A reel type electromagnetic elastic absolute stress monitoring device facilitating pre-winding

Abstract

The application relates to a reel type electromagnetic elastic absolute stress monitoring device facilitating prefabricated winding, which is used in the field of nondestructive testing of ferromagnetic materials and particularly relates to nondestructive testing of absolute stress of ferromagnetic material components. The device is composed of a winding of multiple coils in series or in parallel, multiple dumbbell-shaped soft magnetic material cores and single or multiple detection elements. The device can be directly assembled on a measured ferromagnetic material component to complete installation without on-site winding, and can be mass-produced in a factory, so that the installation of the sensor can be completed on site, and the device is convenient to disassemble and replace, thereby avoiding the problem of winding difficulty of a concave arc surface in a magnetic core during prefabricated winding. Under pulse or alternating excitation signals, the dumbbell-shaped soft magnetic material core with the winding generates a magnetic potential, and a magnetic flux is generated in the sensor and the measured component, so that the measured component is magnetized, an electric signal is output by the detection element, magnetic characteristic quantities related to absolute stress of the component are obtained according to the electric signal, and nondestructive testing of absolute stress of the ferromagnetic material component is realized.

Description

Technical Field

[0001] This invention relates to the field of nondestructive testing, and in particular to a reel-type electromagnetic spring-type absolute stress monitoring device that is easy to pre-wound. Background Technology

[0002] Ferromagnetic material components are widely used in civil engineering, construction, and transportation engineering, such as reinforcing bars, structural steel, steel strands, wire ropes, and parallel wire cables. During use, key ferromagnetic material components in engineering structures often bear enormous loads. For example, prestressed tendons and steel cables, as core load-bearing components of reinforced concrete bridges and cable-stayed structures, may experience stress levels exceeding their material ultimate strength, thus posing significant safety hazards. Therefore, real-time monitoring and analysis of component stress is necessary.

[0003] Currently, commonly used stress monitoring technologies for ferromagnetic materials in engineering include: direct reading of hydraulic pressure gauges, vibration frequency method, resistance strain gauge method, and magnetoelastic effect method. Among these, the direct reading of hydraulic pressure gauges is only suitable for use during the construction of new structures; the vibration frequency method is only suitable for long cables and has limitations on the boundary conditions of the cables; the resistance strain gauge method is suitable for installation before the component is subjected to stress, and has high requirements for the flatness of the component surface, making it difficult to measure the absolute stress value. Sensors based on the magnetoelastic effect method are suitable for installation and use on structural components at any construction stage and can monitor the absolute stress value of the component. For steel strands with an outer PE sheath or prestressed duct protection, the magnetoelastic effect method can also effectively measure their absolute stress.

[0004] In practical engineering, various sensors based on the magnetoelastic effect have been adopted and used, including those with a sleeve-type electromagnetic missile or magnetic flux sensor installed first, a Haver-type electromagnetic missile or magnetic flux sensor installed later, a bypass electromagnetic missile or magnetic flux sensor, and an opening and closing electromagnetic missile or sensor.

[0005] Pre-installed sleeve-type sensors are only suitable for use before installation on ferromagnetic material components, and are difficult to disassemble and maintain later. Post-installed sensors are suitable for use on in-service ferromagnetic material components. However, post-installed Haver-type magnetic flux sensors require on-site winding, which is inconvenient for personnel due to varying on-site environments and heavy workloads. Furthermore, on-site wound sensors cannot guarantee complete consistency with the sensor parameters calibrated in the laboratory, leading to instrument errors.

[0006] The bypass excitation sensor and the magnetic yoke sensor are relatively large. For external prestressed bundles composed of multiple steel strands, the available space around them is small, which makes installation difficult.

[0007] The principle of a hinged sensor is that the coils on the left and right halves are connected through pins or sockets on the mating surface to form a complete circuit. However, this method has a large number of coil interfaces, requiring each coil segment to be connected individually during the splicing process, which is labor-intensive and complex to construct, greatly limiting its engineering applications.

[0008] Another type of split sensor has its main coil wound on two semi-circular rings of soft magnetic material, and the two halves are then directly assembled onto the ferromagnetic component being measured, reducing on-site workload. However, because the semi-circular cross-section has a concave arc surface, it is inconvenient to wind the coil during production, which to some extent hinders large-scale production in factories. Summary of the Invention

[0009] The purpose of this invention is to provide a reel-type electromagnetic spring-type absolute stress monitoring device that is easy to pre-wound, can be mass-produced in the factory, and can be assembled on-site to complete the sensor installation. It is also easy to disassemble and replace, avoiding the problem of difficult winding of concave arc surfaces, thus overcoming the shortcomings of existing sensors listed in the background art.

[0010] To achieve the above objectives, the present invention adopts the following technical solution:

[0011] A reel-type electromagnetic spring-type absolute stress monitoring device with easy pre-made winding is used for non-destructive testing of ferromagnetic material components. The device is characterized in that it includes multiple dumbbell-shaped soft magnetic material cores, each dumbbell-shaped soft magnetic material core having an excitation coil wound on it. The device also includes one or more detection elements. The multiple dumbbell-shaped soft magnetic material cores with wound excitation coils are suitable for surrounding and can be placed around the ferromagnetic component under test without the need for on-site winding.

[0012] Furthermore, the number of dumbbell-shaped soft magnetic material cores with wound excitation coils is an even number, forming an axisymmetric structure.

[0013] Furthermore, the dumbbell-shaped soft magnetic material core is formed by splicing two sector-shaped magnetic yokes and a core rod with a non-concave cross-section located between the two sector-shaped magnetic yokes, and the excitation coil is wound on the core rod with a non-concave cross-section.

[0014] Furthermore, the excitation source for the winding can be either a pulse signal or an AC signal.

[0015] Furthermore, the device also includes a modular support frame, which comprises multiple support frames assembled circumferentially to form a structure that can wrap around the ferromagnetic component being tested. The multiple dumbbell-shaped soft magnetic material cores with wound excitation coils are mounted on the modular support frame.

[0016] Furthermore, the excitation source for the winding can be a pulse signal or an AC signal; the detection element can optionally be an FPC flexible flat cable film, a magnetoelectric laminate, a Hall element, or a secondary coil.

[0017] Furthermore, when the detection element is in the form of an FPC flexible flat cable film, a magnetoelectric laminate element, or a Hall element, the detection element is placed using the aforementioned support frame.

[0018] Furthermore, when the detection element adopts the form of a secondary coil, its winding form can be optionally: the secondary coil is directly wound on the outer or inner layer of the main coil winding, or the main coil is wound on both ends of the soft magnetic material core and the secondary coil is wound in the middle of the soft magnetic material core, or it is directly wound on the component to be tested.

[0019] The present invention has the following beneficial technical effects:

[0020] 1. It can be mass-produced in the factory and prefabricated and installed on site, significantly reducing the workload;

[0021] 2. The soft magnetic material core topology, which has been reasonably optimized, can effectively introduce sufficient magnetic flux into the measured component, thereby making the overall size and weight of the sensor smaller.

[0022] 3. It can avoid or greatly reduce the on-site winding work of coils, effectively monitor the stress of ferromagnetic material components (steel strands, steel bars, steel bars, steel pipes, structural steel, etc.) with different cross-sectional forms, has high measurement accuracy, and the results are visualized, which helps monitoring personnel to analyze and judge the safety of ferromagnetic material components.

[0023] 4. It can be installed and disassembled at any time. For some temporary testing projects, it is not necessary to deploy a large number of sensors at the same time. After use on a certain type of ferromagnetic material component, it can be disassembled and used elsewhere, thereby saving costs. Attached Figure Description

[0024] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein:

[0025] Figure 1 A schematic diagram of assembling a soft magnetic material yoke with a non-concave cross-section magnetic core rod to form a dumbbell-shaped soft magnetic material core;

[0026] Figure 2 A schematic diagram of a single dumbbell-shaped soft magnetic material core;

[0027] Figure 3 A schematic diagram of a single dumbbell-shaped soft magnetic material core with coil windings;

[0028] Figure 4A schematic diagram of an 8-lobed dumbbell-shaped soft magnetic material core wound together by a hinge;

[0029] Figure 5 A schematic diagram of a sensor with 8-lobed coil windings connected in series;

[0030] Figure 6 This is a schematic diagram showing a sensor mounted on a ferromagnetic material component being measured.

[0031] Figure 7 This is a schematic diagram of the sensor's internal framework and detection elements;

[0032] Figure 8 A schematic diagram showing the magnetic flux driven by the magnetomotive force generated in the core of a soft magnetic material passing through the ferromagnetic component under test.

[0033] Figure 9 The simulation results show that the magnetic flux driven by the magnetomotive force generated in a single dumbbell-shaped soft magnetic material core passes through the ferromagnetic component under test.

[0034] Figure 10 A schematic diagram of the cross-section of a four-lobed scroll-type electromagnetic spring-type absolute stress monitoring device;

[0035] Figure 11 A schematic diagram of the cross-section of a 6-lobed scroll-type electromagnetic spring-type absolute stress monitoring device;

[0036] Figure 12 A schematic diagram of the cross-section of an 8-lobed scroll-type electromagnetic spring-type absolute stress monitoring device;

[0037] Figure 13 A schematic diagram of the FPC flexible flat cable film;

[0038] Figure 14 A schematic diagram of FPC flexible flat cable film wound into a detection element;

[0039] Figure 15 This is a schematic diagram of a sensor where the secondary coil is wound around the outer layer of the main coil when the detection element is in the form of a secondary coil;

[0040] Figure 16 This is a schematic diagram of the internal structure of a sensor when the detection element is in the form of a secondary coil, with the secondary coil wound around the outer layer of the main coil.

[0041] Figure 17 This is a schematic diagram of a sensor in which the main coil is wound around both ends of a soft magnetic core and the secondary coil is wound in the middle of the soft magnetic core when the detection element is in the form of a secondary coil.

[0042] Figure 18 This is a schematic diagram of the internal structure of a sensor when the detection element is in the form of a secondary coil, with the main coil wound at both ends of a soft magnetic core and the secondary coil wound in the middle of the soft magnetic core.

[0043] Figure 19 This is a schematic diagram showing the secondary coil being wound on the assembled support frame when the detection element is in the form of a secondary coil.

[0044] Figure 20 This is a schematic diagram of a magnetoelectric laminate.

[0045] Figure 21 A schematic diagram of the assembled support frame for a scroll-type electromagnetic spring-type absolute stress monitoring device;

[0046] Figure 22 Diagram showing the installation process of a roll-type electromagnetic spring-type absolute stress monitoring device;

[0047] Figure 23 A schematic diagram showing the hinged installation of a roll-type electromagnetic spring-type absolute stress monitoring device. Detailed Implementation

[0048] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0049] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures, and should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0050] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0051] Please see Figures 1-23The component numbers in the attached diagram represent: 1. Dumbbell-shaped soft magnetic material core; 2. Assembled support frame; 3. Detection element; 4. Excitation coil; 5. Ferromagnetic component under test; 6. FPC flexible flat cable film; 7. Welding finger; 8. Sub-coil; 9. Magnetostrictive material; 10. Piezoelectric material; 11. Soft magnetic material yoke; 12. Soft magnetic material smooth non-concave cross-section magnetic core rod; 13. Hinge.

[0052] Referring to the accompanying drawings, the present invention provides a spool-type electromagnetic spring-type absolute stress monitoring device that facilitates pre-wound winding, comprising an assembled support frame 2 with two halves bonded together, a detection element 3 embedded in the assembled support frame 2, and multiple dumbbell-shaped soft magnetic material cores 1. Each dumbbell-shaped soft magnetic material core 1 is wound with an excitation coil 4, and the excitation coils 4 can be connected in parallel or in series. Multiple dumbbell-shaped soft magnetic material cores 1 with wound excitation coils 4 are arranged around the outside of the ferromagnetic component 5 being measured.

[0053] The dumbbell-shaped soft magnetic material core 1 is assembled from two fan-shaped magnetic yokes 11 and a non-concave cross-section magnetic core rod 12, such as by bonding or direct molding. The middle section of the soft magnetic material core rod 12 has a smooth, non-concave cross-section for easy winding; the two ends are fan-shaped magnetic yokes 11 to reduce magnetic resistance and leakage flux. The scroll-type electromagnetic spring-type absolute stress monitoring device includes multiple dumbbell-shaped soft magnetic material cores with windings, such as 4-lobed, 6-lobed, and 8-lobed types, respectively, as shown in... Figure 10 , Figure 11 and Figure 12 As shown.

[0054] The process of assembling the scroll-type electromagnetic spring-type absolute stress monitoring device onto the ferromagnetic component 5 under test is as follows: First, the assembled support frame 2 is glued together around the ferromagnetic component 5 under test, such as... Figure 21 As shown, snap-fit ​​or bundling connections can also be used; secondly, the wound magnetic core 1 is arranged around the frame 2 and firmly connected by the hinge 13, thus completing the installation. Figure 22 , Figure 23 As shown, hinge 13 connects two adjacent magnetic cores and allows them to rotate relative to each other. During installation, multiple magnetic cores 1 are assembled around the frame 2, and the first and last magnetic cores are fixed with hinges. Alternatively, they can be fixed to the frame 2 by bonding, bundling, or other methods. The multiple dumbbell-shaped soft magnetic cores with windings are preferably arranged as symmetrically as possible with respect to the ferromagnetic component 5 being tested.

[0055] During installation, the magnetic circuit formed by the soft magnetic core 1 and the ferromagnetic component 5 under test should have the smallest possible magnetic resistance, and the air gap between the yoke and the ferromagnetic component 5 should be as small as possible. To reduce the air gap, the gap between the yoke and the ferromagnetic component 5 under test must be small, so that the magnetic flux in the dumbbell-shaped soft magnetic core 1 can be introduced into the ferromagnetic component 5 under test as much as possible. The dumbbell-shaped soft magnetic core 1 with the yoke should be wound with a sufficiently long excitation coil 4 to produce a uniform magnetization intensity in the middle section of the ferromagnetic component 5 under test, providing stable detection conditions for the detection element.

[0056] One form of the detection element is an FPC flexible flat cable film 6, an alternative is a magnetoelectric element, a second alternative is a Hall element, and a third alternative is a secondary coil 8.

[0057] When the detection element is in the form of an FPC flexible flat cable film 6, the film is tightly attached to the annular groove of the assembled support frame 2, and solder paste is applied to the soldering fingers 7 and melted and soldered with a hot air gun, so that the FPC flexible flat cable film 6 becomes a closed coil. Figure 14 As shown.

[0058] When the detection element is in the form of a secondary coil 8, one winding configuration is that the secondary coil is directly wound on the outer or inner layer of the main coil winding 4, such as... Figure 15 , 16 As shown, another winding configuration involves the main coil being wound around both ends of the soft magnetic core rod 12, and the secondary coil being wound in the middle of the soft magnetic core rod 12, as shown. Figure 17 , 18 As shown, the third winding method involves directly winding the wire onto the ferromagnetic component 5 being tested, such as... Figure 19 As shown. The sensors with the first two different secondary coil winding methods described above can be directly assembled on-site without the need for on-site winding.

[0059] When the detection element is in the form of a magnetoelectric element, the magnetoelectric element is composed of a magnetoelectric laminate material, namely, a supermagnetostrictive material layer 9 / a piezoelectric material layer 10 / a supermagnetostrictive material layer 9, such as... Figure 20 As shown. Under the excitation of an external magnetic field, the giant magnetostrictive material undergoes magnetostrictive strain, causing the piezoelectric material in the middle to respond with an output signal V. output .

[0060] Optionally, magnetic grease is applied between the yoke and the ferromagnetic component 5 under test to further reduce the magnetic resistance of the magnetic circuit and to allow the magnetic flux to be introduced into the ferromagnetic component 5 under test as much as possible.

[0061] Optionally, a pulsed DC or AC current is provided by a magnetic elasticity device. When current passes through the excitation coil 4, the two dumbbell-shaped soft magnetic material cores 1 generate a magnetomotive force and induce a magnetic field around them. When the sensor is placed on the ferromagnetic component 5, when current passes through the excitation coil 4, the magnetic flux at the location with higher magnetomotive force (dumbbell-shaped soft magnetic material core 1) will flow to the location with lower magnetomotive force (the measured ferromagnetic component 5), and the measured ferromagnetic component 5 is magnetized. The direction of the magnetic flux density inside it is as follows: Figure 8 and Figure 9 As shown.

[0062] In practice, the assembled frame 2 can be omitted. Multiple dumbbell-shaped soft magnetic material cores with windings can be directly installed on the outside of the ferromagnetic component 5 under test. They can be connected to each other by bonding, bundling, or directly bonded to the ferromagnetic component 5 under test. The detection element 3 can be in the form of a secondary coil, directly wound on the outer or inner layer of the main coil winding, i.e., the excitation coil 4; or the main coil can be wound on both ends of the soft magnetic material core, and the secondary coil can be wound in the middle of the soft magnetic material core; or it can be directly wound on the ferromagnetic component 5 under test.

[0063] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A spool type electromagnetic elastic absolute stress monitoring device for non-destructive testing of ferromagnetic material components, which facilitates pre-fabrication of winding, characterized in that, The device comprises a plurality of dumbbell-shaped soft magnetic material magnetic cores, each of which is wound with an excitation coil, and one or more detection elements, and the plurality of dumbbell-shaped soft magnetic material magnetic cores with wound excitation coils are adapted to be arranged around the measured ferromagnetic component without the need for on-site winding.

2. A spool type electromagnetic elastic absolute stress monitoring device with pre-wound wire for easy, according to claim 1, characterized in that, The number of dumbbell-shaped soft magnetic material magnetic cores with wound excitation coils is even, forming an axisymmetric structure.

3. A spool type electromagnetic elastic absolute stress monitoring device with pre-wound wire for easy, according to claim 1, characterized in that, The dumbbell-shaped soft magnetic material magnetic core is spliced by two fan-shaped yokes and a magnetic core rod with a non-concave cross section located between the two fan-shaped yokes, and the excitation coil is wound around the magnetic core rod with a non-concave cross section.

4. A spool type electromagnetic elastic absolute stress monitoring device with pre-wound wire for easy, according to claim 1, characterized in that, The excitation source of the winding can be a pulse signal or an alternating current signal.

5. A spool type electromagnetic elastic absolute stress monitoring device with pre-wound wire for easy installation according to claim 1, characterized in that, The device further comprises a spliced support framework, which comprises a plurality of support frameworks spliced in the circumferential direction and forms a structure capable of being wrapped around the measured ferromagnetic component, and the plurality of dumbbell-shaped soft magnetic material magnetic cores with wound excitation coils are mounted on the spliced support framework.

6. A spool type electromagnetic elastic absolute stress monitoring device with pre-wound wire for easy, according to claim 1, characterized in that, The excitation source of the winding can be a pulse signal or an alternating current signal; the detection element can be an FPC soft flat cable film, a magneto-electric laminated element, a Hall element, or a secondary coil.

7. A spool type electromagnetic elastic absolute stress monitoring device with pre-wound wire for easy assembly according to claim 5, characterized in that: When the detection element is in the form of an FPC soft flat cable film, a magneto-electric laminated element, or a Hall element, the support framework is used to place the detection element.

8. A spool type electromagnetic elastic absolute stress monitoring device with pre-wound wire for easy, according to claim 1, characterized in that, When the detection element is in the form of a secondary coil, the winding form can be selected as follows: the secondary coil is directly wound on the outer layer or the inner layer of the main coil winding, or the main coil is wound on both ends of the soft magnetic material magnetic core, the secondary coil is wound on the middle of the soft magnetic material magnetic core, or directly on the measured component.

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