An earthquake motion adjustment method and device for enveloping a target power spectrum and an electronic device

Abstract

Embodiments of the present disclosure provide a ground motion adjustment method and device for envelope target power spectrum and electronic equipment. The method comprises: obtaining a target ground motion power spectrum and an initial ground motion acceleration; calculating a minimum value of a ratio of a power spectrum of a stationary section of the initial ground motion acceleration to the target ground motion power spectrum corresponding to a frequency; determining whether the minimum value of the ratio is less than a first threshold value, and if so, determining a discrete control period of the initial ground motion acceleration; dividing the frequency of the initial ground motion power spectrum and the target ground motion power spectrum into a plurality of adjacent frequency bands with each discrete control period point as the center; and adjusting the initial ground motion acceleration according to the power spectrum in the main control band of each control period of the initial ground motion acceleration and the target ground motion power spectrum corresponding to the frequency band. The adjusted ground motion power spectrum of the present disclosure envelopes the target power spectrum, ensuring effective simulation of the final ground motion on natural ground motion.

Description

Technical Field

[0001] This disclosure relates to the field of earthquake engineering technology, and in particular to a method, apparatus, and electronic device for adjusting seismic motion by envelope target power spectrum. Background Technology

[0002] Nuclear power is a clean, environmentally friendly, and highly efficient energy source. However, under earthquake conditions, a large-scale leak of radioactive materials from a nuclear power plant could have unacceptable catastrophic consequences for the natural environment and human society. Therefore, countries worldwide attach great importance to the seismic safety of nuclear power plants. Seismic analysis of nuclear power plants is a crucial technical means to ensure their seismic safety. This involves conducting numerical simulations or experimental studies on the dynamic response of the nuclear island structure and equipment under seismic input, and then implementing effective engineering measures to improve the seismic safety level of the nuclear power plant. Therefore, scientifically and rationally determining the input seismic motion is a vital prerequisite for ensuring the scientific validity and rationality of the seismic analysis results of nuclear power plants, and ultimately, for ensuring their seismic safety.

[0003] To ensure the conservatism of seismic analysis results for nuclear island structures and critical safety equipment, various regulations, standards, and guidelines require that the power spectrum of the input ground motion enclose the target power spectrum. For example, China's "Guideline for Seismic Qualification Testing of Nuclear Equipment" (HAFJ0053) and the US NUREG-0800 "Standard Review Outline (SRP3.7.1)" both contain relevant provisions. Methods for adjusting a given ground motion to enclose the target power spectrum are very limited, and they only focus on adjusting the ground motion acceleration, ignoring the adverse effects of such adjustments on ground motion velocity and displacement. Such adjustments may cause baseline drift in ground motion velocity and displacement, or result in waveform characteristics that differ significantly from actual ground motion, making it difficult to achieve effective or reasonable simulation of natural ground motion, and in some cases, may even lead to unreasonable seismic analysis results. The US NUREG-0800 "Standard Review Outline (SRP3.7.1)" has clearly defined requirements for the velocity and displacement of the input ground motion for nuclear power plants. Summary of the Invention

[0004] The purpose of this disclosure is to provide a method, apparatus, and electronic device for adjusting seismic motion by enveloping the target power spectrum, thereby solving the aforementioned problems existing in the prior art.

[0005] To achieve the above objectives, the technical solutions adopted in the embodiments of this disclosure are as follows:

[0006] This disclosure proposes a method for adjusting seismic motion within the envelope target power spectrum, the method comprising:

[0007] Obtain a given target ground motion power spectrum and an arbitrary given initial ground motion acceleration, wherein the target ground motion power spectrum and the initial ground motion acceleration exist in the form of a discrete frequency sequence and a discrete time sequence, respectively;

[0008] Calculate the minimum ratio of the power spectrum of the initial ground motion acceleration stationary segment to the power spectrum of the target ground motion at the corresponding frequency;

[0009] Determine whether the minimum value of the ratio of the power spectrum of the initial ground motion acceleration steady segment to the power spectrum of the target ground motion at the corresponding frequency is less than a first threshold. If so, determine the discrete control period of the initial ground motion acceleration. With each discrete control period point as the center, divide the frequencies of the initial ground motion power spectrum and the target ground motion power spectrum into several adjacent frequency bands.

[0010] The initial ground motion acceleration is adjusted based on the power spectrum within the main control frequency band of each control cycle of the initial ground motion acceleration and the power spectrum of the target ground motion in the corresponding frequency band.

[0011] For example, after adjusting the initial ground motion acceleration, the method further includes: recalculating the minimum ratio of the power spectrum of the adjusted initial ground motion acceleration stationary segment to the power spectrum of the target ground motion at the corresponding frequency, until the minimum ratio of the power spectrum of the adjusted initial ground motion acceleration stationary segment to the power spectrum of the target ground motion at the corresponding frequency is not less than a first threshold.

[0012] For example, determining whether the minimum value of the ratio of the power spectrum of the initial ground motion acceleration plateau segment to the power spectrum of the target ground motion at the corresponding frequency is less than a first threshold further includes:

[0013] If not, the initial ground motion acceleration is taken as the final ground motion acceleration.

[0014] For example, after obtaining the given target ground motion power spectrum and any given initial ground motion acceleration, the method further includes:

[0015] The initial ground motion acceleration time series is calibrated so that the peak value of the initial ground motion acceleration is equal to the target peak value of the target ground motion power spectrum, and the initial ground motion time series is scaled accordingly; the specific calibration method is as follows:

[0016]

[0017] Among them, a 0,n This represents the initial ground motion acceleration time series, and also the initial ground motion acceleration at time n. This represents the peak ground acceleration (PGA) of the initial ground motion acceleration sequence, where i represents the time point in the initial ground motion time series where the maximum acceleration occurs, and N represents the total number of points in the ground motion time series. This represents the target peak ground acceleration, which is the power spectrum of the target ground motion.

[0018] For example, determining the discrete control period of the initial ground motion acceleration, with each discrete control period point as the center, involves dividing the frequencies of the initial ground motion power spectrum and the target ground motion power spectrum into several adjacent frequency bands, including:

[0019] Determine the discrete frequency intervals and discrete frequency sequence of the initial ground motion power spectrum.

[0020]

[0021] f p =(p-1)Δf(p=1,2,...,p / 2+1)

[0022] Where Δf represents the discrete frequency interval, f represents the frequency, P represents the total number of frequency points, and Δt represents the discrete time interval. p This represents a discrete frequency sequence, where p represents a specific frequency point.

[0023] Determine the discrete control period T of the initial ground motion power spectrum m The main control frequency band of (m=1,2,...,M) The specific formula is as follows:

[0024]

[0025]

[0026] Among them, T m T represents the discrete control period, that is, the m-th control period point. m-1 T represents the previous control cycle, i.e., the (m-1)th control cycle point. m+1 This indicates the next control cycle, i.e., the (m+1)th control cycle point, and Δf represents the discrete frequency interval. and They represent I respectively p Point and J p The frequency of the point, m represents a discrete periodic point, and M represents the total number of discrete periodic points;

[0027] The frequency of the target ground motion power spectrum is divided into the main control frequency band of the initial ground motion power spectrum. same.

[0028] For example, adjusting the initial ground motion acceleration based on the power spectrum within the main control frequency band and the target ground motion power spectrum of the corresponding frequency band in each control cycle of the initial ground motion acceleration includes:

[0029] Calculate the initial ground motion acceleration during the control period T m The minimum ratio of the power spectrum within the main control frequency band to the target ground motion power spectrum within the corresponding frequency band;

[0030] If the initial seismic acceleration is within the control period T m If the minimum value of the ratio between the power spectrum within the main control frequency band and the target ground motion power spectrum within that frequency band is greater than or equal to the second threshold, then the next control period T for calculating the initial ground motion acceleration is calculated. m+1 The minimum ratio of the power spectrum within the main control frequency band to the target ground motion power spectrum within the corresponding frequency band;

[0031] If the control period T of the initial seismic acceleration m If the minimum ratio of the power spectrum within the main control frequency band to the target ground motion power spectrum within that frequency band is less than the second threshold, then the adjustment control period T is constructed. m The incremental acceleration of the initial ground motion acceleration within the main control frequency band is used to adjust the control period T based on the incremental acceleration. m The initial ground motion acceleration.

[0032] For example, the construction adjustment control period T m The incremental acceleration of the initial ground motion acceleration is used to adjust the control period T. m The initial seismic acceleration includes:

[0033] Extract the initial ground motion acceleration a 0,n The acceleration a in the steady segment s,n ;

[0034] The acceleration a during the steady segment s,n Perform a Fast Fourier Transform to obtain C p′ :

[0035] C p′ =FFT[a s,n ](n=1,2,...,N)(p′=1,2,...,P);

[0036] Among them, C p′ Indicates a s,n The result after Fast Fourier Transform (in the frequency domain):

[0037] Adjust C according to the following formula p′ :

[0038]

[0039] Among them, R L The control period T represents the initial ground motion acceleration. m The minimum ratio of the power spectrum within the main control frequency band to the power spectrum of the target ground motion within that frequency band;

[0040] Determine the incremental acceleration sequence Δa of the initial ground motion acceleration. n :

[0041] Δa n =IFFT[C′ q ]-a s,n (n = 1, 2, ..., N)(I p ≤q≤J p )

[0042] Wherein, IFFT represents the inverse fast Fourier transform;

[0043] For the incremental acceleration sequence Δa n Perform baseline correction:

[0044] Δa″ n =BLC[Δa n (n = 1, 2, ..., N)

[0045] Based on the baseline-corrected incremental acceleration Δa″ n Adjust the initial ground motion acceleration sequence a 0,n , thus obtaining a′ 0,n :

[0046] a′ 0,n =a 0,n +Δa″ n ;

[0047] Where, a′ 0,n This is the adjusted initial ground motion acceleration sequence.

[0048] For example, the incremental acceleration sequence Δa n Baseline correction includes:

[0049] Determine the incremental velocity sequence and incremental displacement sequence of the incremental acceleration sequence:

[0050] Δv n =INT[Δa n ]

[0051] Δd n =INT[Δv n ]

[0052] Where, Δvn Δd represents the incremental velocity sequence, and also the incremental velocity at time n; n This represents the incremental displacement sequence, also known as the incremental displacement at time n. INT indicates integration. Δa n It represents the incremental acceleration sequence, and also the incremental acceleration at time n;

[0053] For the incremental displacement sequence Δd n Tail N R Perform linear fitting on the data:

[0054]

[0055] Among them, X n Y represents the x-coordinate at time n. n Let X represent the vertical axis at time n, Y represent the horizontal axis, n represent a specific time point in the initial ground motion time series, N represent the total number of points in the initial ground motion time series, and Δt represent the discrete time interval. R Let Δd represent the R-th N-th data point. N This represents the incremental displacement at time N;

[0056] Determine the regression coefficients:

[0057]

[0058] Where A represents the regression coefficient, consisting of 2 × 3 numbers A ij The resulting 2x3 matrix, A 11 ~A 23 These represent the elements of the regression coefficient matrix A;

[0059] Determine the fitting parameters:

[0060]

[0061]

[0062] Where β1 and β2 represent the linear fitting parameters, respectively;

[0063] Determine the start time t0 and end time t1 of the correction increment acceleration pulse sequence;

[0064]

[0065] t0 = max(t1 - Δt) BLC ,0)

[0066] Where, Δt BLC Indicates the time interval for baseline correction;

[0067] Determine the incremental acceleration sequence to be used for correction:

[0068]

[0069] Δv′ n =INT[Δa′ n ]

[0070] Δd′ n =INT[Δv′ n ]

[0071] Where, Δa′ n This represents the incremental acceleration sequence used for correction, Δv′ n The incremental velocity sequence used for correction is Δd. n ′ represents the incremental displacement sequence used for correction, and INT represents the integration operation;

[0072] Determine the incremental acceleration sequence Δa obtained from the first correction. 1，n :

[0073]

[0074] Δv 1，n =INT[Δa 1，n ]

[0075] Δd 1，n =INT[Δv 1，n ]

[0076] Where, Δv′ N Δv represents the correction increment velocity at time N. 1，n This represents the incremental velocity sequence obtained from the first correction, Δd. 1，n This represents the incremental displacement sequence obtained from the first correction, Δa. n Represents an incremental acceleration sequence;

[0077] Determine the final incremental acceleration sequence Δa obtained from the second correction. 2，n :

[0078]

[0079] Where, Δa 1，n This represents the incremental acceleration sequence obtained from the first correction, Δd. 1，N Δd represents the incremental displacement at time N obtained from the first correction. N ' represents the corrected incremental displacement at time N; Δa 2，n Equivalent to Δa″ n .

[0080] Another aspect of this disclosure provides a seismic motion adjustment device that encloses a target power spectrum, the device comprising:

[0081] The acquisition module is used to acquire a given target ground motion power spectrum and an arbitrary given initial ground motion acceleration, wherein the target ground motion power spectrum and the initial ground motion acceleration exist in the form of discrete frequency sequences and discrete time sequences, respectively;

[0082] The calculation module is used to calculate the minimum ratio of the power spectrum of the initial ground motion acceleration stationary segment to the power spectrum of the target ground motion at the corresponding frequency;

[0083] The judgment module is used to determine whether the minimum value of the ratio of the power spectrum of the initial ground motion acceleration steady segment to the power spectrum of the target ground motion at the corresponding frequency is less than a first threshold. If so, the discrete control period of the initial ground motion acceleration is determined, and the frequencies of the initial ground motion power spectrum and the target ground motion power spectrum are divided into several adjacent frequency bands with each discrete control period point as the center.

[0084] The adjustment module is used to adjust the initial ground motion acceleration based on the power spectrum within the main control frequency band and the target ground motion power spectrum of the corresponding frequency band for each control cycle of the initial ground motion acceleration.

[0085] The beneficial effects of the embodiments disclosed herein are:

[0086] The embodiments disclosed herein iteratively adjust the initial ground motion acceleration so that its power spectrum encloses the target power spectrum, and ensure that the final obtained ground motion effectively simulates natural ground motion, providing reliable seismic input for seismic analysis of nuclear power plants and ensuring the seismic safety of nuclear power plants. Attached Figure Description

[0087] Figure 1 This is a schematic flowchart of a seismic motion adjustment method for envelope target power spectrum according to an embodiment of the present disclosure;

[0088] Figure 2 This is a schematic diagram of the structure of a seismic motion adjustment device for an envelope target power spectrum according to an embodiment of the present disclosure. Detailed Implementation

[0089] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the embodiments of this disclosure will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the embodiments of this disclosure and are not intended to limit the embodiments of this disclosure.

[0090] This disclosure provides a method and apparatus for adjusting a given ground motion to enclose a target power spectrum and for effectively simulating the velocity and displacement characteristics of natural ground motions.

[0091] like Figure 1As shown, one embodiment of this disclosure proposes a method for adjusting seismic motion within the envelope target power spectrum, the method comprising:

[0092] Step 1: Obtain the given target ground motion power spectrum and any given initial ground motion acceleration, wherein both the target ground motion power spectrum and the initial ground motion acceleration are given in discrete form, that is, the discrete frequency sequence of the target ground motion power spectrum and the discrete time sequence of the initial ground motion acceleration.

[0093] In this embodiment, the target ground motion power spectrum can be an existing ground motion power spectrum in nuclear power specifications. The target ground motion power spectrum can be selected according to different needs and is not limited here. In nuclear power, the US RG1.60 can be used as the target ground motion power spectrum. The initial ground motion acceleration can be any given initial ground motion acceleration time history. It can be the acceleration selected from strong ground motion observation records or an artificial ground motion acceleration generated using stochastic process theory. The initial ground motion acceleration exists in the form of a discrete time series, and the target ground motion power spectrum and other ground motion power spectra exist in the form of discrete frequency series.

[0094] For example, after obtaining the given target ground motion power spectrum and any given initial ground motion acceleration, the method further includes:

[0095] The initial ground motion acceleration time series is calibrated so that the peak value of the initial ground motion acceleration is equal to the target peak ground acceleration value of the target ground motion power spectrum, and the initial ground motion acceleration time series is magnified or reduced accordingly; the specific calibration method is as follows:

[0096]

[0097] Among them, a 0,n This represents the initial ground motion acceleration time series, and also the initial ground motion acceleration at time n. Let represent the peak ground acceleration of the initial ground motion acceleration sequence, i represent a specific time point in the initial ground motion time series where the maximum acceleration occurs, and N represent the total number of points in the ground motion time series. This represents the target peak ground acceleration, which is the power spectrum of the target ground motion.

[0098] This embodiment calibrates the initial ground motion acceleration time series to ensure that, in extreme cases, the time required to adjust the ground motion acceleration does not significantly increase, and the impact on the spectral shape of the ground motion acceleration is minimal. In other words, if the provided initial ground motion acceleration differs significantly from the target peak ground acceleration of the target ground motion power spectrum, without corresponding scaling of the initial ground motion acceleration, it may increase the time required to adjust the ground motion, and it may also significantly affect the spectral shape of the initial ground motion acceleration.

[0099] Step 2: Calculate the minimum ratio of the power spectrum of the initial ground motion acceleration steady segment to the power spectrum of the target ground motion at the corresponding frequency.

[0100] As an example, the calculation of the minimum ratio of the power spectrum of the initial ground motion acceleration stationary segment to the power spectrum of the target ground motion at the corresponding frequency includes:

[0101] Step 21: Calculate the initial ground motion acceleration a 0,n Power spectrum S in the stationary phase p (p = 1, 2, ..., P / 2 + 1):

[0102] S p =POW[a 0,n ]

[0103] Step 22: Determine the power spectrum S of the initial ground motion acceleration stationary phase. p The target ground motion power spectrum S corresponding to the frequency D,p Minimum value of the ratio R T :

[0104]

[0105] Where POW represents the method for determining the power spectrum, R T The power spectrum S represents the initial acceleration phase of the ground motion. p With the target ground motion power spectrum S D,p The minimum value of the ratio between them, S p This represents the power spectrum of the initial ground motion during the acceleration and steady-state phase, that is, the power spectrum of the initial ground motion at frequency point p, S D,p This represents the power spectrum of the target ground motion at frequency point p, where min represents the minimum value, p represents a certain frequency point of the power spectrum, and P represents the total number of frequency points of the power spectrum.

[0106] As an example, the initial seismic acceleration a 0,n Power spectrum S in the stationary phase p The determination method for Proof-of-Work (POW) is as follows:

[0107] Step 211: Determine the initial ground motion acceleration a 0,n The stable part a s,n :

[0108] a s，n =STA[a 0，n ]

[0109] Step 212, for the stable part a s,n Perform a Fast Fourier Transform to obtain C p′ :

[0110] C p′ =FFT[a s,n ](n=1,2,…,N)(p′=1,2,…,P)

[0111] Where FFT stands for Fast Fourier Transform, n represents a natural number, N represents the total number of points in the ground motion time series, p' represents a natural number, p'∈P, and P represents the total number of frequency points in the power spectrum.

[0112] Step 213: Determine the initial ground motion acceleration a 0,n The power spectrum of the stationary portion S p :

[0113]

[0114] Where Δt represents the discrete time interval, s1 and s2 are time indices, and k represents the starting frequency point for summation.

[0115] Step 3: Determine whether the minimum value of the ratio of the power spectrum of the initial ground motion acceleration stationary segment to the power spectrum of the target ground motion at the corresponding frequency is less than a first threshold. If so, determine the discrete control period of the initial ground motion acceleration, and divide the frequencies of the initial ground motion power spectrum and the target ground motion power spectrum into several adjacent frequency bands, centered on each discrete control period point.

[0116] In this embodiment of the disclosure, if the minimum value of the ratio of the power spectrum of the initial stable ground acceleration segment to the power spectrum of the target ground motion at the corresponding frequency is less than a first threshold, i.e., R... T If the initial ground motion acceleration power spectrum is less than 1, it does not meet the requirements of the target power spectrum envelope, and the initial ground motion acceleration needs to be adjusted to meet the envelope requirements. If the minimum value of the ratio of the power spectrum of the initial ground motion acceleration's stationary segment to the target ground motion power spectrum at the corresponding frequency is greater than or equal to a first threshold, i.e., R... T ≥1, the power spectrum of the initial ground motion acceleration meets the requirements of the envelope target power spectrum.

[0117] As an example, the step of determining whether the minimum value of the ratio of the power spectrum of the initial ground motion acceleration plateau segment to the power spectrum of the target ground motion at the corresponding frequency is less than a first threshold further includes: if the power spectrum S of the initial ground motion acceleration plateau segment... p The target ground motion power spectrum S corresponding to the frequency D,p The minimum value of the ratio is greater than or equal to the first threshold, i.e., R T ≥1 indicates that the initial ground motion acceleration power spectrum envelopes the target power spectrum, then the initial ground motion acceleration a 0,nAs the final seismic acceleration sequence a 1,n (n = 1, 2, ..., N). But when R... T When = 1, the initial ground motion acceleration is the final acceleration, and no adjustment is needed. However, the probability of this extreme situation occurring is extremely low.

[0118] For example, the discrete control period for determining the initial ground motion acceleration is defined by dividing the frequencies of the initial ground motion power spectrum and the target ground motion power spectrum into several adjacent frequency bands, centered at each discrete control period point. This includes:

[0119] Step 31: Determine the discrete frequency intervals and discrete frequency sequence of the initial ground motion power spectrum.

[0120]

[0121] f p =(p-1)Δf(p=1,2,…,p / 2+1)

[0122] Where Δf represents the discrete frequency interval, f represents the frequency, P represents the total number of frequency points, and Δt represents the discrete time interval. p This represents a discrete frequency sequence, where p represents a specific frequency point.

[0123] Step 32: Determine the discrete control period T of the initial seismic acceleration. m The main control frequency band of (m=1,2,...,M) The specific formula is as follows:

[0124]

[0125]

[0126] Among them, T m T represents the discrete control period, that is, the m-th control period point. m-1 T represents the previous control cycle, i.e., the (m-1)th control cycle point. m+1 This indicates the next control cycle, i.e., the (m+1)th control cycle point, and Δf represents the discrete frequency interval. and They represent I respectively p Point and J p The frequency of the point, m represents the discrete periodic point, and M represents the total number of discrete periodic points.

[0127] Step 33: Divide the frequency of the target ground motion power spectrum into the main control frequency band of the initial ground motion power spectrum. same.

[0128] Step 4: Adjust the initial ground motion acceleration according to the power spectrum of the main control frequency band and the target ground motion power spectrum of the corresponding frequency band for each control cycle of the initial ground motion acceleration.

[0129] As an example, after adjusting the initial ground motion acceleration, the method further includes: recalculating the minimum ratio of the power spectrum of the adjusted initial ground motion acceleration stationary segment to the power spectrum of the target ground motion at the corresponding frequency, until the minimum ratio of the power spectrum of the adjusted initial ground motion acceleration stationary segment to the power spectrum of the target ground motion at the corresponding frequency is not less than a first threshold.

[0130] If the power spectrum S of the initial seismic acceleration plateau segment p The target ground motion power spectrum S corresponding to the frequency D,p Minimum value of the ratio between them R T If <1, then for each control cycle point T m The initial ground motion acceleration a was calculated using the following steps. 0,n Perform iterative adjustments:

[0131] As an example, adjusting the initial ground motion acceleration based on the power spectrum within the main control frequency band and the target ground motion power spectrum of the corresponding frequency band in each control cycle of the initial ground motion acceleration includes:

[0132] Step 41: Determine the initial seismic acceleration within the control period T. m Main control frequency band Internal power spectrum S p″ The target ground motion power spectrum S corresponding to the frequency band D,p″ Minimum value of the ratio R L :

[0133]

[0134] Among them, S p″ This represents the power spectrum of the initial ground motion at point p″, where p″ represents a certain frequency point, S D,p″ This represents the power spectrum of the target ground motion at point p″, and min represents the minimum value.

[0135] Step 42: If the initial ground motion acceleration is within the control period T m Power spectrum S within the main control frequency band p″ The target ground motion power spectrum S within this frequency band D,p″ The minimum value of the ratio is greater than or equal to the second threshold, i.e., R L If ≥1, then proceed to the next control cycle point T. m+1 The adjustment, namely, calculating the next control period T of the initial seismic acceleration. m+1Power spectrum S within the main control frequency band p″ The target ground motion power spectrum S within the corresponding frequency band D,p″ The minimum value of the ratio R L R L When the control period T is greater than 1, the control period is T. m The initial ground motion acceleration of the main control frequency band does not need to be adjusted, meaning the period point T m The power spectrum corresponding to the initial ground motion acceleration is greater than the power spectrum of the target ground motion in the corresponding frequency band. Periodic point T m The initial ground motion acceleration is taken as the periodic point T. m The final acceleration of the earthquake. R L =1 means that the control period T of the initial ground motion acceleration is 1. m The power spectrum within the main control frequency band is the same as the target power spectrum within the same frequency band, so no adjustment is needed. At this point, it is necessary to compare the power spectrum within the main control frequency band with the target power spectrum within the same frequency band for the next control cycle.

[0136] Step 43: If the initial ground motion acceleration is within the control period T m Power spectrum S within the main control frequency band p″ The target ground motion power spectrum S within this frequency band D,p″ The minimum value of the ratio is less than the second threshold, i.e., R L If <1, then construct an adjustment control period T. m The incremental acceleration of the initial ground motion acceleration is used to adjust the control period T. m The initial ground motion acceleration.

[0137] As an example, the construction adjustment control period T m The incremental acceleration of the initial ground motion acceleration is used to adjust the control period T. m The initial seismic acceleration includes the following steps:

[0138] Step 431: Extract the initial ground motion acceleration sequence a 0,n The stable part a s,n :

[0139] a s，n =STA[a 0，n (n = 1, 2, ..., N)

[0140] Among them, a s,n It represents the stationary portion of the initial seismic acceleration sequence, and also represents the seismic acceleration at time n;

[0141] Step 432: Determine the stationary portion a of the initial ground motion acceleration sequence. s,nFast Fourier Transform C P :

[0142] C p′ =FFT[a s,n ](n=1,2,...,N)(p′=1,2,...,P)

[0143] Among them, C p′ Indicates a s,n The result after Fast Fourier Transform (in the frequency domain);

[0144] Step 433: Adjust C according to the following formula p′

[0145]

[0146] Step 434: Determine the incremental acceleration sequence Δa of the initial ground motion acceleration. n :

[0147] Δa n =IFFT[C′ q ]-a s,n (n = 1, 2, ..., N)(I p ≤q≤J p )

[0148] Here, IFFT stands for Inverse Fast Fourier Transform; the Fast Fourier Transform (FFT) and the Inverse Fast Fourier Transform (IFFT) can be implemented using general algorithms, which will not be elaborated here.

[0149] Step 435: For the incremental acceleration sequence Δa n Perform baseline correction:

[0150] Δa″ n =BLC[Δa n (n = 1, 2, ..., N)

[0151] Where BLC stands for baseline correction;

[0152] Step 436: Based on the baseline-corrected incremental acceleration Δa″ n Adjust the initial ground motion acceleration sequence a 0,n , thus obtaining a′ 0,n :

[0153] a′ 0,n =a 0,n +Δa″ n

[0154] Where, a′ 0,n This represents the adjusted seismic acceleration sequence, for a′ 0,nPerform iterative adjustments until R is reached. T When ≥1, the iterated a′ 0,n For the final seismic acceleration sequence a 1,n .

[0155] In constructing the incremental acceleration for adjusting the initial acceleration, this embodiment utilizes the baseline correction method proposed in this work, which is oriented towards the narrow-band characteristics of incremental acceleration, to correct the incremental acceleration, ensuring that the corresponding incremental velocity and displacement do not exhibit baseline drift. Thus, after superimposing the incremental acceleration on the initial acceleration, it is possible not only to achieve the envelope of the target power spectrum, but also to ensure that the obtained ground motion velocity and displacement achieve a reasonable simulation of natural ground motion.

[0156] As an example, the extraction of the initial seismic acceleration sequence a in step 431 0,n The stable part a s,n ,include:

[0157] Step 431a: Calculate the initial ground motion acceleration sequence a 0,n Normalized cumulative Arias intensity:

[0158]

[0159] Among them, I A,n Arias intensity, representing the intensity of a seismic earthquake. 0,h Let h represent the initial ground motion acceleration at time h, A represent Arias, h represent a specific time point in the ground motion time series, n represent a natural number, and N represent the total number of points in the ground motion time series.

[0160] Step 431b: Determine the start number s1 and end number s2 of the stationary segment of the initial ground motion acceleration sequence, i.e., when n ≤ s1: I A,n ≤0.05

[0161] When n≥s2:I A,n ≥0.75

[0162] s1 and s2 are both time serial numbers;

[0163] Step 431c: Extract the stationary portion a s,n :

[0164]

[0165] Where Δt represents the discrete time interval.

[0166] As an example, the incremental acceleration sequence Δa described in step 435 n Methods for baseline correction include:

[0167] Step 435a: Determine the incremental velocity sequence and incremental displacement sequence of the incremental acceleration sequence:

[0168] Δv n =INT[Δa n ]

[0169] Δd n =INT[Δv n ]

[0170] Where, Δv n This represents the incremental velocity sequence, specifically the incremental velocity at time n, Δd. n This represents the incremental displacement sequence, i.e., the incremental displacement at time n; INT indicates integration. Δa n This represents an incremental acceleration sequence.

[0171] Step 435b: For the incremental displacement sequence Δd n Tail N R Perform linear fitting on the data:

[0172]

[0173] Among them, X n Y represents the x-coordinate at time n. n Let X represent the vertical axis at time n, Y represent the horizontal axis, n represent a specific time point in the initial ground motion time series, N represent the total number of points in the initial ground motion time series, Δt represent the discrete time interval, and Δd represent the vertical axis. N N represents the incremental displacement at time N. R This represents the Rth N-th data point, for example: Δd n Tail N R (10) data points, N R N represents 10 .

[0174] Step 435c: Determine the regression coefficients:

[0175]

[0176] Where A represents the regression coefficient, consisting of 2 × 3 numbers A ij The resulting 2x3 matrix, A 11 ~A 23 This represents the elements of the regression coefficient matrix A.

[0177] Step 435d: Determine the fitting parameters:

[0178]

[0179]

[0180] Where β1 and β2 represent the linear fitting parameters, respectively.

[0181] Step 435e: Determine the start time t0 and end time t1 of the correction increment acceleration pulse sequence;

[0182]

[0183] t0 = max(t1 - Δt) BLC ,0)

[0184] Where, Δt BLC Indicates the time interval for baseline correction.

[0185] Step 435f: Determine the incremental acceleration sequence for correction:

[0186]

[0187] Δv′ n =INT[Δa′ n ]

[0188] Δd′ n =INT[Δv′ n ]

[0189] Where, Δa′ n This represents the incremental acceleration sequence used for correction, Δv n ' represents the incremental velocity sequence used for correction, Δd n ' indicates that it is used to correct the incremental displacement sequence, and INT indicates integration operation;

[0190] Step 435g: Determine the incremental acceleration sequence Δa obtained from the first correction. 1,n :

[0191]

[0192] Δv 1,n =INT[Δa 1,n ]

[0193] Δd 1,n =INT[Δv 1,n ]

[0194] Where, Δv′ N Δv represents the correction increment velocity at time N. 1,n This represents the incremental velocity sequence obtained from the first correction, Δd. 1,n This represents the incremental displacement sequence obtained from the first correction, Δa. n This represents the incremental acceleration sequence. The first correction eliminates the average value of the complex baseline changes that occurred during strong earthquakes, i.e., the baseline drift of the incremental velocity sequence.

[0195] Step 435h: Determine the final incremental acceleration sequence Δa obtained from the second correction. 2,n :

[0196]

[0197] Where, Δa 1,n This represents the incremental acceleration sequence obtained from the first correction, Δd. 1,N Δd represents the incremental displacement sequence obtained from the first correction at time N. N ' represents the corrected incremental displacement at time N; generally, only the above two steps are needed for correction. The second correction eliminates the baseline drift of the incremental displacement sequence, caused by the slope of the linear fit of the velocity-time history after a strong shock. Δa 2,n The final incremental acceleration obtained from the second correction is Δa. 2,n Equivalent to Δa″ n , Δa 2,n With the initial ground motion acceleration sequence a 0,n By superimposing the data, the adjusted seismic acceleration a′ is obtained. 0,n For a′ 0,n Perform iterative adjustments until R is reached. T When a' is ≥1 0,n For the final seismic acceleration sequence a 1,n .

[0198] This disclosure achieves baseline correction of incremental acceleration by integrating the incremental velocity and displacement. Currently, a common technique involves adjusting the ground motion acceleration to meet the envelope of the target power spectrum. However, the adjusted acceleration, velocity, and displacement sequences may exhibit varying degrees of baseline drift. Researchers then need to correct the velocity and displacement, which reduces the degree of envelope of the target power spectrum, sometimes even failing to meet the envelope requirements specified in the standards, necessitating further acceleration adjustments and wasting time. This disclosure, by correcting the incremental time series within a sufficiently small effective range, can achieve this while meeting the envelope of the target power spectrum, preventing baseline drift, complying with the requirements for velocity and displacement, and saving time.

[0199] This disclosure embodiment uses acceleration time series a n The integral DIRInte method, which determines the velocity and displacement sequence, is calculated using the following steps:

[0200] v1 = 0

[0201]

[0202] Where v1 represents the velocity value in the first second, v n v represents the velocity value in the nth second. n-1 This represents the velocity value at the (n-1)th second, where n represents a specific time point in the seismic motion time series, and N represents the total number of points in the seismic motion time series. n Let a represent the acceleration in the nth second. n-1 This represents the acceleration at the (n-1)th second.

[0203] In this embodiment, the initial ground motion acceleration is iteratively adjusted so that its power spectrum encloses the target power spectrum, and the resulting ground motion effectively simulates the natural ground motion velocity and displacement, providing reliable seismic input for the seismic analysis of nuclear power plants and ensuring the seismic safety of nuclear power plants.

[0204] like Figure 2 As shown, another aspect of this disclosure provides a seismic motion adjustment device for an envelope target power spectrum, the device comprising:

[0205] The acquisition module 100 is used to acquire a given target ground motion power spectrum and an arbitrary given initial ground motion acceleration, wherein the target ground motion power spectrum and the initial ground motion acceleration exist in the form of discrete frequency sequences and discrete time sequences, respectively.

[0206] The calculation module 200 is used to calculate the minimum ratio of the power spectrum of the initial ground motion acceleration steady segment to the power spectrum of the target ground motion at the corresponding frequency.

[0207] The judgment module 300 is used to determine whether the minimum value of the ratio of the power spectrum of the initial ground motion acceleration steady segment to the target ground motion power spectrum at the corresponding frequency is less than a first threshold. If so, the discrete control period of the initial ground motion acceleration is determined, and the frequencies of the initial ground motion power spectrum and the target ground motion power spectrum are divided into several adjacent frequency bands with each discrete control period point as the center.

[0208] The adjustment module 400 is used to adjust the initial ground motion acceleration based on the power spectrum within the main control frequency band and the target ground motion power spectrum of the corresponding frequency band for each control cycle of the initial ground motion acceleration.

[0209] After obtaining the adjusted initial ground motion acceleration, the minimum ratio of the power spectrum of the adjusted initial ground motion acceleration stationary segment to the power spectrum of the target ground motion at the corresponding frequency is recalculated until the minimum ratio of the power spectrum of the adjusted initial ground motion acceleration stationary segment to the power spectrum of the target ground motion is greater than or equal to the first threshold.

[0210] Specifically, the adjusted initial ground motion acceleration is used as the initial ground motion acceleration to re-trigger the calculation module, judgment module, and adjustment module until the minimum value of the ratio of the power spectrum of the stable segment of the adjusted initial ground motion acceleration to the target ground motion power spectrum is greater than or equal to the first threshold.

[0211] Another aspect of this disclosure provides a computer device, including:

[0212] At least one processor; and,

[0213] A memory communicatively connected to the at least one processor; wherein,

[0214] The memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform the method as described above.

[0215] Input the following data into the computer device: initial ground motion acceleration time series a 0,n (n=1,2,…N), discrete time interval: Δt, target ground motion power spectrum: S D,p (p = 1, 2, ..., P / 2 + 1), target peak acceleration: Discrete control period: T m (m = 1, 2, ..., M), adjust a 0,n until a 1,n The power spectrum can enclose S D，p Get and output a 1,n .

[0216] By adopting the above-described technical solutions disclosed in the embodiments of this disclosure, the following beneficial effects are obtained:

[0217] Seismic design of nuclear power plants requires dynamic time-history analysis to determine the entire process of structural dynamic response under potential seismic ground motions, thereby achieving seismic fortification goals and ensuring the earthquake safety of the nuclear power plant. This necessitates using the seismic ground acceleration time history, which meets specific seismic environmental and site conditions, as input for structural dynamic response analysis. To ensure the conservatism of seismic analysis results for critical safety equipment in nuclear power plants, the seismic ground motion input used for seismic analysis of the nuclear island building must meet the envelope requirements of the target seismic ground motion power spectrum. Simultaneously, with the accumulation of theoretical and engineering practice in nuclear engineering seismic response analysis, the velocity and displacement characteristics of seismic inputs for nuclear engineering have received increasing attention to ensure the scientific validity and rationality of seismic response analysis results.

[0218] The seismic motion adjustment method proposed in this disclosure can effectively achieve the envelope of the target seismic motion power spectrum, while ensuring that the velocity and displacement of the obtained seismic motion achieve a reasonable simulation of the real seismic motion. Using the seismic motion synthesized by the method of this invention as input, numerical simulation or experimental methods can be used to scientifically evaluate the seismic performance and seismic reliability level of nuclear island structures or nuclear safety equipment. This enables nuclear power plants to more effectively resist possible seismic forces, resulting in economic and social benefits for ensuring the seismic safety of nuclear power plants.

[0219] The above description is only a preferred embodiment of the present disclosure. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present disclosure, and these improvements and modifications should also be considered within the protection scope of the present disclosure.

Claims

1. A method for adjusting seismic motion within the envelope target power spectrum, characterized in that, The method includes: Obtain a given target ground motion power spectrum and an arbitrary given initial ground motion acceleration, wherein the target ground motion power spectrum and the initial ground motion acceleration exist in the form of a discrete frequency sequence and a discrete time sequence, respectively; Calculate the minimum ratio of the power spectrum of the initial ground motion acceleration stationary segment to the power spectrum of the target ground motion at the corresponding frequency; Determine whether the minimum value of the ratio of the power spectrum of the initial ground motion acceleration stationary segment to the power spectrum of the target ground motion at the corresponding frequency is less than a first threshold; if so, determine the discrete control period of the initial ground motion acceleration, and divide the frequencies of the initial ground motion power spectrum and the target ground motion power spectrum into several adjacent frequency bands with each discrete control period point as the center. The initial ground motion acceleration is adjusted based on the power spectrum within the main control frequency band of each control cycle of the initial ground motion acceleration and the power spectrum of the target ground motion in the corresponding frequency band.

2. The method according to claim 1, characterized in that, After adjusting the initial ground motion acceleration, the method further includes: recalculating the minimum ratio of the power spectrum of the adjusted initial ground motion acceleration steady segment to the power spectrum of the target ground motion at the corresponding frequency, until the minimum ratio of the power spectrum of the adjusted initial ground motion acceleration steady segment to the power spectrum of the target ground motion at the corresponding frequency is not less than a first threshold.

3. The method according to claim 1, characterized in that, The step of determining whether the minimum value of the ratio of the power spectrum of the initial ground motion acceleration steady segment to the power spectrum of the target ground motion at the corresponding frequency is less than a first threshold further includes: if not, then the initial ground motion acceleration is taken as the final ground motion acceleration.

4. The method according to any one of claims 1 to 3, characterized in that, After obtaining the given target ground motion power spectrum and any given initial ground motion acceleration, the method further includes: The initial ground motion acceleration time series is calibrated so that the peak value of the initial ground motion acceleration is equal to the target peak value of the target ground motion power spectrum, and the initial ground motion time series is scaled accordingly; the specific calibration method is as follows: ， Among them, a 0,n This represents the initial ground motion acceleration time series, and also the initial ground motion acceleration at time n. This represents the peak ground acceleration (PGA) of the initial ground motion acceleration sequence, where i represents the time point in the initial ground motion time series where the maximum acceleration occurs, and N represents the total number of points in the ground motion time series. This represents the target peak ground acceleration, which is the power spectrum of the target ground motion.

5. The method according to claim 4, characterized in that, The step of determining the discrete control period for the initial ground motion acceleration involves dividing the frequencies of the initial ground motion power spectrum and the target ground motion power spectrum into several adjacent frequency bands, centered on each discrete control period point. Determine the discrete frequency intervals and discrete frequency sequence of the initial ground motion power spectrum. ， ， ， in, Indicates discrete frequency intervals. This represents the frequency, and P represents the total number of frequency points. Represents discrete time intervals. This represents a discrete frequency sequence, where p represents a specific frequency point. Determine the discrete control period of the initial ground motion acceleration , Main control frequency band The specific formula is as follows: ， ， Among them, T m T represents the discrete control period, that is, the m-th control period point. m-1 T represents the previous control cycle, i.e., the (m-1)th control cycle point. m+1 This indicates the next control cycle, specifically the (m+1)th control cycle point. Indicates discrete frequency intervals. and They represent I respectively p Point and J p The frequency of the point, m represents a discrete periodic point, and M represents the total number of discrete periodic points; The frequency of the target ground motion power spectrum is divided into the main control frequency band of the initial ground motion power spectrum. same.

6. The method according to claim 5, characterized in that, The step of adjusting the initial ground motion acceleration based on the power spectrum within the main control frequency band and the target ground motion power spectrum of the corresponding frequency band in each control cycle of the initial ground motion acceleration includes: Calculate the initial ground motion acceleration during the control period T m The minimum ratio of the power spectrum within the main control frequency band to the target ground motion power spectrum within the corresponding frequency band; If the initial seismic acceleration is within the control period T m If the minimum value of the ratio of the power spectrum within the main control frequency band to the target ground motion power spectrum within that frequency band is greater than or equal to the second threshold, then the next control period T for calculating the initial ground motion acceleration is determined. m+1 The minimum ratio of the power spectrum within the main control frequency band to the target ground motion power spectrum within the corresponding frequency band; If the control period T of the initial seismic acceleration m If the minimum ratio of the power spectrum within the main control frequency band to the target ground motion power spectrum within that frequency band is less than the second threshold, then the adjustment control period T is constructed. m The incremental acceleration of the initial ground motion acceleration is used to adjust the control period T. m The initial ground motion acceleration.

7. The method according to claim 6, characterized in that, The construction adjustment control period T m The incremental acceleration of the initial ground motion acceleration is used to adjust the control period T. m The initial seismic acceleration includes: Extract the initial ground motion acceleration a 0,n The acceleration a in the steady segment s,n ; The acceleration a during the steady segment s,n Perform a fast Fourier transform to obtain : ， in, Indicates a s,n The result after Fast Fourier Transform: Adjust according to the following formula : ， in, The control period T represents the initial ground motion acceleration. m The minimum ratio of the power spectrum within the main control frequency band to the power spectrum of the target ground motion within that frequency band; Determine the incremental acceleration sequence Δa of the initial ground motion acceleration. n : ， Wherein, IFFT represents the inverse fast Fourier transform; For the incremental acceleration sequence Δa n Perform baseline correction: ， Based on baseline-corrected incremental acceleration Adjust the initial ground motion acceleration sequence a 0,n ,get : ， in, This is the adjusted initial ground motion acceleration sequence.

8. The method according to claim 7, characterized in that, The incremental acceleration sequence Δa n Baseline correction includes: Determine the incremental velocity sequence and incremental displacement sequence of the incremental acceleration sequence: ， ， in, It represents the incremental velocity sequence, and also the incremental velocity at time n; This represents the incremental displacement sequence, and also the incremental displacement at time n. INT represents the integration operation. It represents the incremental acceleration sequence, and also the incremental acceleration at time n; For incremental displacement sequence Tail N R Perform linear fitting on the data: ， ， Among them, X n Y represents the x-coordinate at time n. n Let X represent the vertical axis at time n, X represent the horizontal axis, Y represent the vertical axis, n represent a specific time point in the initial ground motion time series, and N represent the total number of points in the initial ground motion time series. N represents the discrete time interval. R This represents the Rth data point in N. This represents the incremental displacement at time N; Determine the regression coefficients: ， Where A represents the regression coefficient, consisting of 2 × 3 numbers A ij The resulting 2x3 matrix, A 11~ A 23 These represent the elements of the regression coefficient matrix A; Determine the fitting parameters: ， Where β1 and β2 represent the linear fitting parameters, respectively; Determine the start time t0 and end time t1 of the correction increment acceleration pulse sequence; ， ， Where, Δt BLC Indicates the time interval for baseline correction; Determine the incremental acceleration sequence to be used for correction: ， ， ， in, This represents the incremental acceleration sequence used for correction. This represents the incremental velocity sequence used for correction. This represents the incremental displacement sequence used for correction, and INT indicates integration. Determine the incremental acceleration sequence obtained from the first correction. : ， ， ， in, Represents the correction increment rate at time N; This represents the incremental velocity sequence obtained from the first correction. This represents the incremental displacement sequence obtained from the first correction. Represents an incremental acceleration sequence; Determine the final incremental acceleration sequence obtained from the second correction. : ， in, This represents the incremental acceleration sequence obtained from the first correction. This represents the incremental displacement at time N obtained from the first correction. This represents the corrected incremental displacement at time N; Equivalent to .

9. A seismic motion adjustment device for envelope target power spectrum, characterized in that, The device includes: The acquisition module is used to acquire a given target ground motion power spectrum and an arbitrary given initial ground motion acceleration, wherein the target ground motion power spectrum and the initial ground motion acceleration exist in the form of discrete frequency sequences and discrete time sequences, respectively; The calculation module is used to calculate the minimum ratio of the power spectrum of the initial ground motion acceleration stationary segment to the power spectrum of the target ground motion at the corresponding frequency; The judgment module is used to determine whether the minimum value of the ratio of the power spectrum of the initial ground motion acceleration steady segment to the power spectrum of the target ground motion at the corresponding frequency is less than a first threshold; if so, the discrete control period of the initial ground motion acceleration is determined, and the frequencies of the initial ground motion power spectrum and the target ground motion power spectrum are divided into several adjacent frequency bands with each discrete control period point as the center. The adjustment module is used to adjust the initial ground motion acceleration based on the power spectrum within the main control frequency band and the target ground motion power spectrum of the corresponding frequency band for each control cycle of the initial ground motion acceleration.

10. An electronic device, characterized in that, include: At least one processor; as well as, A memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform the method of any one of claims 1 to 8.

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