are mainly made of stamped steel, which suffers from problems such as high weight and susceptibility to corrosion from rainwater, salt spray, and de-icing salt. To reduce the weight of the guardrail and improve its corrosion resistance, current technology is beginning to use carbon fiber reinforced resin matrix composites to manufacture corrugated beam guardrails.

[0003] Existing carbon fiber corrugated beam guardrails typically employ a layer-by-layer pultrusion and molding process for carbon fiber fabric, or a three-dimensional woven prefabricated structure that is integrally pressed into a corrugated cross-section before resin impregnation and curing. Compared to two-dimensional plywood prefabricated structures, three-dimensional woven prefabricated structures connect axial, cross-sectional, and diagonal yarns into a whole through thickness-direction locking yarns, which can improve the thickness-direction strength of the composite material and reduce the risk of interlaminar delamination.

[0004] However, the cross-section of the corrugated beam guardrail is not a single curvature structure, but rather a continuous series of crests, sloping sections, and troughs along the width of the cross-section, with adjacent crests and troughs exhibiting opposite curvature directions. When the carbon fiber preform forms the target corrugated cross-section from a quasi-straight or low-curvature state, the yarn path length outside the curvature zone increases, while the yarn path length inside the curvature zone decreases. When the yarn extends from the crest curvature zone to the adjacent trough curvature zone, the inner and outer positions of the yarn change, and the required path compensation direction is reversed accordingly.

[0005] For a three-dimensional woven preform that has been completely locked by thickness-direction locking yarns, the cross-sectional and oblique yarns are difficult to migrate relative to each other between adjacent curvature regions. After the preform is forcibly pressed into a waveform, the yarn bundles in the outer arc region are prone to being overstretched, and the yarn bundles in the inner arc region are prone to clustering at the curvature reversal position, thus forming defects such as local thickness reduction, yarn bundle crowding, fiber undulation, or resin enrichment at the curvature reversal position. Since the cross-sectional shape of the waveform beam extends continuously along its length, the above defects may also form continuous curvature mismatch regions along the length of the waveform beam.

[0006] When a vehicle collides with a corrugated beam guardrail, the crests and troughs gradually unfold. The curvature reversal points between adjacent reverse curvature zones are typically areas where cross-sectional rotation, shear transfer, and waveform unfolding are concentrated. When the curvature mismatch area formed during manufacturing coincides with the curvature release area of ​​the corrugated cross-section during the collision, it can easily lead to premature local fiber damage and cause cracks to propagate along the length of the corrugated beam, affecting the energy absorption stability of the carbon fiber corrugated beam guardrail.

[0007] Existing technologies typically improve the forming quality of composite curved surface components by increasing local fiber density, changing ply angles, employing segmented pressurization, or adding thickness-direction reinforcing fibers. However, simply increasing fiber density further restricts yarn migration, and segmented pressurization is unlikely to alter the already formed interlocking relationships within the three-dimensional braided preform. Directly adding thickness-direction reinforcing fibers before waveform forming may also exacerbate yarn path mismatches between adjacent reverse curvature regions. Therefore, existing methods struggle to simultaneously meet the yarn migration requirements during waveform forming and the overall interlocking requirements after forming.

[0008] Therefore, it is necessary to provide a method for manufacturing carbon fiber corrugated beam guardrails, which provides controlled migration space for yarn bundles between adjacent reverse curvature zones during the corrugation forming process, and re-establishes the thickness direction locking relationship after the target waveform is formed, so as to reduce fiber crowding, tension and resin enrichment at the curvature reversal position, while ensuring the overall strength and collision energy absorption stability of the finished corrugated beam guardrail. Summary of the Invention

[0009] The purpose of this invention is to provide a method for manufacturing carbon fiber corrugated beam guardrails and a carbon fiber corrugated beam guardrail, in order to solve the problems that when a three-dimensional woven carbon fiber preform forms a continuous undulating corrugated cross section, the required yarn bundle path lengths for adjacent curvature regions are different, and the main yarn bundles are restricted by the thickness direction locking, resulting in excessive tension of the outer yarn bundles of the waveform, loose aggregation of the inner yarn bundles of the waveform, and uneven distribution of yarn bundles at the curvature reversal position.

[0010] The method for manufacturing a carbon fiber corrugated beam guardrail provided in this application adopts the following technical solution: The process includes the following steps: S1. Based on the target waveform cross-section of the carbon fiber corrugated beam guardrail, determine the first curvature zone and the second curvature zone with opposite curvature directions, as well as the curvature reversal zone located between the first curvature zone and the second curvature zone; select a reference yarn bundle that continuously passes through the first curvature zone, the curvature reversal zone, and the second curvature zone, and determine the target migration direction and target migration interval of the reference yarn bundle within the curvature reversal zone based on the change in path length of the reference yarn bundle in the initial state and the target waveform cross-section state; S2. A carbon fiber preform is woven using continuous carbon fiber yarn. The carbon fiber preform includes axial bearing yarn extending along the length direction of the corrugated beam, cross-sectional yarn extending along the width direction of the target corrugated cross section, oblique interlacing yarn intersecting with the axial bearing yarn and cross-sectional yarn, and pre-set locking yarn arranged along the thickness direction of the carbon fiber preform. Multiple yarn bundle migration units are formed at intervals along the length direction of the carbon fiber preform at positions corresponding to the curvature reversal zone. At least some positions within each yarn bundle migration unit are not provided with the pre-set locking yarn. Pre-set locking units with the pre-set locking yarn are reserved between adjacent yarn bundle migration units. The axial bearing yarn, cross-sectional yarn, and oblique interlacing yarn continuously pass through the yarn bundle migration units and the pre-set locking units. S3. Place the carbon fiber preform in a waveform forming mold, and provide a yarn guide at the yarn transfer unit. The yarn guide restricts the reference yarn from shifting along the length and thickness directions of the carbon fiber preform, and allows the reference yarn to move along the width direction of the target waveform section. S4. Fix the cross-sectional reference area of ​​the carbon fiber preform using the waveform forming mold, and form a first curvature area and a second curvature area from the cross-sectional reference area to both sides in sequence; during the formation of the first curvature area and the second curvature area, move the reference yarn bundle along the target migration direction in the yarn bundle migration unit, and obtain the actual migration amount of the reference yarn bundle relative to its initial position until the actual migration amount is within the target migration range, and the carbon fiber preform reaches the target waveform cross-sectional state; S5. Keep the carbon fiber preform in the target waveform cross section state, and implant the cross-zone locking yarn into the yarn bundle migration unit through the locking operation channel set on the waveform forming mold, so that the cross-zone locking yarn passes through the main yarn bundle at different depth positions in the first curvature zone, the curvature reversal zone and the second curvature zone in sequence, and forms the first anchoring section in the first curvature zone, the cross-zone connecting section across the curvature reversal zone and the second anchoring section in the second curvature zone, so as to restrict the yarn bundle that has migrated to move back along the original migration direction; S6. While the wave forming mold keeps the carbon fiber preform in the target wave cross section state, the yarn guide is removed from the carbon fiber preform, and the carbon fiber preform that has completed the cross-zone locking is impregnated with resin and cured to obtain the carbon fiber wave beam guardrail.

[0011] In step S1, the first initial path length and the second initial path length of the reference yarn bundle located on both sides of the curvature reversal zone in the initial state are obtained, as well as the first target path length and the second target path length of the reference yarn bundle located on both sides of the curvature reversal zone in the target waveform cross section state; based on the difference between the first target path length and the first initial path length, and the difference between the second target path length and the second initial path length, the target migration direction and the target migration interval are determined.

[0012] Multiple yarn bundle migration units are distributed at equal or unequal intervals along the length direction of the carbon fiber preform; the yarn bundle migration units extend to the first curvature region and the second curvature region on both sides of the target waveform cross-section width direction, respectively; the pre-set locking unit is used to maintain the positional relationship between adjacent main yarn bundles during the handling and waveform forming process of the carbon fiber preform.

[0013] The yarn bundle guide includes a guide groove or a rolling guide portion corresponding to the reference yarn bundle; the reference yarn bundle passes through the guide groove or goes around the rolling guide portion, the surface of the guide groove that contacts the reference yarn bundle is an arc surface, or the rolling guide portion can rotate as the reference yarn bundle moves.

[0014] The waveform forming mold includes a wave crest forming component corresponding to the wave crest, a wave trough forming component corresponding to the wave trough, and a slope forming component corresponding to the wave slope. In step S4, the cross-sectional reference area is first fixed by one of the wave trough forming components or the slope forming component, and then the wave crest forming component, wave trough forming component, and slope forming component located on both sides of the cross-sectional reference area are driven in sequence so that the carbon fiber preform forms the target waveform cross section segment by segment from the cross-sectional reference area to both sides.

[0015] A position mark is set on the reference yarn bundle; in step S4, the displacement of the position mark relative to the yarn bundle guide or the waveform forming mold is obtained by the image acquisition device, and the actual migration amount of the reference yarn bundle is determined according to the displacement.

[0016] In step S5, each of the cross-zone locking yarns is repeatedly threaded along the thickness direction of the carbon fiber preform, and the first anchoring section and the second anchoring section pass through multiple main yarn bundles at different depths along the thickness direction of the carbon fiber preform; the cross-zone connecting section extends along the width direction of the target waveform section and crosses the position where the curvature direction changes; multiple cross-zone locking yarns are spaced apart along the length direction of the carbon fiber preform and correspond to multiple yarn bundle migration units respectively.

[0017] In step S6, the carbon fiber preform is impregnated with resin using a resin transfer molding process or a vacuum-assisted resin transfer molding process. After the resin impregnation is completed, the preform is cured while maintaining the relative positions of the first curvature region, the second curvature region, and the curvature reversal region. Once the resin reaches the demolding strength, the wave-shaped molding mold is released from its restriction on the carbon fiber preform.

[0018] A carbon fiber corrugated beam guardrail includes a corrugated beam body extending along its length. The corrugated beam body has a continuously undulating corrugated cross section, which includes a first curvature region and a second curvature region with opposite curvature directions, and a curvature reversal region located between the first and second curvature regions. The corrugated beam body includes axially supporting yarns extending continuously along its length, cross-sectional yarns extending continuously along the width direction of the corrugated cross section, and diagonally interlaced yarns intersecting the axially supporting yarns and cross-sectional yarns. The curvature reversal region is provided with a plurality of yarns extending along the length of the corrugated beam body. The cross-zone locking yarns are distributed at intervals in the degree direction; each cross-zone locking yarn includes a first anchoring section located in a first curvature zone, a second anchoring section located in a second curvature zone, and a cross-zone connecting section connecting the first anchoring section and the second anchoring section. The first anchoring section and the second anchoring section pass through multiple sets of main yarn bundles at different depths in the thickness direction of the corrugated beam body. The cross-zone connecting section crosses the curvature reversal zone along the width direction of the corrugated cross section. The axial bearing yarn, cross section yarn, oblique interlacing yarn and cross-zone locking yarn are impregnated in the resin matrix and cured to form an integral structure.

[0019] The waveform cross section includes multiple peaks and troughs arranged alternately along the width direction of the waveform cross section. At least one peak and an adjacent trough are provided with the curvature reversal zone and cross-zone locking yarn. The multiple cross-zone locking yarns are distributed at intervals along the length direction of the waveform beam body and form a cross-curvature locking structure extending along the length direction of the waveform beam body.

[0020] Compared with existing technologies, the advantages of this application are as follows: 1. This application sets yarn bundle migration units in the curvature reversal region of the corresponding waveform beam of the carbon fiber preform, so that some of the main yarn bundles have limited position adjustment space during the waveform forming process. This allows for redistribution based on the path length changes generated by different curvature regions during the formation of the crests and troughs, avoiding the problem of excessive tension or aggregation of local yarn bundles due to the fixed position of the yarn bundles in the forming process of traditional three-dimensional interlocking structures. This improves the adaptability of the carbon fiber preform to the target waveform cross section.

[0021] 2. This application sets a pre-locking unit between the yarn bundle migration units, so that the carbon fiber preform can retain the local yarn bundle adjustment capability while still using the pre-locking yarn to maintain the positional relationship between yarn bundles in different directions. This avoids the long carbon fiber preform from scattering, twisting or overall deformation during handling, placement and forming due to the local reduction of the locking structure, thus achieving a balance between yarn bundle adjustability and overall stability of the preform.

[0022] 3. This application uses segmented molding parts to perform segmented waveform shaping on the carbon fiber preform, so that the first curvature region and the second curvature region can be gradually formed in a predetermined order. The path length difference generated by adjacent curvature regions is used to drive the reference yarn bundle to move in a directional manner within the yarn bundle migration unit, avoiding the problem of mutual interference between the yarn bundle migration directions caused by the simultaneous action of different curvature regions during the overall pressing process, making the yarn bundle migration process more controllable.

[0023] 4. By setting a yarn bundle guide, this application allows the reference yarn bundle to move along the target migration direction while restricting the displacement of the reference yarn bundle in other directions. This transforms the path compensation effect generated during waveform forming into controlled migration in a predetermined direction, reducing disordered yarn bundle offset and improving the accuracy of fiber structure adjustment.

[0024] 5. This application involves inserting a cross-zone locking yarn after the main yarn bundle has completed its migration, so that the first and second anchoring sections of the cross-zone locking yarn connect the first curvature zone and the second curvature zone respectively, and cross the curvature reversal zone through the cross-zone connecting section, thereby re-establishing the locking relationship within the curvature reversal zone, restricting the main yarn bundle that has completed its position adjustment from shifting back, and improving the stability of the internal fiber structure of the finished carbon fiber corrugated beam guardrail.

[0025] 6. This application sets the yarn bundle migration process before resin impregnation and curing, so that the yarn bundle position adjustment and the composite material curing process are coordinated. After the fiber path optimization is completed, the main yarn bundle, pre-set locking yarn and cross-zone locking yarn are fixed into an integral structure by the resin matrix, avoiding the problem that the fiber structure is difficult to adjust after forming in the traditional manufacturing method.

[0026] 7. In the carbon fiber corrugated beam guardrail finally formed in this application, the axial load-bearing yarn, the cross-sectional yarn and the diagonal interlacing yarn maintain a continuous structure, and the curvature reversal area is reinforced by cross-zone locking yarn, so that a stable connection relationship is formed between different curvature areas of the corrugated beam. While ensuring the lightweight advantages of carbon fiber, the consistency of the corrugated beam structure and the reliability of long-term service are improved. Attached Figure Description

[0027] Appendix Figure 1 This is a schematic diagram of the main body of the carbon fiber corrugated beam.

[0028] Appendix Figure 2This is a schematic diagram of the cross-section of a carbon fiber corrugated beam.

[0029] Appendix Figure 3 This is a schematic diagram of a carbon fiber corrugated beam sand bundle structure.

[0030] Appendix Figure 4 This is a top view schematic diagram of a carbon fiber corrugated beam sand bundle structure.

[0031] Appendix Figure 5 This is a schematic diagram of the yarn bundle migration unit of carbon fiber corrugated beam sand.

[0032] Appendix Figure 6 This is a schematic diagram of a wave-shaped forming mold.

[0033] The labels shown in the attached diagram: 1. Wave-shaped beam body; 2. First curvature zone; 3. Curvature reversal zone; 4. Second curvature zone; 5. Axial bearing yarn; 6. Sectional yarn; 7. Diagonal interlacing yarn; 8. Pre-set locking yarn; 9. Yarn bundle migration unit; 10. Pre-set locking unit; 11. Wave-shaped forming mold; 12. Segmented forming part; 13. Sectional reference zone. Detailed Implementation

[0034] The following is in conjunction with the appendix Figures 1-6 To further describe this application in detail, this application provides a carbon fiber corrugated beam guardrail and a method for manufacturing the same. The carbon fiber corrugated beam guardrail includes a corrugated beam body 1 extending along the length direction. The corrugated beam body 1 has a continuously undulating corrugated cross section, and the corrugated cross section forms interconnected peaks, slopes and troughs along the width direction.

[0035] The core of this application is that, during the process of forming the target waveform cross section of the carbon fiber preform, a yarn migration area is first reserved at the position where the curvature direction changes, allowing some yarn bundles to move. This enables the yarn bundles to adjust their positions according to the changes in path length generated when adjacent curvature areas are formed. After the target waveform cross section is formed, the yarn bundles that have completed the position adjustment are relocked by cross-regional locking yarn. Finally, the overall structure is formed by resin impregnation and curing.

[0036] Carbon fiber yarn bundles have limited elongation capacity. When a relatively flat carbon fiber preform is directly pressed to form continuous peaks and troughs, the yarn bundles on the outer side of the bend require a longer path, while those on the inner side require a relatively shorter path. Especially between peaks and adjacent troughs, the relationship between the inner and outer sides of the yarn bundle changes, causing the required path length of the same continuous yarn bundle to vary in different directions within adjacent areas. If the carbon fiber preform is completely locked by thickness-direction locking yarns before waveform forming, the yarn bundles are difficult to position relative to adjacent yarn bundles, easily leading to excessive tension on the outer side of the bend and causing the inner side of the bend to cluster in the direction of curvature. This application addresses this by altering the local locking state of the carbon fiber preform at different manufacturing stages. It temporarily preserves the yarn bundle movement conditions during waveform forming and re-establishes the locking relationship after waveform forming, thus balancing the yarn bundle path adjustment requirements during waveform forming with the overall stability requirements of the finished product stage.

[0037] Before fabrication, the target corrugated beam guardrail cross-section is first obtained, and the first curvature zone 2, the second curvature zone 4, and the curvature reversal zone 3 are determined based on the curvature direction change of the target corrugated beam cross-section. The curvature directions of the first curvature zone 2 and the second curvature zone 4 are opposite. The curvature reversal zone 3 is located between the first curvature zone 2 and the second curvature zone 4, corresponding to the region where the target corrugated beam cross-section gradually changes from one curvature direction to the opposite curvature direction. For example, between adjacent crests and troughs, the curvature regions near the crests and near the troughs can respectively constitute the first curvature zone 2 and the second curvature zone 4, and the portion where the curvature direction changes between them constitutes the curvature reversal zone 3.

[0038] After determining the first curvature region 2, the second curvature region 4, and the curvature reversal region 3, a yarn bundle continuously passing through the first curvature region 2, the curvature reversal region 3, and the second curvature region 4 is selected as a reference yarn bundle. The reference yarn bundle reflects the positional changes of the yarn bundle within the corresponding region during the waveform forming process; it itself belongs to the main yarn bundle constituting the carbon fiber preform. The paths of the reference yarn bundle in the initial state of the carbon fiber preform and in the target waveform cross-section are determined respectively, and the changes in path length of the reference yarn bundle on both sides of the curvature reversal region 3 are compared.

[0039] When the target path of the reference yarn bundle on the first curvature zone 2 side increases relative to the initial path, while the target path on the second curvature zone 4 side decreases relative to the initial path, it indicates that the first curvature zone 2 side needs to obtain more yarn bundle path, while the second curvature zone 4 side has a relatively relaxed yarn bundle path. Therefore, the target migration direction of the reference yarn bundle is determined to be from the second curvature zone 4 side towards the first curvature zone 2 side. Conversely, the target migration direction is determined to be from the first curvature zone 2 side towards the second curvature zone 4 side. The target migration interval is determined based on the change in path length of the reference yarn bundle in the initial state and the target waveform cross-section state, so that the reference yarn bundle undergoes positional adjustments that adapt to the path changes during waveform forming.

[0040] The target migration range does not require the carbon fiber yarn bundle itself to elongate or shorten, but rather defines the range of movement of the reference yarn bundle relative to its initial position. By generating a finite displacement within the curvature reversal zone 3, the reference yarn bundle redistributes the relatively relaxed yarn path on one side to the area with increased path on the other side, compensating for the path length differences that occurred when the first curvature zone 2 and the second curvature zone 4 were formed. Using a target migration range instead of a single numerical value allows for reasonable migration differences between different yarn bundles due to variations in their cross-relationships and friction states.

[0041] Subsequently, a carbon fiber preform is woven using continuous carbon fiber yarn. The carbon fiber preform includes axial load-bearing yarn 5 extending along the length of the corrugated beam, cross-sectional yarn 6 extending along the width of the target corrugated cross section, diagonal interlacing yarn 7 intersecting with the axial load-bearing yarn 5 and the cross-sectional yarn 6, and pre-placed locking yarn 8 arranged along the thickness direction of the carbon fiber preform. The axial load-bearing yarn 5 is used to form a continuous load-bearing path along the length of the corrugated beam, the cross-sectional yarn 6 is used to connect different curvature regions of the corrugated cross section, the diagonal interlacing yarn 7 is used to transfer loads between the length direction and the cross-sectional width direction, and the pre-placed locking yarn 8 is used to connect the main yarn bundles at different positions in the thickness direction of the carbon fiber preform and maintain the overall shape of the dry carbon fiber preform.

[0042] At positions corresponding to the curvature reversal zone 3, multiple yarn bundle migration units 9 are formed at intervals along the length of the carbon fiber preform. At least some positions within each yarn bundle migration unit 9 are not provided with pre-set locking yarns 8, ensuring that the cross-sectional yarns 6 and oblique interlacing yarns 7 at these positions are not completely fixed by the thickness-direction locking relationship. This provides conditions for the yarn bundles to generate limited displacement along the width direction of the target waveform cross-section. The axial load-bearing yarn 5, the cross-sectional yarn 6, and the oblique interlacing yarn 7 all pass continuously through the yarn bundle migration unit 9 without being cut at it. Therefore, the main load-bearing yarn remains continuous after the waveform is formed.

[0043] A pre-locking unit 10 is provided between two adjacent yarn bundle transfer units 9, and a pre-locked yarn 8 is retained within the pre-locking unit 10. The pre-locking unit 10 is used to limit the relative positions of yarn bundles in different directions within the carbon fiber preform, maintaining the overall stability of the carbon fiber preform during handling, placement, and waveform forming. The yarn bundle transfer units 9 and the pre-locking unit 10 are alternately arranged along the length of the waveform beam, so that the curvature reversal zone 3 has both a region for local movement of the yarn bundles and does not form a completely unlocked region that extends continuously along the length of the waveform beam.

[0044] Therefore, the preset locking units 10 are equivalent to stable regions set on both sides of the yarn bundle migration unit 9, and the movement of the reference yarn bundle mainly occurs between the two preset locking units 10. The yarn bundle migration unit 9 is used to solve the problem that the yarn bundle cannot be adjusted according to the waveform path change in the fully locked state, while the preset locking units 10 are used to prevent the long carbon fiber preform from becoming scattered or deformed due to the local reduction of locking yarn. Together, they keep the movement range of the reference yarn bundle controllable.

[0045] After the carbon fiber preform is woven, it is placed in a waveform forming mold 11. The waveform forming mold 11 includes multiple segmented forming components 12, which are respectively arranged to correspond to the crests, troughs, and slopes of the target waveform cross-section. The multiple segmented forming components 12 act on different cross-sectional areas of the carbon fiber preform, so that the target waveform cross-section can be formed segment by segment in a predetermined order, rather than forming all the crests and troughs in one press by a whole mold.

[0046] A yarn bundle guide is installed at yarn bundle migration unit 9, and the yarn bundle guide cooperates with the reference yarn bundle. The yarn bundle guide restricts the offset of the reference yarn bundle along the length and thickness directions of the carbon fiber preform, while allowing the reference yarn bundle to move along the width direction of the target waveform cross-section. The function of the yarn bundle guide is not to actively pull the reference yarn bundle, but to limit the movable direction of the reference yarn bundle. The force that causes the reference yarn bundle to move originates from the change in path length generated when the first curvature region 2 and the second curvature region 4 are formed. The yarn bundle guide restricts the possible disorderly offset of the reference yarn bundle into controlled movement along the target migration direction.

[0047] During waveform forming, the cross-sectional reference area 13 of the carbon fiber preform is first fixed by one of the segmented forming parts 12 to prevent the carbon fiber preform from shifting along the width direction as a whole during subsequent forming. After the cross-sectional reference area 13 is fixed, the remaining segmented forming parts 12 are driven sequentially from the cross-sectional reference area 13 to both sides of the target waveform cross-section, so that the areas corresponding to the waveform slope, crest and trough reach the target position segment by segment.

[0048] The purpose of segmented forming is to create adjacent first curvature regions 2 and second curvature regions 4 in a predetermined order, giving the path change effect on the reference yarn bundle a clear direction. If the first curvature region 2 and the second curvature region 4 are formed simultaneously, the two regions with opposite curvature directions may simultaneously require the reference yarn bundle to adjust in different directions, easily causing mutual interference in the yarn bundle migration. By first forming one curvature region and then forming the other adjacent curvature region, the reference yarn bundle can move along the target migration direction within the yarn bundle migration unit 9 according to the sequential changes in path length.

[0049] During the formation of the first curvature zone 2 and the second curvature zone 4, the yarn bundle transfer unit 9 remains in a state of not being fully compressed, allowing the reference yarn bundle to move under the constraint of the yarn bundle guide. Since the reference yarn bundle is restricted on both sides by the preset locking units 10, its movement is mainly concentrated within the yarn bundle transfer unit 9. The reference yarn bundle generates a limited displacement along the width direction of the target waveform cross-section relative to the main yarn bundle intersecting with it, and drives the adjacent yarn bundles to coordinate their position adjustments, thereby redistributing the yarn bundle path on the relatively relaxed side to the side with increased path demand.

[0050] To determine whether the reference yarn bundle has completed the predetermined migration, position markers are set on the reference yarn bundle, and the displacement of the position markers relative to the yarn bundle guide or the waveform forming mold 11 is acquired using an image acquisition device. The actual migration amount of the reference yarn bundle is obtained based on the displacement. The purpose of detecting the actual migration amount of the reference yarn bundle is to determine whether the yarn bundle path adjustment inside the carbon fiber preform is complete. The segmented forming component 12 reaching the target position only indicates that the basic shape of the target waveform cross-section has been formed, and does not necessarily mean that the internal yarn bundle has moved to the appropriate position. Therefore, it is necessary to compare the actual migration amount with the target migration range.

[0051] When the actual migration amount of the reference yarn bundle has not yet entered the target migration range, the corresponding segmented forming component 12 continues to be driven to perform waveform forming, so that the reference yarn bundle continues to move along the target migration direction. When the actual migration amount of the reference yarn bundle enters the target migration range, and both the first curvature region 2 and the second curvature region 4 reach the target shape, the movement of the segmented forming component 12 is stopped, and the carbon fiber preform is kept in the target waveform cross-section state by the waveform forming mold 11.

[0052] At this point, the reference yarn bundle and its adjacent yarn bundles have completed the position adjustment to match the target waveform cross-section, but a complete thickness-direction locking relationship has not yet been formed within the yarn bundle migration unit 9. If the restriction of the waveform forming mold 11 is directly released, the completed yarn bundle may move back along the original migration direction; if resin impregnation is performed directly, the resin flow may also affect the position of the yarn bundle. Therefore, it is necessary to implant cross-zone locking yarns into the yarn bundle migration unit 9 while maintaining the state of the target waveform cross-section.

[0053] The waveform forming mold 11 is provided with a locking operation channel corresponding to the yarn bundle transfer unit 9. The cross-zone locking yarn is implanted into the carbon fiber preform through the locking operation channel. The cross-zone locking yarn passes through the main yarn bundle at different depth positions in the first curvature zone 2, the curvature reversal zone 3 and the second curvature zone 4 in sequence, and forms a first anchoring section located in the first curvature zone 2, a cross-zone connecting section crossing the curvature reversal zone 3 and a second anchoring section located in the second curvature zone 4.

[0054] The first anchoring section passes through the main yarn bundles at different depths within the first curvature zone 2, so that one side of the cross-zone locking yarn forms a locking relationship with the main yarn bundles within the first curvature zone 2; the second anchoring section passes through the main yarn bundles at different depths within the second curvature zone 4, so that the other side of the cross-zone locking yarn forms a locking relationship with the main yarn bundles within the second curvature zone 4; the cross-zone connecting section crosses the curvature reversal zone 3 along the width direction of the target waveform section and crosses the area where the reference yarn bundle migrates, thereby connecting the first curvature zone 2 and the second curvature zone 4.

[0055] The function of cross-regional locking yarns differs from that of ordinary thickness-direction locking yarns set in a single region. Pre-set locking yarns 8 are set before waveform forming and are mainly used to maintain the overall stability of the carbon fiber preform; cross-regional locking yarns are set after the reference yarn bundle has completed migration and are mainly used to close the degree of freedom of movement retained by the yarn bundle migration unit 9 during the waveform forming stage and to restrict the yarn bundle that has completed position adjustment from moving back along the original migration direction.

[0056] Cross-zone locking yarns cannot be set before waveform formation. If cross-zone locking yarns are set in advance, the first anchoring section, the cross-zone connecting section, and the second anchoring section will connect and lock the first curvature zone 2 and the second curvature zone 4 in advance, thereby re-restricting the movement of the reference yarn bundle within the curvature reversal zone 3. Only by setting cross-zone locking yarns after the actual migration amount of the reference yarn bundle enters the target migration range and the target waveform cross-section is formed can the migration requirements of the waveform formation stage and the locking requirements of the finished product stage be simultaneously met.

[0057] Multiple cross-zone locking yarns are spaced apart along the length of the carbon fiber preform and correspond to multiple yarn bundle migration units 9 respectively. After the cross-zone locking is completed, the yarn bundle migration units 9 that were originally used to provide local movement conditions are relocked by the cross-zone locking yarns to form a cross-zone locking region connecting the first curvature region 2 and the second curvature region 4.

[0058] After the cross-zone locking is completed, the waveform forming mold 11 continues to keep the carbon fiber preform in the target waveform cross-section state and removes the yarn guide from the carbon fiber preform. Since the yarn bundle that has completed the migration is already restricted by the cross-zone locking yarn, the reference yarn bundle remains in the position after the yarn guide is removed.

[0059] Subsequently, the carbon fiber preform with completed cross-zone locking is impregnated with resin. The resin penetrates the interior of the carbon fiber preform and fully impregnates the axial load-bearing yarn 5, the cross-sectional yarn 6, the oblique interlacing yarn 7, the pre-placed locking yarn 8, and the cross-zone locking yarn. During the resin impregnation and curing process, the waveform forming mold 11 continues to maintain the relative positions between the first curvature zone 2, the second curvature zone 4, and the curvature reversal zone 3 to prevent the resin flow or positional changes caused by the yarn bundle absorbing the resin from affecting the target waveform cross-section.

[0060] After the resin cures, the axial load-bearing yarn 5, the cross-sectional yarn 6, the oblique interlacing yarn 7, the pre-placed locking yarn 8, and the cross-zone locking yarn are all fixed within the resin matrix. The pre-placed locking unit 10 forms a locking area that maintains the normal positional relationship of the main yarn bundle, while the original yarn bundle migration unit 9 is transformed into a stable cross-zone locking area under the combined action of the cross-zone locking yarn and the resin matrix. Therefore, the yarn bundle migration unit 9 is only a temporary structural state during the fabrication of the carbon fiber corrugated beam guardrail, and there are no loose yarn bundle areas that can move freely in the final product.

[0061] After the resin reaches the demolding strength, the corrugated molding mold 11 is released from the restriction on the corrugated beam body 1, resulting in a carbon fiber corrugated beam guardrail. The obtained corrugated beam body 1 has a continuously undulating corrugated cross section. The corrugated beam body 1 is provided with axially supporting yarn 5 extending continuously along its length direction, cross-sectional yarn 6 extending continuously along the width direction of the corrugated cross section, and oblique interlacing yarn 7 intersecting with the axially supporting yarn 5 and the cross-sectional yarn 6.

[0062] The corrugated beam body 1 has multiple inter-zone locking yarns spaced apart along its length within its curvature reversal zone 3. Each inter-zone locking yarn includes a first anchoring section located in the first curvature zone 2, a second anchoring section located in the second curvature zone 4, and an inter-zone connecting section connecting the first and second anchoring sections. The first and second anchoring sections pass through the main yarn bundles at different positions along the thickness direction of the corrugated beam body 1, respectively. The inter-zone connecting section crosses the curvature reversal zone 3 along the width direction of the corrugated cross section. The main yarn bundles and the inter-zone locking yarns are impregnated in a resin matrix and cured to form an integral structure.

[0063] In this application, the various parts are coordinated in a continuous technical relationship. The yarn bundle migration unit 9 provides path adjustment space for the reference yarn bundle, the pre-positioned locking unit 10 maintains the overall stability of the long-dimensional carbon fiber preform, the segmented molding part 12 forms adjacent reverse curvature areas in a predetermined order and generates a yarn bundle migration effect with a clear direction, the yarn bundle guide restricts the non-target direction deviation of the reference yarn bundle, the position marker and image acquisition part are used to determine whether the yarn bundle path adjustment is completed, the cross-region locking yarn is used to close the yarn bundle movement freedom after the waveform is formed, and the resin impregnation and curing permanently fix the fiber structure that has completed the position adjustment.

[0064] Through the above manufacturing process, without cutting the axial bearing yarn 5, the cross-sectional yarn 6, and the oblique interlacing yarn 7, the main yarn bundles on both sides of the curvature reversal zone 3 are positioned according to the change in the path length of the target waveform cross section. This reduces the excessive tension of the outer yarn bundles of the waveform and the aggregation of the inner yarn bundles of the waveform toward the curvature reversal zone 3. Furthermore, through the cross-zone locking after the waveform is formed, the two regions with opposite curvature directions are reconnected stably.

[0065] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for manufacturing a carbon fiber corrugated beam guardrail, characterized in that, Includes the following steps: S1. Based on the target waveform cross section of the carbon fiber corrugated beam guardrail, determine the first curvature zone and the second curvature zone with opposite curvature directions, as well as the curvature reversal zone located between the first curvature zone and the second curvature zone. A reference yarn bundle that continuously passes through the first curvature region, the curvature reversal region, and the second curvature region is selected. Based on the change in path length of the reference yarn bundle in the initial state and the target waveform cross-section state, the target migration direction and target migration range of the reference yarn bundle in the curvature reversal region are determined. S2. A carbon fiber preform is woven using continuous carbon fiber yarn. The carbon fiber preform includes axial bearing yarn extending along the length direction of the corrugated beam, cross-sectional yarn extending along the width direction of the target corrugated cross section, oblique interlacing yarn intersecting with the axial bearing yarn and cross-sectional yarn, and pre-set locking yarn arranged along the thickness direction of the carbon fiber preform. Multiple yarn bundle migration units are formed at intervals along the length direction of the carbon fiber preform at positions corresponding to the curvature reversal zone. At least some positions within each yarn bundle migration unit are not provided with the pre-set locking yarn. Pre-set locking units with the pre-set locking yarn are reserved between adjacent yarn bundle migration units. The axial bearing yarn, cross-sectional yarn, and oblique interlacing yarn continuously pass through the yarn bundle migration units and the pre-set locking units. S3. Place the carbon fiber preform in a waveform forming mold, and provide a yarn guide at the yarn transfer unit. The yarn guide restricts the reference yarn from shifting along the length and thickness directions of the carbon fiber preform, and allows the reference yarn to move along the width direction of the target waveform section. S4. Fix the cross-sectional reference area of ​​the carbon fiber preform using the waveform forming mold, and form a first curvature area and a second curvature area from the cross-sectional reference area to both sides in sequence; during the formation of the first curvature area and the second curvature area, move the reference yarn bundle along the target migration direction in the yarn bundle migration unit, and obtain the actual migration amount of the reference yarn bundle relative to its initial position until the actual migration amount is within the target migration range, and the carbon fiber preform reaches the target waveform cross-sectional state; S5. Keep the carbon fiber preform in the target waveform cross section state, and implant the cross-zone locking yarn into the yarn bundle migration unit through the locking operation channel set on the waveform forming mold, so that the cross-zone locking yarn passes through the main yarn bundle at different depth positions in the first curvature zone, the curvature reversal zone and the second curvature zone in sequence, and forms the first anchoring section in the first curvature zone, the cross-zone connecting section across the curvature reversal zone and the second anchoring section in the second curvature zone, so as to restrict the yarn bundle that has migrated to move back along the original migration direction; S6. While the wave forming mold keeps the carbon fiber preform in the target wave cross section state, the yarn guide is removed from the carbon fiber preform, and the carbon fiber preform that has completed the cross-zone locking is impregnated with resin and cured to obtain the carbon fiber wave beam guardrail.

2. The method for manufacturing carbon fiber corrugated beam guardrail according to claim 1, characterized in that, In step S1, the first initial path length and the second initial path length of the reference yarn bundle located on both sides of the curvature reversal zone in the initial state are obtained respectively, as well as the first target path length and the second target path length of the reference yarn bundle located on both sides of the curvature reversal zone in the target waveform cross section state. The target migration direction and target migration interval are determined based on the difference between the first target path length and the first initial path length, and the difference between the second target path length and the second initial path length.

3. The method for manufacturing carbon fiber corrugated beam guardrail according to claim 1, characterized in that, The multiple yarn bundle migration units are distributed at equal or unequal intervals along the length direction of the carbon fiber preform; The yarn bundle migration unit extends to the first curvature region and the second curvature region on both sides of the target waveform cross-section width direction, respectively. The pre-set locking unit is used to maintain the positional relationship between adjacent main yarn bundles during the handling and waveform forming of the carbon fiber preform.

4. The method for manufacturing the carbon fiber corrugated beam guardrail according to claim 1, characterized in that, The yarn bundle guide includes a guide groove or a rolling guide part that is provided corresponding to the reference yarn bundle; The reference yarn bundle passes through the guide groove or goes around the rolling guide. The surface of the guide groove that contacts the reference yarn bundle is an arc surface, or the rolling guide can rotate as the reference yarn bundle moves.

5. The method for manufacturing a carbon fiber corrugated beam guardrail according to claim 1, characterized in that, The waveform forming mold includes a wave crest forming part corresponding to the wave crest, a wave trough forming part corresponding to the wave trough, and a slope forming part corresponding to the wave slope. In step S4, the cross-sectional reference area is first fixed by one of the trough forming parts or the slope forming parts, and then the crest forming parts, trough forming parts and slope forming parts located on both sides of the cross-sectional reference area are driven in sequence so that the carbon fiber preform forms the target waveform cross section from the cross-sectional reference area to both sides.

6. The method for manufacturing a carbon fiber corrugated beam guardrail according to claim 1, characterized in that, Position marks are provided on the reference yarn bundle; In step S4, the displacement of the position mark relative to the yarn guide or the waveform forming mold is obtained by the image acquisition device, and the actual migration amount of the reference yarn is determined based on the displacement.

7. The method for manufacturing a carbon fiber corrugated beam guardrail according to claim 1, characterized in that, In step S5, each of the cross-zone locking yarns is repeatedly threaded along the thickness direction of the carbon fiber preform, and the first anchoring section and the second anchoring section pass through multiple main yarn bundles at different depths along the thickness direction of the carbon fiber preform. The cross-regional connecting segment extends along the width direction of the target waveform cross section and crosses the position where the curvature direction changes; Multiple inter-zone locking yarns are spaced apart along the length of the carbon fiber preform and correspond to multiple yarn bundle migration units respectively.

8. The method for manufacturing a carbon fiber corrugated beam guardrail according to claim 1, characterized in that, In step S6, the carbon fiber preform is impregnated with resin using a resin transfer molding process or a vacuum-assisted resin transfer molding process. After resin impregnation, the carbon fiber preform is cured while maintaining the relative positions of the first curvature zone, the second curvature zone, and the curvature reversal zone. Once the resin reaches the demolding strength, the restriction of the wave-shaped molding mold on the carbon fiber preform is released.

9. A carbon fiber corrugated beam guardrail, comprising a corrugated beam body extending along its length, the corrugated beam body having a continuously undulating corrugated cross section, the corrugated cross section including a first curvature region and a second curvature region with opposite curvature directions, and a curvature reversal region located between the first curvature region and the second curvature region, characterized in that: The corrugated beam body includes an axially bearing yarn that extends continuously along its length, a cross-sectional yarn that extends continuously along the width of the corrugated cross section, and an obliquely interwoven yarn that intersects with the axially bearing yarn and the cross-sectional yarn. The curvature reversal zone is provided with multiple cross-zone locking yarns that are spaced apart along the length of the waveform beam body; Each of the cross-zone locking yarns includes a first anchoring section located in a first curvature zone, a second anchoring section located in a second curvature zone, and a cross-zone connecting section connecting the first anchoring section and the second anchoring section. The first anchoring section and the second anchoring section pass through multiple sets of main yarn bundles at different depths in the thickness direction of the corrugated beam body, and the cross-zone connecting section crosses the curvature reversal zone along the width direction of the corrugated cross section. The axial bearing yarn, cross-sectional yarn, oblique interlacing yarn, and cross-zone locking yarn are impregnated together in the resin matrix and cured to form an integral structure.

10. The carbon fiber corrugated beam guardrail according to claim 9, characterized in that, The waveform cross section includes multiple wave peaks and troughs arranged alternately along the width direction of the waveform cross section, and at least one wave peak and an adjacent wave trough are provided with the curvature reversal zone and cross-zone locking yarn. Multiple inter-zone locking yarns are distributed at intervals along the length of the corrugated beam body, forming a cross-curvature locking structure extending along the length of the corrugated beam body.

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