Steel cable monitoring device based on organic fiber, manufacturing method and monitoring method

Abstract

The present invention discloses a steel cable monitoring device based on organic fiber, a manufacturing method and a monitoring method, which relate to the field of civil engineering monitoring technology, and include: a woven fiber layer wrapped on the surface of a steel wire to be monitored; wherein the woven fiber layer is woven with a liquid crystal polymer fiber as a base woven bundle; an organic composite conductive fiber is embedded in the base woven bundle; the organic composite conductive fiber is connected to a monitoring host; the steel wire to be monitored is one, multiple or all steel wires in the steel cable to be monitored; the monitoring host determines the stress change and environmental parameter change of the steel wire to be monitored by monitoring the resistance value change of the organic composite conductive fiber. The present invention improves the survival rate of the steel cable monitoring device, eliminates the sensor installation error, reduces the difficulty of transportation and construction, and improves the durability of the steel wire.

Description

Technical Field

[0001] The invention relates to the technical field of civil engineering monitoring, and in particular to a steel cable monitoring device based on organic fibers, a manufacturing method and a monitoring method. Background Art

[0002] Steel cables are key load-bearing and force-transmitting components of cable-supported bridges. They are subject to the coupling of static and dynamic loads and complex environments, and are in a state of high stress and salt and moisture erosion for a long time. After long-term operation, they often suffer from steel wire fatigue and corrosion, which leads to the degradation of steel wire strength and shortened service life, thus affecting the long-term performance of steel cables and even the entire bridge. In addition, under the influence of environmental factors such as sunshine and wind, steel cables are in a non-uniformly changing temperature field, and the temperature will affect the mechanical behavior of steel cables to a certain extent. Therefore, it is particularly important to monitor the distributed stress, temperature, humidity, etc. along the entire length of the steel cables.

[0003] Fiber optic sensors are made of inorganic glass fibers and have the advantages of light weight, small size, and little impact on the structure. Only one optical fiber is needed to read and transmit the information of the structure. By connecting the fiber optic sensor to a demodulator and a computer, physical data signals, numerical values ​​and other information can be obtained. Due to these characteristics of fiber optic sensors, they have great application prospects in the fields of roads, bridges, tunnels, etc., especially in the monitoring of large structures such as pipeline corridors. However, the fiber optic sensor itself is very thin, with an outer diameter of usually only about 125 microns, and it is highly brittle, has poor shear resistance, and is easily broken by external forces. Therefore, the survival rate of fiber optic sensors is low and cannot meet the needs of certain engineering application scenarios.

[0004] The patent with the authorization announcement number CN211522884U records a cable body and an anchoring assembly at both ends. The cable body is provided with a plurality of steel strands, each of which is twisted by a center wire and a plurality of side wires. A groove is provided in the center wire of the steel strand, and a fiber grating sensor is embedded in the groove. The end of the groove is fused with a jumper to evaluate the environment, stress and loss state of the cable during use. The patent with the application publication number CN110847038A records a self-sensing parallel steel wire cable, in which grooves are provided on one or more parallel steel wires, and a fiber grating sensor is embedded in the groove. The invention patent with the application publication number CN102146713A records an embedded steel strand FRP optical fiber intelligent composite reinforcement, which is to embed steel strands and optical fibers or fiber gratings in parallel into fiber reinforced plastic (FRP) reinforcements and integrate them into a single structure through pultrusion technology. In this structure, the steel strand is located in the center of the FRP bar, and the optical fiber or fiber grating is placed on the outer layer of the FRP bar. At the same time, it is also possible to design the optical fiber or fiber grating to be placed in the center of the FRP bar and arrange the steel strand on the outer layer of the FRP bar.

[0005] According to the above method, the fiber optic sensor needs to be implanted on the surface of the steel wire or in the FRP bar, and the optical fiber and jumper need to be led out from the end of the steel wire or FRP bar and connected to the fiber optic demodulator to read the signal. However, due to the high brittleness and poor shear resistance of the optical fiber, it is very easy to damage the optical fiber, especially the outlet end, during the actual transportation, installation, tensioning and subsequent monitoring process, causing the fiber optic sensor to fail, and then leading to the failure of the entire monitoring system. Summary of the invention

[0006] In order to solve the above problems existing in the prior art, the embodiment of the present invention provides a steel cable monitoring device based on organic fiber, a manufacturing method and a monitoring method. The technical solution is as follows:

[0007] On the one hand, a steel cable monitoring device based on organic fibers is provided, comprising: a woven fiber layer wrapped around the surface of a steel wire to be monitored; wherein the woven fiber layer is woven using liquid crystal polymer fibers as a base woven bundle; organic composite conductive fibers are embedded in the base woven bundle; the organic composite conductive fibers are connected to a monitoring host; the steel wire to be monitored is one, multiple or all steel wires in the steel cable to be monitored; the monitoring host determines the stress changes and environmental parameter changes of the steel wire to be monitored by monitoring the changes in the resistance value of the organic composite conductive fibers.

[0008] Optionally, the organic composite conductive fiber includes a stress-measuring organic composite conductive fiber, a temperature-measuring organic composite conductive fiber and a humidity-measuring organic composite conductive fiber; wherein the stress-measuring organic composite conductive fiber is used to monitor stress changes of the steel wire to be monitored; the temperature-measuring organic composite conductive fiber is used to monitor temperature changes of the environment in which the steel wire to be monitored is located; and the humidity-measuring organic composite conductive fiber is used to monitor humidity changes of the environment in which the steel wire to be monitored is located.

[0009] Optionally, in the woven fiber layer, the weaving direction of the base woven bundle containing the stress-measuring organic composite conductive fibers is parallel to the axial direction of the steel wire to be monitored; the angle between the weaving direction of the base woven bundle containing the temperature-measuring organic composite conductive fibers and the base woven bundle containing the humidity-measuring organic composite conductive fibers and the axial direction of the steel wire to be monitored is an acute angle.

[0010] Optionally, the angle between the weaving direction of the base weaving bundle containing the temperature-measuring organic composite conductive fibers and the base weaving bundle containing the humidity-measuring organic composite conductive fibers and the axial direction of the steel wire to be monitored is 45°.

[0011] On the other hand, a method for manufacturing a steel cable monitoring device based on organic fibers is also provided, comprising: using liquid crystal polymer fibers as a base weaving bundle, and embedding organic composite conductive fibers in the base weaving bundle and then impregnating the bundle with resin to form a prepreg; weaving the prepreg on a steel wire to be monitored according to a preset path with preset weaving parameters to form an initial fiber layer; the steel wire to be monitored is one, multiple or all steel wires in the steel cable to be monitored; and curing the initial fiber layer to obtain the woven fiber layer.

[0012] On the other hand, a method for monitoring a steel cable based on organic fibers is also provided, which is applied to a steel cable monitoring device based on organic fibers provided in an embodiment of the present invention; the method comprises: based on the stress-measuring organic composite conductive fiber, monitoring the stress change of the steel wire to be monitored; based on the temperature-measuring organic composite conductive fiber, monitoring the temperature change of the environment in which the steel wire to be monitored is located; based on the humidity-measuring organic composite conductive fiber, monitoring the humidity change of the environment in which the steel wire to be monitored is located; and based on the temperature change and the humidity change, correcting the stress change.

[0013] The embodiments of the present invention provide a steel cable monitoring device, a manufacturing method and a monitoring method based on organic fibers. A fiber layer is woven on the surface of a steel wire by using organic composite conductive fibers. The steel cable is monitored by monitoring the resistance change of the organic composite conductive fibers. The survival rate of the steel cable monitoring device is greatly improved. During transportation and construction, there is no need to pay special attention to local extrusion and excessive bending of the steel cable, thereby reducing the difficulty of transportation and construction, reducing the complex process of externally attaching sensors, saving labor costs and eliminating sensor installation errors. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0015] Figure 1 is a three-dimensional schematic diagram of a steel cable monitoring device based on organic fibers provided in an embodiment of the present invention;

[0016] Figure 2 is a schematic diagram of another organic fiber-based steel cable monitoring device provided in an embodiment of the present invention;

[0017] Figure 3 It is a structural schematic diagram of replacing a steel wire in a steel cable with a steel wire to be monitored provided by an embodiment of the present invention;

[0018] Figure 4 It is a schematic diagram of a structure in which a plurality of steel wires in a steel cable are replaced with a steel wire to be monitored, provided by an embodiment of the present invention;

[0019] Figure 5 It is a schematic diagram of a structure in which all steel wires in a steel cable are replaced with steel wires to be monitored, provided by an embodiment of the present invention;

[0020] Figure 6 It is a flow chart of a method for manufacturing a steel cable monitoring device based on organic fibers provided by an embodiment of the present invention;

[0021] Figure 7 It is a flow chart of a method for monitoring a steel cable based on organic fibers provided in an embodiment of the present invention.

[0022] In the figure: 1. steel wire to be monitored, 2. woven fiber layer, 3. base woven bundle, 4. organic composite conductive fiber, 41. stress measuring organic composite conductive fiber, 42. temperature measuring organic composite conductive fiber, 43. moisture measuring organic composite conductive fiber, 5. steel cable sheath. DETAILED DESCRIPTION

[0023] The technical solution of the present invention is described below in conjunction with the accompanying drawings.

[0024] In the embodiments of the present invention, words such as "exemplarily" and "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "example" in the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of the word "example" is intended to present the concept in a specific way. In addition, in the embodiments of the present invention, the meaning expressed by "and / or" can be both, or it can be either of the two.

[0025] In order to make the technical problems, technical solutions and advantages to be solved by the present invention more clear, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0026] Embodiment 1

[0027] Figure 1 3D schematic diagram of a steel cable monitoring device based on organic fiber provided according to an embodiment of the present invention. Figure 1 As shown, the device includes: a woven fiber layer 2 wrapped on the surface of the steel wire 1 to be monitored; wherein the woven fiber layer 2 is woven with liquid crystal polymer fibers as a base woven bundle 3; organic composite conductive fibers 4 are embedded in the base woven bundle 3; the organic composite conductive fibers 4 are connected to the monitoring host; the steel wire 1 to be monitored is one, multiple or all steel wires in the steel cable to be monitored.

[0028] The monitoring host determines the stress change and environmental parameter change of the steel wire 1 to be monitored by monitoring the change of the resistance value of the organic composite conductive fiber 4 .

[0029] Organic composite conductive fiber is an organic composite conductive fiber suitable for use in fabric sensors. As the stretching rate increases, the resistance changes in two stages: within the stretching range of 0mm to 6mm (0% to 12%), the resistance changes steadily, and within the stretching range of 6mm to 15mm (12% to 30%), the resistance change amplitude increases. Changes in environmental factors also affect the conductive properties of organic composite conductive fibers. As temperature and humidity increase, the resistance value decreases. By weaving this smart fiber on the outside of the steel wire, the stress, temperature and humidity of the steel cable can be monitored by measuring the resistance of the fiber. In addition, by adjusting the temperature of the environment, such as increasing the temperature, a decrease in the resistance value can be observed. The average value of the resistance temperature coefficient α is calculated to be -4.6×10 -3 / ℃.

[0030] Liquid crystal polymer (LCP) is a high-performance thermoplastic engineering plastic that exhibits nematic liquid crystal properties when melted and belongs to the fully aromatic polyester. Liquid crystal polymer fibers made of liquid crystal polymer have many excellent properties such as high strength, high modulus, low dielectric constant, low water absorption, excellent creep resistance, excellent durability, and good vibration reduction characteristics.

[0031] In the embodiment of the present invention, a woven fiber layer 2 with liquid crystal polymer fiber as the base is covered on the outside of the monitored steel wire 1. Since the liquid crystal polymer fiber has the characteristics of extremely low water absorption and excellent durability, it can protect the monitored steel wire 1 at the same time, effectively isolate the steel wire from corrosion by water vapor and salt ions, and improve the durability of the monitored steel wire 1.

[0032] Preferably, the organic composite conductive fibers 4 include stress-measuring organic composite conductive fibers 41 , temperature-measuring organic composite conductive fibers 42 , and humidity-measuring organic composite conductive fibers 43 .

[0033] Specifically, the stress-measuring organic composite conductive fiber 41 is used to monitor the stress change of the steel wire 1 to be monitored;

[0034] The temperature measuring organic composite conductive fiber 42 is used to monitor the temperature change of the environment where the steel wire 1 to be monitored is located;

[0035] The humidity sensing organic composite conductive fiber 43 is used to monitor the humidity change of the environment where the steel wire 1 to be monitored is located.

[0036] Figure 2 FIG. 1 is a schematic diagram of another organic fiber-based steel cable monitoring device provided according to an embodiment of the present invention. Figure 2As shown, in an optional implementation provided by an embodiment of the present invention, in the woven fiber layer 3, the weaving direction of the base woven bundle 3 containing the stress-measuring organic composite conductive fibers 41 is parallel to the axial direction of the steel wire 1 to be monitored; the angle between the weaving direction of the base woven bundle 3 containing the temperature-measuring organic composite conductive fibers 42 and the base woven bundle 3 containing the humidity-measuring organic composite conductive fibers 43 and the axial direction of the steel wire 1 to be monitored is an acute angle.

[0037] Preferably, the angle between the weaving direction of the base braided bundle containing the temperature measuring organic composite conductive fibers 42 and the base braided bundle containing the humidity measuring organic composite conductive fibers 43 and the axial direction of the steel wire 1 to be monitored is 45°.

[0038] The present invention can ensure that the monitoring of temperature and humidity by the temperature-measuring organic composite conductive fiber 42 and the humidity-measuring organic composite conductive fiber 43 is less affected by the axial stretching of the steel wire 1 to be monitored, while saving braiding materials and improving braiding efficiency.

[0039] In some optional implementations provided in the embodiments of the present invention, the steel wire to be monitored is applied to the steel cable, and one, multiple or all of the steel wires in the steel cable are replaced, so that the changes in the cable stress and the ambient temperature and humidity can be monitored by measuring the resistance changes of the organic composite conductive fiber.

[0040] Figure 3 is a schematic diagram of a structure in which a steel wire in a steel cable is replaced with a steel wire to be monitored according to an embodiment of the present invention. Figure 4 is a schematic diagram of a structure in which a plurality of steel wires in a steel cable are replaced with a steel wire to be monitored according to an embodiment of the present invention. Figure 5 1 is a schematic diagram of a structure in which all steel wires in a steel cable are replaced with steel wires to be monitored according to an embodiment of the present invention. Figure 3-5 As shown, the outer surface of the replaced steel cable is also wrapped with a steel cable sheath 5 to protect the steel wire inside the steel cable. Specifically, in practical applications, different implementation methods can be selected according to needs.

[0041] It should be noted that the anchoring of the steel cable using the monitored steel wire adopts cold cast anchor instead of hot cast anchor. This is to prevent the high temperature during the anchoring process from damaging the liquid crystal polymer fiber and the organic composite conductive fiber.

[0042] Embodiment 2

[0043] Figure 6 FIG. 1 is a flow chart of a method for manufacturing a steel cable monitoring device based on organic fibers according to an embodiment of the present invention. Figure 6 As shown, the method specifically comprises the following steps:

[0044] Step S602 , using liquid crystal polymer fibers as a base braided bundle, embedding organic composite conductive fibers in the base braided bundle and then impregnating the fibers with resin to form a prepreg.

[0045] Step S604, weaving the prepreg on the steel wire to be monitored according to a preset path with preset weaving parameters to form an initial fiber layer. The steel wire to be monitored is one, multiple or all steel wires in the steel cable to be monitored.

[0046] Step S606, curing the initial fiber layer to obtain a woven fiber layer.

[0047] Specifically, the manufacturing method of the monitoring device in the first embodiment provided by the embodiment of the present invention uses a liquid crystal polymer fiber bundle as the base of the woven fiber, embeds organic composite conductive fibers in the bundled liquid crystal polymer fiber bundle base and then impregnates with resin to form a prepreg, sets the weaving angle, tension, speed and other parameters of the weaving machine according to the design requirements, and then weaves the prepreg on the steel wire according to the set path. After weaving, the fiber layer needs to be compacted to ensure that the fiber layer is dense and tightly bonded to the surface of the steel wire without bubbles, and finally completes the curing. After the curing is completed, the final result is as shown Figure 1 and Figure 2 The steel wire to be monitored is wrapped with the organic fiber-based steel cable monitoring device provided by an embodiment of the present invention.

[0048] Embodiment 3

[0049] Figure 7 1 is a flow chart of a method for monitoring a steel cable based on organic fibers according to an embodiment of the present invention, and the method is applied to a device for monitoring a steel cable based on organic fibers according to an embodiment of the present invention. Figure 7 As shown, the method specifically comprises the following steps:

[0050] Step S702: monitoring stress changes of the steel wire to be monitored based on the stress-measuring organic composite conductive fiber.

[0051] Step S704, monitoring the temperature change of the environment where the steel wire to be monitored is located based on the temperature measuring organic composite conductive fiber.

[0052] Step S706: Based on the humidity measuring organic composite conductive fiber, the humidity change of the environment where the steel wire to be monitored is located is monitored.

[0053] Step S708, correcting the stress change based on the temperature change and the humidity change.

[0054] An organic fiber-based steel cable monitoring device provided in an embodiment of the present invention can simultaneously monitor the stress and temperature and humidity changes of the steel cable. Specifically, the following implementation methods can be adopted:

[0055] Implementation method 1: Figure 3 As shown, organic composite conductive fibers for different purposes are embedded in fiber bundles in different weaving directions of the same steel wire. One fiber is embedded in the axial fiber bundle to monitor stress, and two fibers are embedded in the non-axial bundle to monitor temperature and humidity respectively. It should be noted that in data post-processing, the temperature and humidity measured by the non-axial fibers are used to calibrate the stress monitoring data measured by the axial fibers.

[0056] Implementation method 2: Figure 4 As shown, multiple organic composite conductive fibers are used as sensors to independently monitor stress and temperature and humidity. For example, multiple steel wires woven with organic composite conductive fibers are installed in a steel cable, one of which is only used to measure temperature changes, one is only used to measure humidity changes, and the other is only used to measure stress changes. Independent temperature and humidity sensors are used to calibrate and compensate the stress monitoring data, thereby distinguishing between stress and environmental influences.

[0057] Implementation method 3: Figure 5 As shown, all the steel wires in the steel cable are made of steel wires woven with organic composite conductive fibers, wherein each steel wire is woven with three kinds of organic composite conductive fibers. The stress changes, temperature changes and humidity changes of all the steel wires in the steel cable can be monitored simultaneously, and anti-corrosion protection can also be provided for all the steel wires, thereby improving the durability and service life of the steel wires and the steel cable.

[0058] From the above description, it can be seen that the embodiments of the present invention provide a steel cable monitoring device, manufacturing method and monitoring method based on organic fibers, wherein a fiber layer is woven on the surface of the steel wire by using liquid crystal polymer fibers and organic composite conductive fibers, and the steel cable is monitored by monitoring the resistance change of the organic composite conductive fibers, thereby greatly improving the survival rate of the steel cable monitoring device. During transportation and construction, there is no need to pay special attention to local extrusion and excessive bending of the steel cable, thereby reducing the difficulty of transportation and construction, reducing the complex process of externally attaching sensors, saving labor costs and eliminating sensor installation errors.

[0059] It should be understood that in various embodiments of the present invention, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0060] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A steel cable monitoring device based on organic fiber, characterized in that: include: A woven fiber layer wrapped around the surface of the steel wire to be monitored; wherein the woven fiber layer is woven with liquid crystal polymer fibers as a base woven bundle; organic composite conductive fibers are embedded in the base woven bundle; the organic composite conductive fibers are connected to the monitoring host; the steel wire to be monitored is one, multiple or all steel wires in the steel cable to be monitored; The organic composite conductive fibers include stress-measuring organic composite conductive fibers, temperature-measuring organic composite conductive fibers, and moisture-measuring organic composite conductive fibers; In the woven fiber layer, the weaving direction of the base woven bundle containing the stress-measuring organic composite conductive fibers is parallel to the axial direction of the steel wire to be monitored; the angle between the weaving direction of the base woven bundle containing the temperature-measuring organic composite conductive fibers and the base woven bundle containing the humidity-measuring organic composite conductive fibers and the axial direction of the steel wire to be monitored is an acute angle; The monitoring host determines the stress change and environmental parameter change of the steel wire to be monitored by monitoring the change of the resistance value of the organic composite conductive fiber.

2. The organic fiber-based steel cable monitoring device according to claim 1, characterized in that: The stress-measuring organic composite conductive fiber is used to monitor the stress change of the steel wire to be monitored; The temperature measuring organic composite conductive fiber is used to monitor the temperature change of the environment where the steel wire to be monitored is located; The humidity-sensing organic composite conductive fiber is used to monitor the humidity change of the environment where the steel wire to be monitored is located.

3. The organic fiber-based steel cable monitoring device according to claim 1, characterized in that: The angle between the weaving direction of the base weaving bundle containing the temperature-measuring organic composite conductive fibers and the base weaving bundle containing the humidity-measuring organic composite conductive fibers and the axial direction of the steel wire to be monitored is 45°.

4. A method for manufacturing a steel cable monitoring device based on organic fiber according to claim 1, characterized in that: include: Liquid crystal polymer fibers are used as a base braided bundle, and organic composite conductive fibers are embedded in the base braided bundle and then impregnated with resin to form a prepreg; The prepreg is braided on the steel wire to be monitored according to a preset path with preset braiding parameters to form an initial fiber layer; the steel wire to be monitored is one, multiple or all steel wires in the steel cable to be monitored; The initial fiber layer is cured to obtain the woven fiber layer.

5. A method for monitoring steel cables based on organic fibers, characterized in that: The organic fiber-based steel cable monitoring device according to claim 1; the method comprising: Based on the stress-measuring organic composite conductive fiber, monitoring the stress change of the steel wire to be monitored; Based on the temperature measuring organic composite conductive fiber, monitoring the temperature change of the environment where the steel wire to be monitored is located; Based on the moisture-measuring organic composite conductive fiber, the humidity change of the environment where the steel wire to be monitored is located is monitored; The stress change is corrected based on the temperature change and the humidity change.

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