Novel Multilayer Structure Coupled Integrated Composite Material

Abstract

The present invention provides a novel multi-layer structure coupled integrated composite material, which relates to the technical field of oil storage tanks. It includes a reinforcing layer and a three-dimensional fabric layer. There are two upper and lower layers of the reinforcing layer, and a sandwich layer is provided between the two reinforcing layers. The three-dimensional fabric layer is filled inside the sandwich layer. Inside the sandwich layer, there are rubber frames, and multiple groups of rubber frames are equidistantly arranged. The rubber frames are embedded inside the three-dimensional fabric layer. Inside the rubber frames, there are supporting rubber sheets, and the supporting rubber sheets are triangular. In the present invention, rubber frames are embedded in the three-dimensional fabric layer. The elastic frame structure of the rubber frames provides a certain amount of buffer potential energy. Cooperating with the triangular supporting rubber sheets inside, the elastic support performance is improved by using the characteristics of triangles, so that the rubber frames can reset after being deformed by force, thereby improving the overall reset and shock absorption function of the material, which is beneficial to providing effective protection when the oil tank is under the action of horizontal vibration loads.

Description

Technical Field

[0001] The present invention relates to the technical field of oil storage tanks, and particularly to a novel multi-layer structure coupled integrated composite material. Background Art

[0002] An oil tank is a container for storing oil products and is the main facility of an oil depot. Oil tanks can be classified into two major categories: non-metallic oil tanks and metallic oil tanks according to their materials. Metallic oil tanks are the most commonly used, and non-metallic oil tanks are generally only used in military field oil depots, including oil-resistant rubber flexible tanks, fiberglass reinforced plastic oil tanks, and plastic oil tanks, etc. Currently, the vertical oil tanks built and under construction in China are all single-bottom plate oil storage tanks. According to investigations, 40% of the corrosion of oil storage tanks occurs on the bottom plate, and 76.4% of the corrosion perforations of the bottom plate lead to the shutdown of the oil storage tank. For some oil storage tanks in coastal oil depots, 20% of the tank bottom plates are perforated due to corrosion within less than 5 years of operation. The main reason is that the single-layer tank bottom plate has inherent defects in leak prevention, leak detection, and post-leak protection. The inherent defects are as follows: The bottom plate of the tank is corroded on both sides, greatly increasing the probability of corrosion perforation; there are limited methods or means for real-time monitoring of the leakage of the tank bottom plate under the condition of storing oil, and it is difficult to detect small leaks and the leakage is not detected in time; after the storage tank stores oil, the lower part of the tank wall is subjected to a large pressure and is prone to rupture accidents. If a sudden crack occurs in the tank body under high liquid level, it is bound to wash away the fire dike and cause all the oil products to leak out. When the out-of-control overflowing oil products are ignited by a fire source, a large area of flowing fire will be formed. The main reasons for the rupture of the storage tank are: improper selection of the storage tank foundation, mistakes in the foundation design or poor foundation treatment, uneven settlement or local collapse of the foundation after the storage tank stores oil, resulting in tearing of the tank wall or fracture of the tank bottom plate. Second, as the operation time of the storage tank increases, the internal and external corrosion of the storage tank, especially the corrosion of the tank bottom plate, will gradually become serious, and finally leakage and other phenomena will occur. Generally, the internal corrosion of the storage tank is more serious than the external corrosion, and its internal corrosion is mainly concentrated on the tank bottom and the tank top. In terms of the degree of corrosion damage, the corrosion rate of the oil tank bottom plate is the fastest; after long-term use of the oil tank, corrosion will occur under the action of internal water accumulation and external soil. The harm of corrosion is multi-faceted. First, it will change some parameter indicators of the oil products, such as gum, acidity and alkalinity, and salt content, thus affecting the normal use of the oil products; second, it will also cause the failure of the oil tank and the leakage of oil products, not only resulting in waste of resources, environmental damage, but even causing serious accidents that endanger human production and life, and then incurring immeasurable losses.

[0003] In view of the serious impact of the corrosion and damage of the bottom of the storage tank and the structural limitations of the single-layer metal tank bottom plate, since the early 1990s, the research on the double-layer tank bottom structure and the new leakage detection method has been carried out. The double-layer tank bottom structure is adopted in the vertical storage tank, which is composed of the upper and lower metal bottom plates and the supporting members (fillers) in the middle. An annular space is formed between the two tank bottom plates, which can avoid the double-sided corrosion of the single-layer tank bottom plate structure, reduce the corrosion rate of the tank bottom plate, prevent the diffusion of pollutants when the oil leaks, and can adopt reliable methods for oil leakage detection. However, the supporting members of the previous double-layer tank bottom composite structure are generally composed of a reinforcing layer and a fabric layer. The fabric is generally composed of cloth, lacking effective elastic shock-absorbing potential energy and being prone to deformation and setting after being pressed for a long time. When the oil tank is under the action of horizontal vibration load, it lacks effective protection; moreover, the reinforcing layer and the three-dimensional fabric layer in the middle are separated from each other. The reinforcing layer is a glass fiber felt paving layer, and it is easy to crack between the layers, reducing the interlayer bonding force. Especially at the lap joint of the glass fiber felt paving layer, it is easy to crack. Once cracked, the stress here is uneven, which will become the starting point of crude oil leakage and cause concentrated corrosion of the tank bottom. At the same time, between the glass fiber felt reinforcing layer and the three-dimensional fabric, only resin is used for bonding, and there is an interface layer. This interface layer is relatively thin, resulting in weak bonding force. Under the action of a large impact, it is easy to stagger, resulting in uneven stress, making this area also a concentrated area of leakage; on the one hand, the supporting member (filler) is to support the inner tank made of fiberglass material, and on the other hand, it is to form an interlayer space for easy leakage detection. After the fabric layer is damaged, the inner tank made of fiberglass loses support, and the stress is uneven, causing the inner tank made of fiberglass material to sink here and become an area where crude oil gathers. The gathering of crude oil reduces the interlayer space and affects leakage detection. Therefore, the present invention proposes a new multi-layer structure coupled integrated composite material to solve the problems existing in the prior art. Summary of the Invention

[0004] In view of the above problems, the present invention proposes a new multi-layer structure coupled integrated composite material, which ensures that the reinforcing layer and the three-dimensional fabric layer are connected as a whole, making the stress more uniform and conducive to improving the durability of the tank bottom.

[0005] To achieve the purpose of the present invention, the present invention is realized through the following technical solutions: a new multi-layer structure coupled integrated composite material, including a reinforcing layer and a three-dimensional fabric layer. The reinforcing layer has upper and lower layers, and there is an interlayer between the two reinforcing layers. The three-dimensional fabric layer is filled inside the interlayer;

[0006] Inside the interlayer, there is a rubber frame, and multiple groups of rubber frames are equidistantly arranged. The rubber frames are embedded inside the three-dimensional fabric layer. Inside the rubber frames, there is a supporting rubber sheet, and the supporting rubber sheet is triangular. The reinforcing layer and the three-dimensional fabric layer are connected by puncture stitching with a stitching thread, and the stitching thread passes through the centers of the rubber frames and the supporting rubber sheet.

[0007] A further improvement lies in that: the reinforcing layer is a fiberglass mat, the three-dimensional fabric layer is a carbon fiber three-dimensional braid, and the stitching thread is infiltrated with resin and forms multiple columns after puncture stitching.

[0008] A further improvement lies in that: the three-dimensional fabric layer is composed of carbon fiber warp threads and carbon fiber weft threads. There are multiple groups of carbon fiber warp threads and carbon fiber weft threads. Multiple groups of the carbon fiber warp threads are horizontally arranged and stacked, and multiple groups of the carbon fiber weft threads cross around multiple groups of the carbon fiber warp threads to form a carbon fiber three-dimensional braid.

[0009] A further improvement lies in that: the superimposed thickness of the upper and lower reinforcing layers and the three-dimensional fabric layer is adapted to the height of the void layer between the double-layer oil tank bottom structures, and there are 1 - 2 layers of fiberglass mats in the reinforcing layer.

[0010] A further improvement lies in that: the lower reinforcing layer serves as the reinforcing bottom layer, and the upper reinforcing layer serves as the reinforcing surface layer. The lower surface of the reinforcing bottom layer is adhered to the inner bottom surface of the outer tank of the double-layer oil tank through an adhesive layer, and the reinforcing surface layer is adhered to the bottom surface of the inner tank of the double-layer oil tank through an adhesive layer.

[0011] A further improvement lies in that: the adhesive layer is bisphenol A epoxy resin, and bisphenol A epoxy resin contains hydroxyl groups, ether bonds, and active epoxy groups.

[0012] A further improvement lies in that: an on-line monitoring sensor is laid between the bottom surface of the reinforcing surface layer and the three-dimensional fabric layer for monitoring seepage and leakage of the bottom surface of the inner tank of the double-layer oil tank.

[0013] A further improvement lies in that: the resin infiltrated in the stitching thread is polyphenol-type glycidyl ether epoxy resin.

[0014] The beneficial effects of the present invention are as follows:

[0015] 1. In the present invention, rubber frames are embedded in the three-dimensional fabric layer. The elastic frame structure of the rubber frames provides a certain amount of buffer potential energy. Cooperating with the internal triangular supporting rubber sheet, the elastic support performance is improved by using the characteristics of the triangle, so that the rubber frames can be reset after being deformed by force, thereby improving the overall reset shock absorption function of the material, which is beneficial to providing effective protection when the oil tank is under the action of horizontal vibration loads.

[0016] 2. The present invention adopts a three-dimensional stitching technique to connect fiberglass mats and three-dimensional carbon fiber braids, so as to enhance the performance of two-dimensional laminate composites in the direction perpendicular to the laminate, making the fiberglass mats and three-dimensional carbon fiber braids into a multi-layer integrated composite material, constructing a sandwich structure, and connecting the laminate materials of the sandwich structure by means of puncture stitching, ensuring that the reinforcing layer and the three-dimensional fabric layer are connected as a whole, making the stress more uniform and conducive to improving the durability of the tank bottom.

[0017] 3. The present invention uses resin-impregnated sutures to stitch the sandwich structure. The sutures become individual columns for support, enhancing the compressive performance in the vertical direction. Through verification, it is obtained that introducing resin columns of sutures can inhibit deformation and strengthen the compressive performance of the composite material to a certain extent.

[0018] 4. The present invention adopts a three-dimensional carbon fiber braid, which has the characteristics of high strength, high modulus, impact resistance, fatigue resistance, low density, light weight, and corrosion resistance. Carbon fiber also has good electrical conductivity and can form an electrochemical corrosion point at the concave part of oil leakage to play an anodic protection role. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is the front view of the present invention;

[0020] Figure 2 is the top cross-sectional view of the present invention;

[0021] Figure 3 is the schematic diagram of the composition of the three-dimensional fabric layer of the present invention.

[0022] Wherein: 1. Reinforcing layer; 2. Three-dimensional fabric layer; 3. Rubber frame; 4. Support rubber; 5. Suture; 6. Carbon fiber warp; 7. Carbon fiber weft. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] In order to deepen the understanding of the present invention, the following will further elaborate on the present invention in combination with embodiments. These embodiments are only used to explain the present invention and do not constitute a limitation to the protection scope of the present invention.

[0024] Embodiment 1

[0025] According to Figure 1 、 2 、and 3, this embodiment proposes a new type of multi-layer structure coupled integrated composite material, including a reinforcing layer 1 and a three-dimensional fabric layer 2. The reinforcing layer 1 has upper and lower layers, and there is an interlayer between the two layers of the reinforcing layer 1. The three-dimensional fabric layer 2 is filled inside the interlayer;

[0026] Inside the interlayer, there is a rubber frame 3, and multiple groups of rubber frames 3 are equidistantly arranged. The rubber frame 3 is embedded inside the three-dimensional fabric layer 2. Inside the rubber frame 3, there is a support rubber 4, and the support rubber 4 is triangular. The reinforcing layer 1 and the three-dimensional fabric layer 2 are connected by puncture stitching with a stitching thread 5, and the stitching thread 5 passes through the center of the rubber frame 3 and the support rubber 4. In the present invention, the material body is composed of the reinforcing layer 1 and the three-dimensional fabric layer 2, and the rubber frame 3 is embedded in the three-dimensional fabric layer 2. The elastic frame structure of the rubber frame 3 provides a certain amount of buffer potential energy. Cooperating with the triangular support rubber 4 inside, the elastic support performance is improved by using the characteristics of the triangle, so that the rubber frame 3 can be reset after being deformed by force, thereby improving the overall reset shock absorption function of the material, which is beneficial to providing effective protection when the oil tank is under the action of horizontal vibration load.

[0027] The reinforcing layer 1 is a glass fiber mat, and the three-dimensional fabric layer 2 is a carbon fiber three-dimensional braid. The reinforcing layer 1 and the three-dimensional fabric layer 2 construct a sandwich structure of glass fiber, carbon fiber, and glass fiber. The sandwich structure is connected by puncture stitching, and multiple layers are connected by the stitching thread 5. The stitching thread 5 is impregnated with resin and forms multiple columns after puncture stitching. In the present invention, a three-dimensional stitching technology is adopted to connect the glass fiber mat and the carbon fiber three-dimensional braid to enhance the performance of the two-dimensional laminated composite material in the direction perpendicular to the laminate direction, making the glass fiber mat and the carbon fiber three-dimensional braid into a multi-layer structure integrated composite material, constructing a sandwich structure of glass fiber, carbon fiber, and glass fiber, and connecting the laminate materials of the sandwich structure by puncture stitching to form a multi-layer structure coupled integrated composite material, ensuring that the reinforcing layer 1 and the three-dimensional fabric layer 2 are connected as a whole, making the force more uniform, and placing it in the void layer inside the bottom of the double-layer oil tank is beneficial to improving the durability of the tank bottom.

[0028] The three-dimensional fabric layer 2 is composed of carbon fiber warp threads 6 and carbon fiber weft threads 7. There are multiple groups of both the carbon fiber warp threads 6 and the carbon fiber weft threads 7. Multiple groups of the carbon fiber warp threads 6 are horizontally arranged and stacked, and multiple groups of the carbon fiber weft threads 7 cross around multiple groups of the carbon fiber warp threads 6 to form a carbon fiber three-dimensional braid. In the present invention, a carbon fiber three-dimensional braid is adopted. This material has the characteristics of high strength, high modulus, impact resistance, fatigue resistance, low density, light weight, and corrosion resistance. Carbon fiber also has good electrical conductivity and can form an electrochemical corrosion point at the concave part where the oil leaks to play an anodic protection role.

[0029] The superimposed thickness of the upper and lower reinforcing layers 1 and the three-dimensional fabric layer 2 is adapted to the height of the void layer between the bottom structures of the double-layer oil tank. The glass fiber mat in the reinforcing layer 1 has 1 layer. This makes the sandwich structure match the void layer between the bottom structures of the double-layer oil tank, and the force-bearing pressure effect is better.

[0030] The resin infiltrated into the suture 5 is polyphenol type glycidyl ether epoxy resin. In the present invention, the suture 5 is infiltrated with resin to suture the sandwich structure. The suture 5 becomes a series of supporting columns, enhancing the compressive performance in the vertical direction. Through finite element simulation, a constitutive model of the suture 5 resin column is established for verification, and it is concluded that introducing the suture 5 resin column can inhibit deformation and strengthen the compressive performance of the composite material to a certain extent.

[0031] Example Two

[0032] According to Figure 1 、 2 As shown, this embodiment proposes a novel multi-layer structure coupled integrated composite material, including a reinforcing layer 1 and a three-dimensional fabric layer 2. The reinforcing layer 1 has upper and lower layers, and there is an interlayer between the two layers of the reinforcing layer 1. The three-dimensional fabric layer 2 is filled inside the interlayer.

[0033] Inside the interlayer, there is a rubber frame 3, and multiple groups of rubber frames 3 are equidistantly arranged. The rubber frame 3 is embedded inside the three-dimensional fabric layer 2. Inside the rubber frame 3, there is a supporting rubber 4, and the supporting rubber 4 is triangular. The reinforcing layer 1 and the three-dimensional fabric layer 2 are connected by puncture suturing with a suture 5, and the suture 5 passes through the center of the rubber frame 3 and the supporting rubber 4. In the present invention, the material body is composed of the reinforcing layer 1 and the three-dimensional fabric layer 2, and the rubber frame 3 is embedded in the three-dimensional fabric layer 2. The elastic frame structure of the rubber frame 3 provides a certain buffer potential energy. Cooperating with the internal triangular supporting rubber 4, the elastic support performance is improved by using the triangular characteristics, so that the rubber frame 3 can be reset after being deformed by force, thereby improving the overall reset shock absorption function of the material, which is beneficial to providing effective protection when the oil tank is under the action of horizontal vibration load.

[0034] The reinforcing layer 1 is a glass fiber mat, and the three-dimensional fabric layer 2 is a carbon fiber three-dimensional braided fabric. The reinforcing layer 1 and the three-dimensional fabric layer 2 construct a sandwich structure of glass fiber, carbon fiber, and glass fiber. The sandwich structure adopts the method of puncture suturing, and multiple layers are connected by the suture 5. The suture 5 is infiltrated with resin and forms multiple columns after puncture suturing. The present invention adopts three-dimensional suturing technology to connect the glass fiber mat and the carbon fiber three-dimensional braided fabric to enhance the performance of the two-dimensional laminate composite material in the direction perpendicular to the laminate, making the glass fiber mat and the carbon fiber three-dimensional braided fabric into a multi-layer structure integrated composite material, constructing a sandwich structure of glass fiber, carbon fiber, and glass fiber, and connecting the laminate materials of the sandwich structure by means of puncture suturing to form a multi-layer structure coupled integrated composite material, ensuring that the reinforcing layer 1 and the three-dimensional fabric layer 2 are connected as a whole, making the force more uniform, and being placed in the void layer at the bottom of the double-layer oil tank, which is beneficial to improving the durability of the tank bottom.

[0035] The lower reinforcing layer 1 serves as the bottom reinforcing layer, and the upper reinforcing layer 1 serves as the surface reinforcing layer. The lower surface of the bottom reinforcing layer is adhered to the inner bottom surface of the outer tank of the double-layer oil tank through an adhesive layer, and the surface reinforcing layer is adhered to the bottom surface of the inner tank of the double-layer oil tank through an adhesive layer. The adhesive layer is bisphenol A epoxy resin, and the bisphenol A epoxy resin contains hydroxyl groups, ether bonds, and active epoxy groups. The present invention uses bisphenol A epoxy resin. Due to the presence of hydroxyl groups, ether bonds, and active epoxy groups in the molecular structure, it has unique high adhesion and excellent mechanical properties, small shrinkage, good resistance to alkalis, acids, water, solvents, and chemicals, high mechanical strength, and can be widely used as an adhesive layer.

[0036] An on-line monitoring sensor is laid between the bottom surface of the surface reinforcing layer and the three-dimensional fabric layer for monitoring the leakage of the inner bottom surface of the double-layer oil tank, ensuring the reliability of preventing oil tank leakage.

[0037] In the present invention, the material body is composed of the reinforcing layer 1 and the three-dimensional fabric layer 2, and a rubber frame 3 is embedded in the three-dimensional fabric layer 2. The elastic frame structure of the rubber frame 3 provides a certain amount of buffer potential energy, which is combined with the internal triangular support rubber 4. By utilizing the triangular characteristics, the elastic support performance is improved, so that the rubber frame 3 can be reset after being deformed by force, thereby improving the overall reset shock absorption function of the material, which is beneficial to providing effective protection when the oil tank is under the action of horizontal vibration loads. Moreover, the present invention adopts a three-dimensional stitching technology to connect the glass fiber mat and the carbon fiber three-dimensional braid, so as to enhance the performance of the two-dimensional laminate composite material in the direction perpendicular to the laminate direction, making the glass fiber mat and the carbon fiber three-dimensional braid into a multi-layer structure integrated composite material, constructing a sandwich structure of glass fiber, carbon fiber, and glass fiber. The laminate materials of the sandwich structure are connected by means of puncture stitching to form a multi-layer structure coupled integrated composite material, ensuring that the reinforcing layer 1 and the three-dimensional fabric layer 2 are connected as a whole, making the force more uniform, and being placed in the void layer at the bottom of the double-layer oil tank, which is beneficial to improving the durability of the tank bottom. The present invention uses resin-impregnated sutures 5 to stitch the sandwich structure. The sutures 5 become individual columns for support, enhancing the compressive performance in the vertical direction. Through finite element simulation, a constitutive model of the resin columns of the sutures 5 is established for verification, and it is obtained that the introduction of the resin columns of the sutures 5 can inhibit deformation and strengthen the compressive performance of the composite material to a certain extent. At the same time, the present invention uses a carbon fiber three-dimensional braid, which has the characteristics of high strength, high modulus, impact resistance, fatigue resistance, low density, light weight, and corrosion resistance. Carbon fiber also has good electrical conductivity and can form an electrochemical corrosion point at the concave part of the oil leakage to play an anodic protection role. In addition, the stitching connection technology increases the integrity of the composite material and is not prone to local stress concentration. The stitching technology can not only effectively improve the damage tolerance between the layers of the composite material, but also has the characteristics of simple process, short production cycle, strong applicability, and good designability.

[0038] The basic principles, main features and advantages of the present invention have been shown and described above. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A novel multi-layer structure coupled integrated composite material, comprising a reinforcing layer (1) and a three-dimensional fabric layer (2), Characterized in that: The reinforcing layer (1) has upper and lower layers, and there is an interlayer between the two layers of the reinforcing layer (1), and the three-dimensional fabric layer (2) is filled inside the interlayer; Inside the interlayer, there is a rubber frame (3), and multiple groups of rubber frames (3) are equidistantly arranged. The rubber frame (3) is embedded inside the three-dimensional fabric layer (2). Inside the rubber frame (3), there is a support rubber (4), and the support rubber (4) is triangular. The reinforcing layer (1) and the three-dimensional fabric layer (2) are connected by puncture stitching with a stitching thread (5), and the stitching thread (5) passes through the center of the rubber frame (3) and the support rubber (4).

2. The novel multi-layer structure coupled integrated composite material according to claim 1, Characterized in that: The reinforcing layer (1) is a glass fiber mat, the three-dimensional fabric layer (2) is a carbon fiber three-dimensional braid, and the stitching thread (5) is impregnated with resin and forms multiple columns after puncture stitching.

3. The novel multi-layer structure coupled integrated composite material according to claim 2, Characterized in that: The three-dimensional fabric layer (2) is composed of carbon fiber warp threads (6) and carbon fiber weft threads (7). There are multiple groups of carbon fiber warp threads (6) and carbon fiber weft threads (7). Multiple groups of carbon fiber warp threads (6) are horizontally arranged and stacked, and multiple groups of carbon fiber weft threads (7) cross around multiple groups of carbon fiber warp threads (6) to form a carbon fiber three-dimensional braid.

4. The novel multi-layer structure coupled integrated composite material according to claim 1, Characterized in that: The superimposed thickness of the upper and lower layers of the reinforcing layer (1) and the three-dimensional fabric layer (2) is adapted to the height of the void layer between the double-layer oil tank bottom structures, and the glass fiber mat in the reinforcing layer (1) has 1 - 2 layers.

5. The novel multi-layer structure coupled integrated composite material according to claim 4, Characterized in that: The lower reinforcing layer (1) serves as the reinforcing bottom layer, and the upper reinforcing layer (1) serves as the reinforcing surface layer. The lower surface of the reinforcing bottom layer is attached to the inner bottom surface of the outer tank of the double-layer oil tank through an adhesive layer, and the reinforcing surface layer is attached to the inner bottom surface of the inner tank of the double-layer oil tank through an adhesive layer.

6. The novel multi-layer structure coupled integrated composite material according to claim 5, Characterized in that: The adhesive layer is bisphenol A epoxy resin, and bisphenol A epoxy resin contains hydroxyl groups, ether bonds, and active epoxy groups.

7. The novel multi-layer structure coupled integrated composite material according to claim 6, Characterized in that: An on-line monitoring sensor is laid between the bottom surface of the reinforcing surface layer and the three-dimensional fabric layer for monitoring the leakage of the inner bottom surface of the double-layer oil tank.

8. The novel multi-layer structure coupled integrated composite material according to claim 2, Characterized in that: The resin impregnated by the stitching thread (5) is polyphenol type glycidyl ether epoxy resin.

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