CN205537696U - Stress and strain monitoring and early warning system for key positions of steel structure - Google Patents

Abstract

The utility model provides a steel construction strategic locations stress and strain monitoring and early warning system, includes a plurality of fiber bragg grating sensor wares, photoelectric detector, AD conversion chip, DA module, treater, alarm module and SMS module, the fiber bragg grating sensor ware including matcing grating array and sensing grating array, matching grating array in be equipped with the piezoelectrics, photoelectric detector pass through amplifier and AD conversion chip and hold with processor input and be connected, DA module, SMS module are connected with the treater output. The utility model discloses a sawtooth wave produces the circuit, makes the center wavelength coincidence of matcing grating array and sensing grating array, reaches the purpose of high precision measurement and early warning.

Description

Stress and strain monitoring and early warning system for key positions of steel structure

technical field

The utility model relates to the technical field of stress and strain monitoring of steel structures, in particular to a stress and strain monitoring and early warning system for key positions of steel structures.

Background technique

In recent years, steel structures have been widely used in buildings, and their structures have become more and more novel, their forms have become more and more complex, and their scales have become larger and larger. It has become one of the most important and active fields in contemporary architectural structures. The development of steel structures has put forward higher requirements for the health monitoring technology of steel structures during construction and in use. The existing steel structure stress monitoring system can monitor the deformation of the common position of the steel structure, but its sensitivity cannot meet the requirements for the key position of the steel structure, and the key position of the steel structure not only needs to be able to monitor the stress and strain, but also needs to be able to monitor the stress and strain at the key position of the steel structure. Therefore, the monitoring and early warning of stress and strain in key positions of steel structures is still a major problem to be solved.

Contents of the invention

In order to solve the above-mentioned defects in the prior art, the utility model provides a stress-strain monitoring and early warning system for key positions of steel structures, through the sawtooth wave generation circuit, the center wavelengths of the matching grating array and the sensing grating array coincide to achieve high precision For measurement and early warning purposes.

The technical solution adopted by the utility model: a stress and strain monitoring and early warning system for key positions of steel structures, including a plurality of fiber grating sensors, photoelectric detectors, A/D conversion chips, D/A modules, processors, alarm modules and short message modules The fiber grating sensor includes a matching grating array and a sensing grating array, and a piezoelectric body is arranged in the matching grating array; the photodetector is connected to the input end of the processor through an amplifier and an A/D conversion chip ; The D/A module and the short message module are connected to the output end of the processor.

Preferably, the P0.7 port of the D/A module is connected to the SDIN serial digital signal input terminal, the P0.6 port is connected to the clock pulse signal, and the P0.5 port is connected to the chip selection signal.

Preferably, the short message module adopts SIM800L module.

Preferably, the A/D conversion chip is an ADS7886 chip.

Preferably, said processor adopts STC90C52RC single-chip microcomputer.

Preferably, the fiber grating sensor is provided with two photocouplers inside.

Preferably, the alarm module adopts sound and light alarm.

Beneficial effects of the utility model: the utility model adopts the matching grating demodulation method to demodulate the information of the fiber grating sensor, and the light emitted by the broadband light source is incident to the sensor fiber grating array through the photocoupler, and only the light satisfying the Bragg condition can It is reflected back, and then enters the matching grating array through the photocoupler again. By applying a sawtooth wave scanning voltage signal to the piezoelectric body of the matching grating array, the central wavelength of the matching grating array is adjusted to change within a certain range. When the reflection spectrum peak of the matching grating array coincides with the reflection spectrum peak of the sensing grating array, the light intensity reflected by the matching grating array is the largest, and the reflected light converges on the photodetector, which is converted into a corresponding electrical signal, which is passed through After the amplifier is amplified, the STC90C52RC single-chip microcomputer chip controls the real-time acquisition of this voltage signal and finds its maximum value. This maximum value is the corresponding maximum light intensity after being reflected by the matching grating array. At the same time, according to the maximum value, the corresponding voltage value applied to the matching grating array can be determined, and then according to the relationship between the peak wavelength of the reflection spectrum and the scanning voltage, it can be concluded that the wavelength drift of the sensing grating array is affected by external physical quantities, and finally The magnitude of the strain can be calculated according to the encoding relationship between the external physical quantity of the sensor and the wavelength. Therefore, the utility model monitors the stress and strain of the steel structure more accurately, can monitor when the strain is very small, and can be applied to key positions of the steel structure.

Description of drawings

Fig. 1 is a system structure block diagram of the present utility model;

Fig. 2 is the utility model sawtooth wave generation circuit diagram;

Fig. 3 is a circuit diagram of the short message sending module of the present invention.

detailed description

The following is a specific embodiment of the present utility model, which will be further described in conjunction with the accompanying drawings.

As shown in Figure 1, a stress and strain monitoring and early warning system for key positions of steel structures includes multiple fiber grating sensors, photodetectors, A/D conversion chips, D/A modules, processors, alarm modules and SMS modules; The fiber grating sensor includes a matching grating array and a sensing grating array, and a piezoelectric body is arranged in the matching grating array; the photodetector is connected to the input end of the processor through an amplifier and an A/D conversion chip; D The /A module and the short message module are connected to the output end of the processor.

In this embodiment, the A/D conversion chip adopts the ADS7886 chip, the processor adopts the STC90C52RC single-chip microcomputer, the fiber grating sensor is provided with two optocouplers inside, and the alarm module adopts sound and light alarm .

As shown in Figure 2, the P0.7 port of the D/A module is connected to the SDIN serial digital signal input terminal, the P0.6 port is connected to the clock pulse signal, and the P0.5 is connected to the chip selection signal, and the D/A is controlled by the STC90C52RC single-chip microcomputer The module outputs a sawtooth wave to drive the piezoelectric body, so that the central wavelength of the matching grating array changes under a certain pressure. At a certain moment, it can completely coincide with the central wavelength of the sensing grating array. Maximum, so as to achieve the purpose of measurement.

The short message module adopts SIM800L module, and the single-chip microcomputer judges according to the strain value measured by the fiber grating sensor, and if it exceeds the set value, the system sends the information of the alarm point to the preset mobile phone number. As shown in Figure 3, it is the wiring diagram of the SMS module, in which the RST pin in the SIM800L module is the module reset pin, which is connected to the RD port of the microcontroller. RXD and TXD are the receiving and sending data pins of the module respectively, which are connected to the corresponding TXD and RXD of the single-chip microcomputer to make the SIM800L module communicate with the single-chip microcomputer.

Claims (7)

1. A steel structure critical position stress and strain monitoring and early warning system is characterized in that: comprise a plurality of fiber grating sensors, photodetectors, A/D conversion chips, D/A modules, processors, alarm modules and short message modules; The fiber grating sensor includes a matching grating array and a sensing grating array, and a piezoelectric body is arranged in the matching grating array; the photodetector is connected to the input end of the processor through an amplifier and an A/D conversion chip; D The /A module and the short message module are connected to the output end of the processor. 2. The stress and strain monitoring and early warning system for key positions of steel structures according to claim 1, characterized in that: the P0.7 port of the D/A module is connected to the SDIN serial digital signal input port, and the P0.6 port is connected to the clock pulse Signal, P0.5 connects chip selection signal. 3. The stress and strain monitoring and early warning system for key positions of steel structures according to claim 1, wherein the short message module adopts SIM800L module. 4. The stress and strain monitoring and early warning system for key positions of steel structures according to claim 1, characterized in that: the A/D conversion chip is an ADS7886 chip. 5. The stress and strain monitoring and early warning system for key positions of steel structure according to claim 1, characterized in that: said processor adopts STC90C52RC single-chip microcomputer. 6. The stress and strain monitoring and early warning system for key positions of steel structures according to claim 1, characterized in that two photocouplers are arranged inside the fiber grating sensor. 7. The stress and strain monitoring and early warning system for key positions of steel structures according to claim 1, characterized in that: the alarm module adopts sound and light alarm.