A gradient FRP reinforcing structure for repairing oil and gas pipelines
Patent Information
- Application Number
- CN202521538358.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-22
- Publication Date
- 2026-08-21
- Estimated Expiration
- 2035-07-22
AI Technical Summary
[0005]鉴于上述现有技术的不足，本实用新型的目的在于提供一种用于修复油气管道的梯度化FRP加固结构，旨在解决现有FRP加固结构存在的脆性破坏、界面粘接强度低和承载能力提升有限的问题
[0016]有益效果：本实用新型提供一种用于修复油气管道的梯度化FRP加固结构，包括通过胶粘层粘接于油气管道表面的若干第一纤维增强复合层、以及粘接于所述第一纤维增强复合层背离所述油气管道表面一侧的若干第二纤维增强复合层；所述第一纤维增强复合层和所述第二纤维增强复合层呈梯度设置；所述胶粘层中嵌设有铁丝网。本实用新型采用呈梯度设置的第一纤维增强复合层作为内层，第二纤维增强复合层作为外层，使不同的纤维增强复合层不同位置具有优化的力学性能分布，从而降低界面应力集中，提高FRP加固结构的整体稳定性；同时，在胶粘层中嵌入铁丝网，形成界面桥联结构，提高界面断裂能，有效抑制裂纹扩展，提升界面抗裂性能。具体地，本实用新型利用梯度化FRP加固结构能够有效提升FRP修复油气管道的性能，增强界面粘接韧性，提高修复管道的极限承载能力，延缓界面裂纹扩展，降低长期服役条件下的疲劳损伤风险，从而实现更可靠、更耐久的FRP加固结构，可广泛由于油气输送、海洋工程、压力管道等领域，具有重要的工程应用价值和推广前景。
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Figure CN224665654U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of structural repair technology, and in particular to a gradient FRP reinforcement structure for repairing oil and gas pipelines. Background Technology
[0002] Oil and gas pipelines are critical infrastructure for energy transportation. During long-term service, they are subject to complex working conditions and harsh environments, which can easily lead to problems such as corrosion, fatigue cracking and mechanical damage. Among these, thinning of the pipeline wall and through-hole defects (such as cracks and perforations) are the most serious structural damages, directly threatening the safe operation of the pipeline.
[0003] Currently, FRP (fiberglass reinforced polymer) reinforcement technology for pipelines mainly employs a wet winding process. This involves coating the damaged pipeline surface with adhesives such as epoxy resin, then winding carbon fiber reinforced polymer (CFRP) or glass fiber reinforced polymer (GFRP) to form a reinforcement layer, thereby restoring the pipeline's load-bearing capacity. However, existing FRP winding repair methods suffer from low interfacial bond strength and insufficient fracture toughness at the FRP-steel pipe interface, making the repaired structure prone to brittle failure. Especially under high stress, interfacial delamination or crack propagation can lead to reinforcement layer failure, reducing the stability and reliability of the repair effect. Furthermore, traditional CFRP winding repair technology relies primarily on the reinforcement effect of the fiber layers, without fully optimizing the mechanical design of the CFRP reinforcement layer. This results in limited improvement in the load-bearing capacity of the CFRP-reinforced steel pipe, making it difficult to effectively restore or surpass the original pipeline's load-bearing capacity. Particularly under internal pressure-bending coupling, FRP-reinforced pipelines may experience localized failure, further reducing the overall load-bearing capacity. Additionally, CFRP reinforcement layers typically use a uniform winding method, failing to fully consider the impact of layup angle, layer number variations, and material gradient design on interfacial strength. In addition, direct contact between CFRP and steel pipe may cause electrochemical corrosion, affecting the long-term durability of the repair layer.
[0004] In summary, existing CFRP repair technologies suffer from problems such as brittle failure, limited improvement in load-bearing capacity, difficulty in controlling crack propagation, simple repair layer structure, and insufficient long-term reliability. Therefore, existing technologies still need to be improved and developed. Utility Model Content
[0005] In view of the shortcomings of the prior art, the purpose of this utility model is to provide a gradient FRP reinforcement structure for repairing oil and gas pipelines, which aims to solve the problems of brittle failure, low interfacial bonding strength and limited improvement of load-bearing capacity of existing FRP reinforcement structures.
[0006] The technical solution of this utility model is as follows:
[0007] A gradient FRP reinforcement structure for repairing oil and gas pipelines includes a plurality of first fiber-reinforced composite layers bonded to the surface of the oil and gas pipeline by an adhesive layer, and a plurality of second fiber-reinforced composite layers bonded to the side of the first fiber-reinforced composite layers facing away from the surface of the oil and gas pipeline; the first fiber-reinforced composite layers and the second fiber-reinforced composite layers are arranged in a gradient; and wire mesh is embedded in the adhesive layer.
[0008] The gradient FRP reinforcement structure for repairing oil and gas pipelines, wherein the surface roughness of the oil and gas pipeline is greater than or equal to 0.05 mm.
[0009] The gradient FRP reinforcement structure for repairing oil and gas pipelines, wherein the mesh size of the wire mesh is between 5mm and 10mm.
[0010] The gradient FRP reinforcement structure for repairing oil and gas pipelines, wherein the first fiber-reinforced composite layer is a glass fiber-reinforced composite layer, a basalt fiber-reinforced composite layer, or an aramid fiber-reinforced composite layer; and the second fiber-reinforced composite layer is a carbon fiber-reinforced composite layer.
[0011] The gradient FRP reinforcement structure for repairing oil and gas pipelines, wherein the number of layers in the first fiber-reinforced composite layer is not less than 4; and the number of layers in the second fiber-reinforced composite layer does not exceed 4.
[0012] The gradient FRP reinforcement structure for repairing oil and gas pipelines, wherein the edge of the first fiber-reinforced composite layer is 4cm-10cm away from the edge of the second fiber-reinforced composite layer, forming a stepped shape.
[0013] The gradient FRP reinforcement structure for repairing oil and gas pipelines, wherein the layup angle between a plurality of the first fiber-reinforced composite layers includes one or more of 0°, 45°, -45°, and 90°.
[0014] The gradient FRP reinforcement structure for repairing oil and gas pipelines, wherein the layup angle between a plurality of second fiber-reinforced composite layers includes one or more of 0°, 45°, -45°, and 90°.
[0015] The gradient FRP reinforcement structure for repairing oil and gas pipelines, wherein the adhesive layer is an epoxy resin layer containing nano-silica particles or graphene.
[0016] Beneficial Effects: This utility model provides a gradient FRP reinforcement structure for repairing oil and gas pipelines, comprising several first fiber-reinforced composite layers bonded to the surface of the oil and gas pipeline by an adhesive layer, and several second fiber-reinforced composite layers bonded to the side of the first fiber-reinforced composite layers facing away from the surface of the oil and gas pipeline; the first and second fiber-reinforced composite layers are arranged in a gradient; and wire mesh is embedded in the adhesive layer. This utility model uses the gradient-arranged first fiber-reinforced composite layers as the inner layer and the second fiber-reinforced composite layers as the outer layer, resulting in optimized mechanical property distribution at different locations of the different fiber-reinforced composite layers, thereby reducing interfacial stress concentration and improving the overall stability of the FRP reinforcement structure; simultaneously, the embedding of wire mesh in the adhesive layer forms an interfacial bridging structure, increasing the interfacial fracture energy, effectively inhibiting crack propagation, and improving the interfacial crack resistance. Specifically, this utility model utilizes a gradient FRP reinforcement structure to effectively improve the performance of FRP in repairing oil and gas pipelines, enhance interfacial bonding toughness, increase the ultimate bearing capacity of the repaired pipeline, delay the propagation of interfacial cracks, and reduce the risk of fatigue damage under long-term service conditions. This results in a more reliable and durable FRP reinforcement structure, which can be widely used in oil and gas transportation, marine engineering, pressure pipelines and other fields, and has significant engineering application value and promotion prospects. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of a gradient FRP reinforcement structure for repairing oil and gas pipelines according to the present invention;
[0018] Figure 2 for Figure 1 Enlarged diagram of A in the middle;
[0019] Explanation of reference numerals in the attached drawings: adhesive layer 10, first fiber-reinforced composite layer 20, second fiber-reinforced composite layer 30, wire mesh 40, oil and gas pipeline 100. Detailed Implementation
[0020] This utility model provides a gradient FRP reinforcement structure for repairing oil and gas pipelines. To make the purpose, technical solution, and effects of this utility model clearer and more explicit, the following provides a more detailed description of this utility model. It should be understood that the specific embodiments described herein are merely illustrative of this utility model and are not intended to limit this utility model.
[0021] In the description of this application, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," and "rear," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of the stated features.
[0022] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein.
[0023] Under complex stress conditions, cracks at the FRP-steel pipe interface tend to propagate rapidly, especially I-II composite cracks (mixed opening and shear cracks). Traditional repair methods struggle to effectively suppress crack propagation, leading to early interface failure and making it difficult to maintain the repair effect long-term. Furthermore, existing FRP-repaired pipelines are susceptible to interface degradation and strength reduction during long-term service due to factors such as temperature changes, moisture penetration, and fatigue loads. Current research lacks sufficient assessment of the long-term service performance of FRP-repaired structures and in-depth studies on environmental aging and fatigue damage, hindering the widespread application of FRP reinforcement solutions in engineering projects.
[0024] like Figure 1 As shown, this utility model provides a gradient FRP reinforcement structure for repairing oil and gas pipelines, including a plurality of first fiber-reinforced composite layers 20 bonded to the surface of an oil and gas pipeline 100 by an adhesive layer 10, and a plurality of second fiber-reinforced composite layers 30 bonded to the side of the first fiber-reinforced composite layers 20 facing away from the surface of the oil and gas pipeline 100; the first fiber-reinforced composite layers 20 and the second fiber-reinforced composite layers 30 are arranged in a gradient; and wire mesh 40 is embedded in the adhesive layer 10.
[0025] In this embodiment, a first fiber-reinforced composite layer arranged in a gradient is used as the inner layer, and a second fiber-reinforced composite layer is used as the outer layer. This allows for optimized mechanical property distribution at different locations within the different fiber-reinforced composite layers, thereby reducing interfacial stress concentration and improving the overall stability of the FRP-reinforced structure. Simultaneously, wire mesh is embedded in the adhesive layer to form an interfacial bridging structure, increasing interfacial fracture energy, effectively inhibiting crack propagation, and enhancing interfacial crack resistance. Specifically, this invention utilizes a gradient FRP reinforcement structure to effectively improve the performance of FRP in repairing oil and gas pipelines, enhance interfacial bonding toughness, increase the ultimate bearing capacity of the repaired pipeline, delay interfacial crack propagation, and reduce the risk of fatigue damage under long-term service conditions. This results in a more reliable and durable FRP reinforcement structure, which can be widely used in oil and gas transportation, marine engineering, pressure pipelines, and other fields, possessing significant engineering application value and promising prospects for promotion.
[0026] Specifically, this invention improves the fracture toughness of the FRP-oil-gas pipeline interface by optimizing the structure of the FRP repair layer and combining it with the interface toughening effect, thereby enhancing the load-bearing capacity and long-term service reliability of the repaired pipeline. Furthermore, by gradient-setting the first and second fiber-reinforced composite layers, using several of the first fiber-reinforced composite layers as an inner layer, external loads can be buffered, reducing interface stress concentration. Simultaneously, direct contact between the second fiber-reinforced composite layer and the steel pipe is isolated, preventing electrochemical corrosion and improving the durability of the gradient FRP reinforcement structure. Meanwhile, the several second fiber-reinforced composite layers are mainly concentrated around the through-hole defect, effectively improving the load-bearing capacity of the repair area. The gradient setting of the first and second fiber-reinforced composite layers ensures a reasonable distribution of interface stress gradient, reducing the risk of interface fracture. On the other hand, the addition of wire mesh creates a micro-bridging effect at the interface, increasing the interface fracture energy and effectively inhibiting crack propagation. The adhesive layer integrates the first fiber-reinforced composite layer, the second fiber-reinforced composite layer, and the wire mesh into a single structure, improving interface toughness without affecting overall adhesion performance.
[0027] In some embodiments, the surface roughness of the oil and gas pipeline is greater than or equal to 0.05 mm.
[0028] Specifically, during actual construction, the damaged area of the oil and gas pipeline is first treated to remove rust and impurities, ensuring that the surface roughness meets the bonding requirements, with a surface roughness of not less than 0.05 mm. Then, epoxy resin is applied to the repair area, and wire mesh is embedded. The outer layer of GFRP and the inner layer of CFRP are then wrapped according to the design requirements, ensuring the layup sequence and bonding quality. Finally, a PE film is wrapped, applying appropriate tension to squeeze out air from the fiber-reinforced composite layer, ensuring a tight fit, reducing interface defects, and improving the overall reinforcement effect. After curing under appropriate temperature and pressure conditions, the PE film is removed, resulting in a gradient FRP reinforcement structure that enhances interfacial bonding. Simultaneously, non-destructive testing methods (such as ultrasonic or fiber optic sensing) can be used to evaluate the repair effect.
[0029] In some embodiments, the mesh size of the wire mesh is between 5mm and 10mm. Providing a wire mesh with a mesh size between 5mm and 10mm allows for better embedding within the adhesive layer, ensuring improved interfacial toughness and enhancing overall bonding performance.
[0030] In some embodiments, the first fiber-reinforced composite layer is a glass fiber reinforced composite layer (GFRP), a basalt fiber reinforced composite layer (BFRP), or an aramid fiber reinforced composite layer (AFRP); the second fiber-reinforced composite layer is a carbon fiber reinforced composite layer (CFRP). The aforementioned first fiber-reinforced composite layer has high toughness, improving impact and fatigue resistance, buffering external loads, reducing interfacial stress concentration, and isolating the CFRP from direct contact with the steel pipe, preventing electrochemical corrosion and improving the durability of the repair system. The CFRP has high stiffness and strength, mainly concentrated around the penetrating defect, effectively improving the load-bearing capacity of the repair area.
[0031] In a preferred embodiment, the first fiber-reinforced composite layer is a glass fiber reinforced composite layer (GFRP); the second fiber-reinforced composite layer is a carbon fiber reinforced composite layer (CFRP). By layering different types of FRP around the outside of the oil and gas pipeline, a gradient repair layer is formed, improving interface toughness and load-bearing capacity. Furthermore, the GFRP layer has a large coverage area, enhancing overall stability and effectively isolating the CFRP from the oil and gas pipeline to prevent electrochemical corrosion. The CFRP layer is mainly concentrated in the penetrating defect area, employing a larger number of layers to improve local load-bearing capacity and reduce stress concentration.
[0032] In some embodiments, the first fiber-reinforced composite layer is made of high-temperature resistant ceramic-based FRP, which can enhance the temperature resistance of the gradient FRP reinforced structure.
[0033] In some embodiments, the number of layers in the first fiber-reinforced composite layer is not less than four; the number of layers in the second fiber-reinforced composite layer does not exceed four. Using a first fiber-reinforced composite layer with a larger number of winding layers to improve load-bearing capacity, and controlling the thickness of the gradient FRP reinforcement structure by controlling the number of layers in the first and second fiber-reinforced composite layers, significantly improves the load-bearing capacity of the pipeline.
[0034] In some embodiments, the edge of the first fiber-reinforced composite layer is 4cm-10cm away from the edge of the second fiber-reinforced composite layer, forming a stepped shape. Through the gradient FRP reinforcement structure design, stress distribution can be optimized and stress concentration reduced; furthermore, embedding wire mesh can effectively suppress crack propagation, increase interfacial fracture energy, and ensure that the repaired oil and gas pipeline can withstand higher internal pressure and bending loads, avoiding brittle failure at the interface between the gradient FRP reinforcement structure and the oil and gas pipeline, thus improving the durability and reliability of the repair system.
[0035] Specifically, the gradient FRP reinforcement structure provided by this utility model can be widely used in the structural repair and reinforcement of oil and gas pipelines, and is especially suitable for the reinforcement of in-service pipelines that have been in service for a long time, providing technical protection for the safety of oil and gas transportation systems.
[0036] In some embodiments, the layup angles between the plurality of first fiber-reinforced composite layers include one or more of 0°, 45°, -45°, and 90°. By designing the layup angles between each fiber-reinforced composite layer, a multi-level stiffness transition structure can be introduced to achieve a smoother stress gradient and improve peel resistance. For example, the first fiber-reinforced composite layer may be a unidirectional glass fiber reinforced composite layer, the second fiber-reinforced composite layer may be a unidirectional glass fiber reinforced composite layer with an angle of 45° to the previous layer, and the third fiber-reinforced composite layer may be a unidirectional glass fiber reinforced composite layer with an angle of -45° to the previous layer, thus forming a multi-directional layup angle, which can optimize the mechanical properties of the gradient FRP reinforced structure.
[0037] In some embodiments, the layup angle between the plurality of second fiber-reinforced composite layers includes one or more of 0°, 45°, -45°, and 90°.
[0038] In some embodiments, the adhesive layer is an epoxy resin layer containing nano-silica particles or graphene. Using an epoxy resin layer containing nano-silica particles or graphene can improve the environmental aging resistance of gradient FRP reinforced structures.
[0039] In summary, this utility model provides a gradient FRP reinforcement structure for repairing oil and gas pipelines, comprising a plurality of first fiber-reinforced composite layers bonded to the surface of the oil and gas pipeline by an adhesive layer, and a plurality of second fiber-reinforced composite layers bonded to the side of the first fiber-reinforced composite layers facing away from the surface of the oil and gas pipeline; the first and second fiber-reinforced composite layers are arranged in a gradient; and wire mesh is embedded in the adhesive layer. This utility model uses the gradient-arranged first fiber-reinforced composite layers as the inner layer and the second fiber-reinforced composite layers as the outer layer, so that different positions of the different fiber-reinforced composite layers have optimized mechanical property distribution, thereby reducing interfacial stress concentration and improving the overall stability of the FRP reinforcement structure; simultaneously, the embedding of wire mesh in the adhesive layer forms an interfacial bridging structure, increasing the interfacial fracture energy, effectively inhibiting crack propagation, and improving the interfacial crack resistance. Specifically, this utility model utilizes a gradient FRP reinforcement structure to effectively improve the performance of FRP in repairing oil and gas pipelines, enhance interfacial bonding toughness, increase the ultimate bearing capacity of the repaired pipeline, delay the propagation of interfacial cracks, and reduce the risk of fatigue damage under long-term service conditions. This results in a more reliable and durable FRP reinforcement structure, which can be widely used in oil and gas transportation, marine engineering, pressure pipelines and other fields, and has significant engineering application value and promotion prospects.
[0040] It should be understood that the application of this utility model is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.
Claims
1. A gradient FRP reinforcement structure for repairing oil and gas pipelines, characterized in that, It includes several first fiber-reinforced composite layers bonded to the surface of an oil and gas pipeline by an adhesive layer, and several second fiber-reinforced composite layers bonded to the side of the first fiber-reinforced composite layers facing away from the surface of the oil and gas pipeline; the first fiber-reinforced composite layers and the second fiber-reinforced composite layers are arranged in a gradient; and wire mesh is embedded in the adhesive layer.
2. The gradient FRP reinforcement structure for repairing oil and gas pipelines according to claim 1, characterized in that, The surface roughness of the oil and gas pipeline is greater than or equal to 0.05 mm.
3. The gradient FRP reinforcement structure for repairing oil and gas pipelines according to claim 1, characterized in that, The mesh size of the wire mesh is between 5mm and 10mm.
4. The gradient FRP reinforcement structure for repairing oil and gas pipelines according to claim 1, characterized in that, The first fiber-reinforced composite layer is a glass fiber-reinforced composite layer, a basalt fiber-reinforced composite layer, or an aramid fiber-reinforced composite layer; the second fiber-reinforced composite layer is a carbon fiber-reinforced composite layer.
5. The gradient FRP reinforcement structure for repairing oil and gas pipelines according to claim 1, characterized in that, The first fiber-reinforced composite layer has no fewer than 4 layers; the second fiber-reinforced composite layer has no more than 4 layers.
6. The gradient FRP reinforcement structure for repairing oil and gas pipelines according to claim 1, characterized in that, The edge of the first fiber-reinforced composite layer is 4cm-10cm away from the edge of the second fiber-reinforced composite layer, forming a stepped shape.
7. The gradient FRP reinforcement structure for repairing oil and gas pipelines according to claim 1, characterized in that, The layup angle between the first fiber-reinforced composite layers includes one or more of 0°, 45°, -45°, and 90°.
8. The gradient FRP reinforcement structure for repairing oil and gas pipelines according to claim 1, characterized in that, The layup angle between several of the second fiber-reinforced composite layers includes one or more of 0°, 45°, -45°, and 90°.
9. The gradient FRP reinforcement structure for repairing oil and gas pipelines according to claim 1, characterized in that, The adhesive layer is an epoxy resin layer containing nano-silica particles or graphene.