A method and system for detecting the subsequent service life of post-earthquake buckling-restrained braces.

Abstract

This application proposes a method and system for detecting the subsequent service life of post-earthquake buckling-restrained braces. Belonging to the field of buckling-restrained brace testing, the method includes: acquiring vibration signals corresponding to different D values ​​of the buckling-restrained brace; processing the vibration signals using a statistically considered frequency response function difference method to obtain AD values ​​under different damage conditions; establishing the relationship between D values ​​and AD values; determining the relationship between D values ​​and subsequent service life based on the frequency of subsequent earthquakes in the area where the test specimen is located and the required reliability of the test specimen; and further determining the relationship between AD values ​​and subsequent service life based on the relationship between D values ​​and AD values. This achieves non-destructive testing of buckling-restrained braces, ensuring the integrity and safety of the component.

Description

Technical Field

[0001] This application relates to the field of buckling-restrained brace testing, and more specifically, to a method and system for testing the subsequent service life of post-earthquake buckling-restrained braces. Background Technology

[0002] The most direct method for detecting damage to buckling-restrained braces (BRBs) is to observe their core plates. However, the core plate surface is often covered with a coating, obscuring the deformation until the coating is removed. This hinders the assessment of the BRB's core plate. Furthermore, visual inspection can only determine whether the BRB is still usable, making it difficult to determine its future service life. Therefore, proposing a method for detecting post-earthquake damage to the core plate to determine its future service life is crucial. Existing technical methods are as follows:

[0003] (1) The invention patent with publication number CN118392478A and invention title "A Performance Failure Detection System and Method for Dampers" describes a system that installs the damper inside a device for testing. It should be noted that a buckling-restrained brace is a type of damper. The drawback of this approach is that since the damper is installed inside the device, the device will also be damaged after an earthquake, making it impossible to remove the buckling-restrained brace from the device. Furthermore, the damage to the buckling-restrained brace is irreversible; disassembly will damage the buckling-restrained brace. Even assuming it could be disassembled for testing, the damage to the buckling-restrained brace would be aggravated after testing.

[0004] (2) The invention patent with publication number CN109540933A and invention title "An X-ray-based Non-destructive Testing Device for Reinforcing Steel Structures" describes a device equipped with a radiographic testing apparatus to achieve continuous testing of reinforcing steel structures. Its drawbacks are: (a) After an earthquake, buckling-restrained braces will be in a damaged state due to plastic deformation. X-rays can only detect internal defects in the components but cannot detect plastic deformation.

[0005] (3) The invention patent with publication number CN117705953A and invention title "A Damage Detection Method and System Based on Acoustic Emission and Tomographic Imaging Technology" is a novel detection technology that effectively combines acoustic emission technology and tomographic imaging technology to improve the accuracy of damage detection, thereby achieving precise location and assessment of minute internal damage in materials. Drawback: This detection method cannot be applied to the detection of the service life of buckling-restrained supports. The reason is as follows: the main damage to the component is concentrated in the core plate, which is surrounded by an outer covering. The transmitting and receiving devices cannot detect the damage to the core plate on the outer covering. Summary of the Invention

[0006] The purpose of this application is to provide a method and system for detecting the subsequent service life of post-earthquake buckling-restrained braces, which can perform non-destructive testing on buckling-restrained braces and accurately determine their subsequent service life.

[0007] This application is implemented as follows:

[0008] Firstly, this application provides a method for detecting the subsequent service life of post-earthquake buckling-restrained braces. This includes the following steps:

[0009] S1: Obtain vibration signals corresponding to different D values ​​of the buckling-restrained support;

[0010] S2: The frequency response function difference method considering statistics is used to process the vibration signal to obtain the AD value under different damage conditions;

[0011] S3: Construct the relationship between D value and AD value;

[0012] S4: Based on the frequency of subsequent earthquakes in the area where the test piece is located and the required reliability of the test piece, determine the relationship between the D value and the subsequent service life, and then determine the relationship between the AD value and the subsequent service life based on the relationship between the D value and the AD value.

[0013] Based on the first aspect, obtaining vibration signals corresponding to different D values ​​of buckling-restrained supports specifically includes:

[0014] The D value of the buckling-restrained brace is calculated using the Miner linear damage theory criterion, as shown in formula (1) below:

[0015]

[0016] In the formula, N i To maintain the number of loading cycles at which the buckling-restrained brace fails under the current stress level, n i This represents the number of cycles applied at this stress level.

[0017] Sensors required for vibration detection are installed at the detection sites of the buckling-restrained brace;

[0018] Adjust the parameters of the signal receiving device;

[0019] An excitation device is used to excite one end of the buckling-restrained support, and a signal receiving device is used to record the vibration signals of the excitation end and the response end.

[0020] Based on the first aspect, the specific steps for installing the vibration detection sensors at the detection sites of the buckling-restrained brace include:

[0021] Two sensors required for vibration detection are installed at the detection sites of the buckling-restrained brace. The locations are as follows: on the long side of the buckling-restrained brace, the sensor is set 50 mm from the edge of the cantilever connection section; on the short side, the sensor is set at the middle of the short side.

[0022] Based on the first aspect, the specific steps for adjusting the parameters of the signal receiving device include:

[0023] The sampling frequency is 2000Hz; the duration is 0.5s; the sampling amplitude is determined based on the magnitude of the excitation and the distance between the two sensors.

[0024] Based on the first aspect, the method of processing vibration signals using the statistically considered frequency response function difference method to obtain AD values ​​under different damage conditions specifically includes:

[0025] S2-1: Acquire the response to ambient noise through sensors and signal receiving devices;

[0026] S2-2: Obtain the vibration signals from the excitation and response ends of the undamaged specimen, and perform noise reduction processing on the vibration signals from the excitation and response ends based on the response to environmental noise.

[0027] S2-3: Using signal processing methods, the vibration signal after noise reduction is filtered and normalized to obtain its frequency response function. Based on this data, damage identification of the test piece is performed.

[0028] S2-4: Perform steps S2-1 to S2-3 on the test piece to obtain the frequency response function;

[0029] S2-5: Make a statistical judgment. If the frequency response function of the test piece is statistically the same as that of the undamaged test piece, the test piece is considered to be an undamaged component; otherwise, the test piece is considered to be a damaged component, and the AD value is calculated using the preset method.

[0030] Based on the first aspect, the AD value is calculated using a preset method, including:

[0031] Suppose that the frequency response function follows a normal distribution, as shown in equation (2):

[0032] |H(jω)|~N(μ(|H(jω)|),σ 2 (ω)) (2)

[0033] In the formula, μ(H(jω)) is the mean value of the amplitude of the frequency response function, and σ 2 (ω) represents the amplitude variance of the frequency response function corresponding to a certain frequency, H(jω) is the frequency response function, and N(μ,σ) is the frequency response function. 2 The expression σ indicates that the function follows a normal distribution with mean μ and variance σ. 2When there is a difference in the frequency response function between the test specimen and the undamaged specimen, the test specimen is considered to be damaged. Since both conform to a normal distribution, the difference between them also conforms to a normal distribution, as shown in equations (3) to (5) below:

[0034] δ|H(jω)|~N(μ(δ|H(jω)|),δσ 2 (ω)) (3)

[0035] δ|H(jω)|=||H0(jω)|-|H u (jω)|| (4)

[0036]

[0037] In the formula, δ|H(jω)| is the difference in amplitude of the frequency response function, and N(μ(δ|H(jω)|), δσ 2 (ω) indicates that the function follows a normal distribution with mean μ(δ|H(jω)|) and variance δσ. 2 (ω), μ(δ|H(jω)|) are the mean values ​​of the amplitude differences of the frequency response function, and δσ 2 (ω) represents the variance of the amplitude difference of the frequency response function, |H0(jω)| represents the amplitude of the frequency response function of the undamaged component, and |H u (jω)| represents the amplitude of the frequency response function of the component under test, σ0 2 (ω) represents the variance of the frequency response function of the undamaged component, σ u 2 (ω) represents the variance of the frequency response function of the component under test;

[0038] The data is normalized to obtain the parameter Z, as shown in equation (6):

[0039]

[0040] In the formula, Z is the standard quantile, used to assess the distance of a sample point from the population mean, ω is the frequency, δ|H(jω)| is the difference in amplitude of the frequency response function, and δσ 2 (ω) represents the variance of the amplitude difference of the frequency response function, and N(0,1) indicates that the function follows a normal distribution with a mean of 0 and a variance of 1; if Z remains within the confidence interval, i.e., |Z|≤Z 1-α / 2 If the null hypothesis is met, the sample being tested is considered undamaged, with a guarantee rate of 1 - α / 2; otherwise, the alternative hypothesis is accepted, i.e., |Z| > Z. 1-α / 2 At that time, it is considered that the test piece is damaged; finally, a parameter is determined based on the test of Z to statistically measure the exceedance amplitude, which is defined as AD; as shown in the following formula (7):

[0041]

[0042] In the formula, AD is a parameter, ω is the frequency, and |Z(ω)| is the absolute value of Z as a function of ω. Z(ω) is greater than Z 1-α / 2 Part, Z 1-α / 2 It represents the standard quantile of 1-α / 2.

[0043] Based on the first aspect, step S3 specifically includes:

[0044] Multiple sets of vibration tests are performed on buckling-restrained braces with the same degree of damage to obtain the corresponding AD values. The mean and standard deviation of the corresponding values ​​are calculated. At the same time, the D values ​​of the corresponding damage stages need to be calculated as well. The D values ​​and AD values ​​are linearly fitted to establish a fitting equation and obtain the relationship between the D values ​​and AD values.

[0045] Secondly, this application provides a system for detecting the subsequent service life of post-earthquake buckling-restrained braces, comprising:

[0046] Acquisition module: Acquires vibration signals corresponding to different D values ​​of the buckling-restrained support;

[0047] Processing module: The vibration signal is processed using a statistical frequency response function difference method to obtain AD values ​​under different damage conditions;

[0048] Module construction: Constructs the relationship between D value and AD value;

[0049] Service life prediction module: Based on the frequency of subsequent earthquakes in the area where the test piece is located and the required reliability of the test piece, the relationship between the D value and the subsequent service life is determined. Then, based on the relationship between the D value and the AD value, the relationship between the AD value and the subsequent service life is determined.

[0050] Thirdly, this application provides an electronic device, comprising:

[0051] Memory, used to store one or more programs;

[0052] processor;

[0053] The above method is implemented when one or more programs are executed by the processor.

[0054] Fourthly, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-described method.

[0055] Compared with the prior art, this application has at least the following advantages or beneficial effects:

[0056] The remaining service life of a buckling-restrained brace can be accurately determined simply by testing it under a specific damage condition.

[0057] Non-destructive testing of buckling-restrained supports was achieved, ensuring the integrity and safety of the components.

[0058] Existing technologies cannot detect damage to internal objects when there are external coverings, while this method can effectively detect damage to the core board. Attached Figure Description

[0059] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0060] Figure 1 This is a flowchart illustrating a method for detecting the subsequent service life of a post-earthquake buckling-restrained brace, as described in this application.

[0061] Figure 2 This is a schematic diagram of vibration testing of a buckling-restrained brace in a method for detecting the subsequent service life of a post-earthquake buckling-restrained brace according to this application;

[0062] Figure 3 This is a schematic diagram illustrating the installation of vibration detection sensors at the detection site of a buckling-restrained brace in a method for detecting the subsequent service life of a post-earthquake buckling-restrained brace according to this application.

[0063] Figure 4 This is a schematic diagram illustrating the relationship between the AD value and the subsequent service life in a method for detecting the subsequent service life of a post-earthquake buckling-restrained brace according to this application.

[0064] Figure 5 This is a structural schematic diagram of a system for detecting the subsequent service life of a post-earthquake buckling-restrained brace, as described in this application.

[0065] Figure 6 This is a schematic diagram of the structure of an electronic device according to this application.

[0066] icon:

[0067] 1. Signal receiving device; 2. Excitation end; 3. Response end; 4. Buckling restraint support; 5. Detection part; 6. Acquisition module; 7. Processing module; 8. Construction module; 9. Service life prediction module; 10. Processor; 11. Memory; 12. Communication interface. Detailed Implementation

[0068] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0069] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the various embodiments and features described below can be combined with each other.

[0070] Example

[0071] Through long-term research and practice, the inventors discovered that the most intuitive method for detecting damage to the buckling restraint brace 4 in existing technologies is to observe its core plate. However, the core plate surface is covered with a covering material, making the deformation of the core plate invisible. After an earthquake, the covering material is damaged and difficult to remove, and forced removal can easily damage the buckling restraint brace 4. In addition, visual observation can only determine whether the buckling restraint brace 4 can continue to be used, but it is difficult to determine its subsequent service life.

[0072] In view of this, this application provides a method for detecting the subsequent service life of a post-earthquake buckling-restrained brace 4, which can perform non-destructive testing on the buckling-restrained brace 4 and accurately determine its subsequent service life.

[0073] Please refer to Figure 1 , Figure 1 A flowchart illustrating a method for determining the subsequent service life of post-earthquake buckling-restrained brace 4; the method includes the following steps:

[0074] S1: Obtain vibration signals corresponding to different D values ​​of buckling-restrained support 4;

[0075] Specifically, the D-value represents the degree of damage. Vibration signals of the buckling-restrained support 4 under different degrees of damage (represented by the D-value) are collected. The D-value is an indicator of the degree of damage to the support, including damage conditions such as cracks and deformation. The vibration signals are obtained from the support by sensors and reflect the vibration characteristics of the support under external forces such as earthquakes.

[0076] S2: The frequency response function difference method considering statistics is used to process the vibration signal to obtain the AD value under different damage conditions;

[0077] Specifically, the frequency response function difference method, which considers statistics, is used to analyze the vibration signal obtained in the previous step. The purpose of this method is to extract information reflecting the degree of support damage from the vibration signal, namely the AD value. AD value definition: The AD value is a quantitative indicator used to measure the degree of difference between the frequency response function of the undamaged component and the test piece. This degree of difference is the basis for determining whether the component is damaged. The AD value is a parameter related to the degree of support damage obtained through signal processing.

[0078] S3: Construct the relationship between D value and AD value;

[0079] Specifically, based on the previously obtained D-value and AD-value data, a mathematical relationship or model is established between them. This model can be used to infer the supporting D-value, i.e., the degree of damage, based on the AD-value.

[0080] S4: Based on the frequency of subsequent earthquakes in the area where the test piece is located and the required reliability of the test piece, determine the relationship between the D value and the subsequent service life, and then determine the relationship between the AD value and the subsequent service life based on the relationship between the D value and the AD value.

[0081] Specifically, considering the frequency of future earthquakes in the region where the test specimen (i.e., buckling-restrained brace 4) is located, as well as the required reliability of the test specimen—that is, the number and intensity of future earthquakes and the safety standards that the test specimen needs to meet in design and use—the remaining service life (i.e., subsequent service years) of the brace is determined based on these factors for different D values ​​(i.e., different degrees of damage). Then, using the previously established relationship between D values ​​and AD values, the remaining service life is converted into an expression related to AD values. With this setup, as long as the AD value of the brace is known, its remaining service life can be estimated. Please refer to the diagram illustrating the relationship between AD values ​​and subsequent service years. Figure 4 .

[0082] In summary, this application provides a method for detecting the remaining service life of a buckling-restrained brace (BRB) 4 after an earthquake. By collecting and analyzing the vibration signals of the BRB 4 and utilizing specific signal processing techniques, the remaining service life of the BRB 4 after an earthquake can be assessed. The method accurately determines the remaining service life by only performing testing under a specific damage state of the BRB 4. This achieves non-destructive testing of the BRB 4, ensuring the integrity and safety of the component.

[0083] In some embodiments of this application, obtaining vibration signals corresponding to different D values ​​of the buckling-restrained support 4 specifically includes:

[0084] Please refer to Figure 2 , Figure 2The diagram illustrates the vibration detection of the buckling restraint brace 4. The signal receiving device 1 uses an oscilloscope and sets an excitation end 2 and a response end 3 at both ends of the detection part 5 of the buckling restraint brace 4. By exciting one end of the buckling restraint brace 4 once, the vibration signals of the excitation end 2 and the response end 3 are recorded.

[0085] S1-1: The D value of the buckling-restrained support 4 is calculated using the Miner linear damage theory criterion, as shown in formula (1) below:

[0086]

[0087] In the formula, N i To maintain the number of loading cycles at which buckling-restrained brace 4 fails under the current stress level, n i This represents the number of cycles applied at this stress level.

[0088] Specifically, the linear cumulative damage theory posits that the fatigue damage of the buckling-restrained support 4 at each stress level occurs independently; that is, the total damage is formed by the linear summation of damage at each stress level. When the accumulated damage value reaches a certain level, fatigue failure occurs. This embodiment uses Miner's linear damage theory criterion to calculate the damage value of the buckling-restrained support 4. i To maintain the number of loading cycles at which buckling-restrained brace 4 fails under the current stress level, this represents the number of loading cycles the brace can withstand before failure at a specific stress level; n i The D value represents the number of cycles applied at this stress level, indicating the actual number of loading cycles applied during the evaluation process. The D value reflects the degree of damage to the support at the current stress level.

[0089] S1-2: Install the sensor required for vibration detection at the detection site 5 of the buckling restraint support 4;

[0090] Please refer to Figure 3 , Figure 3 This diagram illustrates the installation of sensors for vibration detection at the detection site 5 of the buckling-restrained brace 4. Preferably, two sensors are installed at the detection site 5 of the buckling-restrained brace 4, positioned as follows: 50 mm from the edge of the extended connecting section along the long side of the buckling-restrained brace 4; and in the middle of the short side along the short side. The sensors can detect the vibration of the brace when it is excited and convert the vibration information into electrical signals or other measurable forms.

[0091] S1-3: Adjust the parameters of signal receiving device 1;

[0092] Preferably, the signal receiving device 1 is an oscilloscope with the following parameters: sampling frequency of 2000Hz; duration of 0.5s; and the sampling amplitude determined according to the magnitude of the excitation and the distance between the two sensors. The parameters of the signal receiving device 1 are adjusted to ensure accurate and stable reception of the vibration signal.

[0093] S1-4: An excitation device is used to excite one end of the buckling restraint support 4 once, and a signal receiving device 1 is used to record the vibration signals of the excitation end 2 and the response end 3.

[0094] Specifically, an excitation device is used to apply an excitation (such as an impact force or vibration wave) to one end of the buckling-restrained support 4. Then, a signal receiving device 1 is used to record the vibration signals at the excitation end 2 (i.e., the position where the excitation is applied) and the response end 3 (i.e., the position on the support away from the excitation end 2). These vibration signals contain the dynamic response information of the buckling-restrained support 4 when it is excited, which can be used for subsequent analysis and processing.

[0095] Based on the first aspect, the method of processing vibration signals using the statistically considered frequency response function difference method to obtain AD values ​​under different damage conditions specifically includes:

[0096] S2-1: Obtain the response to ambient noise through the sensor and signal receiving device 1;

[0097] Specifically, the "response" here refers to the sensor's perception and conversion of environmental noise; that is, the process by which the noise signal detected by the sensor is captured and processed by the receiving device. The sensor detects noise in the environment and converts it into a processable signal. This signal is then captured and processed by the signal receiving device 1 to obtain information about the environmental noise. Subsequent data processing allows for the accurate identification and removal of the impact of environmental noise on the test results.

[0098] S2-2: Obtain the vibration signals from excitation end 2 and response end 3 of the undamaged specimen, and perform noise reduction processing on the vibration signals from excitation end 2 and response end 3 based on the response to environmental noise.

[0099] Specifically, the undamaged specimen refers to a specimen that has not been damaged or defective before testing. This includes an undamaged buckling-restrained support 4. The excitation end 2 refers to the location where vibration or force is applied to excite the specimen's vibration. Excitation can be generated using some form of vibrator or force hammer. The response end 3 refers to the location on the specimen used to measure the vibration response, located away from the excitation end 2. Sensors are installed at the response end 3 to capture vibration signals. Vibration signals are the data collected from the sensors at the response end 3, describing the specimen's vibration behavior under excitation. Noise reduction processing helps to more accurately analyze the specimen's vibration characteristics.

[0100] S2-3: Using signal processing methods, the vibration signal after noise reduction is filtered and normalized to obtain its frequency response function. Based on this data, damage identification of the test piece is performed.

[0101] Specifically, by analyzing the vibration signal after noise reduction, filtering, and normalization, the frequency response function (FRF) of the test specimen can be obtained. The FRF describes the frequency response of a system to an input excitation. In vibration analysis, the FRF is typically obtained by measuring the system's input (e.g., excitation force) and output (e.g., response acceleration) and is used to analyze the system's modal characteristics (e.g., modal frequencies, modal damping, and modal shapes). By comparing the FRF of the test specimen with that of an undamaged specimen, potential damage can be detected. Damage typically leads to changes in the specimen's modal characteristics, such as shifts in modal frequencies, increases in modal damping, or changes in modal shape. These changes can be detected and quantified by analyzing the FRF, thereby enabling an assessment of the specimen's damage state.

[0102] S2-4: Perform steps S2-1 to S2-3 on the test piece to obtain the frequency response function;

[0103] S2-5: Make a statistical judgment. If the frequency response function of the test piece is statistically the same as that of the undamaged test piece, the test piece is considered to be an undamaged component; otherwise, the test piece is considered to be a damaged component, and the AD value is calculated using the preset method.

[0104] Specifically, statistical judgment involves calculating the differences between two frequency response functions (such as root mean square error, correlation coefficient, etc.) and using statistical methods (such as hypothesis testing, confidence interval estimation, etc.) to determine whether these differences are significant. If the statistical judgment indicates that the frequency response function of the test specimen is not statistically significantly different from that of the undamaged specimen (i.e., the difference is within the allowable range), the test specimen is considered to be an undamaged component. If the statistical judgment indicates that the frequency response function of the test specimen is significantly different from that of the undamaged specimen (i.e., the difference exceeds the allowable range), the test specimen is considered to be potentially damaged. After determining that the test specimen is a damaged component, a pre-defined method needs to be used to calculate the AD value.

[0105] In some embodiments of the present invention, calculating the AD value using a preset method includes:

[0106] Suppose that the frequency response function follows a normal distribution, as shown in equation (2):

[0107] |H(jω)|~N(μ(|H(jω)|),σ 2 (ω)) (2)

[0108] In the formula, μ(H(jω)) is the mean value of the amplitude of the frequency response function, and σ 2 (ω) represents the amplitude variance of the frequency response function corresponding to a certain frequency, H(jω) is the frequency response function, and N(μ,σ) is the frequency response function. 2 The expression σ indicates that the function follows a normal distribution with mean μ and variance σ. 2 When there is a difference in the frequency response function between the test specimen and the undamaged specimen, the test specimen is considered to be damaged. Since both conform to a normal distribution, the difference between them also conforms to a normal distribution, as shown in equations (3) to (5) below:

[0109] δ|H(jω)|~N(μ(δ|H(jω)|),δσ 2 (ω)) (3)

[0110] δ|H(jω)|=||H0(jω)|-|H u (jω)|| (4)

[0111]

[0112] In the formula, δ|H(jω)| is the difference in amplitude of the frequency response function, and N(μ(δ|H(jω)|), δσ 2 (ω) indicates that the function follows a normal distribution with mean μ(δ|H(jω)|) and variance δσ. 2 (ω), μ(δ|H(jω)|) are the mean values ​​of the amplitude differences of the frequency response function, and δσ 2 (ω) represents the variance of the amplitude difference of the frequency response function, |H0(jω)| represents the amplitude of the frequency response function of the undamaged component, and |H u (jω)| represents the amplitude of the frequency response function of the component under test, σ0 2 (ω) represents the variance of the frequency response function of the undamaged component, σ u 2 (ω) represents the variance of the frequency response function of the component under test;

[0113] The data is normalized to obtain the parameter Z, as shown in equation (6):

[0114]

[0115] In the formula, Z is the standard quantile, used to assess the distance of a sample point from the population mean, ω is the frequency, δ|H(jω)| is the difference in amplitude of the frequency response function, and δσ 2 (ω) represents the variance of the amplitude difference of the frequency response function, and N(0,1) indicates that the function follows a normal distribution with a mean of 0 and a variance of 1; if Z remains within the confidence interval, i.e., |Z|≤Z 1-α / 2If the null hypothesis is met, the sample being tested is considered undamaged, with a guarantee rate of 1 - α / 2; otherwise, the alternative hypothesis is accepted, i.e., |Z| > Z. 1-α / 2 At that time, it is considered that the test piece is damaged; finally, a parameter is determined based on the test of Z to statistically measure the exceedance amplitude, which is defined as AD; as shown in the following formula (7):

[0116]

[0117] In the formula, AD is a parameter, ω is the frequency, and |Z(ω)| is the absolute value of Z as a function of ω. Z(ω) is greater than Z 1-α / 2 Part, Z 1-α / 2 It represents the standard quantile of 1-α / 2.

[0118] Based on the first aspect, step S3 specifically includes:

[0119] Multiple sets of vibration tests are performed on buckling-restrained braces 4 with the same degree of damage to obtain the corresponding AD values. The mean and standard deviation of the corresponding values ​​are calculated. At the same time, the D values ​​of the corresponding damage stages need to be calculated together. The D values ​​and AD values ​​are linearly fitted to establish a fitting equation and obtain the relationship between the D values ​​and AD values.

[0120] Preferably, 20 sets of vibration tests are performed on the buckling-restrained brace 4 with the same degree of damage to obtain the corresponding AD value. Specifically, "same degree of damage" means that the buckling-restrained brace 4 has the same damage state or damage level. The vibration test is repeated 20 times on the buckling-restrained brace 4 with the same degree of damage. Sufficient data samples are obtained to improve the reliability and accuracy of the experimental results. This refers to calculating the damage index (AD value) corresponding to each set of tests through vibration test analysis. After obtaining 20 sets of AD values, the mean and standard deviation of these AD values ​​need to be calculated. The mean is used to represent the average level of the AD values, while the standard deviation is used to represent the dispersion or variability of the AD values. These two statistics help to assess the stability and reliability of the AD values, as well as identify possible outliers or errors. "Linear fitting" is a mathematical method used to describe the linear relationship between two variables. Here, it is used to describe the relationship between the D value and the AD value. Through linear fitting, a fitting equation (such as y = mx + b) can be established, where y represents the AD value, x represents the D value, and m and b are the coefficients of the fitting equation. This fitted equation can be used to predict the AD value of the buckling-restrained support 4 under different damage levels, or to infer the damage level of the buckling-restrained support 4 from the AD value. Finally, through the linear fitted equation, we can obtain a quantitative relationship between the D value and the AD value. This relationship helps in practical applications to quickly assess the damage level of the buckling-restrained support 4 by measuring the AD value.

[0121] Please refer to Figure 5 This implementation also provides a system for detecting the subsequent service life of a post-earthquake buckling-restrained brace 4, comprising:

[0122] Acquisition Module 6: Acquire vibration signals corresponding to different D values ​​of buckling-restrained support 4;

[0123] Processing module 7: The vibration signal is processed using the frequency response function difference method that considers statistics to obtain AD values ​​under different damage conditions;

[0124] Module 8: Construct the relationship between D and AD values;

[0125] Service life prediction module 9: Based on the frequency of subsequent earthquakes in the area where the test piece is located and the required reliability of the test piece, determine the relationship between the D value and the subsequent service life, and then determine the relationship between the AD value and the subsequent service life based on the relationship between the D value and the AD value.

[0126] For details on the implementation of the system for detecting the subsequent service life of the post-earthquake buckling-restrained brace 4, please refer to the specific implementation of the method for detecting the subsequent service life of the post-earthquake buckling-restrained brace 4. Further details will not be provided here.

[0127] Please refer to Figure 6 , Figure 6 This is a schematic diagram of the structure of an electronic device according to this application. The electronic device includes:

[0128] Memory 11 is used to store one or more programs;

[0129] Processor 10;

[0130] When one or more programs are executed by processor 10, the above-described method is implemented, such as implementing all or part of the steps of the above-described method. Processor 10 communicates with memory 11 through communication interface 12.

[0131] Fourthly, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor 10, implements the above-described method, such as implementing all or part of the steps of the above-described method.

[0132] It will be apparent to those skilled in the art that this application is not limited to the details of the exemplary embodiments described above, and that this application can be implemented in other specific forms without departing from the spirit or essential characteristics of this application. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this application is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this application. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A method of detecting the post-service life of a post-earthquake buckling restrained brace, characterized by, The method comprises the following steps: S1: obtaining vibration signals corresponding to different D values of the buckling-restrained brace; S2: processing the vibration signals by using a statistical frequency response function difference method to obtain AD values under different damages; S3: establishing a relationship between the D value and the AD value; S4: determining the relationship between the D value and the subsequent service life according to the subsequent earthquake frequency in the region where the test piece is located and the reliability required by the test piece, and then determining the relationship between the AD value and the subsequent service life from the relationship between the D value and the AD value; The specific steps of obtaining the vibration signals corresponding to different D values of the buckling-restrained brace comprise: The D value of the buckling-restrained brace is calculated by using the Miner linear damage theory criterion, and formula (1) is as follows: where N i to maintain the number of cycles to failure of the buckling restrained brace at the current stress level, n i the number of cycles applied at the stress level; Sensors required for vibration detection are arranged at the detection position of the buckling-restrained brace; The parameters of the signal receiving device are adjusted; The one end of the buckling-restrained brace is excited by using an excitation device, and the vibration signals of the excitation end and the response end are recorded by using the signal receiving device; The specific steps of processing the vibration signals by using the statistical frequency response function difference method to obtain the AD values under different damages comprise: S2-1: obtaining the response of the environmental noise by using the sensor and the signal receiving device; S2-2: obtaining the vibration signals of the excitation end and the response end of the undamaged test piece, and performing noise reduction processing on the vibration signals of the excitation end and the response end according to the response of the environmental noise; S2-3: filtering and normalizing the vibration signals after noise reduction processing by using a signal processing method, obtaining the frequency response function, and identifying the damage of the test piece based on the data; S2-4: performing steps S2-1 to S2-3 on the test piece to obtain the frequency response function; S2-5: performing statistical judgment, if the frequency response function of the test piece is the same as the frequency response function of the undamaged test piece in a statistical sense, it is considered that the test piece is an undamaged component, otherwise it is considered that the test piece is a damaged component, and then the AD value is calculated by using a preset method.

2. The method of claim 1, wherein, The specific steps of arranging the sensors required for vibration detection at the detection position of the buckling-restrained brace comprise: Two sensors required for vibration detection are arranged at the detection position of the buckling-restrained brace, and the positions are as follows: in the long edge direction of the buckling-restrained brace, the sensors are arranged at a distance of 50 mm from the edge of the outer extension connecting section; in the short edge direction, the sensors are arranged at the middle position of the short edge.

3. The method of claim 1, wherein, The specific steps of adjusting the parameters of the signal receiving device comprise: The sampling frequency is 2000 Hz; the duration is 0.5 s; and the amplitude of the sampling is determined according to the size of the excitation and the distance between the two sensors.

4. The method of claim 1, wherein, The preset method for calculating the AD value comprises: It is assumed that the frequency response function conforms to the normal distribution, that is, it satisfies formula (2) as follows: |H(jω)| ~ N(μ(|H(jω)|), σ 2 (ω)) (2) In the formula, μ(H(jω)) is the mean value of the amplitude of the frequency response function, σ 2 (ω) is the variance of the amplitude of the frequency response function corresponding to a certain frequency, H(jω) is the frequency response function, N(μ,σ 2 ) indicates that the function conforms to a normal distribution, the mean value of which is μ and the variance of which is σ 2 ; when the frequency response functions of the to-be-tested piece and the undamaged piece are different, it is considered that the to-be-tested piece is damaged; since both conform to a normal distribution, the difference between the two also conforms to a normal distribution, as shown in the following formulas (3)-(5): δ|H(jω)| ~ N(μ(δ|H(jω)|), δσ 2 (ω)) (3) δ | H (jco) | = || H0 (jco) | - | H u (jco) | (4) wherein δ|H(jω)| is the difference of the frequency response function amplitude, N(μ(δ|H(jω)|), δσ 2 (ω)) indicates that the function is in accordance with a normal distribution, the mean value of which is μ(δ|H(jω)|) and the variance is δσ 2 (ω), μ(δ|H(jω)|) is the mean value of the difference of the frequency response function amplitude, δσ 2 (ω) is the variance of the difference of the frequency response function amplitude, |H0(jω)| is the frequency response function amplitude of the undamaged component, |H u (jω)| is the frequency response function amplitude of the component to be tested, σ0 2 (ω) is the frequency response function variance of the undamaged component, σ u 2 (ω) is the frequency response function variance of the component to be tested. The data is normalized to obtain the parameter Z, as shown in formula (6): where Z is the standard quantile used to evaluate the distance of the sample point to the average of the population, ω is the frequency, δ|H(jω)| is the difference of the amplitude of the frequency response function, δσ 2 (ω) is the variance of the difference of the amplitude of the frequency response function, N(0, 1) indicates that the function conforms to the normal distribution, the mean value is 0, and the variance is 1; if Z remains in the confidence interval, that is, |Z|≤Z 1-α / 2 , the original hypothesis is accepted, and it is considered that the sample being tested is undamaged, and the guarantee rate is 1-α / 2; otherwise, the alternative hypothesis is accepted, that is, |Z|>Z 1-α / 2 , it is considered that the test piece to be tested has damage; finally, a parameter is determined according to the test of Z to count the amplitude of the exceedance, which is defined as AD; as shown in the following formula (7): where AD is a parameter, ω is the frequency, |Z(ω)| is the absolute value of the function of Z with respect to ω, ≥Z 1-α / 2 is greater than Z 1-α / 2 part, Z 1-α / 2 denotes the standard quantile of 1 - α / 2.

5. The method of claim 1, wherein the method is used to detect the post-service life of the buckling-restrained brace after an earthquake. Step S3 specifically comprises: For the same damage degree of the buckling-restrained brace, a plurality of vibration tests are performed to obtain corresponding AD values, the corresponding mean value and standard deviation are calculated, at the same time, the D value corresponding to the damage stage is also calculated, the D value and the AD value are linearly fitted, a fitting equation is established, and the relationship between the D value and the AD value is obtained.

6. A system for detecting the post-service life of a post-earthquake buckling restrained brace, characterized by It comprises: An obtaining module is configured to obtain vibration signals corresponding to different D values of the buckling-restrained brace; The processing module: the statistical frequency response function difference method is used to process the vibration signal to obtain the AD value under different damages; The construction module: the relationship between the D value and the AD value is constructed; The service life prediction module: according to the subsequent earthquake frequency in the region where the test piece is located and the reliability required by the test piece, the relationship between the D value and the subsequent service life is determined, and then the relationship between the AD value and the subsequent service life is determined according to the relationship between the D value and the AD value; The specific steps of obtaining the vibration signal corresponding to the different D values of the buckling restrained brace include: The D value of the buckling restrained brace is calculated by using the Miner linear damage theory criterion, and the formula (1) is as follows: where N i to maintain the number of cycles to failure of the buckling restrained brace at the current stress level, n i is the number of cycles applied at the stress level; The sensors required for vibration detection are arranged at the detection position of the buckling restrained brace; The signal receiving device parameters are adjusted; The excitation device is used to excite one end of the buckling restrained brace once, and the vibration signals of the excitation end and the response end are recorded by using the signal receiving device; The specific steps of processing the vibration signal by using the statistical frequency response function difference method to obtain the AD value under different damages include: The response of the environmental noise is obtained by the sensor and the signal receiving device; The vibration signals of the excitation end and the response end of the undamaged test piece are obtained, and the vibration signals of the excitation end and the response end are denoised according to the response of the environmental noise; The denoised vibration signal is filtered and normalized by using the signal processing method, and the frequency response function thereof is obtained, and the damage identification of the test piece is performed based on the data; The vibration signals of the excitation end and the response end of the undamaged test piece are obtained by the sensor and the signal receiving device, and the vibration signals of the excitation end and the response end are denoised according to the response of the environmental noise to obtain the frequency response function; Statistical judgment is performed, if the frequency response function of the test piece is the same as the frequency response function of the undamaged test piece in the statistical sense, it is considered that the test piece is an undamaged component, otherwise it is considered that the test piece is a damaged component, and the AD value is calculated by using the preset method.

7. An electronic device, comprising: It includes: A memory for storing one or more programs; A processor; When the one or more programs are executed by the processor, the method of any one of claims 1-5 is implemented.

8. A computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to implement the method of any one of claims 1-5.

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