Damping ratio identification method and device, electronic equipment and storage medium

Abstract

The invention provides a damping ratio identification method and device, electronic equipment and a storage medium, and is applied to the technical field of civil engineering structures, and the method comprises the steps: obtaining a free attenuation signal generated by a target civil engineering structure; determining a front attenuation signal and a rear attenuation signal according to the free attenuation signal; calculating the front attenuation signal according to Fourier transform to obtain a front power spectrum, and calculating the rear attenuation signal according to Fourier transform to obtain a rear power spectrum; determining a natural vibration frequency and a front power spectrum amplitude according to the front power spectrum, and determining a natural vibration frequency and a rear power spectrum amplitude according to the rear power spectrum; and according to the natural vibration frequency and the front power spectrum amplitude corresponding to the modal peak value of the front attenuation signal of each order and the natural vibration frequency and the rear power spectrum amplitude corresponding to the modal peak value of the rear attenuation signal of each order, identifying the damping ratio corresponding to the modal of each order. According to the method, the complexity of a calculation process is reduced, and the precision and accuracy of a modal damping ratio identification result are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of civil engineering structures, and in particular to a damping ratio identification method, device, electronic equipment and storage medium. Background Art

[0002] Structural damping is an important representation of structural energy dissipation and is crucial for the wind-resistant and earthquake-resistant design of large civil engineering structures. The identification of structural damping refers to estimating the modal damping ratio from the structural dynamic response.

[0003] At present, the methods for calculating the modal damping ratio through the free vibration signal of the structure mainly include logarithmic decay method and least squares fitting method. However, time domain methods such as logarithmic decay method and least squares fitting method are only applicable to single-mode vibration signals, while the free vibration signals of civil engineering structures are mostly multi-modal vibration signals. When applying logarithmic decay method and least squares fitting method, modal decomposition is also required. Due to the insufficient accuracy of existing modal decomposition technology, the single-mode signal after decomposition is distorted, which not only increases the complexity of the calculation process, but also reduces the accuracy of modal damping ratio identification. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a damping ratio identification method, device, electronic device and storage medium to solve the problem that the free vibration signals of civil engineering structures in the prior art are mostly multi-modal vibration signals, and modal decomposition is also required when applying the logarithmic attenuation method and the least squares fitting method. Due to the insufficient accuracy of the existing modal decomposition technology, the single-modal signal after decomposition is distorted, which not only increases the complexity of the calculation process, but also reduces the accuracy of modal damping ratio identification.

[0005] In order to solve the above technical problems, the technical solution proposed by the present invention is: In a first aspect, the present application provides a damping ratio identification method, the method comprising: Obtain the free decay signal generated by the target civil engineering structure; According to the time length of the free decay signal, taking a front decay signal and a rear decay signal with equal time lengths from the free decay signal; Calculating the front attenuation signal according to Fourier transform to obtain a front power spectrum, and calculating the rear attenuation signal according to Fourier transform to obtain a rear power spectrum; Determine the natural frequency and the front power spectrum amplitude corresponding to each order of the front attenuation signal modal peak according to the front power spectrum, and determine the natural frequency and the rear power spectrum amplitude corresponding to each order of the rear attenuation signal modal peak according to the rear power spectrum; According to the natural frequency and the front power spectrum amplitude corresponding to each order front attenuation signal modal peak, and the natural frequency and the rear power spectrum amplitude corresponding to each order rear attenuation signal modal peak, the damping ratio corresponding to each order mode is identified.

[0006] In a second aspect, the present application provides a damping ratio identification device, the device comprising: An acquisition module, used for acquiring a free decay signal generated by a target civil engineering structure; A signal determination module, configured to extract a pre-decay signal and a post-decay signal of equal time length from the free decay signal according to the time length of the free decay signal; A transformation module, configured to calculate the front attenuation signal according to Fourier transform to obtain a front power spectrum, and to calculate the rear attenuation signal according to Fourier transform to obtain a rear power spectrum; A peak determination module, used to determine the natural frequency and the front power spectrum amplitude corresponding to each order of the front attenuation signal modal peak according to the front power spectrum, and to determine the natural frequency and the rear power spectrum amplitude corresponding to each order of the rear attenuation signal modal peak according to the rear power spectrum; The damping ratio identification module is used to identify the damping ratio corresponding to each order mode according to the natural frequency and front power spectrum amplitude corresponding to each order front attenuation signal modal peak, and the natural frequency and rear power spectrum amplitude corresponding to each order rear attenuation signal modal peak.

[0007] In a third aspect, the present application 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 processor executes the program, the damping ratio identification method as described in any embodiment of the present application is implemented.

[0008] In a fourth aspect, the present application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the damping ratio identification method as described in any embodiment of the present application.

[0009] In a fifth aspect, the present application provides a computer program product, including a computer program, which, when executed by a processor, implements the damping ratio identification method as described in any embodiment of the present application.

[0010] Compared with the prior art, the advantages of the present invention are: obtaining the free decay signal generated by the target civil engineering structure; taking the front decay signal and the rear decay signal of equal time length from the free decay signal according to the time length of the free decay signal; calculating the front decay signal according to Fourier transform to obtain the front power spectrum, and calculating the rear decay signal according to Fourier transform to obtain the rear power spectrum; determining the natural frequency and the front power spectrum amplitude corresponding to each order of the modal peak of the front decay signal according to the front power spectrum, and determining the natural frequency and the rear power spectrum amplitude corresponding to each order of the modal peak of the rear decay signal according to the rear power spectrum; identifying the damping ratio corresponding to each order of mode according to the natural frequency and the front power spectrum amplitude corresponding to each order of the modal peak of the front decay signal, and the natural frequency and the rear power spectrum amplitude corresponding to each order of the modal peak of the rear decay signal. That is, the scheme of the present application, on the one hand, after Fourier transform, combines the frequency domain analysis of the front and rear two sections of decay signals and the results of the frequency domain analysis of the two decay signals to realize the damping ratio identification, without the need for modal decomposition, avoiding the situation of single modal signal distortion after modal decomposition, thereby reducing the complexity of the calculation process. On the other hand, the power spectrum is used for damping ratio identification, which improves the noise resistance in the calculation process, reduces the influence of environmental vibration and measurement noise on the identification results, and improves the precision of the modal damping ratio identification results and the accuracy of modal damping ratio identification. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The present invention will be described in more detail below based on embodiments and with reference to the accompanying drawings, wherein: Figure 1 It is a flow chart of the damping ratio identification method provided by the present application; Figure 2a is another flow chart of the damping ratio identification method provided by the present application; Figure 2b is an example diagram of a free decay signal of the damping ratio identification method provided in the present application; Figure 2c is an exemplary analysis diagram of identification results of the damping ratio identification method provided in the present application; Figure 2d is an example diagram of a free vibration signal containing third-order modal information of the damping ratio identification method provided in the present application; Figure 2e is another exemplary recognition result analysis diagram of the damping ratio recognition method provided by the present application; Figure 2f is another exemplary recognition result analysis diagram of the damping ratio recognition method provided by the present application; Figure 2g is another exemplary recognition result analysis diagram of the damping ratio recognition method provided by the present application; Figure 3It is a structural schematic diagram of the damping ratio identification device provided by the present application; Figure 4 It is a structural schematic diagram of the electronic device provided by this application. DETAILED DESCRIPTION

[0012] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited thereby.

[0013] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0014] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0015] In the present invention, unless otherwise clearly specified and limited, the terms "assemble", "connect", "connect", "fix" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0016] Before describing the present application, the background technology of the present application is further introduced: the logarithmic attenuation method of free vibration time domain signal and the least squares fitting method are classical methods for calculating the modal damping ratio. However, due to the influence of factors such as the interference of potential environmental vibration and measurement noise on the signal, the dependence of damping amplitude, etc., the modal damping ratio calculated by the above methods has a large error, especially for small damping structures, which often leads to a significant decrease in the calculation accuracy of the modal damping ratio and cannot meet the requirements of engineering applications. On the other hand, the logarithmic attenuation method and the least squares fitting method are only applicable to single-mode vibration signals, while civil engineering structures are all multi-degree-of-freedom structures, and their free vibration signals are all multi-modal vibration signals. When applying the above methods, modal decomposition is also required. Due to the insufficient accuracy of existing modal decomposition technology, it is not only easy to cause distortion of the single-mode signal after decomposition, but also makes the calculation process too complicated. The current method of calculating the damping ratio of a multi-modal free vibration signal using the attenuation characteristics of the Fourier amplitude spectrum over time cannot reflect all vibration modes of the structure when the signal amplitude is low. Moreover, when the noise or ambient vibration signal component in the free vibration signal is large, the calculation accuracy of the Fourier amplitude spectrum is insufficient, resulting in a large error in the modal damping ratio calculated thereby.

[0017] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] Figure 1 The present invention provides a flow chart of a damping ratio identification method. The method can be performed by a damping ratio identification device, which can be implemented in software and / or hardware. In a specific embodiment, the device can be applied to an electronic device, which can be a computer. The following embodiments will be described by taking the application of the device in an electronic device as an example. Figure 1 , the method may specifically include the following steps: Step 101: Acquire a free decay signal generated by a target civil engineering structure.

[0019] Specifically, for large civil engineering structures, artificial excitation technology can be used to make the structure vibrate freely, and the obtained free vibration response is a free decay signal with a duration of T. .

[0020] Step 102: According to the time length of the free decay signal, a front decay signal and a rear decay signal with the same time length are obtained from the free decay signal.

[0021] Specifically, according to the time length of the free decay signal, the free decay signal is divided into a front decay signal and a rear decay signal of equal time length, which provides a data basis for the subsequent calculation of the damping ratio, thereby increasing the accuracy of the recognition result.

[0022] Step 103: Calculate the front power spectrum of the front attenuation signal according to Fourier transform, and calculate the rear power spectrum of the rear attenuation signal according to Fourier transform.

[0023] Exemplary, free decay signal The duration is T, and the front attenuation signal and the rear attenuation signal are recorded as and , the time length of the two signals is T / 2. Fourier transform is performed on the two signals respectively to obtain the front power spectrum and the back power spectrum.

[0024] Optionally, after step 103, steps 31 to 32 may also be performed.

[0025] Step 31, processing the front power spectrum based on the power spectrum estimation method, determining a plurality of front attenuation signal physical frequency points, and the front power spectrum density amplitude corresponding to each front attenuation signal physical frequency point.

[0026] Optionally, according to the formula Determine the front power spectral density amplitudes corresponding to the physical frequency points of the front attenuated signals.

[0027] in, represents the Fourier transform of the pre-attenuation signal and the post-attenuation signal, Represents dividing the pre-attenuation signal into M segments, r represents the index of the number of segments, and the subscript It is Physical frequency points The index of , represents the frequency resolution, T represents the vector transpose, represents the conjugate transpose of a complex vector, Represents the signal at the frequency point The corresponding power spectrum amplitude at .

[0028] Specifically, the power spectrum estimation method can be a periodogram method, which is based on the formula Process the front power spectrum. Here Represents the pre-attenuation signal The Fourier transform of The representative will signal Divide M segment, r represents the index of the number of segments, subscript It is Physical frequency points The index of , represents the frequency resolution, T represents the vector transpose, represents the conjugate transpose of a complex vector, Represents the signal at the frequency point According to the formula, multiple physical frequency points of the front attenuation signal and the front power spectrum density amplitude corresponding to each physical frequency point of the front attenuation signal are obtained, thereby improving the determination efficiency and accuracy of the front power spectrum density amplitude.

[0029] Step 32: Process the post-power spectrum based on a power spectrum estimation method to determine a plurality of post-attenuation signal physical frequency points and a post-power spectrum density amplitude corresponding to each post-attenuation signal physical frequency point.

[0030] Specifically, according to the formula The power spectrum is processed. Represents the post-attenuation signal The Fourier transform of The representative will signal Divide M segment, r represents the index of the number of segments, subscript It is Physical frequency points The index of , represents the frequency resolution, T represents the vector transpose, represents the conjugate transpose of a complex vector, Represents the signal at the frequency point According to the formula, multiple post-attenuation signal physical frequency points and the post-power spectrum density amplitude corresponding to each post-attenuation signal physical frequency point are obtained, thereby improving the determination efficiency and accuracy of the post-power spectrum density amplitude.

[0031] Optionally, after executing step 31 to step 32, step 33 to step 34 may also be executed.

[0032] Step 33, drawing a frequency spectrum corresponding to the front attenuated signal with the physical frequency point of the front attenuated signal as the horizontal coordinate and the front power spectrum density amplitude corresponding to each physical frequency point of the front attenuated signal as the vertical coordinate.

[0033] For example, ,by is the horizontal axis, As the vertical axis, draw the spectrum corresponding to the pre-attenuation signal.

[0034] Step 34 , plotting a frequency spectrum corresponding to the post-attenuation signal using a plurality of post-attenuation signal physical frequency points as abscissas and a post-power spectrum density amplitude corresponding to each post-attenuation signal physical frequency point as a ordinate.

[0035] For example, ,by is the horizontal axis, As the vertical axis, draw the spectrum corresponding to the pre-attenuation signal.

[0036] Step 104, determining the natural frequency and the front power spectrum amplitude corresponding to each order front attenuation signal modal peak according to the front power spectrum, and determining the natural frequency and the rear power spectrum amplitude corresponding to each order rear attenuation signal modal peak according to the rear power spectrum.

[0037] Optionally, after executing steps 31 to 34 , step 104 can be implemented through steps 1041 to 1042 .

[0038] Step 1041 , determining the natural frequency and the front power spectrum amplitude corresponding to each order of the front attenuation signal modal peak according to the frequency spectrum corresponding to the front attenuation signal.

[0039] Optionally, in the spectrum diagram corresponding to the front attenuation signal, the abscissa corresponding to the modal peak of each order of the front attenuation signal is determined as the natural frequency, and the ordinate of the spectrum diagram corresponding to the front attenuation signal is determined as the front power spectrum amplitude.

[0040] For example, according to the drawn spectrum, there will be obvious peak points near the natural frequency of the structure, and the horizontal and vertical coordinate values ​​corresponding to the peak points of each order of the front attenuation signal mode are obtained, and the front attenuation signal is converted into No. The horizontal coordinate corresponding to the peak point of the order mode, that is, the natural frequency of the structure is recorded as , the corresponding ordinate, that is, the power spectrum density amplitude corresponding to the natural frequency, that is, the former power spectrum amplitude is recorded as .

[0041] Step 1042: determine the natural frequency and post-power spectrum amplitude corresponding to each order of the post-attenuation signal modal peak according to the frequency spectrum corresponding to the post-attenuation signal.

[0042] Optionally, in the spectrum diagram corresponding to the post-attenuation signal, the abscissa corresponding to the modal peak of each order of the pre-attenuation signal is determined as the natural frequency, and the ordinate of the spectrum diagram corresponding to the post-attenuation signal is determined as the post-power spectrum amplitude.

[0043] For example, according to the drawn spectrum, there will be obvious peak points near the natural frequency of the structure, and the horizontal and vertical coordinate values ​​corresponding to the peak points of each order post-attenuation signal mode are obtained, and the post-attenuation signal No. The horizontal coordinate corresponding to the peak point of the order mode, that is, the natural frequency of the structure is recorded as , the corresponding ordinate, that is, the power spectrum density amplitude corresponding to the natural frequency, that is, the power spectrum amplitude is recorded as .

[0044] Step 105 , identifying the damping ratio corresponding to each order mode according to the natural frequency and the front power spectrum amplitude corresponding to each order front attenuation signal modal peak, and the natural frequency and the rear power spectrum amplitude corresponding to each order rear attenuation signal modal peak.

[0045] Optionally, for each mode, according to the ratio of the front power spectrum amplitude corresponding to the front attenuation signal modal peak to the rear power spectrum amplitude corresponding to the rear attenuation signal modal peak, the natural frequency and the formula Identify the damping ratio corresponding to the mode.

[0046] in, is the damping ratio of the i-th mode, is the natural frequency of the i-th mode, represents the amplitude of the front power spectrum corresponding to the modal peak of the front attenuation signal, represents the post-power spectrum amplitude corresponding to the post-attenuation signal modal peak, It is the time length of the pre-decay signal and the post-decay signal.

[0047] Specifically, obtain and No. The horizontal axis natural frequency corresponding to the peak point of the order mode , , and the corresponding power spectrum amplitude before the ordinate , the power spectrum amplitude , use Formula 1 to calculate the damping ratio of each mode.

[0048] Formula 1 in, is the damping ratio of the i-th mode, is the natural frequency of the i-th mode, for Signal No. The power spectral density amplitude corresponding to the first-order mode, that is, the amplitude of the previous power spectrum. for Signal No. The power spectral density amplitude corresponding to the first-order mode is the post-power spectrum amplitude.

[0049] The scheme of the present application obtains the free decay signal generated by the target civil engineering structure; according to the time length of the free decay signal, takes the front decay signal and the rear decay signal of equal time length from the free decay signal; calculates the front decay signal according to Fourier transform to obtain the front power spectrum, and calculates the rear decay signal according to Fourier transform to obtain the rear power spectrum; determines the natural frequency and the front power spectrum amplitude corresponding to each order of the modal peak of the front decay signal according to the front power spectrum, and determines the natural frequency and the rear power spectrum amplitude corresponding to each order of the modal peak of the rear decay signal according to the rear power spectrum; identifies the damping ratio corresponding to each order of mode according to the natural frequency and the front power spectrum amplitude corresponding to each order of the modal peak of the front decay signal, and the natural frequency and the rear power spectrum amplitude corresponding to each order of the modal peak of the rear decay signal. That is, the scheme of the present application, on the one hand, after Fourier transform, combines the frequency domain analysis of the two decay signals and the results of the frequency domain analysis of the two decay signals to realize the damping ratio identification, does not need to perform modal decomposition, avoids the distortion of the single modal signal after modal decomposition, and reduces the complexity of the calculation process. On the other hand, the power spectrum is used for damping ratio identification, which improves the noise resistance in the calculation process, reduces the influence of environmental vibration and measurement noise on the identification results, and improves the precision of the modal damping ratio identification results and the accuracy of modal damping ratio identification.

[0050] Figure 2a is another flow chart of the damping ratio identification method provided by the present application. Figure 1 Based on the illustrated embodiment and various optional implementation schemes, the steps of obtaining the free decay signal of the target civil engineering structure are described in detail. Figure 2a As shown, the method may include the following steps: Step 201, when the target civil engineering structure generates free vibration, obtain a free attenuation signal generated when the target civil engineering structure responds.

[0051] Specifically, when the target civil engineering structure generates free vibration, a free decay signal generated when the target civil engineering structure responds is obtained, so that the free decay signal is more consistent with the actual civil engineering structure, thereby improving the accuracy of the recognition result.

[0052] Step 202: According to the time length of the free decay signal, a pre-decay signal and a post-decay signal with the same time length are obtained from the free decay signal.

[0053] Step 203: Calculate the front power spectrum of the front attenuation signal according to Fourier transform, and calculate the rear power spectrum of the rear attenuation signal according to Fourier transform.

[0054] Step 204, determining the natural frequency and the front power spectrum amplitude corresponding to each order front attenuation signal modal peak according to the front power spectrum, and determining the natural frequency and the rear power spectrum amplitude corresponding to each order rear attenuation signal modal peak according to the rear power spectrum.

[0055] Step 205 , identifying the damping ratio corresponding to each order mode according to the natural frequency and the front power spectrum amplitude corresponding to each order front attenuation signal modal peak, and the natural frequency and the rear power spectrum amplitude corresponding to each order rear attenuation signal modal peak.

[0056] For example, Figure 2b This is an example diagram of a free decay signal of the damping ratio identification method provided in this application. The sampling frequency of the signal is 100 Hz and the natural frequency is =0.5Hz, the damping ratio is =0.02, the initial amplitude is =1m, the initial phase is =0.003, the noise level is to add four kinds of Gaussian distribution random noise with mean zero and standard deviation of 5%, 10%, 15% and 20% of the root mean square (RMS) of the free vibration signal. According to the theoretical formula of free vibration of single degree of freedom structure, a free decay signal is generated and Gaussian white noise with different noise levels is added to obtain Figure 2b An example of a free decay signal is shown. Figure 2c is an exemplary recognition result analysis diagram of the damping ratio recognition method provided by the present application. 100 groups of signals are simulated under each noise level interference, and the damping ratio recognition is performed using the logarithmic attenuation method, the Fast Fourier Transform (FFT) attenuation method and the damping ratio recognition method of the present application respectively. The average recognition error of different methods at each noise level was obtained Value, where is the damping ratio of the i-th mode, and the result is as follows Figure 2c As shown. Figure 2c It can be seen that the recognition error of the logarithmic attenuation method is large, and it increases significantly with the increase of noise level, and its recognition error range is between 4.85% and 19.75%. The recognition error range of the FFT attenuation method is between 2.80% and 5.96%, while the recognition error of the damping ratio recognition method of the present application is always less than 1%. Therefore, the recognition accuracy of the damping ratio recognition method of the present application is higher, and the recognition result is more accurate.

[0057] Figure 2d This is an example diagram of a free vibration signal containing third-order modal information in the damping ratio identification method provided in this application. The signal sampling frequency is 100 Hz and the natural frequency is =1Hz, =2Hz, =4Hz, the initial amplitude is =1m, =0.2m, =0.1m, the initial phase is The noise level is to add four kinds of Gaussian distributed random noise with a mean of zero and a standard deviation of 5%, 10%, 15%, and 20% of the RMS value of the free vibration signal. Using MATLAB software, a free vibration signal containing third-order modal information is generated. The generated signal is as follows Figure 2d The damping ratio of the third-order mode is identified respectively using the logarithmic attenuation method, the FFT attenuation method and the damping ratio identification method of the present application. Figure 2e , Figure 2f as well as Figure 2g are another exemplary recognition result analysis diagram of the damping ratio recognition method provided in the present application, wherein: Figure 2e The error analysis diagrams of the damping ratio identification by the logarithmic attenuation method of the front-order mode, the FFT attenuation method and the damping ratio identification method of the present application are shown in FIG. Figure 2f The error analysis diagrams of damping ratio identification by the logarithmic attenuation method, FFT attenuation method and the damping ratio identification method of the present application are shown in Fig. Figure 2g The error analysis diagrams of the damping ratio identification by the logarithmic attenuation method, the FFT attenuation method and the damping ratio identification method of the present application for the third-order mode are shown in FIG. Figure 2e , Figure 2f as well as Figure 2g It can be seen that the three methods have small errors in identifying the first-order modal damping ratio of the system, which is basically maintained within 1%. The errors in the damping ratio identification results of the latter and third orders are large, but the damping ratio identification method of the present application has the smallest identification error among the three methods. Therefore, the damping ratio identification method of the present application enhances the noise resistance and robustness of the thread damping ratio identification. Therefore, compared with the logarithmic attenuation method and the least squares fitting method, the method of the present application calculates the modal damping ratio in the frequency domain, does not require modal decomposition, and can effectively reduce the impact of environmental vibration and measurement noise on the identification results. On the other hand, due to the use of the power spectrum, it has stronger noise resistance and higher calculation results accuracy than the Fourier amplitude spectrum. Because the calculation formula of the power spectrum attenuation method is simple and easy to understand, it is easy to use and has good engineering adaptability.

[0058] The solution of the present application obtains a free decay signal of the target civil engineering structure response when the target civil engineering structure generates free vibration, so that the free decay signal is more consistent with the actual civil engineering structure, thereby improving the accuracy of the recognition result.

[0059] Figure 3is a schematic diagram of a damping ratio identification device provided in the present application, and the device is suitable for executing the damping ratio identification method provided in the present application. Figure 3 As shown, the device may specifically include: The acquisition module 301 is used to acquire the free attenuation signal generated by the target civil engineering structure.

[0060] The signal determination module 302 is used to extract a pre-decay signal and a post-decay signal with equal time lengths from the free decay signal according to the time length of the free decay signal.

[0061] The transformation module 303 is used to calculate the front power spectrum of the front attenuation signal according to Fourier transformation, and to calculate the rear power spectrum of the rear attenuation signal according to Fourier transformation.

[0062] The peak determination module 304 is used to determine the natural frequency and the front power spectrum amplitude corresponding to each order front attenuation signal mode peak according to the front power spectrum, and to determine the natural frequency and the rear power spectrum amplitude corresponding to each order rear attenuation signal mode peak according to the rear power spectrum.

[0063] The damping ratio identification module 305 is used to identify the damping ratio corresponding to each order mode according to the natural frequency and front power spectrum amplitude corresponding to each order front attenuation signal modal peak, and the natural frequency and rear power spectrum amplitude corresponding to each order rear attenuation signal modal peak.

[0064] In one embodiment, the acquisition module 301 is specifically used to: when the target civil engineering structure generates free vibration, acquire a free attenuation signal generated when the target civil engineering structure responds.

[0065] In one embodiment, the damping ratio identification module 305 is specifically used to: for each order mode, according to the ratio of the front power spectrum amplitude corresponding to the front attenuation signal modal peak to the rear power spectrum amplitude corresponding to the rear attenuation signal modal peak, the natural frequency and the formula Identify the damping ratio corresponding to the mode; wherein, is the damping ratio of the i-th mode, is the natural frequency of the i-th mode, represents the front power spectrum amplitude corresponding to the modal peak of the front attenuation signal, represents the post-power spectrum amplitude corresponding to the post-attenuation signal modal peak, is the time length of the pre-attenuation signal and the post-attenuation signal.

[0066] In one embodiment, the device also includes: an amplitude determination module, which is used to process the front power spectrum based on the power spectrum estimation method after the transformation module 303, to determine multiple physical frequency points of the front attenuation signal, and the front power spectrum density amplitude corresponding to each physical frequency point of the front attenuation signal; and to process the rear power spectrum based on the power spectrum estimation method to determine multiple physical frequency points of the rear attenuation signal, and the rear power spectrum density amplitude corresponding to each physical frequency point of the rear attenuation signal.

[0067] In one embodiment, the amplitude determination module is based on the formula Determine the front power spectrum density amplitude corresponding to multiple physical frequency points of the front attenuation signal; wherein, represents the Fourier transform of the pre-attenuation signal and the post-attenuation signal, represents dividing the pre-attenuated signal into M segments, r represents the index of the number of segments, and the subscript It is Physical frequency points The index of , represents the frequency resolution, T represents the vector transpose, represents the conjugate transpose of a complex vector, Represents the signal at the frequency point The corresponding power spectrum amplitude at .

[0068] In one embodiment, after the amplitude determination module processes the rear power spectrum based on the power spectrum estimation method to determine multiple physical frequency points of the rear attenuation signal and the rear power spectrum density amplitude corresponding to each physical frequency point of the rear attenuation signal, it is also used to: use the multiple physical frequency points of the front attenuation signal as the horizontal coordinates and the front power spectrum density amplitude corresponding to each physical frequency point of the front attenuation signal as the vertical coordinate to draw the frequency spectrum corresponding to the front attenuation signal; use the multiple physical frequency points of the rear attenuation signal as the horizontal coordinates and the rear power spectrum density amplitude corresponding to each physical frequency point of the rear attenuation signal as the vertical coordinate to draw the frequency spectrum corresponding to the rear attenuation signal; the peak determination module 304 is specifically used to: determine the natural frequency and the front power spectrum amplitude corresponding to each order of the front attenuation signal modal peak according to the frequency spectrum corresponding to the front attenuation signal; determine the natural frequency and the rear power spectrum amplitude corresponding to each order of the rear attenuation signal modal peak according to the frequency spectrum corresponding to the rear attenuation signal.

[0069] In one embodiment, the peak determination module 304 is specifically used to determine the natural frequency and the front power spectrum amplitude corresponding to each order modal peak of the front attenuation signal according to the frequency spectrum diagram corresponding to the front attenuation signal, by: determining the abscissa corresponding to each order modal peak of the front attenuation signal in the frequency spectrum diagram corresponding to the front attenuation signal as the natural frequency, and determining the ordinate of the frequency spectrum diagram corresponding to the front attenuation signal as the front power spectrum amplitude; the peak determination module 304 is specifically used to determine the natural frequency and the rear power spectrum amplitude corresponding to each order modal peak of the rear attenuation signal according to the frequency spectrum diagram corresponding to the rear attenuation signal, by: determining the abscissa corresponding to each order modal peak of the front attenuation signal in the frequency spectrum diagram corresponding to the rear attenuation signal as the natural frequency, and determining the ordinate of the frequency spectrum diagram corresponding to the rear attenuation signal as the rear power spectrum amplitude.

[0070] The device of the present application obtains the free decay signal generated by the target civil engineering structure; according to the time length of the free decay signal, a front decay signal and a rear decay signal with equal time length are taken from the free decay signal; the front decay signal is calculated according to Fourier transform to obtain the front power spectrum, and the rear decay signal is calculated according to Fourier transform to obtain the rear power spectrum; the natural frequency and the front power spectrum amplitude corresponding to each order of the modal peak of the front decay signal are determined according to the front power spectrum, and the natural frequency and the rear power spectrum amplitude corresponding to each order of the modal peak of the rear decay signal are determined according to the rear power spectrum; according to the natural frequency and the front power spectrum amplitude corresponding to each order of the modal peak of the front decay signal, and the natural frequency and the rear power spectrum amplitude corresponding to each order of the modal peak of the rear decay signal, the damping ratio corresponding to each order of mode is identified. That is, the scheme of the present application, on the one hand, after Fourier transform, combines the frequency domain analysis of the two decay signals and the results of the frequency domain analysis of the two decay signals to realize the damping ratio identification, without the need for modal decomposition, avoiding the distortion of the single modal signal after modal decomposition, thereby reducing the complexity of the calculation process. On the other hand, the power spectrum is used for damping ratio identification, which improves the noise resistance in the calculation process, reduces the influence of environmental vibration and measurement noise on the identification results, and improves the precision of the modal damping ratio identification results and the accuracy of modal damping ratio identification.

[0071] The present application also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the damping ratio identification method provided in any of the above embodiments when executing the program.

[0072] The present application also provides a computer-readable medium having a computer program stored thereon, and when the program is executed by a processor, the damping ratio identification method provided in any of the above embodiments is implemented.

[0073] Reference below Figure 4, which shows a structural schematic diagram of an electronic device 400 suitable for implementing the present application. Figure 4 The electronic device shown is only an example and should not bring any limitation to the function and scope of use of the present application.

[0074] like Figure 4 As shown, the electronic device 400 includes a central processing unit (CPU) 401, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 402 or a program loaded from a storage part 408 into a random access memory (RAM) 403. In the RAM 403, various programs and data required for the operation of the electronic device 400 are also stored. The CPU 401, the ROM 402, and the RAM 403 are connected to each other via a bus 404. An input / output (I / O) interface 405 is also connected to the bus 404.

[0075] The following components are connected to the I / O interface 405: an input section 406 including a keyboard, a mouse, etc.; an output section 407 including a cathode ray tube (CRT), a liquid crystal display (LCD), etc., and a speaker, etc.; a storage section 408 including a hard disk, etc.; and a communication section 409 including a network interface card such as a LAN card, a modem, etc. The communication section 409 performs communication processing via a network such as the Internet. A drive 410 is also connected to the I / O interface 405 as needed. A removable medium 411, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc., is installed on the drive 410 as needed, so that a computer program read therefrom is installed into the storage section 408 as needed.

[0076] In particular, according to the embodiments disclosed in the present application, the process described above with reference to the flowchart can be implemented as a computer software program. For example, the embodiments disclosed in the present application include a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program contains program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from the network through the communication part 409, and / or installed from the removable medium 411. When the computer program is executed by the central processing unit (CPU) 401, the above-mentioned functions defined in the system of the present application are executed.

[0077] It should be noted that the computer-readable medium shown in the present application may be a computer-readable signal medium or a computer-readable storage medium or any combination of the above two. The computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present application, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in combination with an instruction execution system, device or device. In the present application, a computer-readable signal medium may include a data signal propagated in a baseband or as part of a carrier wave, which carries a computer-readable program code. This propagated data signal may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. Computer-readable signal media may also be any computer-readable medium other than computer-readable storage media, which may send, propagate or transmit a program for use by or in conjunction with an instruction execution system, apparatus or device. The program code contained on the computer-readable medium may be transmitted using any appropriate medium, including but not limited to: wireless, wire, optical cable, RF, etc., or any suitable combination of the above.

[0078] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present application. In this regard, each box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the above-mentioned module, program segment or a part of a code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flow chart, and the combination of the boxes in the block diagram or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0079] The modules and / or units described in this application may be implemented in software or hardware. The modules and / or units described may also be arranged in a processor, for example, it may be described as follows: a processor includes an acquisition module, a signal determination module, a transformation module, a peak determination module, and a damping ratio identification module. The names of these modules do not, in some cases, constitute limitations on the modules themselves.

[0080] As another aspect, the present application also provides a computer-readable medium, which may be included in the device described in the above embodiment; or may exist independently without being assembled into the device. The above computer-readable medium carries one or more programs, and when the above one or more programs are executed by a device, the device performs the following operations: Obtain a free decay signal generated by a target civil engineering structure; according to the time length of the free decay signal, take a front decay signal and a rear decay signal of equal time length from the free decay signal; calculate the front decay signal according to Fourier transform to obtain a front power spectrum, and calculate the rear decay signal according to Fourier transform to obtain a rear power spectrum; determine the natural frequency and the front power spectrum amplitude corresponding to each order of the front decay signal modal peak according to the front power spectrum, and determine the natural frequency and the rear power spectrum amplitude corresponding to each order of the rear decay signal modal peak according to the rear power spectrum; identify the damping ratio corresponding to each order mode according to the natural frequency and the front power spectrum amplitude corresponding to each order of the front decay signal modal peak, and the natural frequency and the rear power spectrum amplitude corresponding to each order of the rear decay signal modal peak.

[0081] According to the technical solution of the present application, a free decay signal generated by a target civil engineering structure is obtained; according to the time length of the free decay signal, a front decay signal and a rear decay signal with equal time length are taken from the free decay signal; the front decay signal is calculated according to Fourier transform to obtain a front power spectrum, and the rear decay signal is calculated according to Fourier transform to obtain a rear power spectrum; the natural frequency and the front power spectrum amplitude corresponding to each order of the modal peak of the front decay signal are determined according to the front power spectrum, and the natural frequency and the rear power spectrum amplitude corresponding to each order of the modal peak of the rear decay signal are determined according to the rear power spectrum; according to the natural frequency and the front power spectrum amplitude corresponding to each order of the modal peak of the front decay signal, and the natural frequency and the rear power spectrum amplitude corresponding to each order of the modal peak of the rear decay signal, the damping ratio corresponding to each order of mode is identified. That is, the solution of the present application, on the one hand, after Fourier transform, combines the frequency domain analysis of the two decay signals and the results of the frequency domain analysis of the two decay signals to realize damping ratio identification, without the need for modal decomposition, avoiding the distortion of the single modal signal after modal decomposition, thereby reducing the complexity of the calculation process. On the other hand, the power spectrum is used for damping ratio identification, which improves the noise resistance in the calculation process, reduces the influence of environmental vibration and measurement noise on the identification results, and improves the precision of the modal damping ratio identification results and the accuracy of modal damping ratio identification.

[0082] An embodiment of the present application also provides a computer program product, including a computer program, which, when executed by a processor, implements the damping ratio identification method provided in any embodiment of the present application.

[0083] In the process of implementation, the computer program product can be written in one or more programming languages ​​or a combination thereof to perform the computer program code of the present application, and the programming language includes an object-oriented programming language, such as Java, Smalltalk, C++, and also includes a conventional procedural programming language, such as "C" language or similar programming language. The program code can be executed completely on the user's computer, partially on the user's computer, as an independent software package, partially on the user's computer and partially on the remote computer, or completely on the remote computer or server. In the case of a remote computer, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computer (for example, using an Internet service provider to connect through the Internet).

[0084] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps recorded in this application can be executed in parallel, sequentially or in different orders, as long as the expected results of the technical solution of this application can be achieved, and this document is not limited here.

[0085] The above specific implementations do not constitute a limitation on the protection scope of this application. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions may occur depending on design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principles of this application should be included in the protection scope of this application.

Claims

1. A damping ratio identification method, characterized in that: The method comprises: Obtain the free decay signal generated by the target civil engineering structure; According to the time length of the free decay signal, taking a front decay signal and a rear decay signal with equal time lengths from the free decay signal; Calculating the front attenuation signal according to Fourier transform to obtain a front power spectrum, and calculating the rear attenuation signal according to Fourier transform to obtain a rear power spectrum; Determine the natural frequency and the front power spectrum amplitude corresponding to each order of the front attenuation signal modal peak according to the front power spectrum, and determine the natural frequency and the rear power spectrum amplitude corresponding to each order of the rear attenuation signal modal peak according to the rear power spectrum; According to the natural frequency and the front power spectrum amplitude corresponding to each order front attenuation signal modal peak, and the natural frequency and the rear power spectrum amplitude corresponding to each order rear attenuation signal modal peak, the damping ratio corresponding to each order mode is identified.

2. The damping ratio identification method according to claim 1, characterized in that: The step of obtaining a free attenuation signal generated by a target civil engineering structure comprises: When the target civil engineering structure generates free vibration, a free attenuation signal generated when the target civil engineering structure responds is obtained.

3. The damping ratio identification method according to claim 1, characterized in that: The identifying the damping ratio corresponding to each order mode according to the natural frequency and the front power spectrum amplitude corresponding to each order front attenuation signal modal peak value, and the natural frequency and the rear power spectrum amplitude corresponding to each order rear attenuation signal modal peak value, comprises: For each mode, according to the ratio of the front power spectrum amplitude corresponding to the front attenuation signal modal peak to the rear power spectrum amplitude corresponding to the rear attenuation signal modal peak, the natural frequency and the formula Identify the damping ratio corresponding to the mode; wherein, is the damping ratio of the i-th mode, is the natural frequency of the i-th mode, represents the front power spectrum amplitude corresponding to the modal peak of the front attenuation signal, represents the post-power spectrum amplitude corresponding to the post-attenuation signal modal peak, is the time length of the pre-attenuation signal and the post-attenuation signal.

4. The damping ratio identification method according to claim 1, characterized in that: After calculating the front power spectrum by Fourier transforming the front attenuated signal and calculating the rear power spectrum by Fourier transforming the rear attenuated signal, the method further includes: Processing the front power spectrum based on a power spectrum estimation method to determine a plurality of front attenuation signal physical frequency points and a front power spectrum density amplitude corresponding to each of the front attenuation signal physical frequency points; The post-power spectrum is processed based on a power spectrum estimation method to determine a plurality of post-attenuation signal physical frequency points and a post-power spectrum density amplitude corresponding to each of the post-attenuation signal physical frequency points.

5. The damping ratio identification method according to claim 4, characterized in that: According to the formula Determine the front power spectrum density amplitude corresponding to multiple physical frequency points of the front attenuation signal; wherein, represents the Fourier transform of the pre-attenuation signal and the post-attenuation signal, represents dividing the pre-attenuated signal into M segments, r represents the index of the number of segments, and the subscript It is Physical frequency points The index of , represents the frequency resolution, T represents the vector transpose, represents the conjugate transpose of a complex vector, Represents the signal at the frequency point The corresponding power spectrum amplitude at .

6. The damping ratio identification method according to claim 4, characterized in that: After processing the post-power spectrum based on the power spectrum estimation method to determine a plurality of post-attenuation signal physical frequency points and a post-power spectrum density amplitude corresponding to each of the post-attenuation signal physical frequency points, the method further includes: With the multiple physical frequency points of the front attenuated signal as the abscissa and the front power spectrum density amplitude corresponding to each physical frequency point of the front attenuated signal as the ordinate, draw a frequency spectrum diagram corresponding to the front attenuated signal; Using the multiple post-attenuation signal physical frequency points as abscissas and the post-power spectrum density amplitude corresponding to each post-attenuation signal physical frequency point as a ordinate, plotting a frequency spectrum corresponding to the post-attenuation signal; The method of determining the natural frequency and the front power spectrum amplitude corresponding to each order front attenuation signal modal peak value according to the front power spectrum, and determining the natural frequency and the rear power spectrum amplitude corresponding to each order rear attenuation signal modal peak value according to the rear power spectrum, comprises: Determine the natural frequency and the front power spectrum amplitude corresponding to the modal peak of each order of the front attenuation signal according to the frequency spectrum corresponding to the front attenuation signal; The natural frequency and the post-power spectrum amplitude corresponding to the modal peak of each order post-attenuation signal are determined according to the frequency spectrum corresponding to the post-attenuation signal.

7. The damping ratio identification method according to claim 6, characterized in that: The determining, according to the frequency spectrum corresponding to the front attenuation signal, the natural frequency and the front power spectrum amplitude corresponding to the modal peak of each order of the front attenuation signal comprises: In the spectrum diagram corresponding to the front attenuation signal, the abscissa corresponding to the modal peak of each order of the front attenuation signal is determined as the natural frequency, and the ordinate of the spectrum diagram corresponding to the front attenuation signal is determined as the front power spectrum amplitude; The determining, according to the frequency spectrum corresponding to the post-attenuation signal, the natural frequency and the post-power spectrum amplitude corresponding to the modal peak of each order post-attenuation signal comprises: In the frequency spectrum diagram corresponding to the post-attenuation signal, the abscissa corresponding to the modal peak of each order of the pre-attenuation signal is determined as the natural frequency, and the ordinate of the frequency spectrum diagram corresponding to the post-attenuation signal is determined as the post-power spectrum amplitude.

8. A damping ratio identification device, characterized in that: The device comprises: An acquisition module, used for acquiring a free decay signal generated by a target civil engineering structure; A signal determination module, configured to extract a pre-decay signal and a post-decay signal of equal time length from the free decay signal according to the time length of the free decay signal; A transformation module, configured to calculate the front attenuation signal according to Fourier transform to obtain a front power spectrum, and to calculate the rear attenuation signal according to Fourier transform to obtain a rear power spectrum; A peak determination module, used to determine the natural frequency and the front power spectrum amplitude corresponding to each order of the front attenuation signal modal peak according to the front power spectrum, and to determine the natural frequency and the rear power spectrum amplitude corresponding to each order of the rear attenuation signal modal peak according to the rear power spectrum; The damping ratio identification module is used to identify the damping ratio corresponding to each order mode according to the natural frequency and front power spectrum amplitude corresponding to each order front attenuation signal modal peak, and the natural frequency and rear power spectrum amplitude corresponding to each order rear attenuation signal modal peak.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the program, the damping ratio identification method according to any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the damping ratio identification method according to any one of claims 1 to 7 is implemented.

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