Method and device for identifying first-order dominant frequency and damping ratio of high-rise building

Abstract

The embodiment of the invention provides a high-rise building first-order dominant frequency and damping ratio identification method and device, and the method comprises the steps: carrying out the preprocessing of an original absolute acceleration time history record obtained in an earthquake, and obtaining a corresponding absolute speed time history and a relative displacement time history; calculating peak points of the absolute speed time history and the relative displacement time history in a certain frequency range by adopting a peak pickup method-auto-power spectrum method of a frequency domain, and taking the frequency corresponding to the peak points as a first-order dominant frequency; identifying the natural vibration period, the damping ratio and the vibration mode of the building structure in the two far-field earthquakes by adopting an SSI method to obtain a corresponding stability diagram; and combining the first-order dominant frequency calculated by adopting a peak pickup method-autopower spectrum method with the stability diagram obtained by adopting an SSI method, and determining the final first-order dominant frequency and damping ratio according to a combination result. According to the invention, the precision and efficiency of high-rise building modal identification can be obviously improved.

Description

Technical Field

[0001] This document relates to the field of computer technology, and in particular to a method and device for identifying the first-order main frequency and damping ratio of a high-rise building. Background Art

[0002] Modal identification of building structures is an important method in structural health monitoring and assessment. It involves identifying the dynamic characteristics of the structure under natural excitation or other external excitation conditions. Modal identification mainly includes the determination of period, vibration mode and damping ratio. From the perspective of time domain and frequency domain, the following are several common modal identification methods for building structures:

[0003] 1. Frequency domain method: The frequency domain method includes spectrum analysis method based on Fourier transform. By analyzing the spectrum of structural response, the modal parameters of each order of the structure can be identified. This method is suitable for modal parameter identification of linear and steady-state systems.

[0004] 2. Time domain method: The time domain method includes algorithms such as Kalman filtering, multi-channel least squares frequency domain identification and stochastic subspace identification (SSI). They directly use time domain data for analysis, can identify the modal parameters of the structure, and can handle nonlinear and non-steady-state problems. SSI is a statistical method suitable for modal parameter identification of linear time-invariant systems. It is based on the state space model and Kalman filtering theory, and can identify the modal parameters of the system from the response data.

[0005] 3. Time-frequency method: Hilbert-Huang Transform (HHT) is a time-frequency analysis method suitable for nonlinear and non-stationary signals. It decomposes the signal into a series of intrinsic mode functions (IMFs) through empirical mode decomposition (EMD), and then uses Hilbert transform to obtain the instantaneous frequency and amplitude of each IMF, thereby identifying the modal parameters of the structure.

[0006] In practical applications, appropriate modal identification methods are selected based on the characteristics of the structure, the required accuracy, and the type of data available. With the development of sensing technology and computing technology, modal identification methods are also constantly improving to meet the more complex and variable structural health monitoring needs.

[0007] 1. The traditional frequency domain method has the following shortcomings: ① It assumes that the system is linear and steady-state. ② The resolution is related to the acquisition time. In order to obtain higher frequency resolution, a longer data acquisition time is required. ③ It is sensitive to noise. Especially in the case of low signal-to-noise ratio, noise may have a significant impact on frequency domain analysis, thereby affecting the accuracy of modal identification.

[0008] 2. The main shortcomings of the time domain method are: ① Large amount of data: The time domain method usually needs to process a large amount of raw time series data, which may lead to large computational workload and high storage requirements, especially when dealing with large structures or long-term monitoring data. ② Sensitive to noise: The time domain method is sensitive to noise in the data because they directly process time series data, and noise may interfere with the accurate identification of modal parameters. ③ Difficult to process long data: For long-term monitoring data, time domain analysis may require more computing resources, and numerical stability problems may occur during the processing. ④ Model assumption limitations: The time domain method is usually based on certain model assumptions, such as the linear time-invariant system assumption. For modal identification of nonlinear or time-varying systems, these assumptions may no longer apply. ⑤ Modal aliasing problem: When the modal frequencies of the structure are close, the time domain method may have difficulty in accurately distinguishing these dense modes, resulting in modal aliasing problems. ⑥ Parameter selection problem: Some algorithms in the time domain method, such as Kalman filtering, require appropriate selection of algorithm parameters. Inappropriate parameter selection may lead to incorrect modal identification results. ⑦Real-time challenges: Time domain methods may face challenges in real-time modal identification applications because they need to process and analyze data quickly to meet the needs of real-time monitoring.

[0009] 3. The main shortcomings of the time-frequency method are: ① Computational complexity: The time-frequency method usually involves complex algorithms, such as short-time Fourier transform (STFT), wavelet transform, Hilbert-Huang transform (HHT), etc. These algorithms are computationally intensive and require high computing resources. ② Time-frequency resolution trade-off: In time-frequency analysis, there is a trade-off between time resolution and frequency resolution. For example, in STFT, the choice of window size determines the time resolution and frequency resolution. A wider window provides better frequency resolution but poorer time resolution; while a narrower window does the opposite. ③ Parameter selection: Some algorithms in the time-frequency method require the selection of appropriate parameters, such as window function, wavelet basis function, number of decomposition layers, etc. Improper parameter selection may lead to incorrect modal identification results. ④ Sensitivity to noise: The time-frequency method is highly sensitive to noise, especially in the case of low signal-to-noise ratio. Noise may have a significant impact on the time-frequency analysis, thereby affecting the accuracy of modal parameter identification. ⑤ Modal aliasing problem: When the modal frequencies of the structure are close, the time-frequency method may have difficulty in accurately distinguishing these dense modes, resulting in modal aliasing problems. ⑥ Data length and continuity requirements: The time-frequency method usually requires a longer data record and has certain requirements for the continuity of the data. In practical applications, this may bring challenges to data collection and processing. ⑦ Interpretation complexity: The results produced by time-frequency analysis may be more complex and require professional knowledge and experience to correctly interpret, which may limit its application among non-professionals. Summary of the invention

[0010] The purpose of the present invention is to provide a method and device for identifying the first-order main frequency and damping ratio of a high-rise building, aiming to solve the above-mentioned problems in the prior art.

[0011] The present invention provides a method for identifying the first-order main frequency and damping ratio of a high-rise building, comprising:

[0012] By preprocessing the original absolute acceleration time history records obtained during earthquakes, the corresponding absolute velocity time history and relative displacement time history are obtained;

[0013] The peak picking method in the frequency domain - the self-power spectrum method is used to calculate the peak points of the absolute velocity time history and the relative displacement time history within a certain frequency range, and the frequency corresponding to the peak point is used as the first-order main frequency;

[0014] The SSI method is used to identify the natural vibration period, damping ratio and mode shape of the building structure in two far-field earthquakes, and the corresponding stability diagram is obtained;

[0015] The first-order main frequency calculated by the peak picking method-self-power spectrum method and the stability diagram obtained by the SSI method are combined, and the final first-order main frequency and damping ratio are determined according to the combined result.

[0016] The present invention provides a device for identifying the first-order main frequency and damping ratio of a high-rise building, comprising:

[0017] A preprocessing module is used to preprocess the original absolute acceleration time history records obtained in the earthquake to obtain the corresponding absolute velocity time history and relative displacement time history;

[0018] A peak picking module, used to calculate the peak points of the absolute velocity time history and the relative displacement time history within a certain frequency range by using the peak picking method in the frequency domain - the self-power spectrum method, and take the frequency corresponding to the peak point as the first-order main frequency;

[0019] The SSI module is used to identify the natural vibration period, damping ratio and vibration mode of the building structure in two far-field earthquakes using the SSI method, and obtain the corresponding stability diagram;

[0020] The combining module is used to combine the first-order main frequency calculated by the peak picking method-self-power spectrum method with the stability diagram obtained by the SSI method, and determine the final first-order main frequency and damping ratio according to the combining result.

[0021] An embodiment of the present invention also provides an electronic device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the computer program is executed by the processor, the steps of the above-mentioned method for identifying the first-order main frequency and damping ratio of a high-rise building are implemented.

[0022] An embodiment of the present invention further provides a computer-readable storage medium, on which a program for implementing information transmission is stored. When the program is executed by a processor, the steps of the above-mentioned method for identifying the first-order main frequency and damping ratio of a high-rise building are implemented.

[0023] By adopting the embodiment of the present invention, by combining the frequency domain and time domain methods and setting a reasonable judgment process, the false main frequency can be removed, and the accuracy and efficiency of high-rise building modal identification can be significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate one or more embodiments of this specification or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0025] Figure 1 is a flow chart of a method for identifying the first-order main frequency and damping ratio of a high-rise building according to an embodiment of the present invention;

[0026] Figure 2is a schematic diagram of an acceleration recording integration process according to an embodiment of the present invention;

[0027] Figure 3 is a schematic diagram of a device for identifying the first-order main frequency and damping ratio of a high-rise building according to an embodiment of the present invention;

[0028] Figure 4 is a schematic diagram of an electronic device according to an embodiment of the present invention;

[0029] Figure 5 1 is a schematic diagram comparing the results of the prior art and the improved peak picking method in the embodiment of the present invention in the x direction;

[0030] Figure 6 1 is a schematic diagram showing a comparison of the results of the prior art and the improved peak picking method in the embodiment of the present invention in the y direction;

[0031] Figure 7 It is a schematic diagram of the result of the improved peak picking method + SSI stability diagram method in the embodiment of the present invention in the x direction;

[0032] Figure 8 It is a schematic diagram of the result of the improved peak picking method + SSI stabilization diagram method in the -y direction according to an embodiment of the present invention. DETAILED DESCRIPTION

[0033] In order to enable those skilled in the art to better understand the technical solutions in one or more embodiments of this specification, the following will be combined with the drawings in one or more embodiments of this specification to clearly and completely describe the technical solutions in one or more embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on one or more embodiments of this specification, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of this document.

[0034] Method Embodiment

[0035] According to an embodiment of the present invention, a method for identifying the first-order main frequency and damping ratio of a high-rise building is provided. Figure 1 is a flow chart of a method for identifying the first-order main frequency and damping ratio of a high-rise building according to an embodiment of the present invention. Figure 1 As shown, the method for identifying the first-order main frequency and damping ratio of a high-rise building according to an embodiment of the present invention specifically includes:

[0036] Step S101, preprocessing the original absolute acceleration time history records obtained in the earthquake to obtain the corresponding absolute velocity time history and relative displacement time history; in step S101, specifically including:

[0037] Performing constant baseline witnessing and bandpass filtering on the original absolute acceleration record to obtain an absolute acceleration time history, and performing one integration and linear baseline correction on the absolute acceleration time history to obtain an absolute velocity time history;

[0038] The original absolute acceleration record is subjected to subtraction of adjacent measuring points to obtain a relative acceleration record, the relative acceleration record is subjected to constant baseline witnessing and bandpass filtering to obtain a relative acceleration time history, the relative acceleration time history is subjected to two integrations and linear baseline correction to obtain a relative displacement time history.

[0039] Step S102, using the peak picking method-autopower spectrum method in the frequency domain to calculate the peak points of the absolute velocity time history and the relative displacement time history within a certain frequency range, and taking the frequency corresponding to the peak point as the first-order main frequency; the certain frequency range is specifically: 0.1-1Hz.

[0040] Step S103, using the SSI method to identify the natural vibration period, damping ratio and mode shape of the building structure in two far-field earthquakes, and obtaining the corresponding stability diagram; specifically includes:

[0041] The maximum order is set to 180, the number of Hankel matrix blocks is set to 90, the frequency tolerance is set to 1%, the mode confidence coefficient MAC tolerance is set to 0.1%, and the response data of the structural array is used. The default input is input from the first floor of the building structure, and the responses of floors above the first floor are used as the data set of the SSI method;

[0042] The SSI method is used to perform random subspace decomposition on the data set, decomposing the data into multiple subspaces. Feature extraction and modal identification are then performed on each subspace to identify the natural vibration period, damping ratio and mode shape of the building structure in two far-field earthquakes, and the corresponding stability diagram is obtained.

[0043] Step S104, combining the first-order main frequency calculated by the peak picking method-autopower spectrum method and the stability diagram obtained by the SSI method, and determining the final first-order main frequency and damping ratio according to the combination result.

[0044] The research on modal identification methods of building structures is developing towards a more efficient and accurate direction, especially in automation and intelligence. In view of the characteristics of the modal characteristics of high-rise buildings, this method combines frequency domain and time domain methods, sets a reasonable judgment process, removes false main frequencies, and can significantly improve the accuracy and efficiency of modal identification of high-rise buildings.

[0045] The above technical solution of the embodiment of the present invention is described in detail below in conjunction with the accompanying drawings.

[0046] An embodiment of the present invention provides a modal identification method that combines frequency domain and time domain and is suitable for high-rise buildings. The main processes of the method include: monitoring data preprocessing, peak picking method to determine the first-order main frequency, mutual verification of the results of SSI stability diagram method and peak picking method to obtain the final first-order main frequency and damping ratio.

[0047] 1. Monitoring data preprocessing: By integrating the absolute acceleration time history records obtained during the earthquake, the corresponding velocity and displacement response time history is obtained. The specific process is as follows: Figure 2 As shown in the figure, the constant baseline correction uses the mean value of the 120s record before the original record is triggered as the correction term, the bandpass filter uses a 4th-order Butterworth filter with a filter band of [0.1Hz, 10Hz], and the linear baseline correction uses a first-order polynomial fitting to obtain a trend line as the correction term.

[0048] 2. Use the peak picking method to determine the first-order main frequency.

[0049] For the top acceleration time history after data preprocessing, the peak picking method-autopower spectrum method in the frequency domain is used to obtain the frequency corresponding to the peak point in the range of 0.1-1Hz as the first-order main frequency.

[0050] 3. Determine the first-order main frequency using the SSI stability diagram method.

[0051] The random subspace method (SSI) is a data-driven method for modal identification. The data set is decomposed into multiple subspaces by random subspace decomposition, and then feature extraction and modal identification are performed on each subspace. The SSI method is used to identify the natural frequency, damping ratio and mode shape of the structure in two far-field earthquakes, and the corresponding stability diagram is obtained. Among them, the maximum order is set to 180, the number of Hankel matrix blocks is 90, the frequency tolerance is 1%, and the mode shape confidence coefficient MAC tolerance is 0.1%. The response data of the structural array is used. The default input is input from the first floor of the building structure, and the responses of the floors above the first floor are used as the data set of the SSI method.

[0052] 4. Combine the peak picking method and SSI stability diagram method to determine the final first-order main frequency.

[0053] The results of the peak picking method and the SSI stabilization graph method are plotted in one graph, and the frequencies determined by the peak picking method and the SSI stabilization graph method are used as the final first-order main frequency and damping ratio. Specifically, the embodiment of the present invention combines the peak picking method and the SSI stabilization graph method, and the main frequency basically overlapped by the two methods is the first-order main frequency, and the damping ratio corresponding to the corresponding SSI method is the determined damping ratio.

[0054] Taking the pulse data of a 160-meter high-rise residential building from 20:00 to 21:00 in the morning as an example, the results of different analysis methods are as follows: Figure 5-8shown.

[0055] Device Example 1

[0056] According to an embodiment of the present invention, a device for identifying the first-order main frequency and damping ratio of a high-rise building is provided. Figure 3 Schematic diagram of a device for identifying the first-order main frequency and damping ratio of a high-rise building according to an embodiment of the present invention. Figure 3 As shown, the device for identifying the first-order main frequency and damping ratio of a high-rise building according to an embodiment of the present invention specifically includes:

[0057] The preprocessing module 30 is used to preprocess the original absolute acceleration time history records obtained in the earthquake to obtain the corresponding absolute velocity time history and relative displacement time history; the preprocessing module 30 is specifically used to:

[0058] Performing constant baseline witnessing and bandpass filtering on the original absolute acceleration record to obtain an absolute acceleration time history, and performing one integration and linear baseline correction on the absolute acceleration time history to obtain an absolute velocity time history;

[0059] The original absolute acceleration record is subjected to subtraction of adjacent measuring points to obtain a relative acceleration record, the relative acceleration record is subjected to constant baseline witnessing and bandpass filtering to obtain a relative acceleration time history, the relative acceleration time history is subjected to two integrations and linear baseline correction to obtain a relative displacement time history.

[0060] The peak picking module 32 is used to calculate the peak points of the absolute velocity time series and the relative displacement time series within a certain frequency range by using the peak picking method in the frequency domain - the self-power spectrum method, and take the frequency corresponding to the peak point as the first-order main frequency; the certain frequency range is specifically: 0.1-1Hz.

[0061] The SSI module 34 is used to identify the natural vibration period, damping ratio and vibration mode of the building structure in two far-field earthquakes by using the SSI method, and obtain the corresponding stability diagram; the SSI module 34 is specifically used to:

[0062] The maximum order is set to 180, the number of Hankel matrix blocks is set to 90, the frequency tolerance is set to 1%, the mode confidence coefficient MAC tolerance is set to 0.1%, and the response data of the structural array is used. The default input is input from the first floor of the building structure, and the responses of floors above the first floor are used as the data set of the SSI method;

[0063] The SSI method is used to perform random subspace decomposition on the data set, decomposing the data into multiple subspaces. Feature extraction and modal identification are then performed on each subspace to identify the natural vibration period, damping ratio and mode shape of the building structure in two far-field earthquakes, and the corresponding stability diagram is obtained.

[0064] The combining module 36 is used to combine the first-order main frequency calculated by the peak picking method-autopower spectrum method and the stability diagram obtained by the SSI method, and determine the final first-order main frequency and damping ratio according to the combining result.

[0065] The embodiment of the present invention is a device embodiment corresponding to the above method embodiment. The specific operations of each module can be understood by referring to the description of the method embodiment, which will not be repeated here.

[0066] Device Example 2

[0067] An embodiment of the present invention provides an electronic device, such as Figure 4 As shown, it includes: a memory 40, a processor 42, and a computer program stored in the memory 40 and executable on the processor 42. When the computer program is executed by the processor 42, the steps described in the method embodiment are implemented.

[0068] Device Example 3

[0069] An embodiment of the present invention provides a computer-readable storage medium, on which a program for implementing information transmission is stored. When the program is executed by the processor 42, the steps described in the method embodiment are implemented.

[0070] The computer-readable storage medium in this embodiment includes, but is not limited to, ROM, RAM, magnetic disk or optical disk, etc.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for identifying the first-order main frequency and damping ratio of a high-rise building, characterized in that: include: By preprocessing the original absolute acceleration time history records obtained during earthquakes, the corresponding absolute velocity time history and relative displacement time history are obtained; The peak picking method in the frequency domain - the self-power spectrum method is used to calculate the peak points of the absolute velocity time history and the relative displacement time history within a certain frequency range, and the frequency corresponding to the peak point is used as the first-order main frequency; The SSI method is used to identify the natural vibration period, damping ratio and mode shape of the building structure in two far-field earthquakes, and the corresponding stability diagram is obtained; The first-order main frequency calculated by the peak picking method-self-power spectrum method and the stability diagram obtained by the SSI method are combined, and the final first-order main frequency and damping ratio are determined according to the combined result.

2. The method according to claim 1, characterized in that By preprocessing the original absolute acceleration time history records obtained in the earthquake, the corresponding absolute velocity time history and relative displacement time history are obtained, including: Performing constant baseline witnessing and bandpass filtering on the original absolute acceleration record to obtain an absolute acceleration time history, and performing one integration and linear baseline correction on the absolute acceleration time history to obtain an absolute velocity time history; The original absolute acceleration record is subjected to subtraction of adjacent measuring points to obtain a relative acceleration record, the relative acceleration record is subjected to constant baseline witnessing and bandpass filtering to obtain a relative acceleration time history, the relative acceleration time history is subjected to two integrations and linear baseline correction to obtain a relative displacement time history.

3. The method according to claim 1, characterized in that The certain frequency range is specifically: 0.1-1 Hz.

4. The method according to claim 1, characterized in that The SSI method is used to identify the natural vibration period, damping ratio and mode shape of the building structure in two far-field earthquakes, and the corresponding stability diagrams are obtained, including: The maximum order is set to 180, the number of Hankel matrix blocks is set to 90, the frequency tolerance is set to 1%, the mode confidence coefficient MAC tolerance is set to 0.1%, and the response data of the structural array is used. The default input is input from the first floor of the building structure, and the responses of floors above the first floor are used as the data set of the SSI method; The SSI method is used to perform random subspace decomposition on the data set, decomposing the data into multiple subspaces. Feature extraction and modal identification are then performed on each subspace to identify the natural vibration period, damping ratio and mode shape of the building structure in two far-field earthquakes, and the corresponding stability diagram is obtained.

5. A device for identifying the first-order main frequency and damping ratio of a high-rise building, characterized in that: include: A preprocessing module is used to preprocess the original absolute acceleration time history records obtained in the earthquake to obtain the corresponding absolute velocity time history and relative displacement time history; A peak picking module, used to calculate the peak points of the absolute velocity time history and the relative displacement time history within a certain frequency range by using the peak picking method in the frequency domain - the self-power spectrum method, and take the frequency corresponding to the peak point as the first-order main frequency; The SSI module is used to identify the natural vibration period, damping ratio and vibration mode of the building structure in two far-field earthquakes using the SSI method, and obtain the corresponding stability diagram; The combining module is used to combine the first-order main frequency calculated by the peak picking method-self-power spectrum method with the stability diagram obtained by the SSI method, and determine the final first-order main frequency and damping ratio according to the combining result.

6. The device according to claim 5, characterized in that The preprocessing module is specifically used for: Performing constant baseline witnessing and bandpass filtering on the original absolute acceleration record to obtain an absolute acceleration time history, and performing one integration and linear baseline correction on the absolute acceleration time history to obtain an absolute velocity time history; The original absolute acceleration record is subjected to subtraction of adjacent measuring points to obtain a relative acceleration record, the relative acceleration record is subjected to constant baseline witnessing and bandpass filtering to obtain a relative acceleration time history, the relative acceleration time history is subjected to two integrations and linear baseline correction to obtain a relative displacement time history.

7. The device according to claim 5, characterized in that The certain frequency range is specifically: 0.1-1 Hz.

8. The device according to claim 5, characterized in that The SSI module is specifically used for: The maximum order is set to 180, the number of Hankel matrix blocks is set to 90, the frequency tolerance is set to 1%, the mode confidence coefficient MAC tolerance is set to 0.1%, and the response data of the structural array is used. The default input is input from the first floor of the building structure, and the responses of floors above the first floor are used as the data set of the SSI method; The SSI method is used to perform random subspace decomposition on the data set, decomposing the data into multiple subspaces. Feature extraction and modal identification are then performed on each subspace to identify the natural vibration period, damping ratio and mode shape of the building structure in two far-field earthquakes, and the corresponding stability diagram is obtained.

9. An electronic device, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the computer program is executed by the processor, the steps of the method for identifying the first-order main frequency and damping ratio of a high-rise building as described in any one of claims 1 to 4 are implemented.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores an implementation program for information transmission, and when the program is executed by a processor, the steps of the method for identifying the first-order main frequency and damping ratio of a high-rise building as described in any one of claims 1 to 4 are implemented.

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