CN109596710B - Device and method for ultrasonic detection of sleeve grouting defects based on wavelet packet energy - Google Patents

Abstract

The invention provides a device and a method for ultrasonically detecting a sleeve grouting defect based on wavelet packet energy, wherein the method comprises the following steps: and obtaining a wavelet packet energy proportion vector through an ultrasonic detection signal on the precast concrete member, obtaining a sleeve grouting defect index according to the vector, and judging the grouting condition of the steel bar sleeve grouting connection according to the value of the grouting defect index. The method provided by the invention can realize the detection of the defects with certain sizes, can meet the requirements in actual engineering, has no special requirements on the prefabricated parts in the detection process, and cannot cause damage.

Description

Device and method for ultrasonic detection of sleeve grouting defects based on wavelet packet energy

technical field

The invention relates to the field of nondestructive testing of concrete defects, in particular to a device and method for ultrasonic testing of sleeve grouting defects based on wavelet packet energy.

Background technique

The widely used connection method of prefabricated concrete structural components is reinforced sleeve grouting connection. The density of the grouting material in the sleeve has a great influence on the quality of the reinforced sleeve grouting connection. If the sleeve grouting is not dense, it will seriously affect the stressed steel bar. The quality of the connection between them leads to the failure of the prefabricated structure as a whole to achieve the design goal of "equivalent to cast-in-place", and there is a major safety hazard. The research on the device and method for detecting the grouting defect of the sleeve can timely find the grouting defect inside the sleeve and deal with it, which will effectively avoid the occurrence of safety accidents and has important practical significance.

Among the defect detection methods, the destructive detection will cause damage to the detection object and cannot be used for the detection of grouting defects in the sleeves of precast concrete members; Defects such as limited applicability and harsh application conditions are not suitable for sleeve grouting defect detection. In contrast, the ultrasonic method has the advantages of good directionality, strong penetrating ability and rich information, so it is more suitable.

Although the ultrasonic method has been widely studied in the field of non-destructive testing, it is rarely involved in the detection of grouting defects in the sleeve of precast concrete members. The reinforced sleeve grouting connection of precast concrete components is composed of external reinforced concrete, sleeves and connecting steel bars. The structure is more complex, and the concealment of grouting defects is intensified. It is difficult to effectively identify grouting defects from traditional single ultrasonic acoustic parameters.

The prior art discloses a method for detecting the fullness of grouting based on the ultrasonic on the surface of the sleeve. The ultrasonic transducer with integrated transceiver function is used for detection, and the sleeve is judged according to the strength of the first wave signal received by the ultrasonic transducer. The grouting situation inside the cylinder, but the concrete protective layer outside the sleeve needs to be removed to form an inspection port, which destroys the integrity of the precast concrete components.

SUMMARY OF THE INVENTION

In view of the problems in the prior art, the present invention provides a device and method for ultrasonic detection of sleeve grouting defects based on wavelet packet energy, which can realize non-destructive detection of sleeve grouting defects.

In a first aspect, the present invention provides a device for ultrasonic detection of sleeve grouting defects based on wavelet packet energy, comprising:

Ultrasonic arbitrary function generator, power amplifier, ultrasonic transmitting transducer, ultrasonic receiving transducer, oscilloscope and calculation processing device;

The ultrasonic transmitting transducer and the ultrasonic receiving transducer are respectively close to the surface of the precast concrete member to be detected,

The transmitted signal of the ultrasonic arbitrary function generator is amplified after passing through the power amplifier, and is transmitted to the ultrasonic transmitting transducer, and the ultrasonic transmitting transducer sends an ultrasonic detection signal to the precast concrete member to be detected;

The ultrasonic receiving transducer receives the ultrasonic detection signal after passing through the precast concrete member to be detected, and transmits it to the oscilloscope;

The oscilloscope is also used to receive the transmission signal amplified by the power amplifier; the output of the oscilloscope is connected to the calculation processing device, and the calculation processing device processes the amplified transmission signal and the ultrasonic detection signal received by the oscilloscope to determine Indicators of grouting defects in precast concrete components to be tested;

Wherein, the prefabricated concrete components to be tested include: reinforced sleeve grouting connection.

It should be noted that the components in the embodiments of the present invention include sleeves, but there are various arrangements of the sleeves.

The precast concrete components here refer to the precast concrete components connected by the steel sleeve grouting connection method.

Optionally, a coupling agent is provided between the ultrasonic transmitting transducer and the ultrasonic receiving transducer and the surface of the precast concrete member to be detected.

Optionally, the coupling agent includes: a water-based polymer compound gel.

Optionally, the ultrasonic arbitrary function generator emission center frequency is a five-cycle sinusoidal ultrasonic wave modulated by a Hanning window with a center frequency of 50 kHz;

The center frequency of the ultrasonic transmitting transducer and the ultrasonic receiving transducer are both 50kHz;

The voltage excitation amplitude of the ultrasonic transmitting transducer is greater than or equal to 10V.

Optionally, the connection line between the ultrasonic arbitrary function generator and the power amplifier is a shielded BNC line;

The connection line between the power amplifier and the ultrasonic transmitting transducer is a shielded BNC line;

The connection line between the power amplifier and the oscilloscope is a shielded BNC line;

The connection line between the ultrasonic receiving transducer and the oscilloscope is a shielded BNC line;

The connection line between the oscilloscope and the computing processing device is a shielded BNC line.

In a second aspect, the present invention provides a method for ultrasonic detection of sleeve grouting defects based on wavelet packet energy, comprising:

S1. The computing and processing device receives an ultrasonic detection signal, and the ultrasonic detection signal is the ultrasonic detection after detecting the precast concrete member to be detected by using the device for ultrasonic detection of sleeve grouting defects based on wavelet packet energy according to any one of the above-mentioned first aspects. Signal;

S2, carrying out the wavelet packet transformation to the ultrasonic detection signal to obtain a wavelet packet energy proportional vector;

S3. Calculate the sleeve grouting defect index of the current test position of the precast concrete member to be detected according to the pre-acquired identification baseline for calibrating grouting defects and the wavelet packet energy ratio vector in the step S2, and based on the calculated sleeve grouting defect index The grouting defect index is used to judge the compaction performance;

Wherein, the pre-acquired identification baseline for calibrating grouting defects is: according to the wavelet packet energy ratio vector of the dense grouting part as a benchmark, the calibration baseline for identifying grouting defects;

The prefabricated concrete components to be tested include grouting connections of steel sleeves in any arrangement.

Optionally, the step S3 includes:

Obtain the sleeve grouting defect index DI according to the pre-acquired calibration grouting defect identification baseline and the wavelet packet energy proportional vector in the step S2;

Judging the grouting condition of the grouting connection of the steel bar sleeve according to the DI;

in,

ER _h =[e _h,1 ,e _h,2 ,e _h,3 ,...,e _h,n ] is the wavelet packet energy proportional vector of the grouting dense part obtained according to the above steps S1 and S2;

ER _i =[e _i,1 ,e _i,2 ,e _i,3 ,...,e _i,n ] is the wavelet packet energy proportional vector of the current test position in the precast concrete member to be detected obtained in step S2;

i and h represent different working conditions;

Among them, e _{h, u are} the elements in the energy ratio vector of the wavelet packet in the grouting dense part, representing the ratio of the wavelet packet energy in different frequency bands of the ultrasonic detection signal of the grouting dense part; The element in the packet energy ratio vector, the ratio of the wavelet packet energy in different frequency bands of the ultrasonic detection signal of the current test part in the precast concrete component to be detected. The beneficial effects that the present invention has:

1) The method of the present invention can realize the non-destructive detection of grouting defects of a certain size in the sleeve, can meet the requirements of actual engineering detection, and provide a realistic basis for the safety evaluation of prefabricated structures.

2) The detection device of the present invention is simple in structure, low in cost, low in environmental requirements and easy to implement.

3) The method of the present invention has no special requirements on the structure of precast concrete members in the detection process, and the integrity of the members will not be damaged during the detection process, and can be used for grouting of precast concrete members in any form using reinforced sleeve grouting connection as the connection method. Defect detection.

Description of drawings

Fig. 1 is the arrangement schematic diagram of ultrasonic transducer of the present invention;

Fig. 2 is the actual diagram of the ultrasonic arbitrary function generator selected by the method of the present invention;

Fig. 3 is the actual picture of the power amplifier selected by the method of the present invention;

Fig. 4 is the actual diagram of the ultrasonic transducer selected by the method of the present invention;

Fig. 5 is the physical diagram of the oscilloscope selected by the method of the present invention;

FIG. 6 is a schematic diagram of a device for ultrasonic detection of grouting connection defects of steel bar sleeves provided by an embodiment of the present invention;

Fig. 7 is the detailed sectional view of the test piece adopted in the testing process of the present invention;

Fig. 8 is the wavelet packet energy ratio vector diagram of measuring point 1 on each test piece in the testing process;

Figure 9 shows the grouting defect index of each grouting compact specimen;

Figure 10 shows the grouting defect index of different grouting defect sizes for the SJ1 group of specimens;

Figure 11 shows the grouting defect index of different grouting defect sizes for the SJ2 group of specimens;

Figure 12 shows the grouting defect index of different grouting defect sizes for the SJ3 group of specimens;

Figure 13 shows the grouting defect index of different grouting defect sizes for the SJ4 group of specimens;

FIG. 14 is a schematic diagram of an ultrasonic detection method for a grouting connection defect of a steel bar sleeve provided by an embodiment of the present invention.

Detailed ways

In order to better explain the present invention and facilitate understanding, the present invention will be described in detail below with reference to the accompanying drawings and through specific embodiments.

In the embodiment of the present invention, a grouting-dense concrete member is first fabricated, and then the device of the present invention is used to perform ultrasonic testing on the grouting-dense concrete member. To detect unknown parts, to judge whether these unknown parts i have grouting defects.

Specifically, the method of the present invention may comprise the following steps:

The first step is to use the ultrasonic longitudinal wave to detect the precast concrete member and receive the transmission detection signal;

The second step is to perform wavelet packet transformation on the ultrasonic detection signal, and further obtain the wavelet packet energy ratio vector;

The third step is to use the wavelet packet energy ratio vector of the grouting dense part as the benchmark to calibrate the grouting defect identification baseline, calculate the sleeve grouting defect index of the unknown part and discriminate.

The method of obtaining the proportional vector of wavelet packet energy through the ultrasonic detection signal on the precast concrete member, obtaining the sleeve grouting defect index DI according to the above vector, and judging the grouting condition of the steel sleeve grouting connection according to the value of the above grouting defect index DI.

所述套筒灌浆缺陷指标DI是提取预制混凝土构件后的超声波检测信号，将上述检测信号进行小波包变换，得到小波包能量向量，以灌浆密实的预制混凝土构件小波包能量向量为基准，代入DI计算公式得到，用以判断未知灌浆情况的预制混凝土构件是否存在灌浆缺陷。in,

The sleeve grouting defect index DI is the ultrasonic detection signal after extracting the precast concrete member, and the above detection signal is subjected to wavelet packet transformation to obtain the wavelet packet energy vector, which is based on the wavelet packet energy vector of the dense grouting precast concrete member, and is substituted into DI. The calculation formula is obtained, which is used to judge whether the precast concrete member with unknown grouting condition has grouting defects.

The wavelet packet energy vector is obtained by the following method: after the ultrasonic probe receives the signal, the wavelet packet energy is obtained through wavelet packet transformation, and then the wavelet packet energy of each frequency band within the frequency range of the excitation signal is selected to form a corresponding proportional vector, and the sleeve is grouted densely. The wavelet packet energy ratio vector of the part is ER _h =[e _h,1 ,e _h,2 ,e _h,3 ,…,e _h,n ], and the wavelet packet energy ratio vector of the unknown grouting quality part is ER _i =[ e _i,1 ,e _i,2 ,e _i,3 ,…,e _i,n ].

The method of the invention can realize the non-destructive detection of grouting defects of a certain size in the sleeve, can meet the requirements of actual engineering detection, and provide a realistic basis for the safety evaluation of prefabricated structures;

In addition, the method of the present invention has no special requirements on the structure of the precast concrete member during the detection, and will not cause damage to the integrity of the member during the detection process, and can be used for any form of precast concrete member using reinforced sleeve grouting connection as the connection method. Grout defect detection.

Embodiment 1 The relevant principle and device explanation of the testing method of the present invention

In this embodiment, the principle of the ultrasonic detection method for grouting connection defects of steel bar sleeves based on wavelet packet energy is as follows.

According to the characteristics of ultrasonic detection signal, wavelet packet analysis decomposes the high frequency part and low frequency part of the signal at the same time, adaptively selects the corresponding frequency band to match the signal spectrum, and improves the time-frequency resolution.

The wavelet packet analysis solves the problem that the frequency resolution is too low when the time resolution of the wavelet analysis is relatively high, and the wavelet packet analysis has a wider application value.

Compared with the ultrasonic transmission detection signal of the dense part of the sleeve grouting, the ultrasonic transmission detection signal of the defect part of the sleeve grouting will receive a significant change in the energy received at the same frequency segment, and the grouting defect can be reflected by analyzing the energy change. condition.

Sleeve grouting defect index DI is the energy proportion vector in the specified frequency range calculated by the ultrasonic transmission detection signal after wavelet packet decomposition, and the root mean square deviation algorithm is used to calculate the energy proportion in the same frequency segment of the detection signal of different parts. Perform an arithmetic square root calculation.

Taking the energy proportional vector of the grouting dense part as the benchmark, the energy proportional vector of the signal of the unknown condition part is compared with the grouting dense part, and the grouting defect index is obtained. This index represents the difference between the energy of the specified frequency band after the ultrasonic detection signal of the grouting dense part and the grouting defect part is decomposed by the wavelet packet.

The grouting defect index is defined as follows:

Assuming that the ultrasonic transmission detection signal S is decomposed by N layers of wavelet packets, sub-signals in 2 ^N frequency bands can be obtained in the last layer to form a signal set {X ₁ , X ₂ , X ₃ ,..., X ₂ ^N }, where

X _j =[x _j,1 ,x _j,2 ,x _j,3 ,…,x _j,m ] (1)

where m——the number of sampled data, j is the frequency band number, j=1,2,3,…,2 ^N

The energy E _i,j of the decomposed signal is

where i is the serial number of the working condition.

Then the wavelet packet energy formed after the original detection signal S under the condition i is decomposed by N layers of wavelet packets can be expressed as

Assuming that the wavelet packet energy formed by the decomposition of the original detection signal under working condition i, the wavelet packet energy of each frequency band in the excitation signal frequency range is E _i,k ,E _i,k+1 ,E _i,k+2 ,…, E _i,k+l , the wavelet packet energy ratio vector in the frequency range of the excitation signal is defined as ER _i =[e _i,1 ,e _i,2 ,e _i,3 ,...,e _i,n ] (4)

in the formula

EP _i is the sum of the wavelet packet energy of each frequency band in the frequency range of the excitation signal in the wavelet packet energy obtained by the decomposition of the detection signal, then

EP _i =E _i,k +E _i,k+1 +E _i,k+2 +...+E _i,k+l (5)

Assuming that the wavelet packet energy proportional vector obtained from the ultrasonic transmission detection signal of the dense part of the sleeve grouting is ER _h = [e _h,1 ,e _h,2 ,e _h,3 ,…,e _h,n ], the sleeve grouting part The wavelet packet energy proportional vector obtained from the ultrasonic transmission detection signal is ER _i =[e _i,1 ,e _i,2 ,e _i,3 ,…,e _i,n ], then the sleeve grouting based on wavelet packet energy is defined The defect ultrasonic detection index DI is

The grouting defect index DI is calculated to screen the frequency band obtained by the wavelet packet decomposition, and select the frequency band where the excitation signal energy is concentrated, which can better eliminate the interference of clutter and highlight the difference between the grouting defect detection signal and the grouting dense detection signal. According to the grouting defect index DI, the existence of sleeve grouting defects is judged.

The method of the invention includes three steps. The first step is to use the ultrasonic longitudinal wave to detect precast concrete components and receive transmission detection signals; The first step is to use the wavelet packet energy ratio vector of the grouting dense part as the benchmark to calibrate the grouting defect identification baseline, calculate the sleeve grouting defect index of the unknown part and discriminate it, as shown in Figure 14.

The selected part of the component device of the present invention can be a product composed of the following, but is not limited to other devices that can realize the same function:

The hardware platform in this embodiment has the structure shown in FIG. 6 , and the software platform is implemented in the PC shown in FIG. 6 , that is, it is used to process the collected ultrasonic detection signals, and solve the corresponding grouting defect indexes of different detection parts.

The hardware platform includes ultrasonic arbitrary function generator, power amplifier, ultrasonic transducer and oscilloscope. The ultrasonic transducer includes a transmitting transducer and a receiving transducer, and its function is to convert between electrical signals and ultrasonic signals; the ultrasonic transducer is closely attached to the surface of the precast concrete member, as shown in Figure 1. The energy detectors are placed in different parts to achieve the purpose of grouting defect detection.

The function of the ultrasonic arbitrary function generator is to emit ultrasonic waves with a specified waveform. The ultrasonic arbitrary function generator selected in the present invention is an Agilent33511B arbitrary function generator. The physical diagram is shown in Figure 2. The excited ultrasonic wave is a 50 kHz five-frequency wave modulated by a Hanning window. Periodic sine wave, as shown in Figure 2. The function of the power amplifier is to amplify the signal emitted by the arbitrary function generator and reduce the interference of the environment. The power amplifier used in the present invention is an Antai ATA-1200 power amplifier, and the physical diagram is shown in FIG. 3 . The ultrasonic transducer is a Shantou ultrasonic 50kHz transducer. There is a pair of transmitting transducer and receiving transducer. The center frequency of the ultrasonic transducer is 50kHz. The transmitting transducer converts the electrical signal emitted by the power amplifier into ultrasonic waves. The receiving transducer converts the ultrasonic signal into an electrical signal and transmits it to the oscilloscope. The actual picture is shown in Figure 4. The oscilloscope is a Tektronix MDO3024, and its function is to collect electrical signals and display the signals. The actual picture is shown in Figure 5; the connection of each instrument adopts a shielded BNC line.

As shown in Fig. 6, the ultrasonic arbitrary function generator as a signal generator outputs an initial signal. The power amplifier receives the initial signal and amplifies it, and then outputs two identical signals, one of which is directly input to channel 2 of the oscilloscope for display, and the other signal is input to the ultrasonic transmitting transducer. After the ultrasonic wave propagates in the precast concrete member, it is received by the receiving transducer, and the received detection signal is input to channel 1 of the oscilloscope. The oscilloscope displays the signals of two channels, which are acquired simultaneously. The ultrasonic detection signal input by each channel is further extracted, and the software platform in the computer is used for processing and analysis, thereby obtaining the grouting defect indicators of different detection positions.

Embodiment 2 The apparatus and method for ultrasonic detection of sleeve grouting defects based on wavelet packet energy of the present invention are used for the test of steel sleeve grouting connection defects

In order to verify the effectiveness of the method of the present invention for detecting grouting connection defects of steel bar sleeves, the following tests were performed to detect the grouting defects of steel bar sleeve specimens.

In this test, 20 test specimens of 3 types and 4 groups were designed: plain concrete + centering sleeve (SJ1 and SJ2), longitudinal reinforcement on both sides + centering sleeve (SJ3), and longitudinal reinforcement on one side + offset sleeve (SJ4) ), and according to the possible existence of the steel sleeve grouting connection defect in the actual project, the sleeve grouting defect is simplified and set as the circumferential defect along the connecting steel bar. The dimensions and defect settings of the specimen are shown in Table 1, and the detailed cross-sectional view of the specimen is shown in Figure 7.

Table 1

The device used in this test is tested according to the apparatus mentioned in Example 1 and the detection steps mentioned in Example 1.

Before the test starts, it is necessary to properly process the test surface and arrange the measurement line in combination with the internal defect settings of the component, so as to ensure that the collected data is more accurate and reasonable. After the test surface preparation, the line layout is carried out. Five measuring points are arranged on each measuring line of the SJ1 group of test pieces, that is, there are five pairs of measuring points on each test piece. SJ2, SJ3 and SJ4 groups of specimens are arranged with 6 measuring points on each measuring line

In the first step, the prepared test piece is detected by the ultrasonic longitudinal wave and the transmission detection signal is received. The detection of ultrasonic longitudinal waves and the acquisition of ultrasonic detection signals are completed by using the hardware platform.

The second step is to perform wavelet packet transformation on the ultrasonic detection signals collected at all measuring points, and further obtain the energy proportional vector of the wavelet packet. In the test, a total of 115 test points on 4 groups of 20 test pieces of 3 types of test pieces were tested, and the proportional vector of wavelet packet energy of one test point on each test piece was selected as the display, as shown in Figure 8.

The third step is to use the wavelet packet energy ratio vector of the grouting dense part as the benchmark to calibrate the grouting defect identification baseline, calculate the sleeve grouting defect index of the grouting defect and identify it.

The grouting defect identification baseline calibrated in the test is shown in Figure 9, and the baseline value is 0.14, that is, when the DI value of all measuring points on the specimen corresponding to a defect of a certain size is greater than 0.14, it is considered to be effectively judged by the DI value. grouting defects of this size.

Figure 10, Figure 11, Figure 12, Figure 13 show the grouting defect indexes of each group of sleeves. For SJ1 type specimens, when the defect size is 37mm (SJ14) and 42.5mm (SJ15), the DI value of all measuring points in the actual measurement is greater than 0.14, that is, the 37mm and 42.5mm grouting defects can be effectively identified by the DI value. For SJ2 type specimens, when the defect size is 40mm (SJ24) and 46.5mm (SJ25), the DI value of all measuring points in the actual measurement is greater than 0.14, and the 40mm and 46.5mm grouting defects can be effectively identified by the DI value. For SJ3 type specimens, when the defect size is 46.5mm (SJ35), the DI value of all measuring points in the actual measurement is greater than 0.14, that is, the 46.5mm grouting defect can be effectively identified by the DI value. For SJ4 type specimens, when the defect size is 40mm (SJ44) and 46.5mm (SJ45), the DI value of all measuring points in the actual measurement is greater than 0.14, that is, the 40mm and 46.5mm grouting defects can be effectively identified by the DI value.

It can be seen from the above results that the present invention can effectively identify grouting defects of a certain size, that is, can detect grouting defects of a certain size. The test verifies the effectiveness of ultrasonic detection of grouting connection defects of steel bar based on wavelet packet energy; the proposed detection device is simple in structure, low in cost, low in environmental requirements and easy to implement; the proposed method and device have no special requirements for the structure of precast concrete members , the inspection process will not cause damage to the integrity of the component.

It should also be noted that the exemplary embodiments mentioned in the present invention describe some methods or systems based on a series of steps or devices. However, the present invention is not limited to the order of the above steps, that is, the steps may be performed in the order mentioned in the embodiment, or may be different from the order in the embodiment, or several steps may be performed simultaneously.

The above embodiments can be referred to each other, and this embodiment does not limit each embodiment.

Finally, it should be noted that the above-mentioned embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that : it can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements to some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the present invention range.

Claims (5)

1. a method for ultrasonic detection of sleeve grouting defects based on wavelet packet energy, is characterized in that, comprising: S1, the computing processing device receives an ultrasonic detection signal, and the ultrasonic detection signal is an ultrasonic detection signal after a device for ultrasonic detection of sleeve grouting defects based on wavelet packet energy is used to detect the precast concrete member to be detected; S2, carrying out the wavelet packet transformation to the ultrasonic detection signal to obtain a wavelet packet energy proportional vector; S3. Calculate the sleeve grouting defect index of the current test position of the precast concrete component to be detected according to the pre-acquired identification baseline for calibrating grouting defects and the wavelet packet energy ratio vector in the step S2, and based on the calculated sleeve grouting defect index The grouting defect index is used to judge the compaction performance; The pre-acquired identification baseline for calibrating grouting defects is: according to the wavelet packet energy proportional vector of the grouting dense part as a benchmark, the grouting defect identification baseline is calibrated; The prefabricated concrete components to be tested include reinforced sleeve grouting connections in any arrangement; The step S3 includes: Obtain the sleeve grouting defect index DI according to the pre-acquired calibration grouting defect identification baseline and the wavelet packet energy proportional vector in the step S2; Judging the grouting condition of the grouting connection of the steel bar sleeve according to the DI; in,

ER _h = [e _{h, 1} , e _{h, 2} , e _{h, 3} , ..., e _{h, n} ] is the wavelet packet energy proportional vector of the grouting dense part obtained according to the above-mentioned steps S1 and S2; ER _i =[ _ei,1 , _ei,2 , _ei,3 ,..., _ei,n ] is the wavelet packet energy proportional vector of the current test position in the precast concrete component to be tested obtained in step S2; i and h represent different working conditions; Among them, e _{h, u are} the elements in the energy ratio vector of the wavelet packet in the grouting dense part, representing the ratio of the wavelet packet energy in different frequency bands of the ultrasonic detection signal of the grouting dense part; Elements in the packet energy ratio vector, the ratio of wavelet packet energy in different frequency bands of the ultrasonic detection signal at the current test position in the precast concrete component to be detected; And, the device for ultrasonic detection of sleeve grouting defects based on wavelet packet energy includes: Ultrasonic arbitrary function generator, power amplifier, ultrasonic transmitting transducer, ultrasonic receiving transducer, oscilloscope and calculation processing device; The ultrasonic transmitting transducer and the ultrasonic receiving transducer are respectively close to the surface of the precast concrete member to be detected, The transmitted signal of the ultrasonic arbitrary function generator is amplified after passing through the power amplifier, and is transmitted to the ultrasonic transmitting transducer, and the ultrasonic transmitting transducer sends an ultrasonic detection signal to the precast concrete member to be detected; The ultrasonic receiving transducer receives the ultrasonic detection signal after passing through the precast concrete member to be detected, and transmits it to the oscilloscope; The oscilloscope is also used to receive the transmission signal amplified by the power amplifier; the output of the oscilloscope is connected to the calculation processing device, and the calculation processing device processes the amplified transmission signal and the ultrasonic detection signal received by the oscilloscope to determine Indicators of grouting defects in precast concrete components to be tested; The prefabricated concrete components to be tested include grouting connections of steel sleeves in any arrangement. 2 . The method according to claim 1 , wherein a coupling agent is provided between the ultrasonic transmitting transducer and the ultrasonic receiving transducer and the surface of the precast concrete member to be detected. 3 . 3. The method according to claim 2, wherein the coupling agent comprises: a water-based polymer compound gel. 4. method according to claim 1, is characterized in that, described ultrasonic arbitrary function generator emission center frequency is that the five-period sinusoidal ultrasonic wave modulated through Hanning window of 50kHz; The center frequency of the ultrasonic transmitting transducer and the ultrasonic receiving transducer are both 50kHz; The voltage excitation amplitude of the ultrasonic transmitting transducer is greater than or equal to 10V. 5. The method of claim 1, wherein The connection line between the ultrasonic arbitrary function generator and the power amplifier is a shielded BNC line; The connection line between the power amplifier and the ultrasonic transmitting transducer is a shielded BNC line; The connection line between the power amplifier and the oscilloscope is a shielded BNC line; The connection line between the ultrasonic receiving transducer and the oscilloscope is a shielded BNC line; The connection line between the oscilloscope and the computing processing device is a shielded BNC line.

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