Disclosure of Invention
The invention aims to provide a monitoring method of a piezoelectric sensor applied to a 3D printing tunnel model to achieve the purposes of improving the embedding accuracy of the piezoelectric sensor and the internal monitoring accuracy of the model.
In order to achieve the purpose, the invention provides the following scheme:
the invention provides a monitoring method of a piezoelectric sensor applied to a 3D printing tunnel model, which comprises the following steps:
printing a tunnel model by using 3D printing equipment, and embedding a piezoelectric sensor at a specified position;
the piezoelectric sensor comprises at least one group of piezoelectric ceramic smart module driver and piezoelectric ceramic smart module receiver, and the piezoelectric ceramic smart module driver and the piezoelectric ceramic smart module receiver are arranged on the same section of the tunnel model at the circumferential direction of the opening;
transmitting an excitation signal by using a waveform generator which is arranged outside the tunnel model and connected with the piezoelectric ceramic smart module driver, exciting the piezoelectric ceramic smart module driver to transmit a stress wave signal, and receiving the stress wave signal by the piezoelectric ceramic smart module receiver and transmitting the stress wave signal to a digital collector outside the tunnel model;
the digital collector analyzes the stress wave signals, decomposes the stress wave signals in different structural states, obtains the stress wave node energy of different nodes, judges the health condition of the structure according to the change condition of the same node energy, and finally achieves the monitoring of the structural damage.
Preferably, a digital filter is connected between the piezoelectric ceramic smart module receiver and the digital collector.
Preferably, the piezoelectric ceramic smart module driver is connected with the waveform generator through a signal line, and the piezoelectric ceramic smart module receiver is connected with the digital collector through a signal line.
Preferably, the piezoelectric ceramic smart module driver and the piezoelectric ceramic smart module receiver remove the oxide film on the surface with alcohol before installation, and cover a layer of liquid insulating glue on the periphery after the surface is dried.
Preferably, the piezoelectric ceramic smart module driver and the piezoelectric ceramic smart module receiver are bonded with bonding blocks on two sides before being embedded into the tunnel model, and the bonding blocks form a wrapping state for the piezoelectric ceramic smart module driver and the piezoelectric ceramic smart module receiver.
Preferably, the piezoelectric ceramic smart module driver and the piezoelectric ceramic smart module receiver are both bonded with the bonding block through a bonding agent, and the bonding agent is epoxy resin added with cement dry powder.
Preferably, the material of the bonding block is the same as that of the tunnel model.
Preferably, the piezoelectric ceramic smart module driver and the piezoelectric ceramic smart module receiver are kept standing for 6 hours at the temperature of 25 ℃ after the bonding of the bonding block and the piezoelectric ceramic smart module driver and the piezoelectric ceramic smart module receiver is completed.
Compared with the prior art, the invention has the following technical effects:
1. according to the invention, the piezoelectric sensor is embedded in the tunnel model by using a 3D printing technology, so that the piezoelectric sensor is accurately positioned, meanwhile, the piezoelectric sensor has the advantages of wide frequency response range, high response speed, simple structure, low power consumption, low cost and the like, and a structural health monitoring system formed by the piezoelectric sensor can sensitively sense and monitor the existence of structural damage and the change condition of strength.
2. According to the invention, the digital filter is connected between the piezoelectric ceramic smart module receiver and the digital collector, so that low-frequency noise signals in stress wave signals are filtered out and then transmitted to the digital collector for collection and analysis, a more accurate analysis structure can be obtained without interference of the low-frequency noise signals, and the monitoring precision of the piezoelectric sensor is improved in a phase-changing manner.
3. According to the invention, the oxide film on the surface of the piezoelectric ceramic smart module driver and the piezoelectric ceramic smart module receiver is removed by alcohol before installation, and a layer of liquid insulating glue is covered on the periphery of the piezoelectric ceramic smart module driver and the piezoelectric ceramic smart module receiver after the surfaces are dried, so that the piezoelectric ceramic smart module driver and the piezoelectric ceramic smart module receiver can be effectively protected from reacting with the material of the tunnel model after printing is finished, and the service life and the use precision of the piezoelectric sensor are influenced.
4. According to the invention, the bonding blocks are bonded on the two sides of the piezoelectric ceramic smart module driver and the piezoelectric ceramic smart module receiver before the piezoelectric ceramic smart module driver and the piezoelectric ceramic smart module receiver are embedded into the tunnel model, and the bonding blocks form a wrapping state for the piezoelectric ceramic smart module driver and the piezoelectric ceramic smart module receiver, so that when the tunnel model is subjected to a 3D printing process, the bonding blocks in the wrapping state can protect the piezoelectric ceramic inductor, and the problem that the piezoelectric ceramic inductor is damaged in the falling impact process of a printing material, and the use of the piezoelectric ceramic inductor is further influenced is solved.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The invention aims to provide a monitoring method of a piezoelectric sensor applied to a 3D printing tunnel model to achieve the purposes of improving the embedding accuracy of the piezoelectric sensor and the internal monitoring accuracy of the model.
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.
Referring to fig. 1, the invention discloses a monitoring method of a piezoelectric sensor applied to a 3D printing tunnel model, comprising the following steps: printing a tunnel model by using 3D printing equipment, and embedding a piezoelectric sensor at a specified position; the piezoelectric sensor comprises at least one group of piezoelectric ceramic smart module driver and piezoelectric ceramic smart module receiver, and the piezoelectric ceramic smart module driver and the piezoelectric ceramic smart module receiver are arranged on the same section of the tunnel model at the circumferential direction of the opening; transmitting an excitation signal by using a waveform generator which is arranged outside the tunnel model and connected with a piezoelectric ceramic smart module driver, exciting the piezoelectric ceramic smart module driver to transmit a stress wave signal, and receiving the stress wave signal by a piezoelectric ceramic smart module receiver and transmitting the stress wave signal to a digital collector outside the tunnel model; the digital collector analyzes the stress wave signals, decomposes the stress wave signals in different structural states, obtains the stress wave node energy of different nodes, judges the health condition of the structure according to the change condition of the same node energy, and finally achieves the monitoring of the structural damage; according to the invention, the piezoelectric sensor is embedded in the tunnel model by using a 3D printing technology, so that the piezoelectric sensor is accurately positioned, meanwhile, the piezoelectric sensor has the advantages of wide frequency response range, high response speed, simple structure, low power consumption, low cost and the like, and a structural health monitoring system formed by the piezoelectric sensor can sensitively sense and monitor the existence of structural damage and the change condition of strength.
Furthermore, a digital filter is connected between the piezoelectric ceramic smart module receiver and the digital collector, low-frequency noise signals in the stress wave signals are filtered out and then transmitted to the digital collector for collection and analysis, a more accurate analysis structure can be obtained without interference of the low-frequency noise signals, and the monitoring precision of the piezoelectric sensor is improved in a phase-changing manner.
Furthermore, the piezoelectric ceramic smart module driver is connected with the waveform generator through a signal line, the piezoelectric ceramic smart module receiver is connected with the digital collector through a signal line, data transmission is carried out through electric signals, stress waves in the tunnel model can be efficiently and rapidly transmitted to the digital collector, and the analysis efficiency of the digital collector is improved.
Furthermore, the piezoelectric ceramic smart module driver and the piezoelectric ceramic smart module receiver are used for removing the oxide film on the surface by alcohol before installation, and a layer of liquid insulating glue is covered on the periphery of the piezoelectric ceramic smart module driver and the piezoelectric ceramic smart module receiver after the surfaces are dried, so that the piezoelectric ceramic smart module driver and the piezoelectric ceramic smart module receiver can be effectively protected from reacting with the material of the tunnel model after printing is finished, and the service life and the use precision of the piezoelectric sensor are influenced.
Further, the quick module driver of piezoceramics and the quick module receiver of piezoceramics both sides bond the piece that bonds before burying tunnel model, the piece that bonds forms the parcel state to quick module driver of piezoceramics and the quick module receiver of piezoceramics, when tunnel model is carrying out 3D printing process, the piece that bonds of parcel state can form the guard action to the piezoceramics inductor, it damages to the piezoceramics inductor to have avoided printing material whereabouts to strike the in-process, and then influence the use problem of piezoceramics inductor itself.
Further, quick module driver of piezoceramics and the quick module receiver of piezoceramics all bond with the bonding piece through the adhesive, the adhesive is the epoxy who adds the cement dry powder, thereby form epoxy cement mortar, high cohesive force has, high compressive strength just does not receive the structural shape restriction, it is impervious, freezing proof, salt-resistant, alkali-resistant, weak acid corrosion resistant's performance is extremely strong, can effectually guarantee that the adhesive is fixed to the bonding of bonding piece with quick module driver of piezoceramics and the quick module receiver of piezoceramics, and simultaneously, can effectually resist the corrosive effect of the material of tunnel model itself to the adhesive, thereby increase piezoelectric sensor's life.
Furthermore, the material of bonding piece is the same with the material of tunnel model, and bonding piece when pouring in the middle of the tunnel model, can be in the same place with the fine integration of tunnel model, has guaranteed tunnel model's wholeness and intensity, and can not form mutual corrosion state because of the difference in the material to when guaranteeing tunnel model bulk strength, increased this tunnel model's life.
Furthermore, after the piezoelectric ceramic smart module driver and the piezoelectric ceramic smart module receiver are bonded with the bonding block, the bonding block is kept still for 6 hours at the temperature of 25 ℃, after the model is maintained, the parameters of the model, such as density, strength, elastic modulus and the like, are very close to the parameters of a rock material, and the compressive strength to tensile strength of the material can reach 10: 1 or more, according to the characteristic of brittle fracture.
The monitoring method of the 3D printing tunnel model applied piezoelectric sensor is implemented as follows:
firstly, determining model parameters and embedding information of a piezoelectric sensor in a model according to theoretical analysis and numerical simulation results, wherein the preferred embedding information is selected as follows, the piezoelectric sensor comprises four piezoelectric ceramic smart module drivers and eight piezoelectric ceramic smart module receivers, the four piezoelectric ceramic smart module drivers are respectively arranged in four directions of a tunnel model portal, two sides of each piezoelectric ceramic smart module driver are respectively provided with one piezoelectric ceramic smart module receiver for receiving stress wave signals, all the piezoelectric ceramic smart module drivers and the piezoelectric ceramic smart module receivers are arranged on the same circumferential section of the tunnel model portal, each piezoelectric ceramic smart module driver is connected with a waveform generator outside the tunnel model through a signal line, and each piezoelectric ceramic smart module receiver is connected with a digital collector outside the tunnel model through a signal line; then, designing and generating a 3D three-dimensional digital model according to model parameters and embedding information by utilizing modeling software, and importing the model into a control system to generate operation paths of two robot arms for 3D printing additive manufacturing and material reducing filling manufacturing; weighing silicate cement, quartz sand, quartz powder, silica fume, copper slag powder, water and additives according to a proportion, putting the silicate cement, the quartz sand, the quartz powder, the silica fume, the copper slag powder, the water and the additives into a stirring pot for mixing and stirring, starting the stirring pot for stirring for 300 seconds until mixed cement-based materials are completely mixed and can be continuously and smoothly extruded out from a palm, putting the mixture into a storage pumping system, starting a pump truck and a vibrator to enable the mixture to smoothly enter a pumping pipeline, connecting the storage pumping system and a printing head fixed at the end part of a double-arm robot by using a pumping pipe, feeding the printing head by using the pumping pipe, printing a model to the height of a piezoelectric sensor to be embedded by using 3D printing equipment, pausing a printing process, etching at the height by using a material reducing and manufacturing machine according to a set printing path, reducing materials and excavating along the path of the piezoelectric sensor to be embedded, then, continuously printing an upper model by using 3D printing equipment to cover the piezoelectric sensor until the whole model is printed and stops working; transmitting an excitation signal by using a waveform generator which is arranged outside the tunnel model and connected with a piezoelectric ceramic smart module driver, exciting the piezoelectric ceramic smart module driver to transmit a stress wave signal, and receiving the stress wave signal by a piezoelectric ceramic smart module receiver and transmitting the stress wave signal to a digital collector outside the tunnel model; the digital collector analyzes the stress wave signals, decomposes the stress wave signals in different structural states, obtains the stress wave node energy of different nodes, judges the health condition of the structure according to the change condition of the same node energy, and finally achieves the monitoring of the structural damage.
The adaptation according to the actual needs is within the scope of the invention.
It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.