Fast evaluation method of dynamic coefficient amplification factor under high-frequency component of strong impact load

Abstract

This invention discloses a rapid evaluation method for the enhancement factor of the dynamic coefficient by the high-frequency component of a strong impact load, belonging to the field of structural dynamic response analysis technology. This method performs time-frequency domain energy accumulation analysis on the strong impact load signal, extracts the concentrated frequency of load energy and its proportion in the total energy, and then, based on this, combines the dynamic amplification factor under the triangular time history assumption to quantitatively calculate the enhancement factor of the dynamic coefficient by the high-frequency component of the strong impact load. This method is further extended to arbitrary frequency components and the entire frequency band to obtain the comprehensive enhancement result of the dynamic amplification factor by the high-frequency effect of the strong impact load. Compared with traditional dynamic analysis methods based solely on idealized time history assumptions, this invention can introduce the real time-frequency characteristics of strong impact loads while maintaining computational efficiency, effectively compensating for the insufficient consideration of high-frequency excitation effects. It is applicable to rapid dynamic response evaluation in engineering fields such as aerospace structures, high-frequency components, and precision equipment.

Description

Technical Field

[0001] This invention relates to the field of structural dynamic response analysis technology, and in particular to a rapid evaluation method for the enhancement factor of dynamic coefficient by the high-frequency component of strong impact load. Background Technology

[0002] Strong impact loads, characterized by short duration and rich frequency components, significantly influence the dynamic response of engineering structures. Generally, the overall natural frequency of the target structure is relatively low, while the natural frequencies of local components or substructures are significantly higher. Although the overall response is often dominated by low-frequency components, secondary energy concentration zones still account for a certain proportion of energy across the entire time-frequency range, exerting a significant influence on the excitation effect of the structure. Especially when the energy concentration frequency band of a strong impact load approaches the overall or local natural frequency of the target structure, resonance or quasi-resonance phenomena are easily induced within the corresponding frequency range, thereby significantly enhancing the load's effective work capacity on the structure. In engineering fields such as spacecraft structures, high-frequency precision instruments, and lightweight, high-rigidity components, the components themselves possess high natural frequencies. Even if the strong impact load is predominantly high-frequency, it may still couple with the structural frequencies, leading to a significant dynamic amplification effect. Therefore, it is necessary to reasonably assess the impact of high-frequency components in strong impact loads on the structural dynamic response.

[0003] However, existing methods for analyzing the dynamic effects of strong impact loads still have significant shortcomings in characterizing the influence of high-frequency components. In related engineering analyses, strong impact loads typically employ an idealized triangular time history as a basic assumption, and the dynamic amplification factor of the structure is calculated accordingly. However, actual strong impact loads exhibit significant non-smoothness and non-stationarity; their energy distribution in the frequency domain dynamically evolves over time, and the accumulation process of strong impact energy along the time axis determines the main concentrated frequency band of the load energy. When this concentrated frequency band is close to the natural frequency of the structure, it will induce strong excitation phenomena within the corresponding range, significantly enhancing the load effect. The aforementioned frequency domain excitation characteristics and their influence on the dynamic amplification factor are difficult to reflect using a simple triangular time history assumption, which may underestimate or ignore the contribution of high-frequency components in strong impact loads to the structural dynamic response.

[0004] As mentioned above, existing dynamic analysis methods for strong impact loads have shortcomings in describing the non-stationary frequency domain characteristics of the load and its impact on the dynamic amplification effect on the structure. In particular, it is difficult to quickly assess the enhancement effect of high-frequency energy components on the traditional dynamic coefficient. Therefore, researching a method that can comprehensively consider the time-frequency distribution characteristics of strong impact load energy and quickly quantify the enhancement factor of its high-frequency components on the dynamic amplification factor is of great significance for improving the accuracy of predicting the dynamic response of structures under strong impact conditions and the efficiency of engineering analysis. Summary of the Invention

[0005] The purpose of this invention is to provide a rapid evaluation method for the enhancement factor of the dynamic coefficient by the high-frequency component of strong impact load. It comprehensively considers the time-frequency distribution characteristics of energy of strong impact load, rapidly quantifies the enhancement factor of the dynamic amplification factor by the high-frequency component, makes up for the shortcomings of traditional methods in not considering the high-frequency excitation effect, and improves the accuracy of predicting the dynamic response of structures under strong impact conditions while ensuring computational efficiency.

[0006] To achieve the above objectives, this invention provides a rapid evaluation method for the enhancement factor of the dynamic coefficient by the high-frequency component of a strong impact load, comprising the following steps: S1: Perform time-frequency analysis on the strong impact load signal to extract the energy concentration frequency of the strong impact load and its proportion in the total energy. ; S2: Based on the triangular time history assumption, calculate the dynamic amplification factor of the structure under strong impact load. ; S3: Calculation of structural natural frequencies The frequency components of the close-range strong impact load affect the dynamic amplification factor. The increase factor ; S4: Calculate the dynamic amplification factor of a strong impact load with arbitrary frequency components. The increase factor ; S5: Energy proportion of each frequency component based on strong impact load Calculate the dynamic amplification factor of high-frequency components of strong impact load. Overall improvement factor .

[0007] Preferably, in step S1, variational mode decomposition combined with Hilbert transform is used to perform cumulative energy analysis of the strong impact load signal in the time and frequency domains, and the energy concentration frequency is the representative frequency of the frequency range in which the strong impact load energy accounts for the largest proportion in the frequency domain.

[0008] Preferably, in step S2, the dynamic amplification factor is determined based on the relationship between the triangular time-history load and the natural vibration period of the structure, and the calculation formula is as follows: (1) in, μ It is the ratio of the load application time to the structure's natural vibration period.

[0009] Preferably, in step S3, the enhancement factor is used to characterize the degree of enhancement of the dynamic amplification effect by the high-frequency component when the energy concentration frequency of the strong impact load is close to the natural frequency of the structure. The calculation formula is as follows: (2) in, The component damping ratio.

[0010] Preferably, in step S4, the boost factor of any frequency component to the power amplification factor is... The frequency is determined by the degree of deviation between the stated frequency and the structure's natural frequency, as well as the structure's damping characteristics. The calculation formula is as follows: (3) in, The natural frequency of the structure, Indicates the frequency of load energy concentration. χ The attenuation coefficient is taken as the component damping ratio. Twice as much.

[0011] Preferably, the structural damping characteristics are characterized by the damping ratio or the attenuation coefficient related to the damping ratio.

[0012] Preferably, in step S5, the overall improvement factor is... By adjusting the boost factor corresponding to each frequency component According to its energy percentage The weighted calculation is as follows: (4).

[0013] Preferably, the method is suitable for rapid assessment of the dynamic effects of structures under non-stationary, non-smooth, strong impact loads.

[0014] Preferably, the method is used to correct the dynamic amplification factor obtained based on the idealized triangular time history assumption.

[0015] A non-transitory computer-readable storage medium storing a computer program, characterized in that, when the computer program is executed by a processor, it implements the method described above for rapidly evaluating the boost factor of the high-frequency component dynamic coefficient of a strong impact load.

[0016] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects: (1) Accurately capture the time-frequency characteristics of strong impact loads. By combining variational mode decomposition and Hilbert transform, we break through the limitations of traditional idealized assumptions, fully restore the real excitation characteristics of high-frequency components, realize the quantitative evaluation of the dynamic amplification effect of high-frequency components, and solve the problem that traditional methods are difficult to characterize non-stationary frequency domain characteristics and underestimate the high-frequency contribution.

[0017] (2) It takes into account both the efficiency of engineering analysis and the accuracy of evaluation. The core formula is simplified and the steps are clear. While introducing real load characteristics, it maintains the ability to calculate quickly. By comprehensively improving the multiplier to correct the traditional dynamic amplification factor, it optimizes the rationality of the structural impact resistance design and reduces safety hazards.

[0018] (3) It has a wide range of applications and is suitable for non-stationary and non-smooth strong impact load scenarios. In particular, it meets the dynamic response evaluation needs of high-frequency natural frequency engineering such as spacecraft structures and high-frequency precision instruments, and expands the application boundaries of strong impact load dynamic analysis.

[0019] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a flowchart of a method for rapidly evaluating the enhancement factor of the dynamic coefficient by the high-frequency component of a strong impact load according to Embodiment 1 of the present invention. Figure 2 The diagram shows the intrinsic mode function of the strong impact load signal based on variational mode decomposition in Embodiment 1 of the present invention. Figure 3 The Hilbert transform and marginal energy spectrum of the strong impact load signal in Embodiment 1 of the present invention are shown, where (a) is the distribution of energy in the time and frequency domains, and (b) is the energy accumulation of each frequency over the entire pulse duration. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0023] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] Example 1 This embodiment uses, as follows: Figure 1 The method shown is a rapid evaluation method for the amplification factor of the dynamic coefficient by the high-frequency component of a strong impact load. It quickly analyzes the amplification factor of the dynamic amplification factor under the triangular time history assumption by the high-frequency component of a certain strong impact load, including the following steps: S1: In this embodiment, the variational mode decomposition of the strong impact load is as follows: Figure 2As shown, variational mode decomposition combined with Hilbert transform is used to perform cumulative energy analysis of the strong impact load signal in the time and frequency domains, such as... Figure 2 As shown. The energy concentration frequency of a strong impact load and its proportion in the total energy are extracted. The energy concentration frequency is the representative frequency of the frequency range in which the energy of a strong impact load accounts for the largest proportion in the frequency domain.

[0025] According to Table 1, the energy concentration frequency f 0 =(4.5+19.3)×0.5=11.8 kHz, which is the proportion of total energy. .

[0026] Table 1. Frequency domain distribution of peak value, duration, and energy of strong impact load. ; S2: Based on the triangular time history assumption, calculate the dynamic amplification factor of the structure under strong impact load. The dynamic amplification factor is determined based on the relationship between the triangular time-history load and the natural vibration period of the structure. The calculation formula is as follows: (1) in, μ This is the ratio of the load application time to the structure's natural vibration period. In this embodiment, the natural frequency of the loaded member... The dynamic amplification factor of a strong impact load can be calculated. .

[0027] S3: Calculation of structural natural frequencies The dynamic amplification factor is affected by the frequency components of similar strong impact loads. The increase factor Increase the multiplier This is used to characterize the enhancement of the dynamic amplification effect by high-frequency components when the energy concentration frequency of a strong impact load is close to the structure's natural frequency. The calculation formula is: (2) in, The damping ratio of the component is the damping ratio of the loaded component in this embodiment. Calculations yielded 18.39.

[0028] S4: Calculate the dynamic amplification factor of the strong impact load with arbitrary frequency components. The increase factor ; Increase factor The damping characteristics of the structure are determined by the degree of deviation between the frequency and the natural frequency of the structure and the damping characteristics of the structure. The damping characteristics of the structure are characterized by the damping ratio or the attenuation coefficient related to the damping ratio.

[0029] Increase multiplier The calculation formula is: (3) in, The natural frequency of the structure, Indicates the frequency of load energy concentration. χ The attenuation coefficient is taken as the component damping ratio. Twice that of the load-bearing component in this embodiment 1. , attenuation coefficient χ Taking 0.04, the calculation yields... .

[0030] S5: Energy proportion of each frequency component based on strong impact load Calculate the dynamic amplification factor of high-frequency components of strong impact load. Overall improvement factor The calculation formula is as follows: (4).

[0031] The analysis results from step S1 show that in this embodiment... Calculation yields In other words, for the strong impact load in this embodiment, if the influence of the actual high-frequency components is considered, the dynamic amplification factor under the triangle assumption is... The improvement factor is 2.83 times.

[0032] The method is applicable to the rapid assessment of the dynamic effects of structures under non-stationary, non-smooth, and strong impact loads, and is used to correct the dynamic amplification factor obtained based on the idealized triangular time history assumption.

[0033] Example 2 A non-transitory computer-readable storage medium storing a computer program, the storage medium including but not limited to: optical disc, hard disk, USB flash drive, solid-state drive, cloud storage space, etc. When the program is executed by a processor, it implements the method for rapidly evaluating the enhancement factor of the high-frequency component dynamic coefficient of a strong impact load, including the following steps: Time-frequency analysis was performed on the input strong impact load signal to extract the concentrated energy frequency and its proportion. ; Calculation of dynamic amplification factor based on the triangular time history assumption ; Calculate the frequency component pairs that are close to the structure's natural frequency. The increase factor ; Calculate arbitrary frequency component pairs The increase factor ; Based on the energy proportion of each frequency component Calculate the overall improvement factor ; Output the evaluation results.

[0034] The remaining technical features in the above embodiments can be flexibly selected by those skilled in the art to meet different specific practical needs according to actual circumstances. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims. In the above description, numerous specific details have been set forth to provide a thorough understanding of the present invention. However, it will be apparent to those skilled in the art that these specific details are not necessary to implement the present invention. In other instances, to avoid obscuring the present invention, well-known techniques, such as specific construction details, operating conditions, and other technical conditions, have not been specifically described.

[0035] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A rapid evaluation method for the enhancement factor of dynamic coefficient by high-frequency components of strong impact load, characterized in that, Includes the following steps: S1: Perform time-frequency analysis on the strong impact load signal to extract the energy concentration frequency of the strong impact load and its proportion in the total energy. ; S2: Based on the triangular time history assumption, calculate the dynamic amplification factor of the structure under strong impact load. ; S3: Calculation of structural natural frequencies The frequency components of the close-range strong impact load affect the dynamic amplification factor. The increase factor ; S4: Calculate the dynamic amplification factor of the strong impact load with arbitrary frequency components. The increase factor ; S5: Energy proportion of each frequency component based on strong impact load Calculate the dynamic amplification factor of high-frequency components of strong impact load. Overall improvement factor .

2. The rapid evaluation method for the enhancement factor of the dynamic coefficient by the high-frequency component of a strong impact load according to claim 1, characterized in that: In step S1, variational mode decomposition combined with Hilbert transform is used to perform cumulative energy analysis of the strong impact load signal in the time and frequency domains, and the energy concentration frequency is the representative frequency of the frequency range in which the strong impact load energy accounts for the largest proportion in the frequency domain.

3. The rapid evaluation method for the enhancement factor of the dynamic coefficient by the high-frequency component of a strong impact load according to claim 1, characterized in that: In step S2, the dynamic amplification factor is determined based on the relationship between the triangular time-history load and the natural vibration period of the structure, and the calculation formula is as follows: （1） in, μ It is the ratio of the load application time to the structure's natural vibration period.

4. The rapid evaluation method for the enhancement factor of the dynamic coefficient by the high-frequency component of a strong impact load according to claim 3, characterized in that: In step S3, the enhancement factor is used to characterize the degree of enhancement of the dynamic amplification effect by the high-frequency component when the energy concentration frequency of the strong impact load is close to the natural frequency of the structure. The calculation formula is as follows: （2） in, The component damping ratio.

5. The rapid evaluation method for the enhancement factor of the dynamic coefficient by the high-frequency component of a strong impact load according to claim 1, characterized in that: In step S4, the boost factor of any frequency component to the dynamic amplification factor is... The frequency is determined by the degree of deviation between the stated frequency and the structure's natural frequency, as well as the structure's damping characteristics. The calculation formula is as follows: （3） in, The natural frequency of the structure, Indicates the frequency of load energy concentration. χ The attenuation coefficient is taken as the component damping ratio. Twice as much.

6. The rapid evaluation method for the enhancement factor of the dynamic coefficient by the high-frequency component of a strong impact load according to claim 5, characterized in that: The structural damping characteristics are characterized by the damping ratio or the attenuation coefficient related to the damping ratio.

7. The rapid evaluation method for the enhancement factor of the dynamic coefficient by the high-frequency component of a strong impact load according to claim 5, characterized in that: In step S5, the overall improvement factor is calculated. By adjusting the boost factor corresponding to each frequency component According to its energy percentage The weighted calculation is as follows: （4）。 8. The rapid evaluation method for the enhancement factor of the dynamic coefficient by the high-frequency component of a strong impact load according to claim 1, characterized in that: The method described is applicable to the rapid assessment of the dynamic effects of structures under non-stationary, non-smooth, and strong impact loads.

9. The rapid evaluation method for the enhancement factor of the dynamic coefficient by the high-frequency component of a strong impact load according to claim 1, characterized in that: The method is used to correct the dynamic amplification factor obtained based on the idealized triangular time history assumption.

10. A non-transitory computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the method for rapid evaluation of the dynamic coefficient enhancement factor of high-frequency component of strong impact load as described in any one of claims 1 to 9.

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