Intelligent bridge force measuring support based on piezoelectric effect and monitoring method

Abstract

The invention discloses a piezoelectric effect-based bridge intelligent force measurement support and a monitoring method, and relates to the technical field of bridge sensors. A piezoelectric ceramic sensor array is pre-buried in the inner surface of the support; when a vehicle passes through the bridge, the piezoelectric ceramic sensor array is influenced by a dynamic load to generate an electric signal, and the wireless acquisition device acquires the electric signal generated by the piezoelectric ceramic sensor array. The bridge support stress monitoring system is used for monitoring the stress state of a bridge support, piezoelectric ceramic sensors are arranged at the position of the bridge support, electric signals are transmitted to a remote control room wireless collecting device in a wireless transmission mode, and the similarity of electric signal oscillogram of a piezoelectric ceramic sensor array is compared; whether the stress state of the bridge support is obviously changed or not under the actual condition is monitored in real time, and therefore early warning is conducted on bridge accidents in advance, and corresponding accidents are reduced. In addition, the PZT piezoelectric ceramic sensor and acquisition equipment adopted by the invention are low in cost and very convenient to maintain.

Description

Technical Field

[0001] The present invention relates to the technical field of bridge sensors, and more particularly to an intelligent bridge force measuring support and a monitoring method based on piezoelectric effect. Background Art

[0002] At present, with the development of the economy, the traffic volume on highway bridges has increased. The unbalanced loading and overloading of vehicles have become more common during the use of bridges, affecting the life of bridges and making bridges more prone to bearing eccentricity, voiding, beam slippage or bearing damage caused by excessive bearing capacity, thus causing serious safety accidents.

[0003] Many safety accidents in bridge structures are related to the stress state of the bearings. Bridge management departments spend a lot of financial and human resources every year to conduct regular inspections of various components of the bridge. However, due to the large number of bridges, the use of manual regular inspections is not only time-consuming and labor-intensive but also has low accuracy. It is also unable to provide long-term monitoring of bridge bearings. Accidents often occur due to the gradual change in the stress state of the bearings during the operation of the bridge.

[0004] Although high-precision dynamic weighing and dynamic speed measurement technologies are available on highways, they have a great impact on traffic due to the road reconstruction and cannot be applied to ordinary highway bridges due to their high cost.

[0005] Regarding bearing monitoring, in addition to manual inspections, regular drone inspections or database image recognition are now more commonly used. The monitoring of bridge bearings is achieved through machine vision inspection, which is more convenient than manual inspection. However, its accuracy is still low and cannot provide a reliable basis for the safe operation of bridges and bearing replacement.

[0006] Piezoelectric ceramic sensors are used in structural health monitoring due to their piezoelectric effect and good performance, such as concrete crack monitoring, concrete internal defect monitoring, wooden structure health monitoring and damage identification, etc. The detection technology based on piezoelectric ceramic sheets is simple, efficient, low-cost and low-accuracy, but it is rarely used in the health monitoring of bridge structures.

[0007] Therefore, how to provide a convenient, fast, low-cost, and highly accurate method for monitoring the stress state of bridge bearings is an urgent problem that needs to be solved by those skilled in the art. Summary of the invention

[0008] In view of this, the present invention provides a bridge intelligent force measuring bearing and monitoring method based on piezoelectric effect, which are used to solve the economic losses and engineering risks caused by the changes in the reaction force of the bridge bearing caused by the dynamic load of the vehicle.

[0009] In order to achieve the above object, the present invention adopts the following technical solution:

[0010] A bridge intelligent force measuring bearing based on piezoelectric effect, the bridge intelligent force measuring bearing comprising: a piezoelectric ceramic sensor array and a wireless acquisition device, wherein the piezoelectric ceramic sensor array is pre-buried in the inner surface of the bearing; when a vehicle passes through the bridge, the piezoelectric ceramic sensor array is affected by the dynamic load to generate an electrical signal, and the wireless acquisition device collects the electrical signal generated by the piezoelectric ceramic sensor array.

[0011] Optionally, the piezoelectric ceramic sensor array includes a plurality of piezoelectric ceramic sensors, and the plurality of piezoelectric ceramic sensors are all arranged in bridge supports, with one sensor being arranged in each bridge support, and are all used to measure beam vibration caused by vehicle dynamic load.

[0012] Optionally, the piezoelectric ceramic sensor array uses lead-based piezoelectric ceramics with lead zirconate titanate as the core.

[0013] A monitoring method for a bridge intelligent force measuring support based on piezoelectric effect comprises the following steps:

[0014] Step 1: When the bridge intelligent force measuring support is in a normal stress state, the electrical signal of the bridge intelligent force measuring support under dynamic load is output and recorded as a standard waveform diagram;

[0015] Step 2: Save the electrical signals emitted by the piezoelectric ceramic sensor array in the intelligent force measuring support of the bridge, and regularly compare the electrical signal waveforms of the same piezoelectric ceramic sensor at different times; control the size of the vehicle dynamic load at different times to be the same as the vehicle's driving speed. If the electrical signal waveforms transmitted by the same piezoelectric ceramic at different times are similar, it is judged that the stress state of the same support has not changed; if the electrical signal waveforms transmitted by the same piezoelectric ceramic at different times are low in similarity, it is judged that the stress state of the same support has changed.

[0016] Optionally, when the dynamic load of the vehicle begins to pass through a section of the bridge road, since the piezoelectric ceramic sensor array is placed in the support and bears the force together with the support, the piezoelectric ceramic will produce a piezoelectric effect due to the influence of the dynamic load of the vehicle. From the piezoelectric effect, it is known that the deformation of the piezoelectric ceramic sensor is proportional to the amount of charge generated. When the vehicle drives at a constant speed to the top of piezoelectric ceramic sensor 1 and piezoelectric ceramic sensor 2, a peak value will appear in the wireless acquisition device. As the vehicle drives away, the waveform of the electrical signal transmitted by piezoelectric ceramic sensor 1 and piezoelectric ceramic sensor 2 gradually weakens, and piezoelectric ceramic sensor 3 and piezoelectric ceramic sensor 4 The waveform of the transmitted electrical signal gradually increases. When the vehicle drives to the top of piezoelectric ceramic sensor 3 and piezoelectric ceramic sensor 4 at the same speed, a signal peak also appears in the wireless acquisition device. At this time, the waveform similarities of piezoelectric ceramic sensors 1-4 are compared to observe in real time whether the bridge bearing has uneven force. If the waveforms of piezoelectric ceramic sensors 1-4 are similar, it is determined that the bearing has no uneven force, otherwise it has uneven force. By comparing the electrical signals emitted by the piezoelectric ceramic sensors of the bearings, the distribution of the reaction force of the bridge bearings is monitored in real time.

[0017] Optionally, when uneven force is applied to the support, the waveforms of the piezoelectric ceramic sensors 1-4 are compared with the standard waveforms one by one, and the force states of the support are summarized into four force states: support empty, support under-pressure, support over-pressure, and support normal; when the output waveform has no obvious peak, it is judged to be a support empty state; when the peak value of the output waveform is less than the peak value of the standard waveform, it is judged to be a support under-pressure state; when the peak value of the output waveform is greater than the peak value of the standard waveform, it is judged to be a support over-pressure state; and when the peak value of the output waveform approaches the peak value of the standard waveform, it is judged to be a normal force state.

[0018] It can be seen from the above technical solutions that, compared with the prior art, the present invention discloses a bridge intelligent force measuring support and monitoring method based on piezoelectric effect, which has the following beneficial effects:

[0019] 1. The present invention uses piezoelectric ceramics to monitor the stress state of the bridge support. When the vehicle is driving, the sensor continuously transmits electrical signals, which can monitor the stress state of the bridge support in real time and effectively monitor the changes in the bridge support reaction force in a short period of time.

[0020] 2. The present invention compares the electrical signals of the same piezoelectric ceramic at different working periods, and can detect the slow change of the bridge's support reaction force over time after the bridge has been working for a long time, and give an early warning before an accident occurs to the bridge.

[0021] 3. The PZT piezoelectric ceramic sensor and acquisition equipment used in the present invention are low in cost and very convenient to maintain. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0023] Figure 1 The overall structure diagram provided by the present invention;

[0024] Figure 2 A schematic diagram of the structure of the intelligent force measuring support for a bridge provided by the present invention;

[0025] Figure 3 A cross-sectional layout diagram of a piezoelectric ceramic sensor provided by the present invention;

[0026] Figure 4 This is a flow chart of the monitoring method provided by the present invention. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] The embodiment of the present invention discloses a bridge intelligent force measuring support based on piezoelectric effect, such as Figure 1 and Figure 2 As shown, the intelligent force measuring bearing of the bridge includes: a piezoelectric ceramic sensor array and a wireless acquisition device. The piezoelectric ceramic sensor array is pre-buried in the inner surface of the bearing; when a vehicle passes through the bridge, the piezoelectric ceramic sensor array is affected by the dynamic load and generates an electrical signal, and the wireless acquisition device collects the electrical signal generated by the piezoelectric ceramic sensor array. An intelligent force measuring bearing for bridges based on the piezoelectric effect is not only simple to install, convenient to maintain and low in cost, but also can realize real-time monitoring of the stress state of the bridge bearing.

[0029] In a specific embodiment, the piezoelectric ceramic sensor array includes piezoelectric ceramic sensor 1, piezoelectric ceramic sensor 2, piezoelectric ceramic sensor 3, and piezoelectric ceramic sensor 4. Piezoelectric ceramic sensors 1-4 are all embedded in the bridge support. Each bridge support is provided with one, and all are used to measure the vibration of the beam body caused by the dynamic load of the vehicle.

[0030] The piezoelectric ceramics in the piezoelectric ceramic sensor array are used to measure the change in the support reaction force caused by the dynamic load of the vehicle. The piezoelectric ceramic sensor is pre-buried in the bridge support, and the sensor layout is simple and easy to maintain.

[0031] The piezoelectric ceramic sensor is set in the bridge support, and the wireless data acquisition device is set in a remote control room. The piezoelectric ceramic sensor transmits the electrical signal to the wireless data acquisition device through wireless transmission.

[0032] In a specific embodiment, the piezoelectric ceramic sensor array uses lead-based piezoelectric ceramics with lead zirconate titanate as the core, which has a maximum operating temperature of about 170°C and is not easy to break. It is suitable for working with the bearing to monitor the stress state of the bridge bearing. Figure 3 As shown, the piezoelectric ceramic sensors are respectively buried in the intelligent force measuring supports of the bridge. When a vehicle enters the bridge, the piezoelectric ceramic sensors are subjected to the dynamic load of the vehicle and are subjected to force together with the supports. The piezoelectric ceramic surface is subjected to force and bends and deforms, thereby generating piezoelectric charges due to the piezoelectric effect. At this time, the received electrical signal is displayed in the acquisition equipment in the remote control room.

[0033] A monitoring method for a bridge intelligent force measuring support based on piezoelectric effect comprises the following steps:

[0034] Step 1: Before formal monitoring, when the bridge intelligent force measuring support is in a normal stress state, use a standard vehicle to pass through the bridge equipped with the intelligent force measuring support, record the electrical signal output by the piezoelectric ceramic sensor array and record it as a standard waveform diagram.

[0035] When the dynamic load of a vehicle begins to pass through a section of bridge pavement, since the piezoelectric ceramic sensor array is placed in the support and bears force together with the support, the piezoelectric ceramic will produce a piezoelectric effect due to the influence of the dynamic load of the vehicle. From the piezoelectric effect, it is known that the deformation of the piezoelectric ceramic sensor is proportional to the amount of charge generated. When the vehicle drives at a constant speed to the top of piezoelectric ceramic sensor 1 and piezoelectric ceramic sensor 2, a peak value will appear in the wireless acquisition device. As the vehicle drives away, the waveform of the electrical signal transmitted by piezoelectric ceramic sensor 1 and piezoelectric ceramic sensor 2 gradually weakens, and the waveform of the electrical signal transmitted by piezoelectric ceramic sensor 3 and piezoelectric ceramic sensor 4 The electrical signal waveform gradually increases. When the vehicle drives to the top of piezoelectric ceramic sensor 3 and piezoelectric ceramic sensor 4 at the same speed, a signal peak also appears in the wireless acquisition device. At this time, the waveform similarities of piezoelectric ceramic sensors 1-4 are compared to observe in real time whether the bridge bearing has uneven force. If the waveforms of piezoelectric ceramic sensors 1-4 are similar, it is determined that the bearing has no uneven force, otherwise it has uneven force. By comparing the electrical signals emitted by the piezoelectric ceramic sensors of the bearings, the distribution of the bridge bearing reaction force is monitored in real time.

[0036] Step 2. When a vehicle passes through a bridge provided with the intelligent support, the electrical signal waveform output by the piezoelectric ceramic sensor array is recorded as a monitoring waveform and saved, and the electrical signal waveforms of the same piezoelectric ceramic sensor at different times are regularly compared; the magnitude of the vehicle dynamic load at different times is controlled to be the same as the vehicle's driving speed. If the electrical signal waveforms transmitted by the same piezoelectric ceramic at different times are similar, it is judged that the stress state of the same support has not changed; if the electrical signal waveforms transmitted by the same piezoelectric ceramic at different times are low in similarity, it is judged that the stress state of the same support has changed.

[0037] When the bearing is subjected to uneven force, the waveforms of the piezoelectric ceramic sensors 1-4 are compared with the standard waveforms one by one, and the bearing force states are summarized into four states: bearing empty, bearing underpressure, bearing overpressure, and bearing normal. The working process is as follows: Figure 4 shown.

[0038] ① When the piezoelectric ceramic sensor does not output an electrical signal, it is judged that the support is in an empty state.

[0039] ② When the peak value of the piezoelectric ceramic sensor output waveform is smaller than the peak value of the standard waveform, it is judged to be in the support under-voltage state.

[0040] ③ When the peak value of the piezoelectric ceramic sensor output waveform is greater than the peak value of the standard waveform, it is judged to be in the support overpressure state.

[0041] ④ When the peak value of the output waveform of the piezoelectric ceramic sensor approaches the peak value of the standard waveform, it is judged to be in a normal stress state.

[0042] From the above content, it can be understood that the present invention is mainly used to monitor the stress state of bridge supports. Piezoelectric ceramic sensors are arranged at the bridge supports to transmit electrical signals to a wireless acquisition device in a remote control room by wireless transmission. The similarity of the electrical signal waveforms of the piezoelectric ceramic sensor array is compared to monitor in real time whether there is a significant change in the stress state of the bridge supports under actual conditions, thereby providing early warning of bridge accidents and reducing the occurrence of corresponding accidents.

[0043] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0044] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A bridge intelligent force measuring support based on piezoelectric effect, characterized in that: The intelligent force measuring bearing of the bridge includes: a piezoelectric ceramic sensor array and a wireless acquisition device. The piezoelectric ceramic sensor array is pre-buried in the inner surface of the bearing. When a vehicle passes through the bridge, the piezoelectric ceramic sensor array is affected by the dynamic load and generates an electrical signal. The wireless acquisition device collects the electrical signal generated by the piezoelectric ceramic sensor array.

2. The intelligent bridge force measuring support based on piezoelectric effect according to claim 1 is characterized in that: The piezoelectric ceramic sensor array includes a plurality of piezoelectric ceramic sensors, which are all arranged in bridge supports, one piezoelectric ceramic sensor is arranged in each bridge support, and are all used to measure the vibration of the beam body caused by the dynamic load of the vehicle.

3. The intelligent bridge force measuring support based on piezoelectric effect according to claim 1 is characterized in that: The piezoelectric ceramic sensor array uses lead-based piezoelectric ceramics with lead zirconate titanate as the core.

4. A monitoring method for a bridge intelligent force measuring support based on piezoelectric effect, characterized in that: The application of a bridge intelligent force measuring support based on piezoelectric effect as described in any one of claims 1 to 3 comprises the following steps: Step 1: When the bridge intelligent force measuring support is in a normal stress state, the electrical signal of the bridge intelligent force measuring support under dynamic load is output and recorded as a standard waveform diagram; Step 2: Save the electrical signals emitted by the piezoelectric ceramic sensor array in the intelligent force measuring support of the bridge, and regularly compare the electrical signal waveforms of the same piezoelectric ceramic sensor at different times; control the size of the vehicle dynamic load at different times to be the same as the vehicle's driving speed. If the electrical signal waveforms transmitted by the same piezoelectric ceramic at different times are similar, it is judged that the stress state of the same support has not changed; if the electrical signal waveforms transmitted by the same piezoelectric ceramic at different times are low in similarity, it is judged that the stress state of the same support has changed.

5. The monitoring method of a bridge intelligent force measuring support based on piezoelectric effect according to claim 4 is characterized in that: When the dynamic load of a vehicle begins to pass through a section of bridge pavement, since the piezoelectric ceramic sensor array is placed in the support and bears force together with the support, the piezoelectric ceramic will produce a piezoelectric effect due to the influence of the dynamic load of the vehicle. From the piezoelectric effect, it is known that the deformation of the piezoelectric ceramic sensor is proportional to the amount of charge generated. When the vehicle drives at a constant speed to the top of piezoelectric ceramic sensor 1 and piezoelectric ceramic sensor 2, a peak value will appear in the wireless acquisition device. As the vehicle drives away, the waveform of the electrical signal transmitted by piezoelectric ceramic sensor 1 and piezoelectric ceramic sensor 2 gradually weakens, and the waveform of the electrical signal transmitted by piezoelectric ceramic sensor 3 and piezoelectric ceramic sensor 4 The electrical signal waveform gradually increases. When the vehicle drives to the top of piezoelectric ceramic sensor 3 and piezoelectric ceramic sensor 4 at the same speed, a signal peak also appears in the wireless acquisition device. At this time, the waveform similarities of piezoelectric ceramic sensors 1-4 are compared to observe in real time whether the bridge bearing has uneven force. If the waveforms of piezoelectric ceramic sensors 1-4 are similar, it is determined that the bearing has no uneven force, otherwise it has uneven force. By comparing the electrical signals emitted by the piezoelectric ceramic sensors of the bearings, the distribution of the bridge bearing reaction force is monitored in real time.

6. The monitoring method of a bridge intelligent force measuring support based on piezoelectric effect according to claim 4 is characterized in that: When uneven force is applied to the support, the waveforms of the piezoelectric ceramic sensors 1-4 are compared with the standard waveforms one by one, and the force states of the support are summarized into four force states: support empty, support under-pressure, support over-pressure, and support normal. When the output waveform has no obvious peak, it is judged to be a support empty state; when the peak value of the output waveform is less than the peak value of the standard waveform, it is judged to be a support under-pressure state; when the peak value of the output waveform is greater than the peak value of the standard waveform, it is judged to be a support over-pressure state; and when the peak value of the output waveform approaches the peak value of the standard waveform, it is judged to be a normal force state.

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