Method and system for constructing a component life estimation model based on physical mechanism

Abstract

This invention proposes a method and system for constructing a component life prediction model based on physical mechanisms, belonging to the field of fatigue life prediction technology. Addressing the problem of low accuracy in existing life prediction results, this invention acquires load data of structural components and bearings, classifies the load data, and statistically analyzes the number of cycles to obtain load cycle statistics, calculating damage characteristic parameters of structural components and bearings under actual working conditions. Based on the structural component damage characteristic parameters, the cumulative damage degree of the structural component is calculated, and the cumulative damage degree of the bearing is calculated based on the bearing damage characteristic parameters. According to the load transfer coupling relationship between the structural component and the bearing, the cumulative damage degree of the structural component and the cumulative damage degree of the bearing are coupled and corrected to obtain corrected cumulative damage degrees of the structural component and bearings. A structural component life prediction model is constructed based on the corrected cumulative damage degree of the structural component, and a bearing life prediction model is constructed based on the corrected cumulative damage degree of the bearing. This invention provides high accuracy in life prediction results.

Description

Technical Field

[0001] This invention relates to the field of fatigue life prediction technology, and in particular to a method and system for constructing a component life prediction model based on physical mechanisms. Background Technology

[0002] During the operation of lifting machinery, metal structural components and rotating support bearings are core components that determine the safe service life and lifespan of the entire machine. Constructing component life prediction models enables accurate prediction of remaining component lifespan and early warning of faults, which has significant engineering implications and practical value for improving equipment reliability and ensuring operational safety.

[0003] Currently, component life prediction methods are typically based on the theory of fatigue damage accumulation. This involves collecting actual operating loads, performing load classification and cyclic statistics, calculating damage characteristic parameters and cumulative damage, and ultimately constructing an independent life prediction model for the structural component or bearing. While this can reflect the fatigue evolution of a single component to some extent, it fails to consider the actual load transfer coupling relationship between the structural component and the bearing. This leads to deviations in the calculation of cumulative damage from actual operating conditions, resulting in low accuracy in life prediction results and making it difficult to meet the needs of refined life assessment for highly reliable equipment.

[0004] Therefore, developing a method and system for constructing a component life prediction model based on physical mechanisms is of great significance for improving the accuracy of life prediction results. Summary of the Invention

[0005] To address the issue of low accuracy in lifespan prediction results in existing technologies, this invention proposes a method for constructing a component lifespan prediction model based on physical mechanisms, specifically including the following steps: S1. Obtain load data of structural components and bearings under actual working conditions, classify the load data and count the number of cycles to obtain load cycle statistics results. S2. Based on the statistical results of load cycles, calculate the damage characteristic parameters of structural components and bearings under actual working conditions; S3. Calculate the cumulative damage degree of the structural components based on the damage characteristic parameters of the structural components, and calculate the cumulative damage degree of the bearings based on the damage characteristic parameters of the bearings. S4. Based on the load transfer coupling relationship between the structural component and the bearing, the cumulative damage degree of the structural component and the cumulative damage degree of the bearing are coupled and corrected respectively to obtain the corrected cumulative damage degree of the structural component and the corrected cumulative damage degree of the bearing. S5. Based on the corrected cumulative damage degree of the structural components, construct a predicted life model for the structural components and a predicted life model for the bearings based on the corrected cumulative damage degree of the bearings.

[0006] Furthermore, in S1, load data of structural components and bearings under actual working conditions are acquired, and the load data is classified and the number of cycles is counted. This includes: collecting load spectra of structural components under various preset working conditions, and using the rainflow counting method to classify the load spectra to obtain the discretized stress characteristic values ​​of the load spectra and their corresponding number of cycles; recording the equivalent dynamic load, speed, running time and occurrence frequency of bearings under various preset working conditions, wherein the combination of equivalent dynamic load and speed under each preset working condition constitutes a load level, and the occurrence frequency corresponds to the number of cycles of the load level.

[0007] Furthermore, in S2, based on the load cycle statistics, the damage characteristic parameters of the structural components and bearings under actual working conditions are calculated, including: for the structural components, based on the discretized stress characteristic values ​​and their corresponding cycle numbers, the total stress cycle number and maximum working stress amplitude of the structural components are calculated; based on the discretized stress characteristic values ​​and their cycle numbers, the total stress cycle number, the maximum working stress amplitude, and the structural component characteristic index, the structural stress spectrum coefficient and actual stress history parameters are calculated; for the bearings, based on the equivalent dynamic load, the bearing's geometric parameters, and material parameters, the contact stress amplitude is calculated.

[0008] Furthermore, in step S3, the cumulative damage degree of the structural component is calculated based on the damage characteristic parameters of the structural component, including: calculating the single-cycle damage degree and residual damage degree based on the actual stress history parameters, maximum working stress amplitude, structural component characteristic index, characteristic fatigue strength and fatigue strength resistance coefficient of the structural component; calculating the total life of the structural component under each preset working condition based on the residual damage degree, structural stress spectrum coefficient and the number of cycles corresponding to the characteristic fatigue strength; and calculating the first total damage degree of the structural component within the statistical period based on the total number of working cycles and total life of the structural component under each preset working condition, and using the first total damage degree as the cumulative damage degree of the structural component.

[0009] Furthermore, in step S3, the cumulative damage degree of the bearing is calculated based on the bearing's damage characteristic parameters, including: calculating the fatigue life of the bearing under the corresponding load based on the bearing's contact stress amplitude, material fatigue constant, and material fatigue index; calculating the damage degree of the bearing under each preset working condition based on the bearing's rotational speed, running time, occurrence frequency, and number of rolling elements; summing the damage degree of each working condition under all preset working conditions to obtain the second total damage degree of the bearing within the statistical period, and using the second total damage degree as the cumulative damage degree of the bearing.

[0010] Furthermore, in step S4, based on the load transfer coupling relationship between the structural component and the bearing, the cumulative damage degree of the structural component and the cumulative damage degree of the bearing are respectively coupled and corrected. This includes: analyzing the mechanical properties of the load transfer path based on the actual connection form between the structural component and the bearing to determine the statically determinate coupling relationship or the statically indeterminate coupling relationship; establishing a corresponding coupling correction model for each type, wherein a correction model for the statically determinate coupling relationship is constructed based on the force and moment balance equation, and a correction model for the statically indeterminate coupling relationship is constructed in combination with the deformation compatibility condition; according to the coupling correction model, the cumulative damage degree of the bearing is used as input to correct the cumulative damage degree of the structural component, resulting in the corrected cumulative damage degree of the structural component; and the cumulative damage degree of the structural component is used as input to correct the cumulative damage degree of the bearing, resulting in the corrected cumulative damage degree of the bearing.

[0011] Furthermore, in step S5, based on the corrected cumulative damage degree of the structural component, a structural component life prediction model is constructed, including: calculating the remaining reliability of the structural component based on the corrected cumulative damage degree of the structural component; calculating the remaining fatigue life of the structural component based on the remaining reliability of the structural component, the corrected cumulative damage degree of the structural component, and the statistical period; and constructing a structural component life prediction model according to the calculation rules of the remaining fatigue life of the structural component.

[0012] Furthermore, in step S5, a bearing life prediction model is constructed based on the corrected cumulative bearing damage, including: calculating the bearing remaining reliability based on the corrected cumulative bearing damage; calculating the bearing remaining fatigue life based on the bearing remaining reliability, the corrected cumulative bearing damage, and the statistical period; and constructing the bearing life prediction model according to the calculation rules for the bearing remaining fatigue life.

[0013] This invention also proposes a system for constructing a component life prediction model based on physical mechanisms. The system is used to execute the component life prediction model construction method based on physical mechanisms described above. The system includes: The hierarchical statistics module is used to acquire load data of structural components and bearings under actual working conditions, classify the load data, and count the number of cycles to obtain load cycle statistics results. The damage characteristic parameter calculation module is used to calculate the damage characteristic parameters of structural components and bearings under actual working conditions based on the statistical results of load cycles. The cumulative damage calculation module is used to calculate the cumulative damage of structural components based on their damage characteristic parameters, and to calculate the cumulative damage of bearings based on their damage characteristic parameters. The coupling correction module is used to perform coupling correction on the cumulative damage degree of the structural component and the cumulative damage degree of the bearing based on the load transfer coupling relationship between the structural component and the bearing, so as to obtain the corrected cumulative damage degree of the structural component and the corrected cumulative damage degree of the bearing. The estimated life model construction module is used to construct an estimated life model for structural components based on the corrected cumulative damage degree of the structural components, and to construct an estimated life model for bearings based on the corrected cumulative damage degree of the bearings.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention acquires load data of structural components and bearings under actual operating conditions, classifies the load data, and statistically analyzes the number of cycles to obtain load cycle statistics. Based on these statistics, damage characteristic parameters of the structural components and bearings under actual operating conditions are calculated. The cumulative damage degree of the structural components and bearings is calculated based on their respective damage characteristic parameters. According to the load transfer coupling relationship between the structural components and bearings, the cumulative damage degrees of both are corrected, resulting in corrected cumulative damage degrees for the structural components and bearings. Based on the corrected cumulative damage degree of the structural components, a predicted life model for both components and bearings is constructed. By analyzing the load transfer coupling relationship between the structural components and bearings, and mutually correcting their cumulative damage degrees, and constructing predicted life models based on the corrected cumulative damage degrees, this invention enables joint life assessment of structural components and bearings within the same mechanical system. This more accurately reflects the actual fatigue damage evolution process of components and effectively improves the accuracy of component life prediction. Attached Figure Description

[0015] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0016] Figure 1 This is a flowchart of the component life prediction model construction method based on physical mechanism provided in the embodiments of the present invention; Figure 2 This is a schematic diagram of the structure of the component life prediction model construction system based on physical mechanism provided in the embodiment of the present invention. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0018] The specific embodiments of the present invention will be described below.

[0019] To address the issue of low accuracy in life prediction results in existing technologies, this invention acquires load data from structural components and bearings, classifies the load data, and counts the number of cycles to obtain load cycle statistics. It then calculates damage characteristic parameters of the structural components and bearings under actual operating conditions. Based on the structural component damage characteristic parameters, it calculates the cumulative damage degree of the structural components, and based on the bearing damage characteristic parameters, it calculates the cumulative damage degree of the bearings. According to the load transfer coupling relationship between the structural components and bearings, it performs coupling correction on the cumulative damage degrees of the structural components and bearings, obtaining corrected cumulative damage degrees for both. Based on the corrected cumulative damage degree of the structural components, it constructs a life prediction model for both structural components and bearings. The life prediction results of this invention have high accuracy.

[0020] Example 1 This invention provides a method for constructing a component life prediction model based on physical mechanisms. Figure 1 This is a flowchart of the component life prediction model construction method based on physical mechanisms provided in this embodiment of the invention, such as... Figure 1 As shown, the specific steps include the following: S1. Obtain load data of structural components and bearings under actual working conditions, classify the load data and count the number of cycles to obtain load cycle statistics results.

[0021] Load data under actual working conditions refers to the set of external loads and operating state parameters that structural components and bearings experience over time during actual operation. Based on load amplitude, working condition type, or operating state, continuously changing load data is divided into multiple discrete levels. The stress response and operating cycles corresponding to each load level are counted to obtain the cycle frequency and total cycle count for each load level. The load cycle statistics include standardized statistical data such as load level, stress characteristics, and number of cycles.

[0022] Specifically, load data of structural components and bearings under actual working conditions is acquired, and the load data is classified and the number of cycles is counted. This includes: collecting load spectra of structural components under various preset working conditions, and using the rainflow counting method to classify the load spectra to obtain the discretized stress characteristic values ​​of the load spectra and their corresponding number of cycles; recording the equivalent dynamic load, speed, running time and occurrence frequency of bearings under various preset working conditions. The combination of equivalent dynamic load and speed under each preset working condition constitutes a load level, and the occurrence frequency corresponds to the number of cycles of the load level.

[0023] Preset operating conditions refer to pre-defined equipment operating states with typical loads and operational characteristics. Load spectrum refers to the sequence of actual force and stress changes in structural components recorded in time history form. Rainflow counting is a stress cycle statistical method suitable for fatigue life analysis. By counting random alternating stress signals, it extracts stress amplitude, mean, and corresponding cycle frequency, providing standard statistical data for stress spectrum calculation and fatigue damage analysis. Discretized stress eigenvalues ​​refer to key characteristic quantities such as typical stress amplitudes at each level obtained after statistical classification. Equivalent dynamic load refers to the equivalent constant dynamic load used for bearing fatigue life calculation.

[0024] Data collection and statistics were performed on structural components and bearings separately. For structural components, load spectra under various preset working conditions were collected, and the rainflow counting method was used to classify and count the load spectra, obtaining discretized stress characteristic values ​​and corresponding cycle numbers. For bearings, the equivalent dynamic load, speed, running time, and occurrence frequency under various preset working conditions were recorded. The equivalent dynamic load and speed were combined to determine the load level, and the occurrence frequency was used as the corresponding cycle number for that load level. Finally, the load cycle statistics results under the unified system of structural components and bearings were formed.

[0025] By uniformly collecting, classifying, and cyclically statistically analyzing the load data of structural components and bearings, standardized basic data under the same working condition system can be provided for structural components and bearings, ensuring the consistency of working conditions in stress calculation and damage analysis, and avoiding data deviations caused by separate statistics.

[0026] S2. Based on the statistical results of load cycles, calculate the damage characteristic parameters of structural components and bearings under actual working conditions.

[0027] Damage characteristic parameters refer to characteristic physical quantities that are calculated from the statistical results of load cycles through physical mechanisms and are used for fatigue damage calculation.

[0028] Specifically, based on the statistical results of load cycles, the damage characteristic parameters of structural components and bearings under actual working conditions are calculated, including: for structural components, based on the discretized stress characteristic values ​​and their corresponding cycle numbers, the total stress cycle number and maximum working stress amplitude of the structural components are calculated; based on the discretized stress characteristic values ​​and their cycle numbers, the total stress cycle number, the maximum working stress amplitude, and the characteristic index of the structural components, the structural stress spectrum coefficient and actual stress history parameters are calculated; for bearings, based on the equivalent dynamic load, the geometric parameters and material parameters of the bearings, the contact stress amplitude is calculated.

[0029] Total stress cycle count refers to the total number of stress cycles of a structural component under a preset working condition, obtained by summing the cycle counts corresponding to each level of discretized stress characteristic value. It is used to characterize the overall fatigue load frequency. Maximum working stress amplitude refers to the maximum amplitude selected from the discretized stress characteristic values, used to reflect the ultimate stress level of the alternating stress on the structural component. Structural component characteristic index refers to inherent characteristic parameters determined by the material properties, cross-sectional shape, and stress state of the structural component, used to characterize the fatigue response characteristics of the structure to cyclic stress loads. Structural stress spectrum coefficient refers to a dimensionless coefficient calculated based on the stress amplitude distribution and cycle frequency, used to quantify the overall load intensity level of the stress spectrum. Actual stress history parameters refer to characteristic parameters that comprehensively reflect the stress alternation history of the structural component under actual working conditions. Geometric parameters refer to inherent parameters characterizing the shape and assembly dimensions of bearing rolling elements, raceways, contact angles, etc. Material parameters refer to parameters characterizing the mechanical properties of bearing materials such as elastic modulus, Poisson's ratio, and fatigue strength. Contact stress amplitude refers to the alternating stress amplitude of the bearing rolling contact area calculated based on Hertzian contact theory, directly used for bearing fatigue damage analysis.

[0030] When calculating the damage characteristic parameters, corresponding physical mechanisms are applied to solve for the structural components and bearings respectively. For the structural components, the total stress cycle number and maximum working stress amplitude are obtained based on the discretized stress characteristic values ​​and their cycle counts. Then, the structural stress spectrum coefficients and actual stress history parameters are further calculated by combining the structural component characteristic indices. For the bearings, the contact stress amplitude is calculated based on the equivalent dynamic load, combined with the bearing's own geometric and material parameters, according to the contact mechanics relationship. Finally, damage characteristic parameters suitable for fatigue damage calculation are formed.

[0031] For example, structural stress spectrum coefficients The calculation formula is: ; in, This represents the fatigue stress amplitude. This represents the frequency of occurrence corresponding to the fatigue stress amplitude. This represents the maximum working stress amplitude of the structural component. denoted as the total number of stress cycles, and m as the characteristic index determined based on the connection form of the structural components.

[0032] Actual stress history parameters The calculation formula is: ; in, The number of working cycles corresponding to the characteristic fatigue strength of the structural component is generally taken as 2 × 10⁻⁶. 6 Second-rate.

[0033] Damage characteristic parameters are obtained by using calculation methods that match the stress characteristics and material properties of structural components and bearings respectively. This ensures the accurate representation of the stress history and load spectrum characteristics of structural components and makes the bearing contact stress calculation conform to the real physical mechanism, thereby improving the reliability and pertinence of damage characteristic parameters.

[0034] S3. Calculate the cumulative damage degree of the structural components based on the damage characteristic parameters of the structural components, and calculate the cumulative damage degree of the bearings based on the damage characteristic parameters of the bearings.

[0035] Specifically, this includes: calculating the single-cycle damage degree and residual damage degree of the structural component based on its actual stress history parameters, maximum working stress amplitude, characteristic index, characteristic fatigue strength, and fatigue strength resistance coefficient; calculating the total lifespan of the structural component under each preset working condition based on the residual damage degree, structural stress spectrum coefficient, and the number of cycles corresponding to the characteristic fatigue strength; and calculating the first total damage degree of the structural component within the statistical period based on the total number of working cycles and total lifespan of the structural component under each preset working condition, and using the first total damage degree as the cumulative damage degree of the structural component.

[0036] Cumulative damage refers to the total damage accumulated by a component under fatigue loads with each load cycle. Characteristic fatigue strength is a material constant related to the connection type, material, and manufacturing process of the structural component, representing the stress amplitude threshold that the structural component can withstand at a specific reference number of cycles. The fatigue strength resistance coefficient is a safety factor that reduces the characteristic fatigue strength in calculations, taking into account factors such as material property dispersion, manufacturing uncertainties, and the working environment, to improve the reliability of life prediction. Single-cycle damage refers to the amount of fatigue damage per unit under a single stress cycle. Residual damage refers to the remaining fatigue damage capacity that the structural component can withstand after the current statistical period, after deducting single-cycle damage. Total life refers to the predicted total number of working cycles that the structural component can withstand from the start of use to fatigue failure under specific preset operating conditions. The first total damage refers to the total cumulative fatigue damage value generated by the load cycles within the statistical period, directly used as the cumulative damage of the structural component.

[0037] Based on the actual stress history parameters, maximum working stress amplitude, structural characteristic index, characteristic fatigue strength, and fatigue strength resistance coefficient of the structural component, the single-cycle damage degree and residual damage degree are calculated. Then, based on the residual damage degree, structural stress spectrum coefficient, and the number of cycles corresponding to the characteristic fatigue strength, the total life of the structural component under each preset working condition is solved. Subsequently, combined with the total number of working cycles and the total life under each preset working condition, the first total damage degree within the statistical period is calculated and used as the cumulative damage degree of the structural component.

[0038] For example, single-instance damage The calculation formula is: ; in, This is the magnification factor; For structural characteristic fatigue strength; This represents the fatigue strength resistance coefficient.

[0039] Residual damage The calculation formula is: ; Total lifespan The calculation formula is: ; in, The residual working stress spectrum coefficient of the structural component. , This is the magnification factor.

[0040] Cumulative damage The calculation formula is: ; in, This represents the total number of work cycles.

[0041] By calculating the cumulative damage step by step based on the material fatigue characteristics and stress history of the structural components, the progressive damage effect of stress cycles on the structural components can be fully reflected. This makes the damage calculation process conform to the physical mechanism of structural fatigue evolution and ensures that the calculation results of the cumulative damage of the structural components are true and reliable.

[0042] Specifically, the cumulative damage degree of the bearing is calculated based on the bearing's damage characteristic parameters, including: calculating the fatigue life of the bearing under the corresponding load based on the bearing's contact stress amplitude, material fatigue constant, and material fatigue index; calculating the damage degree of the bearing under each preset working condition based on the bearing's rotational speed, operating time, frequency of occurrence, and number of rolling elements; summing the damage degree of each working condition under all preset working conditions to obtain the second total damage degree of the bearing within the statistical period, and using the second total damage degree as the cumulative damage degree of the bearing.

[0043] The material fatigue constant is an inherent constant determined by fatigue tests on bearing materials, used as a benchmark to characterize the fatigue performance of materials under alternating contact stress. The material fatigue index is a characteristic index reflecting the variation of bearing material fatigue life with contact stress. Fatigue life refers to the total number of cycles a bearing can operate under corresponding load and contact stress levels before reaching fatigue failure. Damage per operating condition refers to the unit fatigue damage amount generated by the bearing under a single preset operating condition, caused by the load and operating parameters of that condition. The second total damage degree refers to the total damage value obtained by summing the damage degrees of the bearing under all preset operating conditions within a statistical period, directly used as the cumulative damage degree of the bearing.

[0044] For each preset load condition, the contact stress amplitude calculated based on Hertzian contact theory, combined with the fatigue constant and fatigue index of the bearing material, is used to calculate the theoretical fatigue life of the bearing under that constant stress amplitude through the stress-life curve relationship. The actual number of stress cycles experienced by the bearing under that condition is calculated using rotational speed, operating time, and the number of rolling elements. The actual number of cycles is divided by the theoretical fatigue life, and then multiplied by the statistical frequency of that condition to obtain the damage degree caused by that single condition within the statistical period. The above steps are repeated for all preset load conditions to calculate the damage degree for each condition, and the damage degrees of all conditions are summed to obtain the total accumulated damage degree of the bearing throughout the entire statistical period.

[0045] Contact stress amplitude The calculation formula is: ; in, The load magnitude of a single roller in bearing under operating condition I. , Z is the number of rolling elements, E is the elastic modulus, μ is Poisson's ratio, and F is the elastic modulus. I The total equivalent dynamic load on the bearing under operating condition I. R is the contact length of the bearing rolling elements. eq Let be the equivalent radius of curvature of the bearing. It is the equivalent elastic modulus.

[0046] Stress cycle number under load condition I The calculation formula is: ; Where, n I Let t be the bearing speed under operating condition I. I The running time of bearing under operating condition I.

[0047] By calculating the damage degree step by step based on the rolling contact fatigue mechanism of bearings and accumulating the damage under various operating conditions, the comprehensive damage effect of alternating loads under multiple operating conditions on bearings can be accurately reflected. This ensures that the calculation of the cumulative damage degree of bearings closely matches the actual service process and guarantees that the damage results are objective and accurate.

[0048] S4. Based on the load transfer coupling relationship between the structural components and the bearings, the cumulative damage degree of the structural components and the cumulative damage degree of the bearings are coupled and corrected respectively to obtain the corrected cumulative damage degree of the structural components and the corrected cumulative damage degree of the bearings.

[0049] Load transfer coupling refers to the inherent mechanical relationship between structural components and bearings during actual stress processes, where loads, deformations, and stresses influence and transfer each other. Coupling correction refers to the process of bidirectionally adjusting the cumulative damage degree of each component and bearing based on the load transfer coupling relationship between them, in order to eliminate errors caused by independent calculations and make the damage results more consistent with actual working conditions.

[0050] Specifically, based on the load transfer coupling relationship between the structural components and the bearings, the cumulative damage of the structural components and the cumulative damage of the bearings are coupled and corrected. This includes: analyzing the mechanical properties of the load transfer path based on the actual connection form between the structural components and the bearings to determine whether the coupling relationship is statically determinate or statically indeterminate; establishing corresponding coupling correction models for each type, where a correction model for statically determinate coupling is constructed based on the force and moment balance equations, and a correction model for statically indeterminate coupling is constructed by combining deformation compatibility conditions; using the cumulative damage of the bearings as input, the cumulative damage of the structural components is corrected to obtain the corrected cumulative damage of the structural components; and using the cumulative damage of the structural components as input, the cumulative damage of the bearings is corrected to obtain the corrected cumulative damage of the bearings.

[0051] The actual connection form refers to the mechanical connection method between structural components and bearings in the assembled and working states, determining the constraint conditions and force transmission path for load transfer. The load transfer path refers to the route through which the load is transmitted between the structural component and the bearing, passing through components, contact surfaces, and constraint locations. Mechanical properties refer to the constraint characteristics, force transmission method, stiffness distribution, and force balance characteristics exhibited by the load transfer path. A statically determinate coupling relationship refers to a coupled mechanical relationship between the structural component and the bearing where load distribution can be uniquely determined solely by force and moment balance. A statically indeterminate coupling relationship refers to a coupled mechanical relationship between the structural component and the bearing where redundant constraints exist, requiring simultaneous satisfaction of force balance and deformation compatibility to determine load distribution. A coupling correction model refers to a mathematical and mechanical calculation model established based on different coupling relationships for bidirectional correction of cumulative damage. The force and moment balance equations are the mechanical control equations describing a structural system where the resultant force and resultant moment are both zero under load. Deformation compatibility conditions refer to the constraint conditions that ensure continuous deformation and coordinated displacement at the connection interface between the structural component and the bearing.

[0052] Based on the actual connection form between the structural components and the bearings, the mechanical properties of the load transfer path are analyzed to determine whether it is a statically determinate coupling relationship or a statically indeterminate coupling relationship. For statically determinate coupling relationships, a corresponding coupling correction model is established based on the force and moment balance equations. For statically indeterminate coupling relationships, a corresponding coupling correction model is established in conjunction with deformation compatibility conditions. Then, using the cumulative damage degree of the bearing as input, the cumulative damage degree of the structural components is corrected using the coupling correction model to obtain the corrected cumulative damage degree of the structural components. Simultaneously, using the cumulative damage degree of the structural components as input, the cumulative damage degree of the bearing is corrected to obtain the corrected cumulative damage degree of the bearing.

[0053] By distinguishing between statically determinate and statically indeterminate coupling relationships based on the actual connection form and constructing matching correction models for each, the actual mechanical interaction between structural components and bearings can be accurately reflected. Through bidirectional coupling correction, the systematic error caused by independent calculation of damage degree is effectively eliminated, making the corrected cumulative damage degree more consistent with the actual state.

[0054] S5. Based on the corrected cumulative damage degree of the structural components, construct a predicted life model for the structural components and a predicted life model for the bearings based on the corrected cumulative damage degree of the bearings.

[0055] Specifically, based on the corrected cumulative damage degree of the structural component, a structural component life prediction model is constructed, including: calculating the remaining reliability of the structural component based on the corrected cumulative damage degree of the structural component; calculating the remaining fatigue life of the structural component based on the remaining reliability of the structural component, the corrected cumulative damage degree of the structural component, and the statistical period; and constructing a structural component life prediction model according to the calculation rules of the remaining fatigue life of the structural component.

[0056] Residual reliability refers to the probability that a structural component will function normally within a specific future task or time period without fatigue failure. Residual fatigue life refers to the remaining fatigue life of a structural component starting from its current damage state, calculated using a modified damage level as input.

[0057] Based on the coupled-corrected cumulative damage degree of the structural component, the current residual reliability of the structural component is calculated by combining the fatigue characteristics of the structural component material and failure criteria. The residual reliability, the corrected cumulative damage degree of the structural component, and the set statistical period are used as calculation inputs to solve for the residual fatigue life of the structural component according to the preset fatigue life evolution relationship. The complete calculation process and logical relationship of cumulative damage degree, residual reliability, and residual fatigue life are integrated to finally construct a reusable structural component life prediction model. The structural component life prediction model built based on the coupled-corrected cumulative damage degree considers the mutual influence of load transfer between the structural component and the bearing, effectively avoiding errors caused by independent calculations.

[0058] Specifically, based on the corrected cumulative bearing damage, a bearing life prediction model is constructed, including: calculating the bearing's remaining reliability based on the corrected cumulative bearing damage; calculating the bearing's remaining fatigue life based on the bearing's remaining reliability, the corrected cumulative bearing damage, and the statistical period; and constructing the bearing life prediction model according to the calculation rules for the bearing's remaining fatigue life.

[0059] Bearing residual reliability refers to the probability that a bearing can continue operating normally without failures such as contact fatigue in the future. Bearing residual fatigue life is calculated from the current cumulative damage state, representing the remaining operating time or number of cycles the bearing can withstand under preset operating conditions until it reaches the fatigue failure criterion. The bearing estimated life model takes the corrected cumulative bearing damage as input and outputs a standardized calculation model of the bearing's residual fatigue life according to predetermined calculation logic.

[0060] Based on the corrected cumulative bearing damage, combined with the bearing material fatigue characteristics and preset fatigue failure criteria, the remaining reliability of the bearing under its current service state is calculated. This remaining reliability, the corrected cumulative bearing damage, and the statistical period used in previous load statistics and damage calculations are used as input parameters. Based on the bearing fatigue life evolution law and calculation relationships, the remaining fatigue life of the bearing is solved. The complete calculation process and judgment rules for the corrected cumulative damage, remaining reliability, and remaining fatigue life are integrated to construct a bearing life prediction model that can be used to continuously predict the remaining fatigue life of bearings. The bearing life prediction model built based on the coupled corrected cumulative damage considers the mutual influence of load transfer between structural components and the bearing, effectively avoiding errors caused by independent calculations.

[0061] This embodiment acquires load data of structural components and bearings under actual operating conditions, classifies the load data, and performs cycle count statistics to obtain load cycle statistics results. Based on the load cycle statistics results, damage characteristic parameters of structural components and bearings under actual operating conditions are calculated. The cumulative damage degree of the structural components is calculated based on the damage characteristic parameters of the structural components, and the cumulative damage degree of the bearings is calculated based on the damage characteristic parameters of the bearings. According to the load transfer coupling relationship between the structural components and bearings, the cumulative damage degree of the structural components and the cumulative damage degree of the bearings are coupled and corrected respectively to obtain the corrected cumulative damage degree of the structural components and the corrected cumulative damage degree of the bearings. Based on the corrected cumulative damage degree of the structural components, a predicted life model of the structural components is constructed, and based on the corrected cumulative damage degree of the bearings, a predicted life model of the bearings is constructed. By analyzing the load transfer coupling relationship between structural components and bearings, and mutually correcting the cumulative damage degrees of structural components and bearings, and constructing predicted life models based on the coupled and corrected cumulative damage degrees, joint life assessment of structural components and bearings under the same mechanical system can be achieved, more accurately reflecting the actual fatigue damage evolution process of components, and effectively improving the accuracy of component life prediction.

[0062] Example 2 This invention also provides a system for constructing a component life prediction model based on physical mechanisms. Figure 2 This is a schematic diagram of the structure of the component life prediction model construction system based on physical mechanisms provided in this embodiment of the invention, as shown below. Figure 2 As shown, the system includes: The hierarchical statistics module is used to acquire load data of structural components and bearings under actual working conditions, classify the load data, and count the number of cycles to obtain load cycle statistics results. The damage characteristic parameter calculation module is used to calculate the damage characteristic parameters of structural components and bearings under actual working conditions based on the statistical results of load cycles. The cumulative damage calculation module is used to calculate the cumulative damage of structural components based on their damage characteristic parameters, and to calculate the cumulative damage of bearings based on their damage characteristic parameters. The coupling correction module is used to perform coupling correction on the cumulative damage degree of the structural component and the cumulative damage degree of the bearing based on the load transfer coupling relationship between the structural component and the bearing, so as to obtain the corrected cumulative damage degree of the structural component and the corrected cumulative damage degree of the bearing. The estimated life model construction module is used to construct an estimated life model for structural components based on the corrected cumulative damage degree of the structural components, and to construct an estimated life model for bearings based on the corrected cumulative damage degree of the bearings.

[0063] The component life prediction model construction system based on physical mechanism provided in this embodiment is used to execute the component life prediction model construction method based on physical mechanism in the above embodiment, and has the beneficial effects of the above embodiment, which will not be repeated here.

[0064] 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 them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the technical solutions of the embodiments of the present invention.

Claims

1. A method for constructing a component life prediction model based on physical mechanisms, characterized in that, include: S1. Obtain load data of structural components and bearings under actual working conditions, classify the load data and count the number of cycles to obtain load cycle statistics results. S2. Based on the statistical results of load cycles, calculate the damage characteristic parameters of structural components and bearings under actual working conditions; S3. Calculate the cumulative damage degree of the structural components based on the damage characteristic parameters of the structural components, and calculate the cumulative damage degree of the bearings based on the damage characteristic parameters of the bearings. S4. Based on the load transfer coupling relationship between the structural component and the bearing, the cumulative damage degree of the structural component and the cumulative damage degree of the bearing are coupled and corrected respectively to obtain the corrected cumulative damage degree of the structural component and the corrected cumulative damage degree of the bearing. S5. Based on the corrected cumulative damage degree of the structural components, construct a predicted life model for the structural components and a predicted life model for the bearings based on the corrected cumulative damage degree of the bearings.

2. The method for constructing a component life prediction model based on physical mechanisms according to claim 1, characterized in that, In step S1, load data of structural components and bearings under actual operating conditions is acquired, and the load data is classified and the number of cycles is statistically analyzed, including: Load spectra of structural components under various preset working conditions are collected, and the load spectra are graded using the rainflow counting method to obtain the discretized stress characteristic values ​​of the load spectra and their corresponding cycle numbers. Record the equivalent dynamic load, speed, running time and frequency of occurrence of the bearing under various preset operating conditions. The combination of equivalent dynamic load and speed under each preset operating condition constitutes a load level, and the frequency of occurrence corresponds to the number of cycles of the load level.

3. The method for constructing a component life prediction model based on physical mechanisms according to claim 2, characterized in that, In step S2, based on the load cycle statistics, the damage characteristic parameters of the structural components and bearings under actual working conditions are calculated, including: For structural components, based on the discretized stress eigenvalues ​​and their corresponding cycle counts, the total stress cycle count and maximum working stress amplitude of the structural components are calculated; based on the discretized stress eigenvalues ​​and their cycle counts, the total stress cycle count, the maximum working stress amplitude, and the structural component characteristic index, the structural stress spectrum coefficients and actual stress history parameters are calculated. For bearings, the contact stress amplitude is calculated based on the equivalent dynamic load, bearing geometric parameters, and material parameters.

4. The method for constructing a component life prediction model based on physical mechanisms according to claim 3, characterized in that, In step S3, the cumulative damage degree of the structural component is calculated based on the damage characteristic parameters of the structural component, including: Based on the actual stress history parameters, maximum working stress amplitude, structural characteristic index, characteristic fatigue strength and fatigue strength resistance coefficient of the structural component, calculate its single cycle damage degree and residual damage degree. Based on the residual damage degree, structural stress spectrum coefficient and the number of cycles corresponding to the characteristic fatigue strength, the total life of the structural component under each preset working condition is calculated. Based on the total number of working cycles and total lifespan of the structural component under each preset working condition, the first total damage degree of the structural component within the statistical period is calculated, and the first total damage degree is used as the cumulative damage degree of the structural component.

5. The method for constructing a component life prediction model based on physical mechanisms according to claim 3, characterized in that, In step S3, the cumulative damage degree of the bearing is calculated based on the bearing's damage characteristic parameters, including: Based on the bearing's contact stress amplitude, material fatigue constant, and material fatigue index, the fatigue life of the bearing under corresponding loads is calculated. Based on the bearing's rotational speed, running time, frequency of occurrence, and number of rolling elements, the damage degree of the bearing under each preset working condition is calculated. The damage degree of each working condition under all preset working conditions is summed to obtain the second total damage degree of the bearing within the statistical period. The second total damage degree is used as the cumulative damage degree of the bearing.

6. The method for constructing a component life prediction model based on physical mechanisms according to claim 1, characterized in that, In step S4, based on the load transfer coupling relationship between the structural component and the bearing, the cumulative damage degree of the structural component and the cumulative damage degree of the bearing are coupled and corrected, including: Based on the actual connection form between the structural components and the bearings, the mechanical properties of the load transmission path are analyzed to determine the statically determinate coupling relationship or the statically indeterminate coupling relationship. For each type, a corresponding coupling correction model is established. Specifically, a correction model for statically determinate coupling relationship is constructed based on the force and moment balance equation, and a correction model for statically indeterminate coupling relationship is constructed by combining deformation compatibility conditions. Based on the coupled correction model, the cumulative damage degree of the bearing is used as input to correct the cumulative damage degree of the structural component, resulting in the corrected cumulative damage degree of the structural component; the cumulative damage degree of the structural component is used as input to correct the cumulative damage degree of the bearing, resulting in the corrected cumulative damage degree of the bearing.

7. The method for constructing a component life prediction model based on physical mechanisms according to claim 1, characterized in that, In step S5, based on the corrected cumulative damage degree of the structural components, a predicted life model for the structural components is constructed, including: The remaining reliability of the structural component is calculated based on the corrected cumulative damage level of the structural component. The remaining fatigue life of the structural component is calculated based on the remaining reliability of the structural component, the corrected cumulative damage degree of the structural component, and the statistical period. A model for predicting the life of structural components is constructed based on the calculation rules for the remaining fatigue life of structural components.

8. The method for constructing a component life prediction model based on physical mechanisms according to claim 1, characterized in that, In step S5, a bearing life prediction model is constructed based on the corrected cumulative bearing damage, including: Calculate the remaining reliability of the bearing based on the corrected cumulative bearing damage. The remaining fatigue life of the bearing is calculated based on the bearing's remaining reliability, the corrected cumulative bearing damage, and the statistical period. A bearing life prediction model is constructed based on the calculation rules for the remaining fatigue life of bearings.

9. A system for constructing a component life prediction model based on physical mechanisms, characterized in that, The system is used to execute the component life prediction model construction method based on physical mechanisms as described in any one of claims 1-8, and the system includes: The hierarchical statistics module is used to acquire load data of structural components and bearings under actual working conditions, classify the load data, and count the number of cycles to obtain load cycle statistics results. The damage characteristic parameter calculation module is used to calculate the damage characteristic parameters of structural components and bearings under actual working conditions based on the statistical results of load cycles. The cumulative damage calculation module is used to calculate the cumulative damage of structural components based on their damage characteristic parameters, and to calculate the cumulative damage of bearings based on their damage characteristic parameters. The coupling correction module is used to perform coupling correction on the cumulative damage degree of the structural component and the cumulative damage degree of the bearing based on the load transfer coupling relationship between the structural component and the bearing, so as to obtain the corrected cumulative damage degree of the structural component and the corrected cumulative damage degree of the bearing. The estimated life model construction module is used to construct an estimated life model for structural components based on the corrected cumulative damage degree of the structural components, and to construct an estimated life model for bearings based on the corrected cumulative damage degree of the bearings.

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