386 results about "Load spectrum" patented technology

The invention discloses a bridge detection method and system based on a digital twin technology, and relates to the field of bridge structure health monitoring. The method comprises the following steps: acquiring a strain distribution value, a vibration spectrum value and an environmental load spectrum value in real time through a sensor network deployed in a physical bridge, generating a structural response data set, and synchronizing the structural response data set to a digital twinborn body; calculating a damage index value and an accumulated damage quantity value based on the structural response data set; inputting the damage index value and the accumulated damage quantity value into a preset safety criterion, and calculating a safety margin coefficient value and a failure risk grade value; calculating a residual life prediction value based on the safety margin coefficient value and the environmental load spectrum value, and synchronously correcting a degradation rate value of the digital twin; and generating a priority maintenance instruction according to the failure risk grade value, the residual life prediction value and the safety margin coefficient value, and feeding back maintenance effect data to the digital twinborn body to complete updating after execution. The bridge operation and maintenance efficiency and safety are remarkably improved.

The invention relates to the technical field of water photovoltaic flexible support pile foundation construction data processing, in particular to a process for a water photovoltaic flexible support pile foundation, which comprises the following steps: fusing meteorological, hydrological and pile deformation multi-source data through a dynamic weight distribution mechanism, and generating a space-time associated dynamic load spectrum by adopting wavelet packet transformation and entropy feature extraction; a collaborative analysis architecture of a finite element simulation and machine learning agent model is constructed, an anchoring depth mapping relation and a real-time design parameter adjustment instruction are output in parallel, and macroscopic fluid parameters and microscopic material degradation characteristics are associated through a data cascade interaction correction mechanism; full-life-cycle data version management is achieved through the block chain technology, and finite element model re-calibration and protection strategy dynamic updating are triggered. The dynamic load response analysis precision and long-term stability of the pile foundation are improved, and the deformation coordination requirement of the flexible support in the complex water area environment is met.

The invention discloses an automobile chassis lightweight structure design method based on topological optimization, and relates to the technical field of lightweight design. Constructing a macro-micro coupling model, and simulating and quantifying material parameter fluctuation by using Monte Carlo; establishing a rigid-flexible coupling multi-body dynamic model, simulating working conditions such as braking and turning, and generating a load spectrum by using a rain flow counting method; constructing a multi-objective function containing light weight, rigidity and modality, and solving manufacturing constraints such as pattern draft and the like by using an NSGA-II (Non-dominated Sorting Genetic Algorithm-II) algorithm; dividing steel, aluminum and carbon fiber material domains; and fusing bench test data to correct the model. According to the method, multi-scale collaborative optimization is realized, dynamic loads are accurately mapped, and light weight and performance are balanced; the connection reliability is improved through the multi-material gradient design; manufacturability is ensured through feature recognition and process verification; the batch consistency is guaranteed by digital twinning and robustness optimization; the chassis design efficiency and quality are integrally improved, and the service life is prolonged.

The invention discloses a cable-stayed bridge tension and compression support service life evaluation method and system under random traffic flow load, and belongs to the field of bridge engineering and structure health monitoring, and the method comprises the steps: carrying out the statistical analysis of traffic load data, building a random traffic flow load model, and generating a load spectrum; correcting stay cable force and modal frequency based on bridge monitoring data, and constructing a refined multi-scale finite element model; a unit fatigue vehicle load is applied to the model, a stress influence line is obtained, a rain flow counting method is adopted to calculate stress amplitude, cycle index and average stress, the stress amplitude, the cycle index and the average stress are converted into daily average equivalent stress amplitude and equivalent daily cycle index through a fatigue damage equivalence principle, and the fatigue life of the tension-compression support is evaluated by utilizing a Miner criterion. According to the method, the problem that the influence of three-way alternating stress on bolt fatigue damage cannot be accurately reflected in the prior art is solved, the service life prediction precision of the cable-stayed bridge tension and compression support is improved, the damage of the tension and compression support can be early warned in advance, and data support is provided for safe operation and maintenance of the cable-stayed bridge.

The invention relates to the technical field of crane equipment health monitoring, in particular to a crane running state health monitoring system and method. A sensing data acquisition unit is used for acquiring a winding drum vibration harmonic component, a steel wire rope leakage magnetic field gradient and a pulley block real-time load; the data analysis unit performs rotating speed synchronous variational mode decomposition on the vibration component to extract resonance characteristics, performs temperature and stress double-compensation correction on a leakage magnetic field gradient, quantifies an energy entropy attenuation rate through wavelet packet decomposition, constructs a phase difference model of a load and vibration to output a slip risk phase offset, calculates a load spectrum damage cumulant, and calculates a load spectrum damage cumulant; and after the four heterogeneous features are fused, a residual life coefficient is output through a dual-channel convolution-long and short-term memory hybrid neural network, and an execution unit triggers crane speed reduction control when the residual life coefficient is lower than a threshold value, so that the problems of insufficient multi-source data fusion and lack of dynamic compensation in the traditional technology are solved, and the fault early warning accuracy is improved.

The invention provides an automatic leak detection method and system for a dynamic bending durability test of a metal corrugated pipe, and relates to the technical field of metal corrugated pipe performance tests.The method comprises the steps that a to-be-tested metal corrugated pipe is installed on a test station, and test working condition parameters are set through a PLC; the test working condition parameters comprise a bending motion mode, a load spectrum, an internal pressure type, a pressure value, a temperature condition and a test frequency; according to the bending motion mode and the load spectrum, a multi-degree-of-freedom bending motion mechanism is driven to apply a dynamic bending load to the metal corrugated pipe; and when the dynamic bending load is applied, internal pressure is applied to the interior of the metal corrugated pipe according to the internal pressure type and the pressure value, and a temperature environment is synchronously applied, so that a multi-factor coupling load is formed. According to the invention, on the basis of working condition setting, through multi-source data acquisition, correction and fusion determination, an automatic closed loop of test execution, abnormity alarm, helium detection quantification and report generation is realized.

The invention relates to the technical field of load spectrum analysis, and discloses a gear random fatigue load processing method and system based on a GCM counting method.The method comprises the steps that actual operation load data and actual operation environment data of a gear transmission system are collected, and torque is converted into instantaneous contact stress; dividing into a plurality of discrete cells based on discretization processing; carrying out clustering analysis on all discrete cells; constructing a two-dimensional gear counting matrix; the asymmetric cyclic stress is converted into equivalent symmetric cyclic stress, and the total service life of the gear is determined; comparing the equivalent symmetric cyclic stress with cyclic stress under a raindrop counting method to determine an adjustment coefficient, and determining an early warning threshold value according to the total service life of the gear and the adjustment coefficient; and comparing the total fatigue damage value with an early warning threshold value to determine an early warning grade. According to the method, joint statistics of the stress amplitude, the average stress and the environmental characteristics is achieved, and the defects of a raindrop counting method in the aspects of processing meshing discontinuous loads and lacking environmental adaptability are overcome.

The invention discloses a cable-stayed bridge cross brace optimization system based on system reliability and an intelligent algorithm, which relates to the technical field of bridge engineering, and comprises a multi-source parameter input module used for collecting and processing data such as a main beam section, stay cable parameters, a strain sequence, a vibration sequence, a satellite cloud picture, a traffic monitoring flow, laser point cloud and the like; and outputting the structured design data, the monitoring data flow, the dynamic load spectrum, the probability distribution model and the construction error correction parameters. According to the invention, all-dimensional data such as design, monitoring, load, materials and construction errors are integrated through the multi-source parameter input module, and multi-level and dynamic reliability evaluation is carried out on the component, the subsystem and the system level by using the system reliability analysis module, so that the component failure probability, the system reliability index time sequence and the like can be output; therefore, the real reliability level of the cross brace of the cable-stayed bridge in the whole life cycle is reflected more accurately, and the one-sidedness of a traditional method is avoided.

The invention discloses a ship shafting reliability evaluation method and system based on multiple working conditions, and the method comprises the steps: collecting multi-source data of a ship propulsion system through integrating multiple sensors; constructing a dynamic load spectrum based on a time-varying Copula function in combination with parameters such as a stress distribution function and a degradation amount distribution function; a reduced basis finite element method is adopted, experimental strain data are collected, and a reduced-order basis matrix is constructed; based on a three-stage Wiener degradation model, in combination with parameters such as a material degradation rate, activation energy and a temperature average value, the residual life of the ship propulsion system is predicted, and model parameters are adjusted in real time through a Bayesian dynamic updating mechanism; building Hamiltonian through physical constraint reinforcement learning, and optimizing operation parameters of the ship propulsion system in combination with a fault probability threshold value and an energy change rate threshold value; a digital twin engine is utilized to provide real-time visual output. According to the invention, the service life is prolonged to the greatest extent while the system meets the performance requirements; and monitoring and decision making by operators are facilitated.

The invention belongs to the field of data processing, particularly relates to a wind turbine generator gear box tooth surface strength optimization method considering multi-working-condition load distribution, and aims to solve the problem that the optimization effect is affected due to the fact that strength optimization checking is carried out only for a single working condition in the prior art. The method comprises the following steps: acquiring working condition data of the gearbox under various preset working conditions; load spectrum decoupling processing is conducted on the working condition data, a dynamic load distribution matrix synchronous with the tooth surface meshing period is determined, stress field conversion is conducted on the dynamic load distribution matrix, and a tooth root bending stress field and a tooth surface contact stress field are obtained; inputting the tooth root bending stress field and the tooth surface contact stress field into a pre-constructed double-constraint optimization model to obtain a tooth surface strengthening parameter tensor output by the model; and inputting the tooth surface strengthening parameter tensor into a preset process mapping system. Based on the method provided by the invention, the multi-working-condition operation data of the gearbox are synchronously obtained for optimization calculation, and the limitation of traditional single load analysis is broken through.

The invention provides an LNG ship pipe fitting fatigue life modeling optimization method and system. The method comprises the steps that a fatigue life simulation model of a low-temperature pipe fitting is established; fatigue state constraint is applied to a fatigue damage structure in the fatigue life simulation model based on the load spectrum and the temperature spectrum at the monitoring node, and a damage constraint condition of the target low-temperature pipe fitting in a vibration state is obtained; determining the thermal fatigue loss of fatigue life simulation under different low-temperature thermal cycle loads according to the thermal fatigue damage and load spectrum characteristics of each connection part under different low-temperature thermal cycle loads; cost optimization is carried out on fatigue life control parameters of the fatigue life simulation model according to the damage constraint conditions and all the thermal fatigue losses, optimal cost parameters for fatigue life simulation under the thermal-vibration load working condition are obtained, and the local grid density of the fatigue life simulation model is adjusted based on the optimal cost parameters. By the adoption of the scheme, parameter cost optimization of the fatigue life simulation model of the LNG ship pipe fitting under the thermal-vibration load working condition can be achieved.

The invention discloses a method and a system for testing corrosion fatigue of a bone implantation device under a pathological condition, and relates to the technical field of orthopedic medical device evaluation, and the method comprises the following steps: constructing a dynamic load spectrum database covering physiological and pathological states; in-vitro reproduction of a dynamic mechanical environment borne by the bone implantation instrument in physiological and pathological states is completed through a multi-axis servo system; and acquiring service state data of the bone implantation instrument, and analyzing the service state data of the bone implantation instrument to obtain coupling experiment data. According to the invention, the defects of single load mode and environment simulation distortion in the traditional test method are overcome, high-fidelity simulation and comprehensive monitoring of the corrosion fatigue behavior of the bone implantation device under the pathological condition are realized, the consistency of the in-vitro test result and the in-vivo actual service performance is improved, and the application prospect is wide. And a scientific and unified evaluation basis is provided for material screening, structure optimization and service life evaluation of different types of bone implantation instruments.

The invention belongs to the field of helicopter structure fatigue design, and relates to a helicopter composite material propeller hub damage safety test spectrum compilation method. The method comprises the following steps: selecting a square hole and a flexible arm as a fatigue dangerous part of the composite propeller hub of the helicopter; the square hole is located in the position, close to the rotor shaft, of the flexible arm. The characteristic loads are determined to be the flapping bending moment load of the square hole and the flapping shimmy bending moment load of the flexible arm; in order to monitor the characteristic load of the composite material propeller hub, a strain gauge is attached to the corresponding section, and calibration is carried out; during a damage safety test, loads are applied to all flexible arms of the composite propeller hub of the helicopter at the same time; and according to a damage test result, compiling an actual measurement load spectrum of the helicopter composite material propeller hub.

The invention discloses a hydraulic machine intelligent optimization control method based on big data analysis, and relates to the technical field of hydraulic machine intelligent control, and the method comprises the following steps: carrying out the real-time frequency domain analysis of pressure, flow and energy consumption signals during the operation of a hydraulic machine, constructing a load spectrum analysis module, extracting main frequency fluctuation characteristics, and building a corresponding spectrum template; and performing sliding cross matching on the control threshold change curve of the energy-saving mode switching and the frequency spectrum template, identifying a periodic coupling risk section, and labeling and recording the periodic coupling risk section. According to the invention, through frequency domain analysis and a self-adaptive lag mechanism, frequency resonance type oscillation in energy-saving control is effectively suppressed, and the operation stability and the response reliability of the system are improved; meanwhile, a strategy self-learning mechanism based on resonance labels and energy efficiency feedback is introduced, parameters and control strategies are dynamically optimized and judged, the adaptability and long-term robustness of the system to complex working conditions are enhanced, and intelligentization and high efficiency of energy-saving control of the hydraulic equipment are achieved.

The invention discloses a heavy commercial vehicle chassis virtual load spectrum efficient twin system, and relates to the technical field of automobile chassis. The method specifically comprises the following steps: S1, a load spectrum twinning method based on a virtual iteration method; comprising the following steps: S11, constructing a whole vehicle multi-body dynamic model; s2, an AM-P-sLSTM model is constructed; and S3, a load spectrum twinning method based on the AM-P-eLSTM model is carried out. According to the method, refined construction of the whole vehicle MBD model is achieved, the high-precision rigid-flexible coupling vehicle frame multi-body dynamic model with the flexible body as the main body is established mainly through the vehicle mass center, the rotational inertia and actual measurement data of chassis suspension connecting pieces, and a basis is provided for subsequent virtual iteration and load decomposition; by iterating the road surfaces with different characteristics, the time domain and relative damage error of the iteration signal and the target signal under each road surface are small, the iteration precision is high, and the requirements of subsequent virtual load spectrum twinning and fatigue analysis are met.

The invention discloses a method for rapidly evaluating the service life of a turbine cooling blade based on flight parameters, and belongs to the technical field of aero-engines. The method comprises the following steps: acquiring a load spectrum, a material, a structure and working state parameters of the turbine blade; establishing a blade finite element model and performing fluid thermosetting coupling analysis to obtain temperature field and stress field distribution; determining a dangerous part of the blade based on the temperature field and stress field distribution; respectively establishing a creep durability model, a low-cycle fatigue model and a fretting fatigue life model for dangerous parts; and finally, updating the model based on load spectrum data monitored in real time, and calculating the residual life of the blade. According to the method, the intrinsic performance of the material is associated with the characteristic structure of the blade, and the efficient life prediction model is constructed based on limited test data, so that the life consumption of the turbine blade is quickly and accurately evaluated according to actual flight parameters.

The invention relates to the technical field of port cranes and mechanical engineering, in particular to a crane structure fatigue life prediction method and system. The invention provides a crane structure fatigue life prediction method. The crane structure fatigue life prediction method comprises the steps that a finite element model of a crane structure is established, and a stress-load mapping relation matrix of crane structure nodes is generated through dimension reduction processing; collecting actual working data of the crane structure; performing data processing on the actual working data, and constructing an actual working load spectrum; based on the stress-load mapping relation matrix and the actual operation load spectrum, generating a stress-time history used for calculating the fatigue life structure node of the crane; and calculating the fatigue damage of the crane structure and predicting the residual fatigue life by combining a stress-life curve and an accumulative damage theory of a crane structure material. According to the method provided by the invention, online, real-time and accurate prediction and visualization of the fatigue life of all structures of the crane are realized, and a basis is provided for formulating an accurate operation and maintenance plan.

The invention discloses an intelligent variable pitch control method, system and equipment for a wind generating set, and relates to the technical field of wind generating set control, and the method comprises the steps: synchronously collecting multi-source data in real time through a multi-source heterogeneous sensor array, constructing a dynamic load spectrum matrix, and carrying out nonlinear optimization; an optimal pitch angle sequence is generated to drive a variable pitch execution mechanism, meanwhile, the blade stress change rate is monitored in real time, and an aerodynamic load-structure response coupling factor is calculated; when the factor exceeds a safety threshold, the pitch angle command is reconstructed and the pitch angle is forcibly adjusted to a preset safety angle. The technical problems that the power generation efficiency and the structure safety are difficult to consider under the complex turbulence condition and a safety protection mechanism under the over-limit working condition is lacked in the variable pitch control of the existing wind generating set are solved, and the aim that the power generation efficiency and the structure safety are effectively improved through nonlinear optimization control and introduction of an over-limit triggered standby control path is achieved. And the technical effect of dynamic unification of power generation efficiency and structural safety in a complex turbulence environment is achieved.

The invention discloses a bridge anti-fatigue performance analysis and optimization method and system based on finite element analysis. The method comprises the following steps: constructing a bridge finite element basic model and a random fleet time-varying load spectrum, and executing damage-rigidity dynamic coupling iterative calculation; a fatigue sensitive area is automatically identified through the strain energy density gradient, a high-precision sub-model is generated, a basic model stiffness matrix is updated in real time through a sub-model calculation result, and a fatigue evolution cloud picture containing a stiffness degradation track is generated; and finally, identifying a damage hotspot based on the cloud picture, and generating an optimization strategy containing a traffic current limiting threshold and a structure reinforcement opportunity by using a genetic algorithm. According to the method, the problem of prediction deviation of traditional static analysis is solved by simulating the reverse influence of damage on rigidity and internal force redistribution, and accurate evaluation and scientific decision-making of the whole life cycle of the bridge are achieved.

The invention relates to the technical field of data processing, and discloses an aircraft hydraulic pipeline system fault prediction method and system based on digital twinning. The method comprises the steps that flight parameters are acquired through an aircraft data bus for stage identification, and four flight stage identifiers are obtained; carrying out mapping processing on the load spectrum according to the identifier, and constructing a staged digital twin pipeline model; performing weight distribution on the multi-sensor data according to identifiers, and extracting fault feature vectors according to a twin model; and performing prediction processing through the BP neural network in stages to obtain a fault prediction result. The method solves the problem that the existing digital twinborn model cannot adapt to the full flight envelope load difference by adopting fixed parameters, so that the sensor data weight distribution lacks flight stage adaptability, and the fault prediction algorithm cannot accurately identify the differentiated fault features of different flight stages.

The invention discloses a typical mission profile-based water surface aircraft water surface load spectrum compilation method. The method comprises the following steps of: (1) determining a typical mission profile and a take-off and landing sea area of a water surface aircraft; (2) determining a wave parameter distribution condition of the take-off and landing sea area, and further determining a wave parameter distribution diagram; (3) calculating to obtain a gravity center overload time domain curve of the water surface aircraft under different wave parameters of each mission profile; carrying out filtering and statistical analysis on the gravity center overload time domain curve of the water surface aircraft to obtain a gravity center overload exceeding number of each task profile in each state; (4) weighting according to the proportion time of each working condition of the typical mission profile to obtain a gravity center overload override curve of each stage of the water surface aircraft; and (5) compiling a water surface load spectrum table. Technical reference can be provided for evaluation of the take-off and landing fatigue life of the water surface aircraft.

The invention relates to the technical field of building material performance detection, in particular to an integrated house steel structure performance detection method and system, and the method comprises the steps: 1, constructing a full-period load spectrum; step 2, multi-stage load simulation; step 3, multi-source dynamic monitoring: arranging a strain gauge array at a plugging node to capture a micro strain gradient, measuring three-way relative displacement through a cross-joint laser displacement group, and positioning a crack signal by adopting an acoustic emission sensor array; step 4, damage coupling analysis: aligning multi-source monitoring data to generate a space-time matrix, calculating a fatigue damage factor, a connection failure factor and a crack propagation factor, and inputting a neural network model to output a damage thermodynamic diagram; and step 5, performance degradation evaluation: combining the damage thermodynamic diagram and the load occurrence frequency to calculate the remaining life and generate a maintenance list. According to the method, through combination of an advanced monitoring technology and an intelligent analysis method, accurate monitoring and performance evaluation of the whole life cycle of the house steel structure are realized.

The invention provides a service life prediction method and device for an industrial robot RV speed reducer, and relates to the technical field of speed reducer service life prediction.The method comprises the steps that an acceleration load spectrum is determined according to torque and time history data, and multi-stage loads in the acceleration load spectrum are woven into a program block spectrum according to a preset sequence; all levels of loads in the accelerated load spectrum serve as independent working conditions to be applied to the multi-body dynamic model for dynamic simulation, a load and time history curve set of the key weak component is obtained and input to the cumulative damage model for life calculation, the simulated predicted life is obtained, and a damage cloud picture is generated; taking the program block spectrum as a test loading instruction to carry out an RV speed reducer accelerated life test to obtain a test observation life and a physical failure morphology; if the two are in the corresponding preset deviation range, taking the simulated predicted life as the predicted life of the current RV speed reducer; the problems of long test period, high cost and low reliability of a simulation model are solved.

The invention discloses a big data-based extended range generator load spectrum generation method, apparatus and device, and a storage medium, and relates to the technical field of vehicle engineering. The method comprises the following steps: remotely acquiring first big data and second big data of a plurality of extended-range generators through an OTA technology, and preprocessing the first big data and the second big data; determining various typical operation conditions according to the first big data and a preset threshold range; on the basis of the part damage model, the torque, the rotating speed and the part guarantee value of the typical operation conditions and a preset cycle number calculation model, calculating cycle test numbers of various typical operation conditions; determining target cooling water flow and temperature based on the distribution proportion of the cooling water flow and temperature; and generating the load spectrum of the extended range generator based on the cycle test times, the target cooling water parameters, the preset original load spectrum and the typical operation condition. According to the invention, accurate generation of the load spectrum of the extended range generator is realized through big data analysis, the test efficiency and reliability are improved, and the load spectrum better fits the actual use condition.

The invention discloses a mining area load spectrum anomaly detection method based on standard variable analysis, and belongs to the technical field of hydraulic pump anomaly detection.The mining area load spectrum anomaly detection method comprises the steps that S1, standardized data are obtained through data preprocessing, and a typical working condition data set of a hydraulic pump is constructed in combination with working conditions of an excavator; s2, constructing a historical vector and a future vector, and constructing a historical observation matrix and a future observation matrix according to the historical vector and the future vector; s3, constructing a Hankel matrix according to the autocorrelation matrix and the cross-correlation matrix, decomposing the Hankel matrix and determining a model order; s4, mapping the original data to a standard variable space and a residual space, and respectively evaluating the total variable quantity of the standard variable in the state space and the sum of squares of change errors in the residual space; and S5, determining an evaluation threshold value, and if the evaluation threshold value exceeds the control line, judging that the hydraulic pump operates abnormally. The method is based on standard variable analysis, adopts the pressure pulsation data of the hydraulic pump to perform anomaly detection, is sensitive to the internal running state of the pump, is not easily influenced by the external environment, and can perform early warning on faults of the hydraulic pump.

The invention relates to the technical field of electric power fitting testing, in particular to an electric power fitting aging testing device and method, the stress state of an electric power fitting in actual use is simulated through the cooperation of a tensioning mechanism and a mechanical loading mechanism, environmental loads such as temperature change, humidity change and salt mist are applied through an environmental load simulation mechanism, and the aging test of the electric power fitting is achieved. And meanwhile, alternating current is applied to the electric power fitting through the power supply module, so that the actual load of the electric power fitting is comprehensively simulated, a test environment identical to an actual application environment is constructed, and the reliability of a test result is ensured. And meanwhile, an equivalent cable simulation load spectrum is deduced according to historical load data by using a fatigue damage model, and the tensioning mechanism, the mechanical loading mechanism and the environment simulation mechanism act cooperatively according to the cable simulation load spectrum to carry out aging test on the electric power fitting, so that the test time is shortened, and the accuracy of an aging test result is ensured.

The invention relates to a distributed electric drive endurance load spectrum generation method and system. The method comprises the following steps: constructing a distributed electric drive whole vehicle simulation model; constructing a working condition database, wherein the working condition data comprises a plurality of working conditions and a torque distribution strategy corresponding to each working condition; constructing a simulation parameter database of the distributed electric drive whole vehicle based on the vehicle model information of the distributed electric drive whole vehicle; loading the working condition database and the simulation parameter database to the distributed electric drive whole vehicle simulation model to obtain original load data; and carrying out calculation processing on the original load data to generate a standard load spectrum for life check and bench test. According to the method, multiple torque distribution strategies are considered, and the working conditions, the torque distribution strategies and the whole vehicle parameters are associated, so that the generated load spectrum better fits the actual use scene. Therefore, the durability and reliability of the distributed electric drive system and the sub-components thereof can be evaluated more accurately by carrying out life check and bench test on the basis.

The invention discloses a vibration fatigue life prediction method and system based on a working condition adaptive spectrum. According to the method, load information of a target structure under various service conditions is obtained, and frequency domain load descriptions corresponding to different working conditions are subjected to weighted fusion according to working condition weights, so that a working condition adaptive load spectrum capable of reflecting real service characteristics is constructed; on the basis, frequency domain stress response of the structure under the random vibration condition is obtained in combination with a structural dynamics analysis model, equivalent stress description of dominant fatigue damage is further determined through a multi-axis equivalent criterion, and fatigue damage distribution is calculated through a frequency domain fatigue analysis method; and finally, predicting the vibration fatigue life of the structure in combination with a material fatigue performance curve and an environment-related performance correction relation. Compared with the prior art, the method has the advantages that the multi-working-condition load superposition effect and the service environment influence can be effectively considered, and the accuracy and engineering applicability of vibration fatigue life prediction are improved.

The invention relates to a blade root fatigue load prediction and inversion system for an offshore wind turbine, and the system comprises a data collection assembly which obtains a circumferential strain gradient, and synchronously collects wave spectrum energy distribution, leading edge erosion degree and three-dimensional wind field data to establish a joint input spectrum; the hybrid calculation component is used for generating an adversarial network, reconstructing strain distribution of a bolt hole in a non-degraded state, and comparing a circumferential strain gradient to obtain an abnormal blade root dangerous point; and the control output assembly is used for superposing the damage accumulation cloud picture of the blade root dangerous point, displaying the fatigue life consumption rate and calling an equivalent load spectrum duration curve, and generating an independent variable pitch angle instruction according to the combination of asymmetric load distribution and the combined input spectrum. According to the method, quantitative identification and positioning of early-stage micro-damage can be realized, the hysteresis limitation of traditional threshold alarm is broken through, complex fatigue analysis is converted into engineering interpretable indexes, and a fault backtracking technical support is provided; load active compensation control is achieved through an independent variable pitch instruction, and fatigue crack initiation and expansion are effectively restrained.

The invention discloses a ball screw accumulated fatigue damage value calculation method based on a dynamic threshold LLC method, and is applied to the technical field of ball screw pair bearing life research. Comprising the following steps: simplifying a load spectrum of a ball screw based on a dynamic threshold Level-Crossing Counting method; extracting a complete load cycle from the simplified load spectrum by using a rain flow counting method; correcting the stress cycle of the ball screw in combination with a Goodman model; and calculating an accumulated fatigue damage value caused by the corrected stress cycle on the basis of a Palmron-Miner linear accumulated damage theory. According to the method, the calculation accuracy of the accumulated fatigue damage value in the fatigue failure process of the ball screw pair is improved, and the design and performance improvement of the ball screw pair can be better guided.