CN210037714U - Sleeve grouting compactness detection device based on stress wave method - Google Patents
Sleeve grouting compactness detection device based on stress wave method Download PDFInfo
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- CN210037714U CN210037714U CN201920659960.7U CN201920659960U CN210037714U CN 210037714 U CN210037714 U CN 210037714U CN 201920659960 U CN201920659960 U CN 201920659960U CN 210037714 U CN210037714 U CN 210037714U
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Abstract
The utility model relates to a sleeve grout compactness detection device based on stress wave method, including pre-buried in last prefabricated post in be used for connecting the grout sleeve of prefabricated post reinforcing bar and prefabricated post reinforcing bar down, two sets of piezoceramics sensors are pasted to grout sleeve outer wall, and two sets of piezoceramics sensors are laid respectively at grout sleeve end and middle part position, and every piezoceramics sensor quantity of group is two and distributes in the relative both sides of grout sleeve outer wall, and piezoceramics sensor passes through the shielded wire and is connected with the data acquisition appearance, the data acquisition appearance passes through the shielded wire with the computer and is connected. The utility model discloses the sleeve grouting compactness detection device based on stress wave method principle is simple, and is with low costs, convenient operation, and the piezoceramics sensor that uses receives on-the-spot restriction little, and the environmental requirement to equipment is low, can be applicable to the construction operation requirement on-the-spot; the influence of site construction is not easy to occur; the detection result has high accuracy.
Description
Technical Field
The utility model relates to a sleeve closely knit degree detection device of grout based on stress wave method.
Background
The steel bar sleeve grouting connection technology is widely applied to prefabricated buildings at present and is mainly applied to connection of steel bars of member nodes. The steel bar sleeve grouting connector is a combination assembled by a specially processed sleeve, matched grouting materials and steel bars, the steel bars are connected by injecting the rapid-hardening non-shrinkage grouting materials during connecting the steel bars and relying on the bonding and meshing action between materials to connect the steel bars and the sleeve, and the sleeve grouting connector has the advantages of reliable performance, wide applicability, simplicity and convenience in installation and the like. The connection strength of the steel bar nodes mainly depends on the fullness degree of grouting materials in the sleeve, but plugs fall into the sleeve in the production or installation process of the component, the grouting machine has insufficient pressure holding time in the grouting process, untimely plugging and untimely bottom horizontal joint, local slurry leakage of a communicating cavity is caused, and the slurry in the sleeve has backflow phenomenon after grouting is finished, so that the grouting is possibly insufficient, and the overall stress performance and the anti-seismic performance of the fabricated building are further influenced. Meanwhile, an effective detection means is lacked at present, the acceptance check has no sufficient basis, and whether grouting is full can be judged only according to the grout outlet smoothness of the grout outlet hole of the grouting sleeve, so that hidden dangers are buried for the safety of the structure. Therefore, a reasonable nondestructive testing method is urgently needed to determine the fullness degree of the sleeve grouting.
In recent years, the structure health monitoring technology has been widely applied in the construction industry, wherein an X-ray industrial CT method, an embedded steel wire drawing method, an X-ray digital imaging method and the like are developed at home and abroad aiming at the research on the grouting fullness of the sleeve. However, the industrial X-ray CT method is only suitable for prior detection, has higher requirements on equipment environment and can only be carried out under the shielding condition of a laboratory; the pre-embedded steel wire drawing method needs pre-embedding, and the pre-embedded steel wire is easy to be disturbed or damaged in a construction site before detection; the X-ray digital imaging method is only suitable for post detection and is only suitable for sleeves in a single-row arrangement and a quincunx arrangement mode, and the method has radiation and needs safety protection measures on site. Therefore, the existing detection method has the defects of high requirements on equipment environment, high detection cost, easy field construction interference on detection results and the like.
SUMMERY OF THE UTILITY MODEL
In view of this, the utility model aims at providing a sleeve closely knit degree detection device of grout based on stress wave method with low costs, it is little to receive site operation to disturb, and the accuracy is high.
The utility model discloses a following scheme realizes: the utility model provides a sleeve compactness detection device that grouts based on stress wave method, is used for connecting the grout sleeve of prefabricated post reinforcing bar and prefabricated post reinforcing bar down in going up prefabricated post including pre-burying, two sets of piezoceramics sensors are pasted to grout sleeve outer wall, and two sets of piezoceramics sensors are laid respectively at grout sleeve end and middle part position, and every group piezoceramics sensor quantity is two and distributes in the relative both sides of grout sleeve outer wall, and the piezoceramics sensor passes through the shielding wire and is connected with the data acquisition appearance, the data acquisition appearance passes through the shielding wire with the computer and is connected.
Furthermore, the piezoelectric ceramic sensor comprises a piezoelectric ceramic piece packaged in epoxy resin, a shielding wire connected with the piezoelectric ceramic sensor is of a single two-core structure, two wire cores penetrate through the epoxy resin and are respectively welded on two side faces of the piezoelectric ceramic piece, and two side faces of the piezoelectric ceramic piece are coated with wax layers.
Compared with the prior art, the utility model discloses following beneficial effect has: the utility model discloses a sleeve grouting compactness detection device based on stress wave method principle is simple, and is with low costs, convenient operation, and the piezoceramics piece that uses receives on-the-spot restriction little, and the environmental requirement to equipment is low, can be applicable to the construction operation requirement on-the-spot; the phenomenon that misjudgment can be caused by the hardening of residual slurry on the core element of the sensor after the grouting material is grouted back is avoided; the influence of site construction is not easy to occur; the detection result has high accuracy.
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail below with reference to specific embodiments and related drawings.
Drawings
Fig. 1 is a schematic view of the installation of a grouting sleeve according to an embodiment of the present invention;
fig. 2 is a schematic view illustrating the installation of the piezoelectric ceramic sensor on the grouting sleeve according to the embodiment of the present invention;
fig. 3 is a schematic view of a package structure of a piezoelectric ceramic plate in an embodiment of the present invention;
FIG. 4 is a schematic view of the embodiment of the present invention illustrating the welding of the piezoelectric ceramic plate and the shielding wire;
FIG. 5 is a schematic diagram of the operation of the embodiment of the present invention;
fig. 6 is a flow chart of the detection of the embodiment of the present invention;
fig. 7 shows the original signal data of the grouting sleeve end with a compactness of 100% according to an embodiment of the present invention;
fig. 8 shows the original signal data of the middle portion of the grouting sleeve with a compactness of 100% according to the embodiment of the present invention;
fig. 9 shows the original signal data of the grouting sleeve end with 50% compactness according to the embodiment of the present invention;
fig. 10 shows the original signal data of the middle portion of the grouting sleeve with 50% compactness according to the embodiment of the present invention;
fig. 11 is frequency domain signal data of the grouting sleeve end with a compactness of 100% according to an embodiment of the present invention;
fig. 12 shows frequency domain signal data in the middle of a grouting sleeve with a compactness of 100% according to an embodiment of the present invention;
fig. 13 is frequency domain signal data of the grouting sleeve end with 50% compactness according to an embodiment of the present invention;
fig. 14 shows frequency domain signal data of the middle of the grouting sleeve with 50% compactness according to an embodiment of the present invention;
the reference numbers in the figures illustrate: 100-upper prefabricated column, 110-upper prefabricated column steel bar, 200-lower prefabricated column, 210-lower prefabricated column steel bar, 300-grouting sleeve, 400-piezoelectric ceramic piece, 410-shielding lead, 420-wax layer, 430-piezoelectric ceramic piece, 500-data acquisition instrument, 600-computer and 700-epoxy resin.
Detailed Description
As shown in fig. 1-6, a sleeve grouting compactness detection device based on stress wave method, including being buried in the grout sleeve 300 that is used for connecting prefabricated post reinforcing bar 110 and prefabricated post reinforcing bar 210 down in last prefabricated post 100 in advance, two sets of piezoceramics sensors are pasted to grout sleeve 300 outer wall, and every piezoceramics sensor quantity of group is two and distributes in the relative both sides of grout sleeve 300 outer wall, and piezoceramics sensor passes through shielding wire 410 and is connected with the data acquisition instrument, data acquisition instrument 500 is connected through shielding wire with computer 600, and two kinds of shielding wires are RVV type shielding wire, can effectively reduce the influence of the noise signal in the collection signal. One of the two piezoelectric ceramic sensors in the same group is used as a receiving end, the other is used as a reflecting end and is respectively connected with the data acquisition instrument 500, and the two groups of piezoelectric ceramic sensors are respectively arranged at the end head and the middle position of the grouting sleeve and staggered by 90 degrees in the circumferential direction.
This sleeve closely knit degree detection device's detection principle of filling based on stress wave method:
(1) acquiring a piezoelectric signal by sticking a piezoelectric ceramic sensor on the outer surface of the grouting sleeve and establishing a relation between the piezoelectric signal and the grouting compactness of the sleeve;
(2) the grouting material in the grouting sleeve is different in material properties at the end and the middle of the sleeve, and piezoelectric ceramic sensors are required to be respectively placed at the end and the middle;
(3) denoising the signals acquired by the data acquisition instrument by adopting a wavelet packet default threshold denoising method so as to extract signal characteristic parameters with high sensitivity;
(4) and (4) adopting a time domain analysis method and a frequency domain analysis method to provide an index for judging grouting compactness.
The data acquisition instrument 500 adopts an NI USB-6363 data acquisition instrument of NI company, controls the piezoelectric ceramic sensor to generate high-frequency stress waves through LabView software on a computer, acquires stress wave signals, adopts sine sweep signals as selected excitation signals, has a voltage amplitude of 10V and a period of 1s, and takes the noise frequency mainly concentrated in a low-frequency range into consideration in order to reduce the interference of the noise signals on target signals, so that the frequency of sampling signals is 10 kHz-200 kHz; the method comprises the steps of denoising acquired signals by using a wavelet packet default threshold, denoising by using a function of an MATLAB program, analyzing a time domain and a frequency domain, establishing a relation between an energy signal and grouting compactness by using a wavelet packet energy method during time domain analysis, and obtaining a spectrogram by performing Fourier transform on the signals acquired in the time domain analysis so as to establish a relation between signal frequency spectrum variation and grouting compactness.
The time domain analysis adopts a wavelet packet energy method, X is a structural dynamic response signal measured by a piezoelectric ceramic plate serving as a sensor in the structural health monitoring process, and when the structural dynamic response signal is subjected to i-layer wavelet packet decomposition, 2 layers with different frequency bands are formed at the last layernSub-signals, then the original signal X can be expressed as the following relation:
Xjcan be expressed as:
（2）
in the formula (2), j is the node serial number of the ith layer in the wavelet packet decomposition tree structure, and m is the number of data points. After X is decomposed by i layers of wavelet packets, the node [ i, j]The corresponding sub-band signal energy is
（3）
The wavelet packet energy spectrum characteristic vector E of the original signal at the i-th layer decomposition can be further obtained by the formula (3)i
Total energy of each sub-signal is（6）
The decomposed wavelet packet energy value is equivalent to the energy value of the original signal, and whether the sleeve grouting is compact or not is judged by comparing the difference of the wavelet packet energy values, so that the sleeve damage condition is detected.
To the time domain signal that gathers on the data acquisition instrument 500, carry out fast Fourier transform, change into the frequency domain signal, compare the characteristic parameter Y on the frequency domain signal, assess the closely knit degree of sleeve grout, reach the purpose that detects, characteristic parameter Y can be expressed as following relational expression:（6）
in this embodiment, the piezoelectric ceramic sensor includes a piezoelectric ceramic piece 400 encapsulated in epoxy resin 700, the shielding lead connected to the piezoelectric ceramic sensor is a single two-core structure, and the two cores penetrate through the epoxy resin 700 and are respectively welded to two side surfaces of the piezoelectric ceramic piece 400, the welding time is not too long, and the welding point is small and flat, so as to prevent the piezoelectric ceramic piece from losing piezoelectric performance due to the temperature exceeding the curie temperature point of the piezoelectric ceramic piece; two side surfaces of the piezoelectric ceramic piece 400 are coated with wax layers 420 to prevent epoxy resin from hardening to damage the piezoelectric ceramic piece; the piezoelectric ceramic piece is lead zirconate titanate piezoelectric ceramic, the selected piezoelectric ceramic piece is a PZT-4 type piezoelectric ceramic piece, and has two functions of transmitting and receiving, wide signal range and strong adaptability; the electric ceramic sensor is adhered to a grouting sleeve by epoxy resin AB glue, the part of the grouting sleeve, which is used for adhering the piezoelectric ceramic piece 400, is polished to be smooth by a polisher, and then is cleaned by alcohol.
The manufacturing process of the packaging structure comprises the following steps: the method comprises the following steps of enclosing a paperboard to form a frame-shaped die, wherein a through hole for a shielding wire to penetrate through is formed in one side wall of the die, and transparent adhesive is attached to the inner wall of the die, so that the die can be more easily demolded; brushing a layer of epoxy resin release agent on the inner wall of the mould, penetrating a shielding lead into the mould through a through hole, respectively welding two wire cores of the shielding lead on two side surfaces of the piezoelectric ceramic piece, coating wax layers 420 on the two side surfaces of the piezoelectric ceramic piece, then pouring epoxy resin in the mould to embed the piezoelectric ceramic piece in the poured epoxy resin, wherein the epoxy resin adopts epoxy resin AB glue with the proportion of 1:1, and removing the mould and polishing after the epoxy resin is hardened.
Piezoelectric Ceramics (PZT): the piezoelectric ceramic material is an information functional ceramic material capable of mutually converting mechanical energy and electric energy, namely, the piezoelectric effect, and the piezoelectric ceramic material has dielectric property, elasticity and the like besides piezoelectric property. The piezoelectric ceramic is manufactured by utilizing the piezoelectric effect that the material causes the relative displacement of the centers of positive and negative charges in the material under the action of mechanical stress to generate polarization, so that bound charges with opposite signs appear on the surfaces of two ends of the material, and the piezoelectric ceramic has sensitive characteristics.
Stress wave: stress waves are a form of propagation of stress and strain perturbations. Mechanical perturbations in a deformable solid medium are manifested as changes in particle velocity and corresponding changes in stress and strain states. When the stress and the strain are in a linear relation, elastic waves propagate in the medium; in the case of a nonlinear relationship, these are plastic waves and shock waves.
Utilize for the inspection the utility model discloses the closely knit degree detection device of sleeve grout based on stress wave method carries out the validity and the accuracy that closely knit degree detected of grout, carries out the analysis with actual data that record now. As shown in fig. 7 to 10, the data of the end and the middle of the grouting sleeve test piece with the grouting compactness of 100% and 50% are shown.
The original signal is subjected to time domain analysis after being denoised, and results obtained by analysis by a wavelet packet total energy method are shown in table 1.
Table 1 shows that the measured signal of the grouting sleeve specimen with 50% grouting compactness is about 2.24 times of the compactness of 100%, which indicates that the index is feasible.
The denoised signal is subjected to frequency domain analysis, and fast fourier transform is utilized, and the result is shown in fig. 11-14. The results obtained by the relational expression (6) are shown in Table 2.
Table 2 shows that the signal measured by the grouting sleeve test piece with the grouting compactness of 50% is about 1.3 times of the compactness of 100%, and the index can be applied to the requirement of the sleeve grouting compactness detection.
Utilize the utility model discloses sleeve grout closely knit degree detection device based on stress wave method carries out closely knit degree and detects and has following advantage: the detection principle is simple, the operation is convenient, compared with an X-ray industrial CT method and an X-ray digital imaging method, the used piezoelectric ceramic piece is slightly restricted by the site, and the external-pasting piezoelectric ceramic piece is adopted as the sensor, so that misjudgment caused by hardening of residual slurry on a core element of the sensor after grouting material is grouted back can be avoided; compared with an embedded steel wire drawing method, the packaged piezoelectric sensor is not easily influenced by site construction.
Compared with the prior art, the utility model discloses intend to adopt piezoceramics piece technique, grouting sleeve compactness detection method based on stress wave method principle is simpler, economy and accurate, and this kind of detection method can reach following several targets: (1) the adopted damage index has high sensitivity, and can provide more accurate data for further research on the piezoelectric signal rule of the grouting compactness of the grouting sleeve; (2) the requirement on the environment of equipment is low, and the method can be suitable for the requirement on site construction operation; (3) the theory is simple, and the algorithm is easy to realize.
Any technical solution disclosed in the present invention is, unless otherwise stated, disclosed a numerical range if it is disclosed, and the disclosed numerical range is a preferred numerical range, and any person skilled in the art should understand that: the preferred ranges are merely those values which are obvious or representative of the technical effect which can be achieved. Because numerical value is more, can't be exhaustive, so the utility model discloses just disclose some numerical values with the illustration the technical scheme of the utility model to, the numerical value that the aforesaid was enumerated should not constitute right the utility model discloses create the restriction of protection scope.
The utility model discloses if disclose or related to mutual fixed connection's spare part or structure, then, except that other the note, fixed connection can understand: a detachable fixed connection (for example using bolts or screws) is also understood as: non-detachable fixed connections (e.g. riveting, welding), but of course, fixed connections to each other may also be replaced by one-piece structures (e.g. manufactured integrally using a casting process) (unless it is obviously impossible to use an integral forming process).
In addition, the terms used in any aspect of the present disclosure as described above to indicate positional relationships or shapes include similar, analogous, or approximate states or shapes unless otherwise stated.
The utility model provides an arbitrary part both can be assembled by a plurality of solitary component parts and form, also can be the solitary part that the integrated into one piece technology was made.
Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting the same; although the present invention has been described in detail with reference to preferred embodiments, it should be understood by those skilled in the art that: the invention can be modified or equivalent substituted for some technical features; without departing from the spirit of the present invention, it should be understood that the scope of the claims is intended to cover all such modifications and variations.
Claims (2)
1. The utility model provides a closely knit degree detection device of sleeve grout based on stress wave method which characterized in that: including pre-burying in last prefabricated post in be used for connecting the grout sleeve of prefabricated post reinforcing bar and prefabricated post reinforcing bar down, grout sleeve outer wall pastes two sets of piezoceramics sensors, and two sets of piezoceramics sensors are laid respectively at grout sleeve end and middle part position, and every group piezoceramics sensor quantity is two and distributes in the relative both sides of grout sleeve outer wall, and piezoceramics sensor passes through the shielded wire and is connected with the data acquisition appearance, the data acquisition appearance passes through the shielded wire with the computer and is connected.
2. The stress wave method-based sleeve grouting compactness detection device according to claim 1, characterized in that: the piezoelectric ceramic sensor comprises a piezoelectric ceramic piece packaged in epoxy resin, a shielding wire connected with the piezoelectric ceramic sensor is of a single two-core structure, two wire cores penetrate into the epoxy resin and are respectively welded on two side faces of the piezoelectric ceramic piece, and two side faces of the piezoelectric ceramic piece are coated with a wax layer.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN109991244A (en) * | 2019-05-09 | 2019-07-09 | 福建工程学院 | Sleeve Grouted density detection device and method based on stress wave |
| CN112580192A (en) * | 2020-11-25 | 2021-03-30 | 福建工程学院 | Construction method of grouting material uniaxial stress-strain constitutive model special for sleeve |
| CN113252789A (en) * | 2021-06-11 | 2021-08-13 | 东莞理工学院 | Nonlinear ultrasonic harmonic detection method for rail joint screw hole cracks |
| CN113945641A (en) * | 2021-10-19 | 2022-01-18 | 合肥工业大学 | Ultrasonic-based prestressed pipeline grouting quality detection method |
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2019
- 2019-05-09 CN CN201920659960.7U patent/CN210037714U/en active Active
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109991244A (en) * | 2019-05-09 | 2019-07-09 | 福建工程学院 | Sleeve Grouted density detection device and method based on stress wave |
| CN109991244B (en) * | 2019-05-09 | 2024-07-26 | 福建工程学院 | Device and method for detecting grouting compactness of sleeve based on stress wave method |
| CN112580192A (en) * | 2020-11-25 | 2021-03-30 | 福建工程学院 | Construction method of grouting material uniaxial stress-strain constitutive model special for sleeve |
| CN112580192B (en) * | 2020-11-25 | 2022-06-17 | 福建工程学院 | Construction method of grouting material uniaxial stress-strain constitutive model special for sleeve |
| CN113252789A (en) * | 2021-06-11 | 2021-08-13 | 东莞理工学院 | Nonlinear ultrasonic harmonic detection method for rail joint screw hole cracks |
| CN113252789B (en) * | 2021-06-11 | 2022-03-08 | 东莞理工学院 | Nonlinear ultrasonic harmonic detection method for rail joint screw hole cracks |
| CN113945641A (en) * | 2021-10-19 | 2022-01-18 | 合肥工业大学 | Ultrasonic-based prestressed pipeline grouting quality detection method |
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