A high-strength bolt composite load fatigue performance test method and system

Abstract

The application relates to the technical field of load fatigue performance testing, and discloses a high-strength bolt composite load fatigue performance testing method and system. The system comprises the following modules: a load information acquisition module, which is used for acquiring load response data of a high-strength bolt to be tested under the action of a composite load and extracting a composite load coupling feature representing the interaction relationship of different loads according to the load response data; a state evaluation module, which is used for generating a fatigue state evaluation result based on the composite load coupling feature; a progressive verification module, which is used for performing progressive verification on data of subsequent N detection cycles when the fatigue state evaluation result meets preset conditions; and a failure confirmation module, which is used for determining a fatigue damage grade of the high-strength bolt to be tested according to the progressive verification result and outputting a composite load fatigue performance evaluation result according to the fatigue damage grade. The application can reflect the real fatigue state of the bolt more in line with actual working conditions, and effectively improves the fitting degree of the test result and the actual fatigue performance.

Description

Technical Field

[0001] This invention relates to the field of load fatigue performance testing technology, and more specifically, to a method and system for testing the fatigue performance of high-strength bolts under combined loads. Background Technology

[0002] For high-strength bolts subjected to multiple composite loads such as axial, transverse, and torsional loads under actual working conditions, existing testing schemes mostly only test a single load individually, without considering the influence of the coupling effect between different loads on the development of fatigue damage. This can easily lead to discrepancies between the test results and the bolt fatigue performance under actual working conditions.

[0003] Therefore, it is necessary to design a high-strength bolt composite load fatigue performance testing method and system to solve the problems existing in the current technology. Summary of the Invention

[0004] In view of this, the present invention proposes a method and system for testing the fatigue performance of high-strength bolts under combined loads, aiming to solve the technical problem that the influence of the coupling effect between different loads on bolt fatigue damage is not considered in the current technology, resulting in a large deviation between the test results and the actual performance.

[0005] This invention proposes a fatigue performance testing system for high-strength bolts under combined loads, comprising: The load information acquisition module is used to acquire the load response data of the high-strength bolt under test during the combined load process, and extract the combined load coupling characteristics that characterize the interaction relationship of different loads based on the load response data. The condition assessment module is used to generate fatigue condition assessment results based on the composite load coupling characteristics; The progressive verification module is used to progressively verify the data of the subsequent N detection cycles when the fatigue state assessment result meets the preset conditions. The failure confirmation module is used to determine the fatigue damage level of the high-strength bolt under test based on the progressive verification results, and output the composite load fatigue performance evaluation results based on the fatigue damage level.

[0006] Furthermore, the load response data includes axial load response data, transverse load response data, torsional load response data, and corresponding deformation response data.

[0007] Furthermore, the composite load coupling characteristics include load synchronous change characteristics, load fluctuation correlation characteristics, and deformation response consistency characteristics.

[0008] Furthermore, when generating fatigue state assessment results based on the aforementioned composite load coupling characteristics, the process includes: The load synchronous change characteristics, load fluctuation correlation characteristics, and deformation response consistency characteristics are quantified respectively to obtain the corresponding feature evaluation values; Calculate the composite load coupling index based on the evaluation values ​​of each of the aforementioned features; The coupling deviation is obtained by comparing the composite load coupling index of the current detection cycle with the composite load coupling index of the reference detection cycle. The degree of fatigue state change is determined based on the coupling deviation, and the corresponding fatigue state assessment result is generated.

[0009] Furthermore, when determining the degree of fatigue state change based on the coupling deviation and generating the corresponding fatigue state assessment result, the process includes: Obtain the corresponding deviation level range; Determine the deviation level range in which the coupling deviation amount falls to obtain the corresponding state change level; Calculate the cumulative value of state change by combining the state change levels of the M consecutive detection cycles preceding the current detection cycle; The degree of fatigue state change is determined based on the cumulative value of the state change, and the corresponding fatigue state assessment result is generated.

[0010] Further, determining whether the fatigue state assessment result meets the preset conditions includes: Obtain the degree of fatigue state change corresponding to the current detection cycle and the historical degree of fatigue state change corresponding to the K consecutive detection cycles. The degree of fatigue state change in the current detection cycle is mapped to obtain the current state feature value; Calculate the consistency parameter between the current state level and the historical state feature values ​​corresponding to the K consecutive historical detection periods; When the consistency parameter reaches the consistency threshold, it is determined that the fatigue state assessment result meets the preset condition, and the progressive verification module is triggered to perform progressive verification for the next N detection cycles.

[0011] Furthermore, when performing progressive verification on the data from the subsequent N detection cycles, it includes: The load response data for the i-th subsequent detection cycle is acquired, and the corresponding composite load coupling features are extracted to obtain the coupling feature parameters for the i-th detection cycle, where i = 1, 2, ..., N; Based on the coupling feature parameters of the i-th detection cycle, generate the corresponding i-th fatigue state evaluation result, and determine whether the i-th fatigue state evaluation result meets the preset fatigue state conditions. When the number of detection cycles that meet the conditions reaches the first preset threshold, the progressive verification is determined to have entered the effective verification stage, and the number of detection cycles that meet the conditions is continuously counted. When the number of detection cycles that meet the conditions reaches the second preset threshold, the progressive verification result is determined to be the fatigue damage confirmation result. When the number of detection cycles that meet the conditions does not reach the first preset threshold, the progressive verification result is determined to be in a non-damaged state, and subsequent damage statistics are stopped.

[0012] Furthermore, when determining the fatigue damage level of the high-strength bolt under test based on the progressive verification results, the following steps are included: When the progressive verification result is a fatigue damage confirmation result, the cumulative fatigue damage value is calculated by combining the changing trend of the fatigue state assessment results corresponding to the subsequent M detection cycles. The fatigue damage level of the high-strength bolt to be tested is determined by comparing the cumulative fatigue damage value with the preset damage level range. When the progressive verification result is a non-damaged state, the fatigue damage level of the high-strength bolt under test is determined to be a no-damage level.

[0013] Furthermore, based on the fatigue damage level, the composite load fatigue performance evaluation results are output, including: The fatigue damage level is mapped to the corresponding composite load fatigue performance evaluation level or index. The output report of the fatigue performance evaluation results under the composite load is generated, including fatigue damage level, composite load coupling characteristic analysis results, and fatigue state change trend information; The fatigue performance evaluation results under the composite load are output through a display module or data interface for subsequent analysis, maintenance, or design improvement.

[0014] Compared with existing technologies, the beneficial effects of this invention are as follows: By extracting the coupling characteristics between different loads, this invention fully considers the influence of multiple load coupling effects on the fatigue damage development of high-strength bolts under actual working conditions, and can more closely reflect the true fatigue state of bolts under actual working conditions, effectively improving the consistency between test results and actual fatigue performance; at the same time, by using a progressive verification method to confirm the fatigue state of the preliminary assessment in multiple cycles, it avoids damage misjudgment caused by single detection errors, which can effectively improve the accuracy of fatigue damage judgment and obtain more accurate composite load fatigue performance evaluation results, providing reliable data support for the performance design and working condition maintenance of high-strength bolts.

[0015] In another aspect, the present invention also proposes a method for testing the fatigue performance of high-strength bolts under combined loads, comprising the following steps: The load response data of the high-strength bolt under test under combined load is obtained, and the combined load coupling characteristics that characterize the interaction relationship of different loads are extracted based on the load response data. Fatigue state assessment results are generated based on the aforementioned composite load coupling characteristics; When the fatigue state assessment result meets the preset conditions, the data of the subsequent N detection cycles are progressively verified; The fatigue damage level of the high-strength bolt to be tested is determined based on the progressive verification results, and the composite load fatigue performance evaluation results are output based on the fatigue damage level.

[0016] It is understandable that the above-mentioned high-strength bolt composite load fatigue performance testing method and system have the same beneficial effects, and will not be elaborated further here. Attached Figure Description

[0017] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 This is a structural block diagram of the high-strength bolt composite load fatigue performance testing system provided in an embodiment of the present invention; Figure 2 A flowchart of a method for testing the fatigue performance of high-strength bolts under combined loads, provided in an embodiment of the present invention. Detailed Implementation

[0018] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, embodiments and features in the embodiments of the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0019] See Figure 1 As shown in some embodiments of this application, this embodiment provides a high-strength bolt composite load fatigue performance testing system, including: The load information acquisition module is used to acquire the load response data of the high-strength bolt under test during the combined load process, and extract the combined load coupling characteristics that characterize the interaction relationship of different loads based on the load response data. The condition assessment module is used to generate fatigue condition assessment results based on the coupling characteristics of composite loads; The progressive verification module is used to progressively verify the data of the subsequent N detection cycles when the fatigue state assessment results meet the preset conditions. The failure confirmation module is used to determine the fatigue damage level of the high-strength bolt under test based on the progressive verification results, and output the composite load fatigue performance evaluation results based on the fatigue damage level.

[0020] It is understandable that this embodiment, by extracting the coupling characteristics between different loads, fully considers the impact of multiple load coupling effects on the fatigue damage development of high-strength bolts under actual working conditions. This allows it to better reflect the true fatigue state of bolts in accordance with actual working conditions, effectively improving the consistency between test results and actual fatigue performance. At the same time, by using a progressive verification method to confirm the fatigue state of the initial assessment over multiple cycles, it avoids damage misjudgment caused by single detection errors, effectively improving the accuracy of fatigue damage determination and obtaining more accurate composite load fatigue performance evaluation results. This can provide reliable data support for the performance design and working condition maintenance of high-strength bolts.

[0021] Specifically, the load response data includes axial load response data, transverse load response data, torsional load response data, and the corresponding deformation response data.

[0022] Understandably, in actual working conditions, high-strength bolts often bear axial preload, working tensile and compressive forces, transverse shear force on the connection surface, and torsional load from threaded connections simultaneously. The combined effect of multiple loads can have an interactive effect, accelerating the expansion of fatigue damage. Collecting multi-dimensional load and deformation response data can provide complete and comprehensive basic data support for the subsequent extraction of accurate coupling features, avoiding incomplete extraction of coupling features due to missing data, and ensuring the accuracy of subsequent evaluation and verification.

[0023] Specifically, the characteristics of composite load coupling include synchronous load change characteristics, load fluctuation correlation characteristics, and deformation response consistency characteristics.

[0024] Understandably, the load synchronization characteristic refers to the degree of synchronization of the timing of different load changes during bolt loading. It can be calculated by the time difference of the peak occurrence of different load response data and the synchronous correlation of the changing trends, reflecting the coupling relationship of different loads in the timing of action. The load fluctuation correlation characteristic refers to the degree of correlation of the fluctuation amplitude of different loads. It can be calculated by the covariance or correlation coefficient of different load response data, used to characterize the degree of mutual influence during load fluctuation. The deformation response consistency characteristic refers to the degree of correspondence and matching between the overall deformation of the bolt and the response of different loads. It can be calculated by the deviation between the actual deformation and the predicted deformation under the action of different loads alone, reflecting the comprehensive change characteristics of deformation response under the coupling action of multiple loads. The three types of characteristics comprehensively characterize the coupling relationship between different loads from different dimensions, ensuring the comprehensiveness of subsequent fatigue state assessment.

[0025] Specifically, when generating fatigue state assessment results based on the coupling characteristics of composite loads, the following are included: The characteristics of synchronous load change, load fluctuation correlation, and deformation response consistency are quantified to obtain the corresponding feature evaluation values. Calculate the composite load coupling index based on the evaluation values ​​of each characteristic; The coupling deviation is obtained by comparing the composite load coupling index of the current detection cycle with the composite load coupling index of the reference detection cycle. The degree of fatigue state change is determined based on the coupling deviation, and the corresponding fatigue state assessment results are generated.

[0026] Understandably, the load synchronization variation characteristics, load fluctuation correlation characteristics, and deformation response consistency characteristics are quantified separately to obtain corresponding feature evaluation values. Specifically, the load synchronization variation characteristic characterizes the degree of synchronous variation of axial load, lateral load, and torsional load within the same detection cycle, and can be characterized using the synchronization variation coefficient S; the load fluctuation correlation characteristic characterizes the degree of correlation between different load fluctuation trends, and can be characterized using the fluctuation correlation coefficient C; the deformation response consistency characteristic characterizes the degree of matching between load changes and bolt deformation response, and can be characterized using the response consistency coefficient D. After normalizing the synchronization variation coefficient S, fluctuation correlation coefficient C, and response consistency coefficient D, a weighted calculation is performed according to preset weights to obtain the composite load coupling index F, calculated using the following formula: F = α × S + β × C + γ × D; Wherein, α, β, and γ are the weight coefficients of the corresponding feature evaluation values, and α + β + γ = 1. In this embodiment, α is 0.4, β is 0.35, and γ is 0.25.

[0027] Subsequently, the composite load coupling index F1 corresponding to the current detection cycle is compared with the composite load coupling index F0 corresponding to the reference detection cycle to obtain the coupling deviation ΔF, which is calculated using the following formula: ΔF = |F1 - F0| / F0.

[0028] Wherein, F0 represents the reference coupling index established when the bolt is in a normal state, F1 represents the coupling index calculated in the current detection cycle, and ΔF is used to characterize the degree of deviation of the current composite load state from the reference state.

[0029] It is understandable that the synchronous change coefficient S, fluctuation correlation coefficient C, and response consistency coefficient D are all calculated from the load response data. Specifically, the synchronous change coefficient S characterizes the degree of synchronous change of axial load, lateral load, and torsional load within the same testing period. It can be determined by the proportion of sampling points with consistent load signal change directions to the total number of sampling points—when multiple loads increase or decrease simultaneously, it is considered a synchronous change. The fluctuation correlation coefficient C characterizes the correlation between different load fluctuation trends, which can be obtained by calculating the correlation between the time series of axial load, lateral load, and torsional load, for example, by using the average value of the Pearson correlation coefficient. The response consistency coefficient D characterizes the degree of matching between load change and bolt deformation response, which can be determined by the fitting degree between the comprehensive load change curve and the deformation response curve, for example, by using the coefficient of determination R. 2 It can be characterized by the reciprocal of the normalization error.

[0030] It is understandable that the composite load coupling index F0 corresponding to the benchmark testing cycle and the composite load coupling index F1 corresponding to the current testing cycle are both calculated based on the characteristics of synchronous load change, load fluctuation correlation, and deformation response consistency. The specific process is as follows: First, the axial, transverse, and torsional load data collected in each testing cycle are preprocessed, including noise removal, smoothing filtering, and standardization; then, three types of coupling features are extracted—the synchronous load change feature is used to evaluate the consistency of load changes in each direction within the same cycle, the load fluctuation correlation feature is used to evaluate the correlation of different load fluctuation trends, and the deformation response consistency feature is used to evaluate the degree of matching between load changes and bolt deformation response; then, each feature is quantified into a corresponding evaluation value and normalized, and then weighted to obtain the composite load coupling index for that cycle. Among them, F0 is calculated in the testing cycle at the beginning of the test or when the bolt has not shown obvious fatigue damage, and serves as a benchmark reference; F1 is calculated using the same method for the current testing cycle, reflecting the current composite load coupling state of the bolt. By comparing the difference between F1 and F0, the degree of change in the bolt fatigue state can be evaluated.

[0031] Specifically, when determining the degree of fatigue state change based on the coupling deviation and generating the corresponding fatigue state assessment results, the process includes: Obtain the corresponding deviation level range; Determine the deviation level range in which the coupling deviation amount falls to obtain the corresponding state change level; Calculate the cumulative value of state change by combining the state change levels of the M consecutive detection cycles preceding the current detection cycle; The degree of fatigue state change is determined based on the cumulative value of state change, and the corresponding fatigue state assessment result is generated.

[0032] Understandably, when determining the degree of fatigue state change based on the coupling deviation and generating the corresponding fatigue state assessment result, a pre-established deviation level interval is first obtained. The coupling deviation ΔF characterizes the degree of deviation of the composite load coupling state between the current testing cycle and the reference testing cycle. In this embodiment, the deviation level interval is divided into three levels: when 0 ≤ ΔF < 0.10, it corresponds to the first-level state change level L = 1, representing a slight change; when 0.10 ≤ ΔF < 0.20, it corresponds to the second-level state change level L = 2, representing a moderate change; and when ΔF ≥ 0.20, it corresponds to the third-level state change level L = 3, representing a significant change. The system obtains the corresponding state change level L based on the deviation level interval where the coupling deviation ΔF of the current testing cycle falls.

[0033] Understandably, the cumulative state change value A is calculated by combining the state change levels corresponding to the M consecutive detection cycles preceding the current detection cycle. Here, M represents the number of detection cycles used for historical state analysis; in this embodiment, M is 5. Li represents the state change level corresponding to the i-th detection cycle; wi represents the weight coefficient of the corresponding detection cycle, with cycles closer to the current detection cycle having higher weights. In this embodiment, a weighted summation method is used to calculate the cumulative state change value A.

[0034] Understandably, the degree of fatigue state change is determined based on the cumulative value A of the state change. In this embodiment, the range for determining the degree of fatigue state change is set as follows: when A < 1.50, it is determined to be a low-risk fatigue state; when 1.50 ≤ A < 2.50, it is determined to be a medium-risk fatigue state; and when A ≥ 2.50, it is determined to be a high-risk fatigue state. Since this embodiment calculates A = 2.15, the current high-strength bolt under test is determined to be in a medium-risk fatigue state, and the corresponding fatigue state assessment result is generated.

[0035] Understandably, by introducing state change levels and cumulative state change values, we can not only reflect the fatigue state of the current testing cycle, but also comprehensively consider the state evolution trend of multiple historical testing cycles, thereby reducing the impact of single testing fluctuations on the evaluation results and improving the stability and accuracy of fatigue state assessment.

[0036] Specifically, determining whether the fatigue state assessment results meet preset conditions includes: Obtain the degree of fatigue state change corresponding to the current detection cycle and the historical degree of fatigue state change corresponding to the K consecutive detection cycles. The degree of fatigue state change in the current detection cycle is mapped to obtain the current state feature value; Calculate the consistency parameter between the current state level and the historical state feature values ​​corresponding to the K consecutive historical detection periods; When the consistency parameter reaches the consistency threshold, the fatigue state assessment result is determined to meet the preset conditions, and the progressive verification module is triggered to execute progressive verification for the next N detection cycles.

[0037] Understandably, when determining whether the fatigue state assessment result meets the preset conditions, the system first obtains the fatigue state change degree Scurr corresponding to the current detection cycle, and the historical fatigue state change degree sequence Shist={S1,S2,…,SK} corresponding to the K consecutive historical detection cycles. Here, Scurr and Si are both numerical indicators of the fatigue state change degree, ranging from 0 to 3 in this embodiment, corresponding to low risk, low-medium risk, medium-high risk, and high risk states, respectively. Subsequently, the fatigue state change degree Scurr of the current detection cycle is mapped to a state feature value Fcurr. The mapping method can be linear normalization or discrete level mapping; for example, this embodiment uses linear normalization, linearly converting the 0-3 interval to the 0-1 interval, i.e., Fcurr=Scurr / 3. Similarly, the fatigue state change degree Si of the K consecutive historical detection cycles is mapped to a historical state feature value sequence Fhist={F1,F2,…,FK}, where K is the number of historical detection cycles used for consistency analysis; in this embodiment, K=5.

[0038] Understandably, the system calculates a consistency parameter C based on the current state feature value Fcurr and the historical state feature value sequence Fhist to measure the degree of conformity between the current state and the historical state trends. This embodiment uses the weighted average absolute deviation method to calculate this consistency parameter.

[0039] It is understandable that when the calculated consistency parameter C is greater than or equal to the preset consistency threshold Cth (Cth is 0.85 in this embodiment), the system determines that the fatigue state assessment result of the current detection cycle meets the preset conditions and triggers the progressive verification module to perform progressive verification for the next N detection cycles, thereby realizing the judgment of the continuity and reliability of the fatigue state.

[0040] Specifically, when performing progressive verification on the data from the subsequent N detection cycles, it includes: The load response data for the i-th subsequent detection cycle is acquired, and the corresponding composite load coupling features are extracted to obtain the coupling feature parameters for the i-th detection cycle, where i = 1, 2, ..., N; Based on the coupling feature parameters of the i-th detection cycle, the corresponding fatigue state evaluation result is generated, and it is determined whether the fatigue state evaluation result of the i-th fatigue state meets the preset fatigue state conditions. When the number of detection cycles that meet the conditions reaches the first preset threshold, the progressive verification is determined to have entered the effective verification stage, and the number of detection cycles that meet the conditions is continuously counted. When the number of detection cycles that meet the conditions reaches the second preset threshold, the progressive verification result is determined to be the fatigue damage confirmation result. When the number of detection cycles that meet the conditions does not reach the first preset threshold, the progressive verification result is determined to be in a non-damaged state, and subsequent damage statistics are stopped.

[0041] Understandably, when progressively verifying the data for the subsequent N detection cycles, the load response data corresponding to the i-th subsequent detection cycle is first obtained, and the corresponding composite load coupling features are extracted to obtain the coupling feature parameter Pi corresponding to the i-th detection cycle, where i represents the detection cycle number in the progressive verification stage, i=1, 2, ..., N, and N represents the preset total number of detection cycles in the progressive verification stage. In this embodiment, N is 10. The coupling feature parameter Pi is used to characterize the comprehensive coupling state between axial load, transverse load, torsional load, and deformation response in the current detection cycle, and can be characterized using the aforementioned composite load coupling index.

[0042] Next, based on the coupling feature parameter Pi corresponding to the i-th detection cycle, the corresponding fatigue state assessment result Ri is generated, and it is determined whether the fatigue state assessment result Ri meets the preset fatigue state conditions. Here, Ri represents the fatigue state level corresponding to the i-th detection cycle, which is divided into three levels in this embodiment: low risk, medium risk, and high risk; the preset fatigue state conditions are used to determine whether there is an obvious fatigue damage development trend in the current detection cycle, which is set to "fatigue state level reaches medium risk or above" in this embodiment.

[0043] To improve the reliability of the judgment results, the system counts the number of detection cycles that meet the preset fatigue state conditions and sets a first preset threshold T1 and a second preset threshold T2. T1 is used to determine whether the effective verification stage has begun, and T2 is used to determine whether a fatigue damage confirmation result has been formed, with T2 being greater than T1. In this embodiment, T1 is set to 3, and T2 is set to 6.

[0044] During the progressive verification process, whenever the fatigue state assessment result Ri corresponding to a certain detection cycle meets the preset fatigue state conditions, the condition-meeting count value Q is incremented by 1. When the condition-meeting count value Q reaches the first preset threshold T1, the progressive verification is determined to have entered the effective verification stage, and the number of detection cycles that meet the preset fatigue state conditions in subsequent detection cycles continues to be counted to further verify whether the fatigue state change trend persists. When the condition-meeting count value Q reaches the second preset threshold T2, the progressive verification result is determined to be a fatigue damage confirmation result. If, after completing N detection cycles of verification, the condition-meeting count value Q still does not reach the first preset threshold T1, the progressive verification result is determined to be a non-damage state, and subsequent damage statistics are stopped.

[0045] Specifically, when determining the fatigue damage level of the high-strength bolt under test based on the progressive verification results, the following are included: When the progressive verification result is a fatigue damage confirmation result, the cumulative fatigue damage value is calculated by combining the changing trend of the fatigue state assessment results corresponding to the subsequent M detection cycles. The fatigue damage level of the high-strength bolt to be tested is determined by comparing the cumulative fatigue damage value with the preset damage level range. When the progressive verification result is a non-damaged state, the fatigue damage level of the high-strength bolt under test is determined to be a no-damage level.

[0046] Understandably, when determining the fatigue damage level of a high-strength bolt to be tested based on the progressive verification results, the progressive verification results must first be judged. If the result confirms fatigue damage, the cumulative fatigue damage value C is calculated by combining the changing trends of the fatigue state assessment results over the subsequent M testing cycles. Here, M is the number of consecutive testing cycles to be considered after the effective verification stage; in this embodiment, M=5. The fatigue state assessment results are weighted and accumulated using the aforementioned medium-risk and high-risk levels of Ri, resulting in a cumulative fatigue damage value C ranging from 0 to 100. A higher C value indicates a more severe degree of fatigue damage. Subsequently, C is compared with a preset damage level range (e.g., 0–20 for minor damage, 21–50 for moderate damage, 51–80 for severe damage, and 81–100 for extremely severe damage), and the fatigue damage level of the bolt to be tested is determined accordingly. For example, when C=62, it is determined to be a severe damage level.

[0047] If the progressive verification result is a non-damaged state (i.e., the number of detection cycles that meet the preset fatigue state conditions in the progressive verification stage has not reached the first preset threshold T1), then the fatigue damage level of the high-strength bolt under test is directly determined to be a non-damaged level. In this embodiment, the non-damaged level corresponds to C=0. By combining the progressive verification result with the fatigue state change trend of the subsequent M detection cycles, the fatigue damage of the high-strength bolt can be quantified, and a reproducible fatigue damage assessment can be achieved.

[0048] Specifically, the fatigue performance evaluation results under combined loads are output based on the fatigue damage level, including: Map fatigue damage levels to corresponding composite load fatigue performance evaluation levels or indicators. The system generates an output report of the fatigue performance evaluation results under combined loads, including fatigue damage level, combined load coupling characteristic analysis results, and fatigue state change trend information. The results of fatigue performance evaluation under combined loads are output through a display module or data interface for subsequent analysis, maintenance, or design improvement.

[0049] Understandably, when outputting composite load fatigue performance evaluation results based on fatigue damage levels, the fatigue damage level D must first be mapped to the corresponding composite load fatigue performance evaluation level or index P. This mapping can be achieved through a preset mapping table, for example: D = no damage corresponds to P = excellent, D = slight damage corresponds to P = good, D = moderate damage corresponds to P = average, D = severe damage corresponds to P = poor, and D = extremely severe damage corresponds to P = very poor. In this embodiment, the mapping process can be completed through a simple lookup function to ensure the reproducibility of the results. Subsequently, the system generates an output report R of the composite load fatigue performance evaluation results, which contains three types of core information: fatigue damage level D, composite load coupling characteristic analysis results C (including the quantitative values ​​of load synchronous change characteristics, load fluctuation correlation characteristics, and deformation response consistency characteristics, as well as the corresponding composite load coupling index), and fatigue state change trend information T (such as the state change level and cumulative value of the previous M detection cycles). Finally, the output report R will be displayed on the user interface via the display module, or transmitted to the host computer, data server, or maintenance terminal via a standard data interface (such as CAN bus, Ethernet interface, or USB interface), providing support for subsequent analysis, structural maintenance, or design optimization. In this embodiment, the composite load coupling index ranges from 0 to 100, and the state change level ranges from 0 to 5; the output report can be stored in JSON or CSV format to ensure data reproducibility and traceability.

[0050] See Figure 2 As shown in some embodiments of this application, this embodiment provides a method for testing the fatigue performance of high-strength bolts under combined loads, including the following steps: The load response data of the high-strength bolt under test under combined load is obtained, and the combined load coupling characteristics that characterize the interaction relationship of different loads are extracted based on the load response data. Fatigue state assessment results are generated based on the aforementioned composite load coupling characteristics; When the fatigue state assessment result meets the preset conditions, the data of the subsequent N detection cycles are progressively verified; The fatigue damage level of the high-strength bolt to be tested is determined based on the progressive verification results, and the composite load fatigue performance evaluation results are output based on the fatigue damage level.

[0051] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program goods. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program goods embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0052] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program goods according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0053] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0054] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A fatigue performance testing system for high-strength bolts under combined loads, characterized in that, include: The load information acquisition module is used to acquire the load response data of the high-strength bolt under test during the combined load process, and extract the combined load coupling characteristics that characterize the interaction relationship of different loads based on the load response data. The condition assessment module is used to generate fatigue condition assessment results based on the composite load coupling characteristics; The progressive verification module is used to progressively verify the data of the subsequent N detection cycles when the fatigue state assessment result meets the preset conditions. The failure confirmation module is used to determine the fatigue damage level of the high-strength bolt under test based on the progressive verification results, and output the composite load fatigue performance evaluation results based on the fatigue damage level.

2. The high-strength bolt composite load fatigue performance testing system according to claim 1, characterized in that, The load response data includes axial load response data, transverse load response data, torsional load response data, and corresponding deformation response data.

3. The high-strength bolt composite load fatigue performance testing system according to claim 2, characterized in that, The composite load coupling characteristics include load synchronous change characteristics, load fluctuation correlation characteristics, and deformation response consistency characteristics.

4. The high-strength bolt composite load fatigue performance testing system according to claim 3, characterized in that, When generating fatigue state assessment results based on the aforementioned composite load coupling characteristics, the following are included: The load synchronous change characteristics, load fluctuation correlation characteristics, and deformation response consistency characteristics are quantified respectively to obtain the corresponding feature evaluation values; Calculate the composite load coupling index based on the evaluation values ​​of each of the aforementioned features; The coupling deviation is obtained by comparing the composite load coupling index of the current detection cycle with the composite load coupling index of the reference detection cycle. The degree of fatigue state change is determined based on the coupling deviation, and the corresponding fatigue state assessment result is generated.

5. The high-strength bolt composite load fatigue performance testing system according to claim 4, characterized in that, When determining the degree of fatigue state change based on the coupling deviation and generating the corresponding fatigue state assessment result, the process includes: Obtain the corresponding deviation level range; Determine the deviation level range in which the coupling deviation amount falls to obtain the corresponding state change level; Calculate the cumulative value of state change by combining the state change levels of the M consecutive detection cycles preceding the current detection cycle; The degree of fatigue state change is determined based on the cumulative value of the state change, and the corresponding fatigue state assessment result is generated.

6. The high-strength bolt composite load fatigue performance testing system according to claim 5, characterized in that, Determining whether the fatigue state assessment result meets the preset conditions includes: Obtain the degree of fatigue state change corresponding to the current detection cycle and the historical degree of fatigue state change corresponding to the K consecutive detection cycles. The degree of fatigue state change in the current detection cycle is mapped to obtain the current state feature value; Calculate the consistency parameter between the current state level and the historical state feature values ​​corresponding to the K consecutive historical detection periods; When the consistency parameter reaches the consistency threshold, it is determined that the fatigue state assessment result meets the preset condition, and the progressive verification module is triggered to perform progressive verification for the next N detection cycles.

7. The high-strength bolt composite load fatigue performance testing system according to claim 6, characterized in that, When performing progressive verification on data from the subsequent N detection cycles, the following is included: The load response data for the i-th subsequent detection cycle is acquired, and the corresponding composite load coupling features are extracted to obtain the coupling feature parameters for the i-th detection cycle, where i = 1, 2, ..., N; Based on the coupling feature parameters of the i-th detection cycle, generate the corresponding i-th fatigue state evaluation result, and determine whether the i-th fatigue state evaluation result meets the preset fatigue state conditions. When the number of detection cycles that meet the conditions reaches the first preset threshold, the progressive verification is determined to have entered the effective verification stage, and the number of detection cycles that meet the conditions is continuously counted. When the number of detection cycles that meet the conditions reaches the second preset threshold, the progressive verification result is determined to be the fatigue damage confirmation result. When the number of detection cycles that meet the conditions does not reach the first preset threshold, the progressive verification result is determined to be in a non-damaged state, and subsequent damage statistics are stopped.

8. The high-strength bolt composite load fatigue performance testing system according to claim 7, characterized in that, When determining the fatigue damage level of the high-strength bolt to be tested based on the progressive verification results, the following are included: When the progressive verification result is a fatigue damage confirmation result, the cumulative fatigue damage value is calculated by combining the changing trend of the fatigue state assessment results corresponding to the subsequent M detection cycles. The fatigue damage level of the high-strength bolt to be tested is determined by comparing the cumulative fatigue damage value with the preset damage level range. When the progressive verification result is a non-damaged state, the fatigue damage level of the high-strength bolt under test is determined to be a no-damage level.

9. The high-strength bolt composite load fatigue performance testing system according to claim 8, characterized in that, The fatigue performance evaluation results under combined loads are output based on the fatigue damage level, including: The fatigue damage level is mapped to the corresponding composite load fatigue performance evaluation level or index. The output report of the fatigue performance evaluation results under the composite load is generated, including fatigue damage level, composite load coupling characteristic analysis results, and fatigue state change trend information; The fatigue performance evaluation results under the composite load are output through a display module or data interface for subsequent analysis, maintenance, or design improvement.

10. A method for testing the fatigue performance of high-strength bolts under combined loads, applied to the high-strength bolt combined load fatigue performance testing system as described in any one of claims 1-9, characterized in that, include: The load response data of the high-strength bolt under test under combined load is obtained, and the combined load coupling characteristics that characterize the interaction relationship of different loads are extracted based on the load response data. Fatigue state assessment results are generated based on the aforementioned composite load coupling characteristics; When the fatigue state assessment result meets the preset conditions, the data of the subsequent N detection cycles are progressively verified; The fatigue damage level of the high-strength bolt to be tested is determined based on the progressive verification results, and the composite load fatigue performance evaluation results are output based on the fatigue damage level.

Images