KR20230100859A - External magnetization system using plurality of small solenoid modules and operation method therefor - Google Patents

Abstract

An external magnetization system using a plurality of small solenoid modules according to the present embodiment includes a ferromagnetic frame including a first support and a second support disposed to face the first support; A first magnetization device including a plurality of left solenoid modules provided in a longitudinal direction along the first support and generating a plurality of first lines of magnetic force in a first predetermined direction; a second magnetization device including a plurality of right solenoid modules provided in a longitudinal direction along the second support and generating a plurality of second lines of magnetic force in a predetermined second direction; a sensing device implemented with a plurality of Hall sensors for measuring a change in magnetic flux density associated with the plurality of first lines of magnetic force and the plurality of second lines of magnetic force; And a control device interlocked with the sensing device to control the first magnetization device and the second magnetization device, wherein the plurality of left solenoid modules and the plurality of right solenoid modules include a control device wound on bobbins included in the The diameter is characterized in that it is determined within a predetermined range.

Description

External magnetization system using a plurality of small solenoid modules and operation method therefor

The present specification relates to an external magnetization device using a plurality of solenoid modules and an operation method therefor, and more particularly, to a prestressed concrete member using an inverse magnetostrictive effect in which permeability changes according to the stress state of a magnetic body. An external magnetization system using a plurality of solenoid modules that magnetize PS steel materials (eg, PS tendons and steel bars) included in a prestressed concrete bridge girder (hereinafter referred to as 'PSC girder') to measure the tension stress of and an operation method therefor It is about.

A prestressed concrete bridge (hereinafter referred to as 'PSC bridge') refers to a bridge having a structure in which deflection or cracking is reduced by introducing tension to a prestressed concrete member (hereinafter referred to as 'PC member') using PS steel.

In particular, due to the aging of PCS Type I bridges currently in use, the safety level is continuously declining, and the risk of bridge collapse due to loss of tension in aged PCS structures is continuously increasing.

Although regular safety inspections are conducted for the maintenance of aged PCS bridges, they are mainly conducted for visual inspections such as external cracks and deflection, rather than inspections for tension on prestressed concrete members. As a result, cracks in PCS bridges After the occurrence, it is difficult to guarantee the safety of the bridge.

In particular, when a magnetic field is applied from the outside of the conventional PSC girder as a whole, the external magnetic field does not reach the PS tendon of the deep part due to the magnetic field shielding phenomenon caused by concrete and reinforcing bars, so it is difficult to completely measure the inside of the PSC girder. There was a limit.

Accordingly, in order to measure the tension of PSC bridges, research is being conducted on nondestructive testing methods for measuring tension, such as tension estimation using ultrasonic and elastic wave velocities, tension estimation using vibration characteristics, and tension estimation using magnetic fields.

However, tension diagnosis is possible only for non-attached prestressed tendons exposed by non-destructive testing techniques or newly constructed PSC bridges, and there is no non-destructive strain diagnosis method for existing old PSC bridges.

As a conventional proposal, reference may be made to Patent Publication No. 10-2015-0073349 regarding 'Method for measuring tension stress and degree of corrosion of prestressed steel using inverse magnetostriction and induced magnetic field and electromagnet device therefor'.

An object of the present specification is to provide an external magnetization system using a plurality of small solenoid modules, which is advantageous for miniaturization as the remote magnetization function is greatly improved and the size of the sensor head is reduced compared to the conventional one, and an operation method therefor.

An external magnetization system using a plurality of small solenoid modules according to the present embodiment includes a ferromagnetic frame including a first support and a second support disposed to face the first support; A first magnetization device including a plurality of left solenoid modules provided in a longitudinal direction along the first support and generating a plurality of first lines of magnetic force in a first predetermined direction; a second magnetization device including a plurality of right solenoid modules provided in a longitudinal direction along the second support and generating a plurality of second lines of magnetic force in a predetermined second direction; a sensing device implemented with a plurality of Hall sensors for measuring a change in magnetic flux density associated with the plurality of first lines of magnetic force and the plurality of second lines of magnetic force; And a control device interlocked with the sensing device to control the first magnetization device and the second magnetization device, wherein the plurality of left solenoid modules and the plurality of right solenoid modules include a control device wound on bobbins included in the The diameter is characterized in that it is determined within a predetermined range.

According to the present embodiment, an external magnetization system using a plurality of small solenoid modules with significantly improved remote magnetization function and an operation method therefor are provided.

Specifically, in the external magnetization system using the solenoid module according to the present embodiment, the application of the solenoid structure not only increases the number of windings (N) of the coil compared to the conventional method of winding a coil around a ferromagnetic material in the form of a plate, but also generates a magnetic field. The surface area of the part may increase.

Accordingly, since the magnetic field generated by the external magnetization system according to the present embodiment reaches the deep PS tendon, and thus the change in the magnetic hysteresis effect is easily detected, more accurate residual tension estimation may be possible.

In the external magnetization system using the solenoid module according to the present embodiment, magnetic flux applied to a specific position of the tendon, such as changing the size and angle of the sensor head and the number of coils wound around the sensor head by applying the solenoid-type sensor head An increase in density can be facilitated.

Furthermore, in the external magnetization system according to the present embodiment, the solenoid-shaped sensor head can be installed as close as possible to the PCS I-type bridge to prevent the strength of the magnetic field applied from the outside from being lowered due to the miniaturization.

1 is a diagram for explaining a principle of focusing a composite magnetic field of a plurality of externally generated magnetic fields.
2 is a perspective view showing an external magnetization system using a plurality of small solenoid modules according to an exemplary embodiment.
3 is a block diagram of an external magnetization system using a plurality of small solenoid modules according to an exemplary embodiment.
4 is a view showing the structure of a small solenoid module according to this embodiment.
5 is a conceptual diagram illustrating a magnetization process by an external magnetization system using a plurality of small solenoid modules according to an exemplary embodiment.

All of the foregoing characteristics and the following detailed description are exemplary to help the description and understanding of the present specification. That is, the present specification is not limited to such embodiments and may be embodied in other forms. The following embodiments are only examples for completely disclosing this specification, and are descriptions for conveying this specification to those skilled in the art to which this specification belongs. Therefore, when there are several methods for implementing the components of the present specification, it is necessary to clarify that the implementation of the present specification is possible with any of the specific methods or those identical thereto.

In this specification, if there is a reference that a certain component includes specific elements or a certain process includes specific steps, it means that other elements or other steps may be further included. That is, terms used in this specification are only for describing a specific embodiment, and are not intended to limit the concept of this specification. Furthermore, the examples described to aid understanding of the invention include complementary embodiments thereof.

Terms used in this specification have meanings commonly understood by those skilled in the art to which this specification belongs. Commonly used terms should be interpreted with a consistent meaning according to the context of the present specification. In addition, terms used in this specification should not be interpreted in an overly idealistic or formal sense, unless the meaning is clearly defined. Hereinafter, embodiments of the present specification will be described through the accompanying drawings.

The "transverse direction" referred to in this specification is the PS steel member 21 is disposed long and the PC member 2 is horizontally orthogonal to the direction in which the tension force is introduced to the PC member 2 (eg, Z axis in FIG. 2). It means the width direction (eg, the Y axis of FIG. 2).

Meanwhile, the “longitudinal direction” referred to herein is the height direction (eg, X in FIG. 2 ) of the external magnetization system 200 perpendicularly perpendicular to the width direction (eg, Y axis in FIG. 1 ) of the PC member 2 . axis).

1 is a diagram for explaining a principle of focusing a composite magnetic field of a plurality of externally generated magnetic fields.

The present specification relates to a Synthesized Magnetic Field Focusing (SMF) technology capable of appropriately controlling a vector of a magnetic field using several direct current control transmission (Tx) coils.

In the present specification, an arrangement of individual current sources, Tx coils, and receiving (Rx) points indicated by dots may be modeled as shown in (a) of FIG. 1 .

Meanwhile, in order to obtain a magnetic field distribution concentrated on the Rx plane, the size of each current source must be determined.

)으로부터 생성된 자기장 밀도벡터(

)는 Biot-Savart 법칙에 따라 1차원 모델에 대해 하기 수학식 1과 같이 정의될 수 있다.On the other hand, referring to (b) of FIG. 1, a current source in free space (

) The magnetic field density vector generated from (

) may be defined as in Equation 1 below for a one-dimensional model according to the Biot-Savart law.

For reference, both k and l in Equation 1 may be defined as integers greater than or equal to 1.

은 하기 수학식 2와 같이 정의될 수 있다.On the other hand, in Equation 1

Can be defined as in Equation 2 below.

)는 하기 수학식 3과 같이 정의될 수 있다.On the other hand, the total magnetic field density, which is the sum of all contributions made by all current sources (

) may be defined as in Equation 3 below.

Referring to Equations 1 to 3 mentioned in FIG. 1 , it will be understood that the magnetic field can be focused at a location desired by the user by adjusting current values applied to a specific system.

The synthetic magnetic field focusing principle described in FIG. 1 is described in more detail in a paper (Synthesized Magnetic Field Focusing Using a Current-Controlled Coil Array) published in IEEE MAGNETICS LETTERS (volume 7) in 2016.

2 is a perspective view showing an external magnetization system using a plurality of solenoid modules according to an exemplary embodiment.

1 and 2, the external magnetization system 200 using a plurality of solenoid modules according to the present embodiment includes a ferromagnetic frame P_STR, a plurality of magnetization devices 210_L and 210_R, a sensing device 220, and A control device (not shown) may be included.

The ferromagnetic frame P_STR of FIG. 2 may include a first support part S_L and a second support part S_R.

For example, the first support part S_L and the second support part S_R may be disposed parallel to the longitudinal direction (X axis). In addition, the first support part (S_L) and the second support part (S_R) may be spaced apart by a preset interval (eg, 1 m) to facilitate application to the PCS girder.

For reference, in order to concentrate the magnetization toward the center of the PCS girder, the ferromagnetic frame P_STR of FIG. 1 may be composed of the same or different types of components.

For example, the ferromagnetic frame P_STR, the first support portion S_L, and the second support portion S_R are made of a ferromagnetic material, and since the ferromagnetic material has high electrical conductivity, it serves to minimize current loss and suppress magnetic field loss. can do. Here, the ferromagnetic material may be ferrite or a nickel alloy.

The plurality of magnetizers 210_L and 210_R of FIG. 2 include a plurality of solenoid modules 210_L1 to 210_L6 and 210_R1 to 210_R6 generating a plurality of lines of magnetic force for magnetization of the PS steel 21 in the PC member 2. can do.

For example, the first magnetizer 210_L may include a plurality of left solenoid modules 210_L1 to 210_L6.

For example, the plurality of left solenoid modules 210_L1 to 210_L6 are disposed along the first support part S_L, and each of the plurality of left solenoid modules 210_L1 to 210_L6 is in the longitudinal direction (X side). may be provided in parallel.

In this case, the plurality of left solenoid modules 210_L1 to 210_L6 may generate a plurality of first lines of magnetic force in a first predetermined direction under the control of a control device (not shown).

For example, the second magnetizer 210_R may include a plurality of right solenoid modules 210_R1 to 210_R6.

For example, the plurality of right solenoid modules 210_R1 to 210_R6 are disposed along the second support part S_R, and each of the plurality of right solenoid modules 210_R1 to 210_R6 is in the longitudinal direction (X side). may be provided in parallel.

In this case, the plurality of right solenoid modules 210_R1 to 210_R6 may generate a plurality of second lines of magnetic force in a predetermined second direction under the control of a control device (not shown).

On the other hand, the plurality of left solenoid modules 210_L1 to 210_L6 and the plurality of right solenoid modules 210_R1 to 210_R6 are along the transverse direction (Y direction) to magnetize the PS steel located in the core of the PC member. They may be placed facing each other.

The sensing device 220 of FIG. 2 may be disposed at a predetermined position on the first support part S_L and the second support part S_R.

For example, the sensing device 220 of FIG. 2 may be disposed on one side of a U-shaped holder for the plurality of left solenoid modules 210_L1 to 210_L6. Also, although not shown in FIG. 2 , the sensing device 220 may be disposed on one side of a U-shaped holder for the plurality of right solenoid modules 210_R1 to 210_R6.

In other words, the sensing device 220 has a U-shaped holder for the plurality of left solenoid modules 210_L1 to 210_L6 and a U-shaped holder for the plurality of right solenoid modules 210_R1 to 210_R6 in the transverse direction. (Y direction) may be arranged to face each other.

here. The sensing device 220 of FIG. 2 is implemented based on a plurality of Hall sensors for measuring the change in magnetic flux density (ie, the strength of the magnetic field) of a plurality of magnetic lines of force associated with the degree of magnetization of the PS steel 21. It can be.

Information on the change in magnetic flux density measured by the sensing device 220 of FIG. 2 may be transmitted to a control device (not shown).

The control device (not shown) of FIG. 2 may be implemented to independently control the plurality of magnetizers 210_L and 210_R by interlocking with the sensing device 220 implemented with a plurality of Hall sensors.

In the present specification, the plurality of solenoid modules 210_L1 to 210_L6 and 210_R1 to 210_R6 individually adjust the current value applied from the control module (not shown) based on the principle of focusing the synthetic magnetic field of the plurality of magnetic fields of FIG. 1 described above. By adjusting, the magnetic field at a specific location can be amplified or attenuated.

3 is a block diagram of an external magnetization system using a plurality of solenoid modules according to an exemplary embodiment.

1 to 3, the external magnetization system 300 using a plurality of solenoid modules of FIG. 3 includes a first magnetizer 310_L, a second magnetizer 310_R, a sensing device 320, and a control device ( 330) may be included.

The first magnetization device 310_L and the second magnetization device 310_R of FIG. 3 may be understood as structures corresponding to the first magnetization device 210_L and the second magnetization device 210_R of FIG. 2 .

For example, the first magnetization device 310_L of FIG. 3 generates a plurality of first magnetic lines of force by a plurality of left solenoid modules (eg, 210_L1 to 210_L6 of FIG. 2 ) under the control of the control device 330 . can generate (i.e., generate a magnetic field).

For example, in order to amplify or attenuate a magnetic field corresponding to a specific position, a plurality of input currents individually set for each of a plurality of left solenoid modules (eg, 210_L1 to 210_L6 in FIG. 2 ) are transmitted from the control device 330. may be authorized.

Similarly, the second magnetizer 310_R of FIG. 3 generates a plurality of magnetic lines of force (ie, generates a magnetic field) by a plurality of right solenoid modules (eg, 210_R1 to 210_R6) under the control of the control device 330. )can do.

For example, in order to amplify or attenuate a magnetic field corresponding to a specific position, a plurality of individually set input currents for each of a plurality of right solenoid modules (eg, 210_R1 to 210_R6) are transmitted from the control device 330. may be authorized.

The sensing device 320 of FIG. 3 may be implemented based on a plurality of hall sensors provided at predetermined positions (eg, S_L, S_R, and B of FIG. 2 ).

Here, the plurality of hall sensors may measure changes in magnetic flux density of a plurality of magnetic lines of force associated with the PS steel material (eg, 21 in FIG. 2 ).

The control device 330 of FIG. 3 may control overall operations of the first magnetizer 310_L and the second magnetizer 310_R in conjunction with the sensing device 320 .

That is, the control device 330 may be implemented to calculate a change in stress of a magnetic material (ie, steel) according to the inverse magnetostriction effect based on the information measured by the sensing device 320 .

Meanwhile, the control device 330 may include at least one processor, a computer readable storage medium, and a communication bus. Here, the processor may cause the control device 330 to operate according to the exemplary embodiment mentioned above.

For example, a processor may execute one or more programs stored on a computer readable storage medium. The one or more programs may include one or more computer executable instructions, and the computer executable instructions may be configured to cause the control device 330 to perform operations according to example embodiments when executed by a processor. .

Meanwhile, the computer-readable storage medium may be configured to store computer-executable instructions or program codes, program data, and/or other suitable forms of information. A program stored on a computer readable storage medium includes a set of instructions executable by a processor.

In one embodiment, the computer readable storage medium includes memory (volatile memory such as random access memory, non-volatile memory, or a suitable combination thereof), one or more magnetic disk storage devices, optical disk storage devices, flash memory devices. , other types of storage media that can be accessed by the control device 330 and store desired information, or a suitable combination thereof.

Meanwhile, the communication bus may interconnect various other components of the control device 330, including a processor and a computer readable storage medium.

Control device 330 may also include one or more input/output interfaces providing interfaces for one or more input/output devices and one or more network communication interfaces.

An input/output interface and a network communication interface may be connected to the communication bus. The input/output device may be connected to other components of the control device 330 through an input/output interface.

Exemplary input/output devices include a pointing device (such as a mouse or trackpad), a keyboard, a touch input device (such as a touchpad or touchscreen), an input device such as a voice or sound input device, various types of sensor devices, and/or a photographing device; and/or output devices such as display devices, printers, speakers, and/or network cards.

The exemplary input/output device may be included inside the control device 330 as a component constituting the control device 330, or may be connected to the processor as a separate device distinct from the control device 330.

4 is a diagram showing the structure of a solenoid module according to this embodiment.

Referring to FIGS. 1 to 4 , it will be understood that the structure of the solenoid module 40 shown in FIG. 4 is applied to the plurality of solenoid modules 210_L1 to 210_L6 and 210_R1 to 210_R6 of FIG. 2 .

Referring to FIG. 4 , the solenoid module 40 may be implemented using a bobbin 411 and a wire 413 .

For example, a predetermined material (eg, nickel alloy) may be used for the bobbin 411 .

In addition, it will be understood that the wire 413 may be wound in a predetermined direction as well as a predetermined number of turns (N, for example, 600 times) on the bobbin 411 .

For example, it will be appreciated that the magnitude of the magnetic field generated by the solenoid module 40 may be determined according to the magnitude of current applied from a previous control device (eg, 330 in FIG. 3 ).

Meanwhile, the diameter of the coil, that is, the wire 413 wound around the plurality of solenoid modules (eg, 210_L1 to 210_L6 and 210_R1 to 210_R6 in FIG. 2 ) may be related to the magnitude of the current passing through the wire 413 .

In other words, since the resistance value decreases when the diameter of the wire 413 is increased, it may be advantageous to increase the strength of the magnetic field according to the amplification of the current passing through the wire 413, but the sensor head around which the wire 413 is wound, that is, The diameter of the bobbin 413 also needs to be considered.

Accordingly, the diameter of the wire 413 wound around the plurality of solenoid modules (eg, 210_L1 to 210_L6 and 210_R1 to 210_R6 in FIG. 2 ) according to the present embodiment is preferably determined between 2 and 3 mm.

5 is a conceptual diagram for explaining a magnetization process by an external magnetization system using a plurality of solenoid modules according to an exemplary embodiment.

1 to 5, the plurality of left solenoid modules 510_L1 to 510_L6 of FIG. 5 correspond to the plurality of left solenoid modules of FIG. 2 (eg, 210_L1 to 210_L6 of FIG. 2). can do.

Also, the plurality of right solenoid modules 510_R1 to 510_R6 of FIG. 5 may correspond to the plurality of right solenoid modules (eg, 210_R1 to 210_R6) of FIG. 2 .

Current may be transmitted to each of the plurality of left solenoid modules 510_L1 to 510_L6 of FIG. 5 through a wire connected to a control device (not shown).

For example, the first left-current I_L1 is defined as a current applied from a control device (not shown) to the first left solenoid module 510_L1, and the second left-current (I_L2) may be defined as a current applied from a control device (not shown) to the second left solenoid module 510_L2.

For example, the third left-current I_L3 is defined as a current applied from a control device (not shown) to the third left solenoid module 510_L3, and the fourth left-current (I_L4) may be defined as a current applied from a control device (not shown) to the fourth left solenoid module 510_L4.

For example, the fifth left-current I_L5 is defined as a current applied from a control device (not shown) to the fifth left solenoid module 510_L5, and the sixth left-current (I_L6) may be defined as a current applied from a control device (not shown) to the sixth left solenoid module 510_L6.

For example, the first right-current I_R1 is defined as the current applied from the control device (not shown) to the first right solenoid module 510_R1, and the second right-current (I_R2) may be defined as a current applied from a control device (not shown) to the second right solenoid module 510_R2.

For example, the third right-current I_R3 is defined as the current applied from the control device (not shown) to the third right solenoid module 510_R3, and the fourth right-current (I_R4) may be defined as a current applied from a control device (not shown) to the fourth right solenoid module 510_R4.

For example, the fifth right-current I_R5 is defined as the current applied from the control device (not shown) to the fifth right solenoid module 510_R5, and the sixth right-current (I_R6) may be defined as a current applied from a control device (not shown) to the sixth right solenoid module 510_R6.

According to this embodiment, each of the plurality of left solenoid modules 510_L1 to 510_L6 in FIG. 5 may be independently controlled based on different current magnitudes (or frequencies). That is, the magnitudes and directions of the first to sixth left currents I_L1 to I_L6 may be individually set.

For example, the first left-current I_L1 and the sixth left-current I_L6 may be currents having predetermined magnitudes and directions (eg, 38.19A). The second left-current I_L2 and the fifth left-current I_L5 may be currents having predetermined magnitudes and directions (eg, -59.67A). The third left-current I_L3 and the fourth left-current I_L4 may be currents having predetermined magnitudes and directions (eg, 90.39 A).

Similarly, each of the plurality of right solenoid modules 510_R1 to 510_R6 of FIG. 5 may be independently controlled based on different current magnitudes (or frequencies). That is, the magnitudes and directions of the first right to sixth right currents I_R1 to I_R6 may be individually set.

According to this embodiment, it can be controlled so that current of the same direction and magnitude is applied between a pair of solenoid modules existing at positions corresponding to each other.

For example, the first right-current I_R1 may have the same magnitude and direction as the first left-current I_L1 (eg, 38.19A). The second right-current I_R2 may have the same magnitude and direction as the second left-current I_L2 (eg, -59.67A).

For example, the third right-current I_R3 may have the same magnitude and direction as the third left-current I_L3 (eg, 90.39 A). The fourth right-current I_R4 may have the same magnitude and direction as the fourth left-current I_L4 (eg, 90.39 A).

For example, the fifth right-current I_R5 may have the same magnitude and direction as the fifth left-current I_L5 (eg, -59.67A). The sixth right-current I_R6 may have the same magnitude and direction as the sixth left-current I_L6 (eg, 38.19A).

Current may be transmitted to each of the plurality of right solenoid modules 510_R1 to 510_R6 of FIG. 5 through a wire connected to a control device (not shown). In addition, each of the plurality of right solenoid modules 510_R1 to 510_R6 may be independently controlled based on the magnitude (or frequency) of each different current.

It is understood that the present specification is not limited to the number of solenoid modules (six on the left and right) shown in FIGS. 2 and 5, and the number of solenoid modules may be added or reduced depending on the operating environment. It will be.

In addition, although the arrangement of the plurality of solenoid modules shown in FIGS. 2 and 5 is shown as being arranged in parallel along the Z-axis, it will be understood that the present specification is not limited thereto.

In other words, according to the position or shape of the PC member, the plurality of solenoid modules may be arranged in parallel along a specific axis (eg, X axis or Y axis).

5 is a flowchart illustrating an operation of an external magnetization system using a plurality of solenoid modules according to an exemplary embodiment.

1 to 5, in step S510, the external magnetization system (eg, 200 in FIG. 2) according to the present embodiment includes a plurality of solenoid modules (eg, 210_L1 to 210_L6, 210_ R1 to 210_R6 in FIG. 2) It is possible to generate a plurality of magnetic lines of force (ie, magnetic fields) in a predetermined direction (eg, 21 in FIG. 2) by using.

In step S520, the external magnetization system (eg, 200 in FIG. 2 ) according to the present embodiment is based on the sensing operation of the sensing device (eg, 220 in FIG. 2 ) including a plurality of Hall sensors provided at predetermined positions. As a result, it is possible to detect a change in magnetic flux density for a plurality of previously generated magnetic lines of force (ie, magnetic fields).

Here, detection information associated with changes in magnetic flux densities of the plurality of magnetic lines of force may be transmitted to a control device (eg, 330 in FIG. 3 ).

In step S530, the external magnetization system (eg, 200 in FIG. 2) according to the present embodiment can grasp the stress change of the PS steel material (eg, 21 in FIG. 2) based on the detection information associated with the change in magnetic flux density. Rather, it is possible to derive the tension stress of the PS steel (eg, 21 in FIG. 2).

As mentioned above in relation to the background art, according to the Villari Effect or inverse magnetostriction effect, which is widely known in the field of physics of magnetic material, a change in the stress of a magnetic material is accompanied by a change in magnetic permeability.

Here, the mathematical relationship between the change in stress and the change in magnetic permeability of steel is already known through various known technologies, including Korean Patent Registration No. 10-0573735.

According to this embodiment, since the magnetic field can reach the deep part of the old PSC bridge, which cannot be confirmed by the existing precise safety diagnosis technique, the tension and internal state of the bridge can be diagnosed more precisely.

That is, since efficient and reliable precision diagnosis of PSC bridges is possible, efficient maintenance and accident prevention of major social infrastructures may be possible.

In addition, maintenance cost can be reduced through immediate repair and reinforcement through improved maintenance efficiency through condition diagnosis of PSC bridges, as well as PSC bridge demolition and removal by increasing the service life of PSC bridges through efficient management of bridges. Reduction of social costs may be possible due to re-construction.

In the detailed description of the present specification, specific embodiments have been described, but various modifications are possible without departing from the scope of the present specification. Therefore, the scope of the present specification should not be limited to the above-described embodiments and should not be defined by those equivalent to the claims of this invention as well as the claims to be described later.

300: external magnetization system
310_L: first magnetizer
310_R: 2nd magnetizer
320: detection device
330: control device

Claims (1)

a ferromagnetic frame including a first support portion and a second support portion disposed to face the first support portion;
a first magnetization device including a plurality of left solenoid modules provided in a longitudinal direction along the first support and generating a plurality of first lines of magnetic force in a predetermined first direction;
a second magnetizer including a plurality of right solenoid modules provided in a longitudinal direction along the second support and generating a plurality of second lines of magnetic force in a predetermined second direction;
a sensing device implemented with a plurality of Hall sensors for measuring a change in magnetic flux density associated with the plurality of first magnetic lines of force and the plurality of second lines of magnetic force; and
A control device interlocked with the sensing device to control the first magnetization device and the second magnetization device,
Characterized in that the diameters of the wires wound on the bobbins included in the plurality of left solenoid modules and the plurality of right solenoid modules are determined within a predetermined range.
External magnetization system using multiple small solenoid modules.

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