KR101220311B1 - Bending sensor apparatus - Google Patents

Abstract

The present invention relates to a bending sensor device that can measure the deflection, settlement, slope, etc. by bending measurement, in the present invention, the optical fiber strain sensor or electrical resistance strain gauge is fixedly installed and the physical quantity change such as sag, settlement, slope Is provided between the bending portion that is generated when bending, the outer protective tube holder is fixed to the left and right of the bending portion, the connecting rod holder is formed to protrude to the outside of the outer protective tube holder, respectively, and the outer protective tube holder is installed from the outside Provided is a bending sensor device, comprising: an outer protective tube for protecting against foreign matter or external pressure and limiting an angle changed by bending to prevent damage such as breakage of the sensor; and a bending sensor connecting rod fixed to the connecting rod holder. do.

Description

Bending sensor device {BENDING SENSOR APPARATUS}

The present invention relates to a bending sensor device that can measure deflection, settlement, inclination, etc., by bending measurement. In particular, when a bridge is very high, such as a bridge, or when a bridge space is a river or sea, it is difficult to install a fixed point. If the vertical deflection cannot be measured with the bending sensor, the vertical deflection can be measured by measuring the small angle change of the bridge with the bending sensor, and the angle change by the bending measurement can be measured to determine the internal displacement of the tunnel, the slope or the ground. The present invention relates to a bending sensor device capable of measuring underground slopes, slopes of bridge pylons or bridges, slopes of building structures, settlement of soft ground, and relative displacements of dam structures.

The vertical deflection of the bridge is a very important measurement for evaluating the condition of the bridge 81, but the conventional measurement method is mainly a ring displacement meter fixed by a contact displacement meter (91 in FIG. 1) or a connecting wire (93 in FIG. 1). It measures by (92 of FIG. 1). This conventional method is a very convenient method that can be installed in the case where the high school bridge is not high or the school space is composed of the ground. However, when the bridge is high, such as a bridge installed on the Han River, or when the river or vehicle passes through the river, it is difficult to install a fixed point, so the method using a contact displacement gauge or a ring displacement gauge has limitations in application.

In order to overcome this disadvantage, recently, methods using a laser displacement meter, an image processing technique, and a high precision inclinometer have been tried.

The technique using the laser displacement meter and the image processing has the advantage that it can be easily applied when the bridge space is the ground surface even though the bridge height is high, but when the bridge space is flowed by the river or the vehicle, it should be installed in the bridge or bridge piers. In order to measure the vertical deflection of bridges, a method of measuring deflection by installing a laser displacement meter in a pier during long-term measurement is most commonly used. This method is very expensive for a displacement deflection and a pier or shift vibration. Because it is hard to be regarded as an absolute fixed point due to the influence of long-term deformation or long-term deformation, it always includes an error in the measurement deflection and has a disadvantage of being affected by climatic conditions due to the laser characteristics.

Some techniques for estimating the deflection of a bridge using an ultra-precise inclinometer have been applied.However, the ultra-precision inclinometer for estimating the vertical deflection of a bridge can be applied only within a limited range because only static measurement is possible and dynamic measurement is not possible. Was implicated.

In order to solve the above problems, the present invention provides a bending sensor that can measure the deflection, settlement, inclination, etc. by bending measurement, it is possible to measure the vertical deflection of the bridge irrespective of the state of bridge and bridge space By using FBG fiber optic sensor, multiple bending sensors can be installed in one cable by using multiplexing function that can install multiple sensors with different center wavelengths in one cable. Compensation for temperature must be performed when measuring strain, and by providing an optical fiber sensor above and below a bending part, a bending sensor device for measuring vertical deflection of a bridge, which is configured to be compensated by temperature change, is provided. The purpose is.

In addition, by measuring the angular change by the bending principle, which is the same principle, the internal displacement of the tunnel, the slope of the slope or ground, the slope of the bridge pylon or bridge, the slope of the building structure, the settlement of the soft ground, the relative displacement of the dam structure, etc. An object of the present invention is to provide a bending sensor device capable of measuring a back and the like.

The object of the present invention relates to a bending sensor device that can measure the deflection, settlement, inclination, etc. by bending measurement, the optical fiber strain sensor or electrical resistance strain gauge is fixedly installed and the physical quantity change, such as deflection, settlement, slope Is provided between the bending portion that is generated when bending, the outer protective tube holder is fixed to the left and right of the bending portion, the connecting rod holder is formed to protrude to the outside of the outer protective tube holder, respectively, and the outer protective tube holder is installed from the outside By a bending sensor device comprising a bent sensor connecting rod fixed to the connecting rod holder to protect from foreign matter or external pressure, to limit the angle changed by bending to prevent damage, such as breakage of the sensor Is achievable.

In addition, the optical fiber sensor 2 may not only be fixed to the bending part 7 but also fixed to the outer protective tube holder 6, and may be configured to react more sensitively than when fixed to the bending part 7. In addition, the bending portion may be provided with a rotating hinge portion at the center of the outer protective tube holder 6 or the bending portion 7. In addition, the sensor may be configured using not only an optical fiber sensor but also an electric resistance strain gauge of a full bridge.

By providing the bending sensor device as described above, it is possible to measure the vertical deflection of the bridge irrespective of the state of bridge and bridge space, multiplexing is possible, it is possible to install a number of bending sensors in one cable, self-temperature Compensation is possible. In addition, by measuring the angular change by the measurement of bending, which is the same principle, the internal displacement of the tunnel, the slope of the slope or ground, the slope of the bridge pylon or bridge, the slope of the building structure, the settlement of the soft ground, the collapse of the slope, the dam Relative displacements of structures and the like can be measured.

1 is an example for explaining a conventional method of measuring the vertical deflection of the bridge.
Figure 2 is an exemplary view for explaining the bending sensor device and the vertical deflection of an embodiment according to the present invention.
3 is an explanatory diagram illustrating a configuration of a bending sensor using the optical fiber strain sensor and a change state of the optical fiber strain sensor by bending.
4 is an explanatory diagram illustrating a method of installing the bending sensor device of the present invention on a bridge and an explanatory diagram for mathematically explaining the bending amount.
5 shows various modifications of the bending sensor of the present invention.
6 is a block diagram of a bending sensor using an electrical resistance strain gauge.
Figure 7 is an embodiment using a bending sensor device for measuring the internal displacement of the tunnel.
Figure 8 is an embodiment using a bending sensor device for measuring the slope of the ground and ground slope.
Figure 9 is an embodiment using a bending sensor device for slope collapse monitoring.
Figure 10 is an embodiment using a bending sensor device for monitoring the deformation caused by the hydraulic pressure of the dam structure.

Hereinafter, a preferred embodiment of the bending sensor according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 2 is a diagram illustrating a bending sensor device according to an exemplary embodiment of the present invention, in which a bending sensor device is installed in a bridge and a case in which vertical sag occurs in the bridge. The bending sensor device includes a bending sensor 1 and a bending sensor connecting rod 11. As shown in the upper figure of FIG. 2, the bridge is provided with several bending sensors 1 connected by the bending sensor connecting rods 11. As shown in the lower view of FIG. 2, when deflection occurs in the bridge 81 due to the load 82, the bending sensor connecting rod 11 provided in the bending sensor 1 differs from the initial installation state by a corresponding deflection amount. A slight angular change is generated and the amount of change is measured using the bending sensor 1 to measure the vertical deflection of the piers.

3A is an example of a bending sensor in accordance with the present invention. The bending sensor 1 includes a bending part 7 which is bent by a force applied from the outside, an outer protective tube holder 6 which fixes the left and right sides of the bending part 7 at left and right sides of the bending part 7, External rods protruding to the outside of the outer protective tube holder (6), respectively, the connecting rod holder 12 is fixed to the bending sensor connecting rod, the outer protective tube holder (6) is screwed to the outside to block and protect the bending portion (7) from the outer space It consists of a protective tube (3). The outer protective tube 3 is a component that protects the sensing unit from foreign matter or external pressure from the outside and limits the angle changed by bending to prevent damage such as breakage of the sensor. The bending sensor connecting rod is fitted to the connecting rod holder 12, and then connected to each other by the connecting rod fixing nut 14 and the connecting rod fixing bolt 13 provided in the connecting rod holder 12.

The bending part 7 is fixed or attached to the optical fiber strain sensor 2 or the electrical resistance strain gauge 31, and is a portion in which bending occurs when physical quantities such as sag, settlement, and slope change. Only one of the two outer protective tube holders 6 provided in the bending sensor 1 is fixedly installed on the bridge and the other one is connected to the bending sensor connecting rod 11 in a state in which it is not fixedly installed on the bridge. Therefore, when vertical deflection occurs in the bridge, deflection by the outer protective tube holder 6 which is not fixedly installed in the bridge can be measured by the optical fiber strain sensor 2 provided in the bending part as shown in FIG. 3B. That is, as shown in FIG. 3B, the vertical deflection of the bridge can be measured by measuring the change in strain of the optical strain sensor to which the prestrain provided in the bending part 7 is applied. will be.

In general, the fiber optic sensor responds to temperature and strain at the same time, so it is necessary to compensate the temperature when measuring strain using the FBG fiber optic sensor. To this end, the optical fiber sensor 2 of the present invention is attached to the upper and lower surfaces of the bending part 7 simultaneously, thereby simultaneously reacting to temperature changes, and when bending occurs, an absolute physical quantity is the same but a change in physical quantity whose sign is opposite by compression or tension is performed. By causing it, there is a feature that can provide a bending sensor capable of self-temperature compensation that can remove the influence of the temperature by the equation (1).

4A is a view for explaining an example where a bending sensor device is installed on a bridge. As shown in FIG. 4A, only one of the two outer protective tube holders 6 is fixed to the bridge by using the bending sensor holder 21 and the other one of the bending sensor connecting rods 11 is not fixed to the bridge. This is an installation diagram showing the connection with. 4B is an explanatory diagram for mathematically explaining a case in which bending occurs in a bending sensor device installed in the same manner as in FIG. 4A. In Equation 2, the vertical deflection distance δ is a horizontal distance l and a bending angle θ. Expressed by the value of.

5 and 6 relates to a bending sensor that can be modified in various forms, and is configured to react more sensitively than when the optical fiber sensor 2 is fixed to the outer protective tube holder 6 and fixed to the bending part 7. This can be done (FIG. 5 (a)). As another example, in forming the bending part, the rotating hinge 22 may be installed at one side of the outer protective tube holder 6 (FIG. 5B), or the rotating hinge 22 may be installed at the center of the bending part. (FIG. 5 (c)) is shown. As shown in FIG. 6, in addition to the optical fiber sensor, the bending part may be configured using an electric resistance strain gauge 31 of a full bridge.

Hereinafter, the bending sensor device according to the present invention suggests that not only the vertical sag of the bridge can be installed and utilized in various fields. As shown in FIG. 7, by installing a bending sensor device in a structure 83 having a circular cross section such as a tunnel, the hole displacement of the tunnel may be measured. As shown in FIG. 8, FIG. 9, and FIG. 10, it is also possible to measure the slope of the ground installed on the slope or ground. In addition, it can be used to measure various physical quantities that can convert external physical quantity changes such as the slope of bridge pylons or bridges, the slope of building structures, the settlement of soft ground, the collapse of slopes, and the relative displacement of dam structures. It features.

The present invention described above is not limited to the above-described embodiments and drawings, and various substitutions, modifications, and changes are possible within the scope without departing from the technical spirit of the present invention. It will be apparent to those who have

1 bending sensor 2 optical fiber strain sensor
3: outer protective tube 4: outer protective tube fixing nut
5: outer protective tube fixing bolt 6: outer protective tube fixing
7: bending part 11: bending sensor connecting rod
12: connecting rod fixing rod 13: connecting rod fixing bolt
14: connecting rod fixing nut 21: bending sensor holder
22: rotating hinge portion 31: electrical resistance strain gauge
81: bridge 82: working load
83: tunnel 84: slope
85: breaking activity surface 86: dam structure
91: contact displacement meter 92: ring-shaped displacement meter
93: ring-shaped displacement meter connection wire

Claims (5)

The present invention relates to a bending sensor device that can measure deflection, settling and tilting by bending measurement.
A bending part in which an optical fiber strain sensor or an electrical resistance strain gauge is fixedly installed, and bending occurs when physical quantities such as sag, settlement, and slope change;
An outer protective tube holder fixed to the left and right sides of the bending part,
Connecting rod holders protruding from the outer protective tube holders, respectively;
An external protective tube installed between the external protective tube holders to protect the bending part from foreign matter or external pressure from the outside, and to limit an angle changed by bending to prevent damage such as breakage of the sensor; and
Bending sensor device characterized in that it comprises a bending sensor connecting rod fixed to the connecting rod holder.
The method of claim 1,
The optical fiber strain sensor is attached to a state in which a pre-strain is applied, bending sensor device, characterized in that attached to the upper and lower portions of the bending portion at the same time.
The method of claim 1,
The optical fiber strain sensor is bent sensor device, characterized in that also installed in the outer protective tube holder.
The method of claim 1,
Bending sensor device, characterized in that the bending portion includes a rotary hinge.
The method of claim 1,
The electrical resistance strain gauge is a bending sensor device, characterized in that provided as a full bridge electrical resistance strain gauge.

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