Interlayer hybrid composite material vehicle body B column reinforcer and preparation method thereof
By using interlayer mixed composite materials in the body B-pillar reinforcement, combined with the design of specific laying order and fiber volume fraction, the multi-target needs of lightweight, corrosion resistance, thermal matching and low-cost in the prior art are solved, and a high-performance and low-cost body B-pillar reinforcement is achieved.
Patent Information
- Application Number
- CN202510445309.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-10
- Publication Date
- 2025-06-03
AI Technical Summary
The prior art has failed to effectively solve the multi-target needs of lightweight, corrosion resistance, thermal matching and low cost, especially in the design of B-pillar reinforcement of the vehicle body.
Using interlayer hybrid composite materials, specifically, a body B-pillar reinforcement that meets the multi-target needs is prepared by combining carbon fibers and glass fibers in a specific laying order, combining appropriate fiber volume fractions and selection of binders.
The top pressure strength is equivalent to that of all carbon fiber reinforcements, a material cost reduction of more than 40%, and a small difference in electrochemical corrosion resistance and thermal expansion coefficient, meeting the multi-target needs of lightweight, low cost, corrosion resistance and thermal matching.
Smart Images
Figure CN120080918A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of lightweight automotive body structures, and particularly to an interlayer hybrid composite body B-pillar reinforcement and a preparation method thereof, which are suitable for improving the safety performance of the body and reducing the manufacturing cost. Background Art
[0002] The body B-pillar is a key component for automotive collision safety and needs to have high roof crush strength to ensure the survival space of the occupants. The traditional solution uses metal reinforcements, but there are problems such as high weight and high cost. Although carbon fiber composites are lightweight and high-strength, the cost of all-carbon fiber reinforcements is too high, and the interface with metal is prone to electrochemical corrosion, and the difference in thermal expansion coefficients is large. The prior art has not effectively solved the multi-objective requirements of lightweight, corrosion resistance, thermal matching, and low cost. Summary of the Invention
[0003] Technical problems to be solved: Aiming at the deficiencies of the prior art, the present invention provides an interlayer hybrid composite body B-pillar reinforcement and a preparation method thereof, which meet the multi-objective requirements of lightweight, low cost, resistance to electrochemical corrosion, and small difference in thermal expansion coefficient of the body B-pillar reinforcement.
[0004] Technical solution: An interlayer hybrid composite body B-pillar reinforcement according to the present invention, the lay-up sequence of the reinforcement is: [45G / 0C / 0C / -45G / 0C / 0C / -45G / 0C / 0C / 90G / 0C / 0C / 90G / 0C / 0C / 45G / 0C / 0C / 45G / 0C / 0C / -45G] s ; wherein, G represents a single layer of glass fiber; C represents a single layer of carbon fiber; the subscript s in the square brackets represents symmetric lay-up, and the laying angle is the angle between the fiber direction in the single layer and the central axis of the reinforcement; The total number of layers of the reinforcement is 44 layers, including 28 layers of 0° carbon fiber single layers, 12 layers of ±45° glass fiber single layers, and 4 layers of 90° glass fiber single layers; The reinforcement is installed in the cavity of the body B-pillar, and is attached to the inner metal plate of the B-pillar and fixed by bonding with an adhesive, and the position and size of the opening in the middle are the same as the original holes in the inner plate of the body B-pillar.
[0005] Preferably, the resin matrix of the adhesive is a thermosetting epoxy resin or a thermoplastic resin that is simultaneously applicable to glass fiber and carbon fiber, and its thermal expansion coefficient is greater than that of the metal material of the body B-pillar.
[0006] Preferably, when the body B-pillar is made of steel plate material, the fiber volume fraction of the outermost and innermost 45° glass fiber single layers of the reinforcement is 35% - 65%.
[0007] Preferably, when the vehicle body B-pillar is made of aluminum alloy material, the fiber volume fraction of the outermost layer and the innermost layer of the 45° glass fiber monolayer of the reinforcing member is 20% - 30%.
[0008] Preferably, the thickness of both the glass fiber monolayer and the carbon fiber monolayer of all the reinforcing members is 0.125 mm; except for the outermost layer and the innermost layer of the 45° glass fiber monolayer, the fiber volume fraction of the remaining glass fiber monolayers and carbon fiber monolayers is 60%.
[0009] Preferably, the axial elastic modulus of the glass fiber monolayer is greater than 70 GPa, and the axial tensile strength is greater than 1000 MPa; the axial elastic modulus of the carbon fiber monolayer is greater than 120 GPa, and the axial tensile strength is greater than 1800 MPa.
[0010] The present invention discloses a preparation method of a reinforcing member, comprising the following steps: Step 1: Lay a 0° layer glass fiber prepreg monolayer in a mold, close the mold and apply a trial pressure. Step 2: Determine the cutting scheme according to the wrinkles and fiber deflection of the monolayer after the trial pressure. Step 3: Tear off the films on the upper and lower surfaces of the 0° monolayer, cut and splice according to the cutting scheme, and re-lay the film. Step 4: Repeat Step 3 until all the 0° monolayers are pre-treated. Step 5: Lay the 45° and 90° glass fiber prepreg monolayers in a mold for shaping, and keep the film to avoid bonding of each layer. Step 6: Tear off the films of each monolayer, stack and place them in the mold according to the lay-up sequence described in Claim 1. Step 7: After closing the mold and shaping, sew and reinforce the edges of the reinforcing member and the edges of the openings. Step 8: Place the sewn and reinforced reinforcing member in the mold, carry out compression molding and curing according to the set curing temperature and pressure, then open the mold, cool at room temperature and drill holes.
[0011] Preferably, the molds used in Step 1, Step 5, Step 6 and Step 8 are the same mold or multiple molds.
[0012] Preferably, the sewing reinforcement uses Kevlar fiber bundles or a metal edge protection structure.
[0013] The present invention provides a laminated hybrid composite vehicle body B-pillar reinforcing member and its preparation method. Through the interlayer hybrid arrangement of carbon fiber and glass fiber, combined with the adjustment of the specific lay-up sequence and fiber volume fraction, the following technical effects are achieved: 1. The top pressure strength of the reinforcing member is equivalent to that of a fully carbon fiber reinforcing member. The 0° layer uses carbon fiber to bear the axial load, and the ±45° and 90° layers use low-cost glass fiber. 2. The outermost layer of glass fiber monolayer of the reinforcement reduces the risk of electrochemical corrosion; 3. The reinforcement optimizes the coefficient of thermal expansion by adjusting the fiber volume fraction, effectively reducing the stress at the metal interface; 4. The material cost of the reinforcement is reduced by more than 40%. Description of the Drawings
[0014] Figure 1 It is a drawing of the preparation method of the body B-pillar reinforcement of the present invention; Figure 2 It is a schematic structural diagram of the body B-pillar reinforcement ((a) front view; (b) side view); Figure 3 It is Figure 2 A schematic structural diagram of the sewing reinforcement structure at the hole edge of the middle body B-pillar reinforcement ((a) front view of the hole edge; (b) side view of the hole edge or the reinforcement edge); Figure 4 It is a schematic structural diagram of the interlayer hybrid composite material layup of the body B-pillar reinforcement; Figure 5 It is a top pressure test diagram of a pure carbon fiber reinforcement according to the layup structure of the present invention; Figure 6 It is Figure 5 A top pressure test curve diagram of the pure carbon fiber reinforcement in Figure 7 It is a comparison diagram of the load-displacement curve simulation and test of the body B-pillar reinforcement with two layup structures.
[0015] Reference numerals: 1. Reinforcement; 2. Hole; 3. Reinforcement edge reinforcement line; 4. Hole edge reinforcement line. Detailed Embodiments
[0016] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be described clearly and completely below. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the present invention belong to the scope of protection of the present invention. Figures 1 - 7
[0017] Figures 2 - 4 Example 1: As Figures 2 - 4 shown, the present invention discloses an interlayer hybrid composite material body B-pillar reinforcement, and the layup sequence of the reinforcement 1 is: [45G / 0C / 0C / -45G / 0C / 0C / -45G / 0C / 0C / 90G / 0C / 0C / 90G / 0C / 0C / 45G / 0C / 0C / 45G / 0C / 0C / -45G] s; where G represents a single layer of glass fiber; C represents a single layer of carbon fiber; the subscript s in square brackets represents a symmetric ply (as Figure 4 shown), and the laying angle is the angle between the fiber direction in the single layer and the central axis of the reinforcement 1. The total number of layers of the reinforcement 1 is 44 layers, including 28 layers of 0° carbon fiber single layers, 12 layers of ±45° glass fiber single layers, and 4 layers of 90° glass fiber single layers. The thickness of all glass fiber single layers and carbon fiber single layers of the reinforcement 1 is 0.125 mm. The axial elastic modulus of the glass fiber single layer is greater than 70 GPa, and the axial tensile strength is greater than 1000 MPa; the axial elastic modulus of the carbon fiber single layer is greater than 120 GPa, and the axial tensile strength is greater than 1800 MPa.
[0018] When the body B-pillar is made of steel plate material, the fiber volume fraction of the outermost and innermost 45° glass fiber single layers of the reinforcement 1 is 35% - 65%. When the body B-pillar is made of aluminum alloy material, the fiber volume fraction of the outermost and innermost 45° glass fiber single layers of the reinforcement 1 is 20% - 30%. Except for the outermost and innermost 45° glass fiber single layers, the fiber volume fraction of the remaining glass fiber single layers and carbon fiber single layers is 60%.
[0019] The reinforcement 1 is installed in the cavity of the body B-pillar, and is attached to the inner metal plate of the B-pillar and fixed by bonding. The resin matrix of this adhesive uses a thermosetting epoxy resin or a thermoplastic resin that is applicable to both glass fiber and carbon fiber, and its thermal expansion coefficient is greater than that of the body B-pillar metal material.
[0020] As Figures 2 - 3 shown, the opening position and size of the body B-pillar reinforcement 1 are the same as those of the original holes 2 in the inner plate of the body B-pillar. Sewing reinforcement is carried out on the reinforcement edge reinforcement line 3 and the hole edge reinforcement line 4. The sewing reinforcement uses Kevlar fiber bundles or a metal edge protection structure.
[0021] Example 2: As Figure 1 shown, the present invention discloses a preparation method of a reinforcement, including the following steps: Step 1: Lay a single layer of 0° layer glass fiber prepreg in the mold, close the mold and apply pressure. Step 2: Determine the cutting plan according to the wrinkles and fiber deflection of the single layer after pressure testing. Step 3: Tear off the films on the upper and lower surfaces of the 0° single layer, cut and splice according to the cutting plan, and re-lay the film. Step 4: Repeat Step 3 until all 0° single layers are pre-treated. Step 5: Lay the 45° and 90° glass fiber prepreg single layers in the mold for shaping, and keep the film to avoid bonding of each layer. Step 6: Tear off the films of each single layer, and stack them in the mold according to the ply sequence described in Claim 1. Step 7: After the mold is closed and shaped, sew and reinforce the edges of the reinforcement member 1 and the edges of the openings. The sewing reinforcement uses Kevlar fiber bundles or a metal edge protection structure; Step 8: Place the sewn and reinforced reinforcement member 1 in the mold, perform compression molding and curing according to the set curing temperature and pressure, then open the mold, cool at room temperature and drill holes.
[0022] It should be noted that the molds used in Step 1, Step 5, Step 6 and Step 8 are the same mold or multiple molds.
[0023] The following conducts a top pressure test on the interlayer hybrid composite body B-pillar reinforcement member of the present invention and the pure carbon fiber reinforcement member 1 with the ply structure according to the present invention.
[0024] As Figures 5 - 7As shown, the interlayer hybrid composite body B-pillar reinforcement of the present invention and the pure carbon fiber reinforcement 1 with the ply structure according to the present invention have enabled the roof crush performance of a certain vehicle model to reach the Good level of the roof crush performance of the North American IIHS regulation, meeting the user requirements. The interlayer hybrid composite body B-pillar reinforcement 1 of the present invention has a total of 44 plies, including 28 plies of 0° plies, a total of 12 plies of ±45° plies, and a total of 4 plies of 90° plies. Under the roof crush condition, the body B-pillar reinforcement 1 mainly bears the load along the axial direction of the reinforcement 1, that is, the 0° direction load. All 0° plies are made of high-performance carbon fiber single plies, and all ±45° plies and 90° plies are made of glass fiber single plies; through calculation, the modulus of the carbon fiber single ply at 0° is about 2 times that of the glass fiber single ply at 0°. Due to the transverse isotropy characteristics of carbon fiber, the moduli of the carbon fiber single plies at 45° and 90° are only 50% of the moduli of the glass fiber single plies at 45° and 90°. From the perspective of strength, under the roof crush load, the failure of the B-pillar reinforcement 1 is mainly determined by the mechanical properties of the 0° carbon fiber single ply, and the contributions of the ±45° and 90° single plies can be ignored. Replacing the ±45° and 90° single plies with glass fiber will not reduce the roof crush strength of the reinforcement 1; from the perspective of modulus, replacing the ±45° and 90° single plies with glass fiber slightly improves the elastic modulus of the reinforcement 1; through simulation and experimental analysis, it can be proved that replacing the ±45° and 90° single plies with glass fiber has almost no effect on the roof crush performance of the B-pillar reinforcement 1. Compared with the all-carbon fiber body B-pillar reinforcement 1, the interlayer hybrid composite body B-pillar reinforcement provided by the present invention can meet the requirement of no reduction in mechanical properties. From the perspective of cost, the cost of each square meter of high-performance carbon fiber single ply is about 100 yuan, and the cost of the same size of glass fiber single ply is only 5 yuan. The body B-pillar reinforcement 1 of the present invention can reduce the material cost by 40%, and can solve the problem of too high cost of the all-carbon fiber solution. From the perspective of electrochemical corrosion, glass fiber has better electrochemical corrosion resistance than carbon fiber single ply. In the technical solution of the present invention, the outermost layer is a 45° glass fiber single ply, which can largely avoid the electrochemical corrosion between the reinforcement 1 and the metal of the body B-pillar. From the perspective of the difference in thermal expansion coefficient, a large thermal expansion coefficient will cause fretting stress corrosion at the contact interface between the reinforcement 1 and the metal structure of the body B-pillar in a large temperature difference environment. By adjusting the fiber volume content in the outermost 45° single ply of glass fiber, the thermal expansion coefficient of the outermost single ply can be made close to that of the metal, and the influence of the difference in thermal expansion coefficient on the structural performance can be reduced to a large extent. In summary, the body B-pillar reinforcement 1 prepared by the present invention can simultaneously meet the multi-objective requirements of high performance, low cost, electrochemical corrosion resistance, and small difference in thermal expansion coefficient from metal.
[0025] The preparation method of the reinforcement member 1 of the present invention has a better coincidence between the cutting plan determined by the pre-forming step and the actual situation. The treatment of sewing after cutting can effectively avoid fiber deflection and interlayer overlap caused during the laying process; retaining the film pre-forming during the process can avoid adhesion between the single layer and the mold; tearing off the film can avoid defects caused by the remaining film in the sewing thread; re-laying the film after sewing can ensure that the batch raw materials will not adhere to each other during stacking; finally tearing off the film can achieve effective bonding of each layer during the re-molding process. For small batch production requirements, the molds involved in each step can be the same mold, and this mold needs to have heating and pressurizing functions, which can reduce the mold cost; for large batch production requirements, the molds involved in each step can be multiple molds, and the final molding mold needs to have heating and pressurizing functions, and the molds for the remaining steps only need to have pressurizing functions. In this way, the efficiency can be significantly improved through assembly line operation.
[0026] The above is the preferred implementation mode of the present invention. It should be noted that for those of ordinary skill in the art of this technology, without departing from the principle of the present invention, several improvements and retouches can be made, and these improvements and retouches should also be regarded as the protection scope of the present invention.
Claims
1. A hybrid composite material vehicle body B-pillar reinforcement, characterized in that: The ply laying sequence of the reinforcement member (1) is: [45G / 0C / 0C / -45G / 0C / 0C / -45G / 0C / 0C / 90G / 0C / 0C / 90G / 0C / 0C / 45G / 0C / 0C / 45G / 0C / 0C / -45G] s ; Wherein, G represents a single layer of glass fiber; C represents a single layer of carbon fiber; the square bracket subscript s represents a symmetrical layer, and the laying angle is the angle between the fiber direction in the single layer and the central axis of the reinforcement (1); The total number of layers of the reinforcement (1) is 44, including 28 layers of 0° carbon fiber single layers, 12 layers of ±45° glass fiber single layers and 4 layers of 90° glass fiber single layers; The reinforcement member (1) is installed in the cavity of the B-pillar of the vehicle body, and is bonded to the metal inner plate of the B-pillar and fixed by adhesive, wherein the position and size of the central opening are consistent with the original hole (2) of the inner plate of the B-pillar of the vehicle body.
2. The interlayer hybrid composite vehicle body B-pillar reinforcement according to claim 1, characterized in that: The resin matrix of the adhesive is a thermosetting epoxy resin or a thermoplastic resin suitable for both glass fiber and carbon fiber, and its thermal expansion coefficient is greater than the thermal expansion coefficient of the metal material of the B-pillar of the vehicle body.
3. The interlayer hybrid composite vehicle body B-pillar reinforcement according to claim 1, characterized in that: When the vehicle body B-pillar is made of steel plate material, the fiber volume fraction of the outermost and innermost 45° glass fiber single layers of the reinforcement (1) is 35% to 65%.
4. The interlayer hybrid composite vehicle body B-pillar reinforcement according to claim 1, characterized in that: When the vehicle body B-pillar is made of aluminum alloy material, the fiber volume fraction of the outermost layer and the innermost layer of the 45° glass fiber single layer of the reinforcement (1) is 20% to 30%.
5. The interlayer hybrid composite vehicle body B-pillar reinforcement according to claim 3 or 4, characterized in that: The thickness of the glass fiber single layer and the carbon fiber single layer of all the reinforcements (1) is 0.125 mm; except for the outermost and innermost 45° glass fiber single layers, the fiber volume fractions of the remaining glass fiber single layers and the carbon fiber single layers are 60%.
6. The interlayer hybrid composite vehicle body B-pillar reinforcement according to claim 1, characterized in that: The axial elastic modulus of the glass fiber single layer is greater than 70 GPa, and the axial tensile strength is greater than 1000 MPa; the axial elastic modulus of the carbon fiber single layer is greater than 120 GPa, and the axial tensile strength is greater than 1800 MPa.
7. A method for preparing a reinforcement member according to claim 1, characterized in that: The following steps are involved: Step 1: Lay a single layer of 0° glass fiber prepreg in the mold, close the mold and test the pressure; Step 2: Determine the cutting plan based on the wrinkles and fiber deflection of the single layer after the pressure test; Step 3: Tear off the 0° single-layer upper and lower surface films, cut and splice according to the cutting plan, and re-cover the film; Step 4: Repeat step 3 until all 0° single layers are pre-treated; Step 5: Lay a single layer of 45° and 90° glass fiber prepreg in the mold to shape it, and keep the film to prevent the layers from sticking together; Step 6: tear off each single layer of film, and stack them in a mold according to the layering sequence of claim 1; Step 7: After the mold is closed and the shape is finalized, the edges of the reinforcement member (1) and the edges of the opening are sewn and reinforced; Step 8: Place the sewing reinforced reinforcement (1) in the mold, perform compression molding and curing according to the set curing temperature and pressure, open the mold, cool at room temperature and open the hole.
8. The method for preparing a reinforcement member according to claim 7, characterized in that: The mold used in step 1, step 5, step 6 and step 8 is the same mold or multiple molds.
9. The method for preparing a reinforcement member according to claim 7, characterized in that: The sewing reinforcement adopts Kevlar fiber bundle or metal edge protection structure.