Deep-sea pressure hull and health monitoring method of deep-sea pressure hull

Abstract

The application discloses a deep-sea pressure-resistant cabin and a health monitoring method of the deep-sea pressure-resistant cabin. The carbon nanotube film preparation method and the film matrix arrangement method for health monitoring are provided, the health condition of the structure is monitored by monitoring the resistance change rate and the temperature change rate of the matrix film. The micro-nano scale film structure can enhance the infiltration of the epoxy resin, improve the interlaminar toughness of the composite material, and the film does not need to be insulated by using insulating materials. The application can provide key materials, technologies and equipment support for the smooth implementation of the pressure-resistant cabin for high-pressure gas storage in deep sea.

Description

TECHNICAL FIELD

[0001] The present application particularly relates to a deep-sea pressure hull and a health monitoring method of the deep-sea pressure hull, and belongs to the technical field of deep-sea pressure equipment. BACKGROUND

[0002] Hydrogen energy is a kind of secondary energy with abundant sources, green and low carbon, and wide application, and is gradually becoming one of the important carriers of global energy transformation development. Hydrogen storage and transportation technology is one of the main obstacles restricting the development of hydrogen energy. The storage methods of hydrogen mainly include high-pressure gaseous hydrogen storage, low-temperature liquid hydrogen storage, organic liquid hydrogen storage and solid hydrogen storage. High-pressure gaseous hydrogen storage has the characteristics of low cost, low energy consumption and fast charging and discharging speed, and is mainly divided into three types: vehicle hydrogen storage tank, transportation hydrogen storage tank and fixed hydrogen storage equipment. As the core component of hydrogen fuel cell vehicles, hydrogen storage high-pressure deep-sea pressure hull needs to store enough hydrogen to ensure the endurance of the vehicle. Due to the development of hydrogen energy vehicles, vehicle hydrogen storage tanks are the main way, among which 70MPa carbon fiber winding type IV hydrogen storage deep-sea pressure hull is the current international mainstream technology. However, excessive pressure, external load, temperature change and harsh environment may cause excessive strain and stress of the hydrogen storage deep-sea pressure hull, and thus threaten its safety.

[0003] Composite materials are widely used in aerospace, marine, automotive and mechanical fields due to their light weight and high strength. However, composite materials are a multiphase system composed of reinforcing fibers, matrix materials and interfaces, and their structure is prone to internal damage such as cracks, fiber debonding or breaking, delamination and the like, which reduces the reliability and safety of the structure and limits the use of composite materials. Therefore, real-time health monitoring and damage evaluation of composite materials are needed. Therefore, health monitoring of high-pressure composite deep-sea pressure hulls is particularly important.

[0004] To solve this problem, many researchers use sensor technology to monitor the stress and temperature inside the deep-sea pressure hull by installing sensors inside and outside the deep-sea pressure hull, so as to know the safety state of the deep-sea pressure hull. The most commonly used structural health monitoring methods at present include guided wave piezoelectric ceramic sensors and fiber grating sensors. Guided wave monitoring is to bury piezoelectric ceramic sensors in the interior of composite materials or paste them on the surface of composite materials during the manufacturing process of composite materials. However, the propagation of guided waves in composite materials is anisotropic, multi-mode aliasing and has strong amplitude attenuation, so it is difficult to realize high-precision monitoring of large composite structures. Fiber grating sensors are widely used in the field of composite structure health monitoring, but fiber grating sensors are brittle and easy to break, and it is difficult to control in complex structure areas, and the cost is also high. In addition, the size of the other two sensors is large, which will implant defects in the composite material after being buried in the composite material, and will cause certain influence on the mechanical properties of the composite structure. In addition, these methods generally only install sensors between the inner container and the fiber winding layer and outside the fiber winding layer, and when the fiber winding layer is thick, the monitoring results are not comprehensive, and there is a certain monitoring error. SUMMARY

[0005] The main purpose of the present application is to provide a deep-sea pressure hull and a health monitoring method for the deep-sea pressure hull, which can provide key materials, technologies and equipment support for the safe service of the pressure hull for high-pressure deep sea, so as to overcome the shortcomings in the prior art.

[0006] To achieve the above-mentioned purposes, the technical scheme adopted by the present application comprises:

[0007] The first aspect of the embodiment of the present application provides a deep-sea pressure hull, comprising an inner container and a shell wrapping the inner container, the shell comprising at least one first fiber winding layer and at least one second fiber winding layer stacked in the radial direction of the inner container in sequence, and the deep-sea pressure hull further comprising:

[0008] z health monitoring modules and z electric joint groups, the health monitoring modules being arranged between the first fiber winding layer or the second fiber winding layer and the inner container and / or between the first fiber winding layer and the second fiber winding layer, the health monitoring module comprising a flexible printed circuit and x*y strain sensitive elements, the resistance of the strain sensitive element changing with the deformation of itself, x*y strain sensitive elements being respectively distributed in x*y detection areas of the pressure hull, the flexible printed circuit having x row connection lines arranged at intervals in the column direction and y column connection lines arranged at intervals in the row direction, the x row connection lines and the y column connection lines being arrayed and electrically connected at the intersection, x*y strain sensitive elements being arrayed on the flexible printed circuit, each strain sensitive element being independently electrically connected with a row connection line and a column connection line,

[0009] The electric connector groups are arranged outside the shell, each of the electric connector groups comprises x row connection line connectors and y column connection line connectors, the x row connection line connectors are electrically connected with x row connection lines respectively, and the y column connection line connectors are electrically connected with y column connection lines respectively; when the health monitoring data acquisition device is connected with the mth row connection line connector and the nth column connection line connector, only one of the strain sensitive elements is located in the same series circuit with the mth row connection line connector and the nth column connection line connector, wherein 1≤m≤x, 1≤n≤y, and 1≤z.

[0010] Further, the x*y strain sensitive elements contained in each of the health monitoring modules are fixedly combined with the flexible printed circuit as a whole.

[0011] Further, the row direction is parallel to the axial direction of the inner container, and the column direction is parallel to the circumferential direction of the inner container.

[0012] Further, the plurality of strain sensitive elements located in the same row and / or the same column are arranged at equal intervals.

[0013] Further, each of the detection areas is provided with p strain sensitive elements, and the p strain sensitive elements located in the same detection area are respectively distributed at different depth positions along the radial direction of the pressure-resistant cabin, and 1≤p.

[0014] Further, the strain sensitive element comprises a carbon nanotube film.

[0015] Further, the thickness of the carbon nanotube film is 50-60 μm, and the resistivity is 0.2-0.4 Ω / cm.

[0016] Further, the shape and size of the carbon nanotube film in the x*y strain sensitive elements contained in the health monitoring module are preferably the same.

[0017] Further, the carbon nanotube film is formed by single-walled carbon nanotubes grafted with amino groups and multi-walled carbon nanotubes grafted with carboxyl groups.

[0018] Further, the mass ratio of the single-walled carbon nanotubes grafted with amino groups to the multi-walled carbon nanotubes grafted with amino groups is 1:1.

[0019] Further, the first fiber winding layer and the second fiber winding layer are formed by carbon fiber reinforced resin matrix composites through ring winding or spiral winding.

[0020] Further, the carbon fiber reinforced resin matrix composite is carbon fiber impregnated with mixed colloid.

[0021] Further, the mixed colloid comprises epoxy resin, curing agent and additive, and the weight ratio of the epoxy resin, the curing agent and the additive is 10:10:3.

[0022] For example, the epoxy resin is bisphenol A type epoxy resin 863, the curing agent is 4207, and the accelerator is dibutyl phthalate acid and other additives.

[0023] Further, the mass content of the mixed colloid in the shell is 60%-70%.

[0024] The second aspect of the embodiment of the present application provides a health monitoring method of the deep-sea pressure hull, which comprises:

[0025] The deep-sea pressure hull and the health monitoring data acquisition device are provided, and the health monitoring data acquisition device is connected with a row of connection line joints and a column of connection line joints of the health monitoring module, so as to obtain a plurality of resistance values of a selected strain sensitive element in the same series circuit with the row of connection line joints and the selected column of connection line joints at a plurality of time points, thereby obtaining a resistance change rate of the selected strain sensitive element, and the health condition of the position of the selected strain sensitive element is judged through the resistance change rate.

[0026] Further, a resistance value-time curve of the selected strain sensitive element is constructed, and when the measured resistance value deviates from the curve, it is determined that the area where the selected strain sensitive element is located is damaged.

[0027] It should be noted that the resistance value / resistance value change amount of the strain sensitive element is linear, and when damage occurs, the measured data deviates from the resistance value / resistance value change amount-time curve, and an alarm is immediately sent out, indicating that the position of the selected strain sensitive element is damaged. Of course, the resistance value / resistance value change amount-time curve of the strain sensitive element can also be obtained through the fatigue life test in advance.

[0028] Compared with the prior art, the advantages of the present application include:

[0029] 1) The deep-sea pressure hull provided by the embodiment of the present application introduces a health monitoring module based on carbon nanotube film between the layers of the shell and the inner container, which reduces wiring and reduces the influence on the layer structure, and the edge realizes the sealing of the internal structure through a waterproof structure.

[0030] 2) The deep-sea pressure hull provided by the embodiment of the present application, the thickness of the carbon nanotube film is very thin, the epoxy resin can completely infiltrate the film, and the embedding of the carbon nanotube film does not affect the interlayer mechanical properties of the pressure hull itself. On the contrary, the micro-nano scale film enhances the interlayer toughness of the shell, and the interlayer toughness is increased by at least 10%

[0031] 3) Combined with experiments and simulation, the carbon nanotube film can be embedded in any layer of the deep-sea pressure cabin, and the number and position can be completely autonomously controlled;

[0032] 4) The carbon nanotube film provided by the deep-sea pressure cabin does not need to be insulated by using insulating materials. Experiments show that there is a layer of resin between the carbon nanotube film and the carbon fiber of fiber winding, and mutual insulation exists;

[0033] 5) The outer layer of the deep-sea pressure cabin provided by the application is carbon fiber composite material, which can provide good waterproof, sealing, impact resistance, wear resistance, corrosion resistance and flexibility;

[0034] 6) The deep-sea pressure cabin provided by the embodiment has strong applicability and high engineering application value, and has important significance for providing key materials, technologies and equipment support for the smooth implementation of the high-pressure gas storage deep-sea pressure cabin. BRIEF DESCRIPTION OF DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiment or prior art description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments described in the present application, and those skilled in the art can obtain other drawings according to these drawings without creating any creative labor.

[0036] Figure 1 The structure schematic diagram of the high-pressure composite material deep-sea pressure cabin based on the carbon nanotube film provided by the present application;

[0037] Figure 2 The circuit structure schematic diagram of the health monitoring module provided by the present application;

[0038] Figure 3 The structure schematic diagram of the health monitoring module provided by the present application;

[0039] Figure 4 The strain test process of the carbon nanotube film;

[0040] Figure 5 The microscopic photograph of the carbon nanotube film;

[0041] Figure 6 The tensile resistance change rate of the health monitoring module provided by the present application;

[0042] Figure 7 The bending resistance change rate of the health monitoring module provided by the present application. DETAILED DESCRIPTION

[0043] In view of the deficiencies in the prior art, the present inventors have, through long-term research and a large number of practices, come up with the technical solutions of the present application. The technical solutions, implementation process and principles thereof will be further explained in combination with the accompanying drawings and specific implementation cases. Unless otherwise specified, the carbon fiber, carbon nanotube, epoxy resin, curing agent, additive, conductive silver adhesive and flexible circuit manufacturing process used in the embodiments of the present application are known in the art.

[0044] Embodiment 1

[0045] Please refer to Figure 1 and Figure 2 , a deep-sea pressure cabin, comprising an inner container, an outer shell wrapping the inner container, a plurality of health monitoring modules located between the inner container and the outer shell and / or inside the outer shell, a plurality of electrical connector groups arranged outside the outer shell, each of the health monitoring modules comprising a flexible printed circuit and 6*9 strain sensitive elements (R1-1, R1-2…R1-9, R2-1…R2-9…R6-1, R6-2…R6-9), the resistance of the strain sensitive elements changes with the deformation of itself, the 6*9 strain sensitive elements are respectively distributed in 6*9 detection areas of the pressure cabin, the flexible printed circuit has 6 row connection lines arranged at intervals in the column direction and 9 column connection lines arranged at intervals in the row direction, the 6 row connection lines and the 9 column connection lines are arrayed and electrically connected at the intersection, and the 6*9 strain sensitive elements are arrayed on the flexible printed circuit, each of the strain sensitive elements is independently electrically connected with a row connection line and a column connection line, each of the electrical connector groups comprises 6 row connection line connectors L1-L6 and 9 column connection line connectors C1-C9, each row connection line connector is electrically connected with a row connection line, and each column connection line connector is electrically connected with a column connection line; when the health monitoring data acquisition equipment is connected with the mth row connection line connector and the nth column connection line connector, only one of the strain sensitive elements is in the same series circuit with the health monitoring data acquisition equipment, and the health monitoring data acquisition equipment can acquire the resistance of the strain sensitive element in the same series circuit with itself.

[0046] In the present embodiment, the working principle of the health monitoring data acquisition equipment is to measure the resistance change rate of the strain sensitive elements between L1-L6 and C1-C9 at regular intervals, analyze the data to judge the health condition of the corresponding position of the deep-sea pressure cabin. The temperature of the resistance can be calculated through the resistance-temperature curve of the strain sensitive element. Assuming that the position of the strain sensitive element R3-5 is damaged, the health monitoring data acquisition equipment will appear abnormal when measuring the resistance change rate between L3 and C5. In this way, the strain of the position where the strain sensitive element is arranged can be monitored.

[0047] In the embodiment, the strain sensitive element is a carbon nanotube film, the thickness of the carbon nanotube film is 50-60 μm, and the resistivity is 0.2-0.4 Ω / cm.

[0048] The resistance strain measurement method is the most widely used method in health monitoring stress analysis application. The method is to measure the strain inside the composite material by using the strain sensitive element (carbon nanotube film), and then to obtain the stress state inside the composite material according to the strain-stress relationship, so as to analyze the stress of the pressure hull.

[0049] The general process of strain measurement of the carbon nanotube film is as follows (this part seems to prove the characteristics of the carbon nanotube film itself, which can respond to deformation and cause resistance change, rather than the scheme of the present application to judge the deformation of the pressure cabin shell by collecting resistance): The carbon nanotube film is embedded in the inside of the deep-sea pressure cabin, and then connected to the measurement circuit. With the deformation of the shell of the deep-sea pressure cabin under pressure, the carbon nanotube film also deforms, causing the resistance value to change. The change of the resistance value is proportional to the strain of the measurement point of the deep-sea pressure cabin. The signal generated by the resistance change of the carbon nanotube film is amplified by the measurement amplification circuit and then output. It is indicated or recorded by an indicating instrument or recording instrument. It is a method of converting mechanical strain into electrical quantity, and the conversion process is as shown in Figure 4 The output signal of the measurement circuit can also be amplified and converted into digital signal, and then directly transmitted to the computer for data processing.

[0050] Specifically, the limiting photo of the carbon nanotube film is as shown in Figure 5 The carbon nanotube has a high aspect ratio and has the characteristics of radial nanometer level and axial micrometer level. Therefore, the high specific surface area brings easy agglomeration and entanglement between adjacent carbon nanotubes, forming a multi-directional conductive network. The total resistance Rc of the film prepared from the carbon nanotube is composed of two parts, the contact resistance Rj and the inherent resistance Rg, that is

[0051] R c =g j R j +g g R g (1)

[0052] Wherein the coefficient g i is affected by the length L i of the conductor and the effective contact area A i , which can be expressed as

[0053]

[0054] where Rj represents the contact resistance between the randomly networked carbon nanotubes in the film, ignoring the wire and electrode resistance, the contact resistance is mainly excited by the spatial domain of the adjacent carbon nanotubes through the tunneling effect.

[0055] Considering the random distribution of carbon nanotubes, the possible tunneling effect mainly includes two types of conduction mechanisms: the in-plane conduction network formed by the closely distributed carbon nanotubes; and the out-of-plane conduction network formed by the closely overlapped carbon nanotubes. Since the gap region between the carbon nanotubes is more or less filled with the matrix, the contact resistance Rj is several orders of magnitude higher than the intrinsic resistance Rg, so Rg can be ignored. Rj can be represented as

[0056]

[0057] where B is a constant, J0 is the width of the tunneling barrier, J1 is the width of the intersection, and T is the temperature.

[0058] The contact resistance Rj is analyzed using the Neugebauer-Webb theory. When an electron moves from one carbon nanotube to another, the electron transfer between the charged carbon nanotube and the neutral carbon nanotube is a tunneling process, so the contact resistance Rj of the carbon nanotube is related to its tunneling barrier. The tunneling barrier is approximately regarded as a square barrier, and Rj can be changed to

[0059]

[0060] where C and k are constants, and d is the distance between the centers of the two carbon nanotubes.

[0061] The resistance of the carbon nanotube film can be represented as

[0062]

[0063] Assuming that the initial contact resistance of the two carbon nanotubes is R0, where d0 is the initial distance between the centers of the two carbon nanotubes. When the strain is small, k is basically unchanged, so the resistance change rate is:

[0064]

[0065] Let

[0066]

[0067] Substituting equation (7) into equation (6) gives

[0068]

[0069] The only variable in the formula is δ, which is only related to the spacing of the carbon nanotubes. During the strain monitoring of the carbon nanotube film, the stretching and shrinking of the carbon nanotube film will affect the size of the spacing d between the centers of the carbon nanotubes, thereby affecting the value of δ, and finally affecting the change of ΔR / R with the strain of the film, that is, the change of the resistance change rate of the carbon nanotube film can obtain the change amount of the strain of the relative position. c

[0070] In the embodiment, referring to Figure 3 The plurality of strain sensitive elements included in each of the health monitoring modules are fixedly combined with the flexible printed circuit by conductive silver paste or the like.

[0071] In the embodiment, the health monitoring module is prepared by the following method:

[0072] 1) Functionalized modified carbon nanotubes, that is, functional groups are grafted to the carbon nanotubes to enhance the compatibility of the film with the epoxy resin.

[0073] Sulfuric acid and nitric acid are prepared into a mixed acid solution with a mass ratio of 3:1, then carbon nanotubes are added, and ultrasonic treatment is performed in a constant temperature water bath;

[0074] After the reaction is completed, cool to room temperature, dilute with deionized water, filter, wash with a large amount of deionized water until neutral, then dry in a freeze dryer, and obtain carbon nanotubes grafted with carboxyl groups;

[0075] Then, the carbon nanotubes grafted with carboxyl groups are ultrasonically dispersed in ethylenediamine and a coupling agent, then washed several times with anhydrous ethanol and deionized water, and dried to obtain carbon nanotube powder grafted with amino groups.

[0076] In the embodiment, the carbon nanotubes can be single-walled carbon nanotubes or multi-walled carbon nanotubes or a mixture of the two. Single-walled carbon nanotubes have excellent electrical conductivity and good film flexibility, but are expensive, with a price more than ten times that of multi-walled carbon nanotubes. Preferably, the single-walled carbon nanotubes grafted with amino groups and the multi-walled carbon nanotubes grafted with carboxyl groups used in the present application are mixed in a mass ratio of 1:1.

[0077] In the embodiment, the sulfuric acid, nitric acid, anhydrous ethanol, ethylenediamine and coupling agent are all of analytical purity, wherein the coupling agent can be silane coupling agent, titanate coupling agent, zirconate coupling agent, aluminate coupling agent, double metal coupling agent (aluminum-zirconate, aluminum-titanium composite coupling agent), rare earth coupling agent, phosphorus-containing coupling agent, boron-containing coupling agent, etc. Preferably, an epoxy silane coupling agent is used in the present application.

[0078] 2) Mix the obtained functionalized modified carbon nanotube powder with deionized water to obtain a mixed solution, use a homogenizer to stir the carbon nanotubes in the mixed solution uniformly, and then use a microfluidic device to obtain a carbon nanotube solution.​

[0079] 3) Pour the dispersed carbon nanotube solution into a vacuum filtration device, and obtain a wet carbon nanotube film after filtration, and place the wet carbon nanotube film into a vacuum oven for drying, and after cooling, peel off the carbon nanotube film from the filter paper to obtain the carbon nanotube film, and the thickness of the dried carbon nanotube film is 50-60 μm, and the resistivity is 0.2-0.4 Ω / cm, and then according to the need, cut to the required size and shape.

[0080] 4) According to the design of the corresponding circuit shown in FIG. Figure 2 Print the flexible printed circuit, cut the carbon nanotube film, and adhere the two ends of the carbon nanotube film to the printed circuit using conductive silver adhesive, and place the printed circuit with the adhered carbon nanotube film into a constant temperature drying oven for curing, and take out after the conductive silver adhesive is fully dried.

[0081] In the embodiment, the flexible printed circuit is made by electronic printing, and is a printed board in which point-to-point connections and components are formed on a general substrate, and the main function is to connect various electronic components to form a predetermined circuit, and to relay transmission. The flexible printed circuit is a soft film (flexible insulating substrate) on which silver-white (silver paste) conductive patterns and position patterns are printed, and the patterns are obtained by a screen printing method, and the printed board is also called a flexible silver paste printed board.

[0082] In the embodiment, the conductive silver adhesive is an adhesive, and the matrix is an epoxy resin adhesive, and can be cured at room temperature to 150 DEG C.

[0083] In the embodiment, the shell of the deep-sea pressure-resistant cabin is formed by winding a carbon fiber reinforced resin-based composite material on the inner container.

[0084] In the embodiment, the carbon fiber reinforced material of the carbon fiber reinforced resin-based composite material is T700S, the matrix is bisphenol A type epoxy resin 863, the curing agent is 4207, and the accelerator is dibutyl phthalate and other additives.

[0085] The deep-sea pressure-resistant cabin in the embodiment has designability, and the winding sequence, the number of winding layers and the winding angle can be optimized through finite element mechanics analysis. Under the premise of meeting the hoop strength, axial strength and hoop stability, the mechanical properties of the deep-sea pressure-resistant cabin are improved by optimizing the winding process parameters.

[0086] In the embodiment, the deep-sea pressure-resistant cabin is prepared by the following method, and a plurality of production equipment is used in the manufacturing process, and the main production equipment is: a full-automatic carbon fiber winding machine, a numerical control tension sensor, a glue dipping machine, an automatic temperature regulating curing furnace and the like, which are known in the art:

[0087] 1) First, the rubber preparation: according to the weight ratio of epoxy resin: curing agent: additive = 10:10:3, the epoxy resin, curing agent, additive are put into the mixer in turn, and the stirrer is continuously stirred at 100-300 r / min for 20 min to obtain a uniform mixture.

[0088] 2) Winding to form a shell:

[0089] First, install the inner container of the deep-sea pressure cabin on the winding machine, slowly pour the mixed glue into the glue tank heated in the water bath, and control the temperature of the mixed glue at 50-60℃; under the action of the tensioner, pass the carbon fiber yarn through the glue tank, so that the glue liquid is fully immersed in the fiber;

[0090] According to the mechanical requirements and the design of the reinforcement fiber layer, the carbon fiber T700S immersed in the mixed glue is wound on the inner container according to different angles, spirals and circumferential mixed forms, to reach a certain number of layers and thickness to meet the strength requirements. The specific number of layers can be determined according to the strength and stability requirements of the deep-sea pressure cabin. The wire tension during winding is controlled at 10-30 N to ensure that the glue content of the entire shell is 60-70%, and the actual tension size is controlled according to the quality of the finished product.

[0091] Finally, the deep-sea pressure cabin is cured: the completed deep-sea pressure cabin is placed in the curing oven for rotary centrifugal curing, the mold and workpiece are in a centrifugal rotating state during the entire curing process, the centrifugal speed is 100-130 r / min, and the uniform speed state is provided with hot air internal circulation, and the curing steps are as follows:

[0092] 2.1) The temperature of the curing oven is raised to 90-100℃ within 30-40 min, and cured at this temperature for 100-120 min;

[0093] 2.2) The temperature of the curing oven is raised to 120-130℃ within 30 min, and after holding for 100-120 min, the temperature of the curing oven is raised to 160℃, and holding for 240 min;

[0094] 2.3) After natural cooling to room temperature, it is ready for use.

[0095] In this embodiment, during the process of winding to form a shell, the health monitoring module is arranged as needed between the shell and the inner container and / or between different winding layers of the shell, as shown in Figure 1 , and continue to wind until the winding of the deep-sea pressure cabin shell is completed. It should be noted that the joints of the health monitoring module are connected from the head end of the deep-sea pressure cabin, and L1-L6 and C1-C9 are reserved. Figure 1 , and Figure 2Just an example, actual can be customized according to actual demand. In addition, the deep-sea pressure hull can be pre-embedded with multiple layers of health monitoring modules in the body, Figure 1 Only one layer of health monitoring module is shown in the middle. After the deep-sea pressure hull is wound, it is placed in a curing box for curing. After curing, the interface of the flexible printed circuit is connected to the health monitoring data acquisition equipment.

[0096] In this embodiment, the carbon nanotube film is used for structural health monitoring of the deep-sea pressure hull. The rectangular 1.5cm×3cm film is embedded in the glass fiber reinforced epoxy resin composite material. The health monitoring module is embedded in the middle position with 20 layers of fiber winding layers. Tensile and three-point bending tests are carried out respectively, and the resistance of multiple carbon nanotube films is collected to realize strain and damage monitoring of the deep-sea pressure hull. The results are shown in Figure 6 、 Figure 7

[0097] The above-described embodiments described with reference to the accompanying drawings are exemplary and are used only to explain the present application, and should not be construed as limiting the present application. It should be noted that the embodiments of the present application are intended to explain and illustrate the structure of the pressure hull, the connection / cooperation relationship between the constituent structures, and the manufacturing process. Unless otherwise specified, the shape, size, material, and proportion of each constituent structure of the pressure hull can be selected according to the specific circumstances, and no special limitation or description is made here.

[0098] On the contrary, the present application encompasses any alternative, modification, equivalent method and scheme made in the spirit, principle and scope of the present application defined by the claims. Further, in order to enable the public to have a better understanding of the present application, some specific details are described in the following detailed description of the present application. The present application can also be completely understood without the description of these details by those skilled in the art. In addition, when using position terms such as both sides, both ends, up and down, etc., it should be understood that they are only used for convenience and description, considering that the structure can be oriented to other positions.​

Claims

1. A deep-sea pressure hull comprising an inner liner and an outer shell wrapping the inner liner, the outer shell comprising at least one layer of first fiber-wound layer and at least one layer of second fiber-wound layer stacked in sequence along a radial direction of the inner liner, characterized in that, Also included are: z health monitoring modules and z electrical connector groups, the health monitoring modules being arranged between the first fiber winding layer or the second fiber winding layer and the inner container and / or between the first fiber winding layer and the second fiber winding layer, the health monitoring modules comprising a flexible printed circuit and x y strain sensitive elements, the resistance of the strain sensitive elements changing with the deformation of the strain sensitive elements, x y strain sensitive elements, the strain sensitive elements being respectively distributed on the pressure-resistant cabin in x y detection areas, the flexible printed circuit having x row connection lines arranged at intervals in a column direction and y column connection lines arranged at intervals in a row direction, the x row connection lines and the y column connection lines being arrayed and electrically connected at the intersections, x y strain sensitive elements being arrayed on the flexible printed circuit, each of the strain sensitive elements being independently electrically connected with a row connection line and a column connection line, The electrical connector groups are arranged outside the shell, each of the electrical connector groups includes x row connection line connectors and y column connection line connectors, the x row connection line connectors are respectively electrically connected with x row connection lines, and the y column connection line connectors are respectively electrically connected with y column connection lines; when the health monitoring data acquisition device is connected with the mth row connection line connector and the nth column connection line connector, only one of the strain sensitive elements is located in the same series circuit with the mth row connection line connector and the nth column connection line connector, wherein 1≤m≤x, 1≤n≤y, and 1≤z.

2. The deep-sea pressure hull according to claim 1, characterized in that: x y strain sensitive elements are fixedly combined with the flexible printed circuit.

3. The deep-sea pressure hull according to claim 1, characterized in that: The row direction is parallel to the axial direction of the inner container, and the column direction is parallel to the circumferential direction of the inner container.

4. The deep-sea pressure hull according to claim 1 or 3, characterized in that: The plurality of strain sensitive elements located in the same row and / or the same column are arranged at equal intervals.

5. The deep-sea pressure hull according to claim 1 or 3, characterized in that: Each of the detection areas is provided with p strain sensitive elements, and the p strain sensitive elements located in the same detection area are respectively distributed at different depth positions along the radial direction of the pressure cabin, and 1≤p.

6. The deep-sea pressure hull according to claim 1, characterized in that: The strain sensitive element includes a carbon nanotube film.

7. The deep-sea pressure hull according to claim 6, characterized in that: The thickness of the carbon nanotube film is 50-60 μm, and the resistivity is 0.2-0.4 Ω / cm.

8. The deep-sea pressure hull according to claim 6, characterized in that: The health monitoring module comprises x The shape and size of the carbon nanotube film in the y strain sensitive elements are the same.

9. The deep-sea pressure hull according to claim 6, characterized in that: The carbon nanotube film is formed by single-walled carbon nanotubes grafted with amino groups and multi-walled carbon nanotubes grafted with carboxyl groups.

10. The deep-sea pressure hull according to claim 9, characterized in that: The mass ratio of the single-walled carbon nanotubes grafted with amino groups to the multi-walled carbon nanotubes grafted with carboxyl groups is 1:

1.

11. The deep-sea pressure hull according to claim 1, characterized in that: The first fiber winding layer and the second fiber winding layer are formed by winding a carbon fiber reinforced resin-based composite material in a ring direction or a spiral direction.

12. The deep-sea pressure hull according to claim 11, characterized in that: The carbon fiber reinforced resin-based composite material is carbon fiber impregnated with a mixed colloid.

13. The deep-sea pressure hull according to claim 12, characterized in that: The mixed colloid includes epoxy resin, curing agent and additive, and the weight ratio of the epoxy resin, the curing agent and the additive is 10:10:

3.

14. The deep-sea pressure hull of claim 12, wherein: The mass content of the mixed colloid in the shell is 60%-70%.

15. A method of health monitoring of a deep-sea pressure hull, characterized by, Provided are the deep-sea pressure hulls and the health monitoring data acquisition devices according to any one of claims 1-14, the health monitoring data acquisition device is connected with a row connection line connector and a column connection line connector of the health monitoring module to obtain a plurality of resistance values of a strain sensitive element located in the same series circuit with the row connection line connector and the column connection line connector at a plurality of time points, thereby obtaining a resistance change rate of the strain sensitive element, and the health condition of the position of the strain sensitive element is determined according to the resistance change rate. A resistance value change curve of a selected strain sensitive element over time is constructed, and when the measured resistance value deviates from the change curve, it is determined that the area where the selected strain sensitive element is located is damaged.

16. The method of claim 15, wherein: ​

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