CN201043923Y - Fiber Bragg Grating Pressure Sensor for Geotechnical Applications - Google Patents

Abstract

The utility model relates to an optical fiber grating type pressure sensor for rock and soil, comprising an optical fiber grating, an optical fiber grating temperature sensor, an equal-intensity beam and a cylinder body, the optical fiber grating is pasted on the equal-intensity beam, and the equal-intensity beam is fixedly installed on the bottom surface of the cylinder body On the lower part of the upper cover of the cylinder body, there is a downward protrusion corresponding to the equal-strength beam. The fiber grating is connected in series with a fiber grating temperature sensor in a free state without force through the optical fiber. The optical fiber channel on the cylinder body is connected with the optical signal mediation and processing device. After the upper cover of the cylinder body bears pressure, it acts on the other end of the equal-intensity beam, causing deformation, causing the strain of the optical grating, which is transmitted to the optical signal mediation and processing device for analysis and processing through the optical fiber. The utility model has the characteristics of high precision, high sensitivity, simple structure, intrinsically safe, anti-corrosion, anti-electromagnetic interference, strong durability, high reliability, easy to form a network and the like.

Description

Fiber Bragg Grating Pressure Sensor for Geotechnical Applications

technical field

The utility model relates to a detection sensor, specifically a fiber grating type pressure sensor used for pressure detection and long-term safety monitoring of geotechnical engineering (including water conservancy and hydropower, tunnels, highways, municipal buildings, coal mines, etc.) sensor.

Background technique

At present, most of the sensors used to monitor the pressure in the construction process of geotechnical engineering are vibrating wire sensors. The basic principle is to use the energized coil to generate electromagnetic excitation to make the vibrating wire vibrate according to its natural frequency, and change the tension of the vibrating wire to obtain different vibration frequencies. . Due to the harsh working environment of geotechnical engineering and various interferences during the construction process, the life, reliability, and accuracy of electromagnetic sensors such as vibrating wires, resistance strain gauges, and magnetostrictive pressure cannot be guaranteed, and it is even more unfavorable. Long-term health monitoring.

Contents of the invention

In order to overcome the deficiencies of the above-mentioned prior art, the utility model provides a kind of fiber grating for rock and soil with high precision, high sensitivity, simple structure, intrinsically safe, anti-corrosion, anti-electromagnetic interference, strong durability, high reliability, and easy to form a network sensor.

The purpose of this utility model is achieved in this way: a fiber grating type pressure sensor for rock and soil, which includes fiber grating, fiber grating temperature sensor, equal strength beam and cylinder body, fiber grating is pasted on the equal strength beam, and the equal strength beam It is fixedly installed on the bottom surface of the cylinder body, and the lower part of the upper cover of the cylinder body is provided with a downward protrusion corresponding to the equal-strength beam; the fiber grating is connected in series with a free-state fiber grating temperature sensor through an optical fiber, and the cylinder body An optical fiber channel is arranged on the cylinder body, and the optical fiber passes through the optical fiber channel on the cylinder body to connect with the optical signal mediation and processing device.

The equal-strength beam is in an inverted L shape, and the protrusion at the lower part of the upper cover of the cylinder body is a plane.

The equal-strength beam is wedge-shaped with an inclined upper surface, and the protrusion on the lower part of the upper cover of the cylinder body is inclined to match the upper surface of the equal-strength beam.

The utility model pastes the optical fiber grating on the equal-strength beam, and the equal-strength beam is fixedly installed on the wall of the cylinder body. After the upper cover of the cylinder body bears pressure, it acts on the other end of the equal-strength beam, causing deformation and causing the strain of the optical grating. The optical fiber is transmitted to the optical signal mediation and processing device for analysis and processing. In order to compensate the temperature change of the sensor, a free-state unforced fiber grating temperature sensor is connected in series with the measuring grating to eliminate the influence of temperature. Effectively avoid all kinds of interference caused by the harsh working environment in the process of geotechnical engineering construction. The utility model has the characteristics of high precision, high sensitivity, simple structure, intrinsic safety, anti-corrosion, anti-electromagnetic interference, strong durability, high reliability, easy to form a network and the like.

The optical signal mediation and processing device in the present invention is an existing equipment, and will not be repeated here.

Description of drawings

Fig. 1 is the structural representation of the utility model embodiment 1;

Fig. 2 is the structural representation of the utility model embodiment 2;

Among them, 1. Cylinder body, 2. Cylinder body upper cover, 3. Equal strength beam, 4. Fiber grating, 5. Fiber grating temperature sensor, 6. Optical fiber, 7. Fiber channel.

Detailed ways

Below in conjunction with accompanying drawing and embodiment the utility model is further described.

Embodiment 1, the structure is shown in Figure 1, the fiber grating 4 is pasted on the inverted L-shaped equal-strength beam 3, the equal-strength beam 3 is fixedly installed on the inner bottom surface of the cylinder body 1, and the lower part of the upper cover 2 of the cylinder body is provided with a The lower plane protrusion corresponding to the equal strength beam 3. The upper cover 2 of the cylinder block acts on the other end of the equal-strength beam 3 after being under pressure, causing deformation and causing the strain of the optical fiber grating 4. In order to compensate for the temperature change of the sensor, a free-state unstressed optical fiber grating temperature sensor 5 and The aforementioned fiber gratings 4 are connected in series to eliminate the influence of temperature. The fiber grating 4 and the fiber grating temperature sensor 5 are connected in series through an optical fiber, and the optical fiber passes through the optical fiber channel 7 on the cylinder body 1 to connect with the optical signal mediation and processing device, and the received signal is transmitted to the optical signal mediation and processing device through the optical fiber 6 for processing .

Embodiment 2: The structure is shown in Figure 2. The fiber grating 4 is pasted on the wedge-shaped equal-intensity beam 3 whose upper surface is inclined. The equal-intensity beam 3 is fixedly installed on the inner bottom surface of the cylinder body 1. There is a downward inclined protrusion corresponding to the equal strength beam 3 . The upper cover 2 of the cylinder block acts on the other end of the equal-strength beam 3 after bearing the pressure, causing deformation and causing the strain of the optical fiber grating 4. In order to compensate the temperature change of the sensor, a free-state unstressed optical fiber grating temperature sensor 5 and The aforementioned fiber gratings 4 are connected in series to eliminate the influence of temperature. The fiber grating 4 and the fiber grating temperature sensor 5 are connected in series through an optical fiber, and the optical fiber passes through the optical fiber channel 7 on the cylinder body 1 to connect with the optical signal mediation and processing device, and the received signal is transmitted to the optical signal mediation and processing device through the optical fiber 6 for processing .

Claims (3)

1. A fiber grating type pressure sensor for rock and soil, it comprises fiber grating, fiber grating temperature sensor, equal strength beam and cylinder body, is characterized in that: fiber grating is pasted on equal strength beam, and equal strength beam is fixedly installed in the cylinder On the bottom surface of the body, the lower part of the upper cover of the cylinder body is provided with a downward protrusion corresponding to the equal-strength beam. The fiber grating is connected in series with a fiber grating temperature sensor in a free state without force through an optical fiber. There is a fiber optic channel on the cylinder body. , the optical fiber passes through the optical fiber channel on the cylinder body to connect with the optical signal mediation and processing device. 2. The fiber grating type pressure sensor for geotechnical application according to claim 1, characterized in that: the equal-strength beam is in an inverted L shape, and the protrusion at the lower part of the upper cover of the cylinder body is a plane. 3. The fiber Bragg grating type pressure sensor for geotechnical use according to claim 1, characterized in that: the equal-strength beam is a wedge shape with an upper surface inclination, and the protrusion at the lower part of the cylinder body loam cake is equal to that of the equal-strength beam. The upper surface is inclined to match.

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