A method for identifying wide-band dynamic oscillation pyrotechnic impact loads

Abstract

The invention relates to a method for identifying a wide-band dynamic oscillation pyrotechnic impact load, which belongs to the field of inverse problems of engineering structure dynamics. The invention relates to a method for identifying a pyrotechnic impact load, which belongs to the field of inverse problems of engineering structure dynamics. The invention constructs a pyrotechnic impact load test device, measures acceleration response data of the pyrotechnic impact load test device, establishes a time domain history equation of the pyrotechnic impact load test device, constructs a dynamic inverse problem equation under an augmented fine integration algorithm, establishes a constraint equation, calculates the consistency coefficient of the identification load under the condition of only considering the amplitude continuity constraint and the identification load under the condition of simultaneously considering the amplitude continuity and the first-order derivative continuity constraint, and outputs the pyrotechnic impact load identification result according to a judgment rule. The invention realizes the identification and solution of a 100-100kHz wide-band dynamic oscillation load, and proposes a method for verifying the accuracy of load identification in the absence of an accurate load measurement value.

Description

Technical Field

[0001] The invention belongs to the field of inverse problems of engineering structure dynamics, and relates to a method for identifying wide-band dynamic oscillation pyrotechnic impact loads. Background Art

[0002] Pyrotechnic unlocking devices are widely used in various spacecraft. The 100-100kHz wide-band dynamic shock load generated by the device has a very prominent destructive effect on the products and structures on the spacecraft. However, it is difficult to obtain an accurate time-domain history curve of the pyrotechnic impact load through experimental measurement methods, and it is difficult to carry out accurate simulation analysis of the pyrotechnic impact. In the field of engineering design, the main extrapolation methods based on experimental and empirical data are used, including empirical model method, data extrapolation method, subpath structure extrapolation method, etc. This type of method can give a rough estimate of the impact environment, but it requires a higher margin and allowance, resulting in the impact environment conditions being too harsh, which is not conducive to the lightweight and refined design of spacecraft products. In this case, solving the inverse problem of dynamics and inverting the pyrotechnic impact load through the measured acceleration data has become a feasible solution and an urgent need for lightweight and refined design in engineering.

[0003] Currently, there is no specific identification method for 100-100kHz wide-band dynamic oscillation pyrotechnic impact loads. The load identification methods in the literature are mainly based on the Duhamel Integral, central difference, Newmark or Wilson-θ methods to establish the direct problem equation, and then establish the inverse dynamic problem for solution. Among them, in order to ensure the accuracy of modeling, it is assumed that the sampling frequency is high enough to ensure that the sampling resolution can fully describe the time characteristics of the load. The sampling resolution is usually required to be 20 times the highest frequency component of the load, and at least 6 to 8 times. For general loads, this assumption can be met, but for pyrotechnic impact loads whose action duration is often less than 20ms and the main frequency bandwidth reaches the range of 100Hz to 100kHz, this means that the sampling frequency needs to be at least 600 to 800kHz, and 2000kHz or more is better. However, the highest frequency of sampling equipment that can be publicly purchased on the market is only about 240kHz, which is far from meeting the application requirements of the above method. Otherwise, due to the mismatch between the solution time step and the upper limit of the load frequency, inaccurate calculation results will be obtained, and even the calculation will diverge and cannot be solved.

[0004] In addition, how to determine the accuracy of the identified pyrotechnic impact load, the load identification methods in the literature mainly evaluate the accuracy of the identification results by comparing the consistency of the load measurement results with the identification results, or by comparing the consistency of the acceleration response reconstructed from the identification results with the measurement results. However, on the one hand, since it is extremely difficult to obtain the time domain history curve of the pyrotechnic impact load through experimental measurement methods, it is not feasible to evaluate the identification accuracy by comparing the consistency of the load measurement results with the identification results; on the other hand, due to the non-uniqueness of the solution to the inverse problem of dynamics, even if the acceleration response reconstructed from the identification results is consistent with the measurement results, it cannot prove the consistency of the load identification results with the actual time domain history of the load.

[0005] In summary, there is currently no method similar to the method proposed in this patent, which reconstructs the 100-100kHz wide-band dynamic oscillation pyrotechnic impact load based on the acceleration data obtained at a maximum sampling rate of 240kHz by solving the inverse dynamic problem, and evaluates the accuracy of load identification in the absence of accurate experimental measurement data. Summary of the invention

[0006] The technical problem solved by the present invention is: to overcome the shortcomings of the prior art, to propose a method for identifying a wide-band dynamic oscillation pyrotechnic impact load, to realize the identification and solution of a 100-100kHz wide-band dynamic oscillation load, and to propose a method for verifying the accuracy of load identification in the absence of accurate load measurement values.

[0007] The solution of the present invention is:

[0008] A method for identifying a wide-band dynamic oscillating pyrotechnic impact load comprises the following steps:

[0009] Step 1: construct an impact load test device for explosives;

[0010] Step 2: measuring the acceleration response data of the pyrotechnic impact load test device;

[0011] Step 3: Set the time of measuring the acceleration response data for the kth time to t k The time when the k+1th acceleration response data is measured is t k+1 ; Establish the time domain history equation of the impact load test device of explosives; Construct the dynamic inverse problem equation under the augmented precise integration algorithm; Establish the constraint equation; Calculate the identification load considering only the amplitude continuity constraint condition and identification loads considering both amplitude continuity and first-order derivative continuity constraints

[0012] Step 4: Calculation and The consistency coefficient

[0013] Step 5: Set the threshold A. Compared with A; when When it is greater than A, judge and The consistency is good, that is, the recognition result is accurate. As the result of the impact load identification of the pyrotechnic device; When it is less than or equal to A, judge and The consistency is not good, that is, the recognition result is inaccurate. Return to step 2, replace it with a data acquisition device with higher frequency and higher accuracy, increase the measurement points, and restart the recognition.

[0014] In the above-mentioned wide-band dynamic oscillation pyrotechnic impact load identification method, in the step 2, at least 4 channels of acceleration response data are measured; when measuring the acceleration response data, the sampling frequency is not less than 200kHz, and the measurement signal-to-noise ratio is better than -20dB.

[0015] In the above-mentioned wide-band dynamic oscillation pyrotechnic impact load identification method, in step 3, the time domain history equation of the pyrotechnic impact load test device is:

[0016]

[0017] Where, t k is the time when the acceleration response data is measured for the kth time, k=1, 2, ..., n;

[0018] is the constant term coefficient;

[0019] is the coefficient of the first-order term;

[0020] is the coefficient of the quadratic term;

[0021] is the cubic coefficient;

[0022] t is the independent variable of the time domain history equation;

[0023] The inverse problem equation of dynamics is:

[0024]

[0025] Where D z and D zf are the recursive coefficient matrices in the augmented precise integration algorithm; and D z With D zf The relationship is:

[0026]

[0027] B k is a Bohr matrix containing only 0 and 1 elements related to the acceleration measurement degrees of freedom in the finite element model;

[0028] The subscript T is the transpose of the matrix;

[0029] R is the coefficient in the augmented precise integration algorithm, specifically:

[0030]

[0031] c k is the coefficient matrix, specifically:

[0032]

[0033] Among them, K, C and M are the system stiffness matrix, damping matrix and mass matrix respectively; x, and are the displacement, velocity and acceleration vectors of each degree of freedom of the system respectively; M -1 To find the inverse of M.

[0034] In the above-mentioned wide-band dynamic oscillation pyrotechnic impact load identification method, in step 3, the constraint equation is:

[0035]

[0036] In the formula, S 1 is the first sub-coefficient matrix;

[0037] S 2 is the second sub-coefficient matrix;

[0038] When only the load amplitude is considered to be continuous, S 1 and S 2 They are:

[0039]

[0040] S 2 =[-1 0 0 0] (8)

[0041] When considering both load amplitude continuity and first-order derivative continuity, S 1 and S 2 They are:

[0042]

[0043]

[0044] In the above-mentioned wide-band dynamic oscillation pyrotechnic impact load identification method, in the step 3, formula (2) and formula (6) are combined to obtain a set of equations; when S in the constraint equation 1 The value is formula (7), S 2 The value is formula (8), or S 1 The value is formula (9), S 2 When the value is taken as formula (10), two different sets of equations are obtained. After solving the equations to obtain the load coefficient column vector, they are substituted into formula (1) respectively. k to k+1 Perform piecewise interpolation calculation within the sampling interval of k = 1, 2, 3, ..., n-1; obtain the identification load corresponding to different constraint conditions and in To consider only the identified loads under the amplitude continuity constraint, To identify loads under the constraints of both amplitude continuity and first-order derivative continuity.

[0045] In the above-mentioned wide-band dynamic oscillation pyrotechnic impact load identification method, at least 8-point interpolation is used when performing slice interpolation calculation, otherwise there is a probability that the time resolution cannot capture the dynamic oscillation characteristics of the time domain history.

[0046] In the above-mentioned wide-band dynamic oscillation pyrotechnic impact load identification method, in step 4, the consistency coefficient The calculation method is:

[0047]

[0048] In the formula, |||| 2 Take the 2-norm of a vector.

[0049] In the above-mentioned wide-band dynamic oscillation pyrotechnic impact load identification method, in step five, the threshold value A is 0.9.

[0050] In the above-mentioned wide-band dynamic oscillation pyrotechnic impact load identification method, in step 5, when When it is less than or equal to A, the calculation error is large due to the low sampling frequency and small number of measurement points, resulting in inaccurate recognition results.

[0051] The beneficial effects of the present invention compared with the prior art are:

[0052] (1) The present invention establishes a solution equation for the inverse dynamics problem based on the augmented precise integration method, which reduces the requirement of sampling resolution in the traditional solution equation for the inverse dynamics problem, which is usually 20 times of the highest frequency component of the load, or at least 6 to 8 times, to 2 to 3 times. Under the current engineering limitation that only 240kHz sampling rate acceleration measurement data can be obtained, the identification and solution of 100 to 100kHz wide-band dynamic oscillation loads can be realized, and the stability and accuracy of the solution are guaranteed on a theoretical basis.

[0053] (2) Based on the solution equation of the inverse problem of dynamics, the present invention proposes two constraints: load amplitude continuity and first-order derivative. Based on the consistency requirement of the identification results under different constraints, a load identification accuracy verification method is proposed, which better overcomes the difficulty of how to confirm the load identification accuracy when there is a lack of accurate measurement values. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 This is the attitude coupling control flow chart of the present invention.

[0055] Figure 2 It is a schematic diagram of a numerical example model of an embodiment;

[0056] Figure 3 It is the global time history curve of 0~0.02s of pyrotechnic impact load without numerical noise in the embodiment;

[0057] Figure 4 It is the local time history curve of 0.002~0.0022s of the pyrotechnic impact load in the case of no numerical noise in the embodiment;

[0058] Figure 5 This is the 0-0.02s global time history curve of the pyrotechnic impact load under the condition of -30dB numerical noise in the embodiment;

[0059] Figure 6 This is the local time history curve of 0.002 to 0.0022s of the pyrotechnic impact load under the condition of -30dB numerical noise in the embodiment;

[0060] Figure 7 This is the global time history curve of the displacement of node 9 from 0 to 0.02s reconstructed according to the recognition result under the condition of -30dB numerical noise in the embodiment;

[0061] Figure 8 This is the local time history curve of the displacement of node 9 of 0.002 to 0.008 s reconstructed according to the recognition result under the condition of -30 dB numerical noise in the embodiment;

[0062] Fig. 9This is the global time history curve of the speed of node 9 from 0 to 0.02s reconstructed according to the recognition result under the condition of -30dB numerical noise in the embodiment;

[0063] Fig.10 This is the local time history curve of the speed of node 9 at 0.002 to 0.008 s reconstructed according to the recognition result under the condition of -30 dB numerical noise in the embodiment;

[0064] Fig.11 This is the global time history curve of acceleration 0-0.02s of node 9 reconstructed according to the recognition result under the condition of -30dB numerical noise in the embodiment;

[0065] Fig.12 This is the local time history curve of the acceleration of node 9 of 0.002 to 0.0024 s reconstructed according to the recognition result under the condition of -30 dB numerical noise in the embodiment. DETAILED DESCRIPTION

[0066] The present invention will be further described below in conjunction with the embodiments.

[0067] The present invention provides a method for identifying a wide-band dynamic oscillation pyrotechnic impact load. By using acceleration measurement data with a sampling rate of only 240kHz that can be obtained in current engineering practice, the identification and solution of a wide-band dynamic oscillation load of 100 to 100kHz is realized, and in the absence of accurate load measurement values, a method for verifying the accuracy of load identification is proposed.

[0068] Wide-band dynamic oscillation pyrotechnic impact load identification method, such as Figure 1 As shown, the specific steps include:

[0069] Step 1: Construct an pyrotechnic impact load test device; the frequency bandwidth of the pyrotechnic impact load is usually 100 to 100 kHz.

[0070] Step 2: Measure the acceleration response data of the pyrotechnic impact load test device; at least four acceleration response data must be measured and collected to ensure that the pyrotechnic impact load test device is within t k to k+1 The time domain history of the pyrotechnic impact load F(t) within the Δt sampling interval can be expanded using the third-order Taylor series as shown in formula (1). At this time, there are 4 unknown parameters in each Δt time interval, and the number of measurement channels is greater than or equal to the number of unknown parameters. When the number of acquisition channels is less than 4, formula (1) needs to be changed to a lower-order Taylor series expansion form to ensure that the number of measurement channels is greater than or equal to the number of unknown parameters. In this case, the solution accuracy will be reduced.

[0071] The sampling frequency is required to be at least 200kHz. Otherwise, the sampling frequency load may not meet the requirement that it is 2 to 3 times higher than the highest frequency component of the load, and the characteristics of the wide-band oscillation of the load within 100 to 100kHz may not be fully captured, resulting in the subsequent consistency coefficient calculation results not meeting the threshold requirements, and it is impossible to determine whether the recognition result is accurate.

[0072] The measurement signal-to-noise ratio is required to be at least better than -20dB. Otherwise, due to the influence of measurement noise, it may be impossible to determine whether the recognition result is accurate.

[0073] Step 3: Set the time of measuring the acceleration response data for the kth time to t k The time when the k+1th acceleration response data is measured is t k+1 ; Establish the time domain history equation of the impact load test device of pyrotechnics; Construct the dynamic inverse problem equation under the augmented precise integration algorithm;

[0074] The time domain history equation of the pyrotechnic impact load test device is:

[0075]

[0076] Where, t k is the time when the acceleration response data is measured for the kth time, k=1, 2, ..., n;

[0077] is the constant term coefficient;

[0078] is the coefficient of the first-order term;

[0079] is the coefficient of the quadratic term;

[0080] is the cubic coefficient;

[0081] t is the independent variable of the time domain history equation;

[0082] The inverse problem equation of dynamics is:

[0083]

[0084] Where D z and D zf are the recursive coefficient matrices in the augmented precise integration algorithm; after clarifying the load function form shown in formula (1), its construction method is common knowledge and will not be repeated here; is the Bohr matrix containing only 0 and 1 elements related to the acceleration measurement degree of freedom in the finite element model, and its construction method is common knowledge and will not be repeated here;

[0085] And D z With Dzf The relationship is:

[0086]

[0087] B k is a Bohr matrix containing only 0 and 1 elements related to the acceleration measurement degrees of freedom in the finite element model;

[0088] The subscript T is the transpose of the matrix;

[0089] R is the coefficient in the augmented precise integration algorithm, specifically:

[0090]

[0091] c k is the coefficient matrix, specifically:

[0092]

[0093] Among them, K, C and M are the system stiffness matrix, damping matrix and mass matrix respectively; x, and are the displacement, velocity and acceleration vectors of each degree of freedom of the system respectively; M -1 To find the inverse of M.

[0094] Establish the constraint equation; the constraint equation is:

[0095]

[0096] In the formula, S 1 is the first sub-coefficient matrix;

[0097] S 2 is the second sub-coefficient matrix;

[0098] When only the load amplitude is considered to be continuous, S 1 and S 2 They are:

[0099]

[0100] S 2 =[-1 0 0 0] (8)

[0101] When considering both load amplitude continuity and first-order derivative continuity, S 1 and S 2 They are:

[0102]

[0103]

[0104] Calculation of identified loads taking into account only the amplitude continuity constraint and identification loads considering both amplitude continuity and first-order derivative continuity constraints Combining formula (2) and formula (6), we obtain a set of equations. When S in the constraint equation 1 The value is formula (7), S 2 The value is formula (8), or S 1 The value is formula (9), S 2 When the value is taken as formula (10), two different sets of equations are obtained. After solving the equations to obtain the load coefficient column vector, they are substituted into formula (1) respectively. k to k+1 Perform piecewise interpolation calculation within the sampling interval of k = 1, 2, 3, ..., n-1; obtain the identification load corresponding to different constraint conditions and in To consider only the identified loads under the amplitude continuity constraint, In order to simultaneously consider the identification load under the constraints of amplitude continuity and first-order derivative continuity, at least 8-point interpolation is used when performing piecewise interpolation calculations, otherwise there is a probability that the time resolution cannot capture the dynamic oscillation characteristics of the time domain history.

[0105] There are two points to note during the calculation process. First, the equations obtained by combining formula (2) and formula (6) are usually ill-conditioned and need to be solved by a special solution algorithm. The GCV method is recommended. Other regularization methods can also be used. The relevant content belongs to common knowledge and will not be repeated here. Second, when using formula (1) to calculate the time history of the load and identify the load, it is recommended to use at least 8 points of interpolation in each time interval to, otherwise the time resolution may not be able to accurately capture the dynamic oscillation characteristics of the time domain history.

[0106] Step 4: Calculation and The consistency coefficient Coefficient of consistency The calculation method is:

[0107]

[0108] In the formula, |||| 2 Take the 2-norm of a vector.

[0109] When the two are completely consistent, the consistency coefficient is 1, and when the two are completely unrelated, the consistency coefficient is 0. If the load identification result is accurate, it should be close to the result. Otherwise, it can be considered that the result obtained by identification only satisfies the acceleration measurement result in terms of value, but cannot truly reflect the external load actually acting on the structure.

[0110] Step 5: Set the threshold A to 0.9. Compared with A; when When it is greater than A, judge and The consistency is good, that is, the recognition result is accurate. As the result of the impact load identification of the pyrotechnic device; When it is less than or equal to A, judge and If the consistency is not good, that is, the recognition result is inaccurate, return to step 2, replace it with a higher frequency and higher precision data acquisition device, add measurement points, and restart the recognition. When it is less than or equal to A, the calculation error is large due to the low sampling frequency and small number of measurement points, resulting in inaccurate recognition results.

[0111] Example

[0112] For example Figure 2 The numerical example model of the 10-node spring oscillator shown in the figure takes the stiffness of each spring as k = 1 × 1010 N / m, the mass of each mass point as m = 1 kg, and the two coefficients in the proportional damping model as α = 5.31 × 10 -8 , β = 5.59. Let the external load act on the third node, and assume that the acceleration data of nodes 2, 5, 7 and 9 can be measured. The external load is in the form of a decaying sine wave, and the construction method is shown in formula (12). The maximum amplitude is 10000N, and the frequencies are 100000Hz, 64000Hz, 32000Hz, 16000Hz, 8000Hz, 4000Hz, 2000Hz, 1000Hz, 500Hz, 250Hz and 125Hz, respectively. The sampling frequency is 240kHz, which meets the requirement that the sampling frequency is 2 to 3 times higher than the highest frequency component, and the time history is taken as 20ms. Considering the normal distributed random noise, the definition of numerical noise is shown in formula (13), where is the acceleration on the measurable degree of freedom calculated by precise integration, max{} represents the maximum value, rand(0,1) represents a normally distributed random number with a mean of 0 and a variance of 1, SN is the signal-to-noise ratio, which is -30dB, It is the acceleration of the measurable degree of freedom after superimposing the noise signal

[0113]

[0114]

[0115] The consistency coefficients of the two cases without numerical noise and considering -30dB numerical noise are shown in Table 1. As can be seen from the table, in the case of no numerical noise, the recognition results are consistent with the exact value F A Basically consistent, consistency verification coefficient is 0.9998, is 1.0000, The reason why the consistency check coefficients among the three are not equal to 1 is that when calculating the identification load in step (4), the regularization coefficient λ is introduced by applying the GCV method, which causes a slight change in the characteristics of the solution equation, but does not affect the overall correctness of the solution algorithm. Under the condition of -30dB numerical noise, the calculation accuracy is slightly reduced, and the consistency check coefficient is 0.8557, is 0.8719. However, due to It is 0.9659, which meets the consistency coefficient judgment requirement of greater than 0.9, and the recognition result is considered accurate.

[0116] The global and local time domain history curves of the load obtained under the two conditions of no numerical noise and considering -30dB numerical noise are shown in the figure below: Figures 3 to 6 As shown in the figure, in the absence of noise, the recognition result is almost completely consistent with the accurate result; under the influence of -30dB noise, the recognition result has a certain error, but the overall trend and local details of the load curve obtained by recognition accurately reflect the characteristics of the real load. and In comparison, due to During the calculation process, only the amplitude continuity was considered, while the first-order derivative continuity was ignored, resulting in the appearance of the identified load at each Δt junction. The case where the derivative is discontinuous.

[0117] By identification results The global and local time domain history curves of the displacement, velocity and acceleration of node 9 obtained by reconstruction are as follows: Figures 7 to 12 As shown in the figure, the error of load identification is mainly reflected in the displacement curve, and the reconstruction results of velocity and acceleration curves are almost consistent with the accurate values.

[0118] Table 1

[0119]

[0120] The above calculation results can serve as numerical proof of the feasibility and accuracy of the method proposed in this patent in identifying wide-band dynamic oscillation pyrotechnic impact loads.

[0121] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A method for identifying a wide-band dynamic oscillating explosive impact load, characterized in that: The steps include: Step 1: construct an impact load test device for explosives; Step 2: measuring the acceleration response data of the pyrotechnic impact load test device; In the step 2, at least 4 channels of acceleration response data are measured; when measuring the acceleration response data, the sampling frequency is not less than 200kHz, and the measurement signal-to-noise ratio is better than -20dB; Step 3: Set the time of measuring the acceleration response data for the kth time to t k The time when the k+1th acceleration response data is measured is t k+1 ; Establish the time domain history equation of the impact load test device of explosives; Construct the dynamic inverse problem equation under the augmented precise integration algorithm; Establish the constraint equation; Calculate the identification load considering only the amplitude continuity constraint condition and identification loads considering both amplitude continuity and first-order derivative continuity constraints In step 3, the time domain history equation of the pyrotechnic impact load test device is: Where, t k is the time when the acceleration response data is measured for the kth time, k=1, 2, ..., n; is the constant term coefficient; is the coefficient of the first-order term; is the coefficient of the quadratic term; is the cubic coefficient; t is the independent variable of the time domain history equation; The inverse problem equation of dynamics is: Where D z and D zf are the recursive coefficient matrices in the augmented precise integration algorithm; and D z With D zf The relationship is: B k is a Bohr matrix containing only 0 and 1 elements related to the acceleration measurement degrees of freedom in the finite element model; The subscript T is the transpose of the matrix; R is the coefficient in the augmented precise integration algorithm, specifically: c k is the coefficient matrix, specifically: Among them, K, C and M are the system stiffness matrix, damping matrix and mass matrix respectively; x, and are the displacement, velocity and acceleration vectors of each degree of freedom of the system respectively; M -1 To find the inverse of M; Step 4: Calculation and The consistency coefficient Step 5: Set the threshold A. Compared with A; when When it is greater than A, judge and The consistency is good, that is, the recognition result is accurate. As the result of the impact load identification of the pyrotechnic device; When it is less than or equal to A, judge and The consistency is not good, that is, the recognition result is inaccurate. Return to step 2, replace it with a data acquisition device with higher frequency and higher accuracy, increase the measurement points, and restart the recognition.

2. A method for identifying a wide-band dynamic oscillation pyrotechnic impact load according to claim 1, characterized in that: In step 3, the constraint equation is: Where S1 is the first sub-coefficient matrix; S2 is the second sub-coefficient matrix; When only the load amplitude is considered to be continuous, S1 and S2 are: S2＝[-1 0 0 0] (8) When considering both load amplitude continuity and first-order derivative continuity, S1 and S2 are:

3. A method for identifying a wide-band dynamic oscillation pyrotechnic impact load according to claim 2, characterized in that: In step 3, formula (2) and formula (6) are combined to obtain a system of equations. When the value of S1 in the constraint equation is formula (7) and the value of S2 is formula (8), or the value of S1 is formula (9) and the value of S2 is formula (10), two different systems of equations are obtained. After solving the system of equations to obtain the column vector of the load coefficient, they are substituted into formula (1) respectively. k to k+1 Perform piecewise interpolation calculation within the sampling interval of k = 1, 2, 3, ..., n-1; obtain the identification load corresponding to different constraint conditions and in To consider only the identified loads under the amplitude continuity constraint, To identify loads under the constraints of both amplitude continuity and first-order derivative continuity.

4. A method for identifying a wide-band dynamic oscillating explosive impact load according to claim 3, characterized in that: When performing slice interpolation calculations, at least 8-point interpolation is used, otherwise there is a probability that the time resolution cannot capture the dynamic oscillation characteristics of the time domain history.

5. A method for identifying a wide-band dynamic oscillating explosive impact load according to claim 4, characterized in that: In step 4, the consistency coefficient The calculation method is: Where 2 is the 2-norm of the vector.

6. A method for identifying a wide-band dynamic oscillating explosive impact load according to claim 5, characterized in that: In the step five, the threshold A is 0.

9.

7. A method for identifying a wide-band dynamic oscillating explosive impact load according to claim 6, characterized in that: In step 5, when When it is less than or equal to A, the calculation error is large due to the low sampling frequency and small number of measurement points, resulting in inaccurate recognition results.

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