36 results about "Fatigue loading" patented technology

The application discloses a component fatigue micro-damage early identification method based on a nonlinear static component, and particularly relates to the technical field of material nondestructive testing and structural health monitoring, which comprises the following steps: arranging an excitation probe and a receiving probe on the surface of a component to be measured; selecting an excitation frequency based on a frequency dispersion curve and generating a Hanning window modulated wave; collecting a propagation response signal; extracting a static component amplitude A and a fundamental wave amplitude A through time-frequency processing; calculating a nonlinear static parameter beta=A / A²; further calculating a first derivative S(N) and a second derivative ΔS(N) of beta with respect to a fatigue loading cycle N; and identifying a dislocation dominant stage, a dislocation saturation or rearrangement stage, a micro-crack initiation stage and a macro-crack formation stage according to the first derivative S(N) and the second derivative ΔS(N). The application can be used for early stage identification of the evolution process of component fatigue micro-damage.

The application particularly relates to a cast stainless steel multiaxial low-cycle fatigue prediction method, which comprises the following steps: measuring or calculating the axial strain amplitude and the corresponding axial stress, the shear strain amplitude and the corresponding shear stress, and the phase difference between the axial strain amplitude and the shear strain amplitude of a cast stainless steel concerned part; calculating the equivalent axial strain amplitude and the equivalent shear strain amplitude of the cast stainless steel concerned part after correction and containing the influence of thermal aging; and substituting the equivalent axial strain amplitude and the equivalent shear strain amplitude of the cast stainless steel concerned part after correction and containing the influence of thermal aging and the phase difference therebetween into a cast stainless steel multiaxial low-cycle fatigue prediction model containing the influence of thermal aging to calculate the multiaxial low-cycle fatigue life and the fatigue crack direction of the cast stainless steel after thermal aging. The cast stainless steel multiaxial low-cycle fatigue prediction method can accurately predict the fatigue life of the cast stainless steel under multiaxial low-cycle fatigue loading and the direction of fatigue crack initiation and initial propagation.

This application discloses a wind turbine operation control method, device, equipment, and storage medium, relating to the field of wind turbine generator control technology. The method includes: preprocessing initial pitch angle setpoints to obtain a target pitch angle setpoint time series; determining the inflection point positions of the target pitch angle setpoint time series and the change amplitude of adjacent inflection points to form a change amplitude set; determining the target change amplitude corresponding to a preset time period in the change amplitude set; and determining the number of target amplitudes from the target change amplitudes based on a preset amplitude threshold; determining whether the number of target amplitudes is greater than a preset number threshold; if greater, then controlling the target wind turbine to operate based on a preset low-fatigue operation mode. In this way, characteristic variables such as the pitch angle setpoint are used to equivalently describe the wind speed changes on the turbine rotor surface, thereby reducing fatigue load and improving the safety and stability of turbine operation.

This application discloses a wind turbine blade structure and a generator set. The wind turbine blade structure includes: a blade root section; a first connecting plate assembly, the first end of which is connected to the mating end face of the blade root section, and the second end extending along the blade axis in a direction away from the blade root section; a second connecting plate assembly, the first end of which extends along the blade axis toward the mating end face of the blade root section and is inserted into the first connecting plate assembly; and a blade tip section, which is connected to the second end of the second connecting plate assembly. In this application, the first connecting plate assembly and the second connecting plate assembly are pre-fixed at the mating end faces of the blade root section and the blade tip section, respectively, without damaging the main blade structure and without adding extra weight. Due to the absence of stress concentration caused by openings, the mechanical properties of the blade connection points are not reduced, and the blade can withstand fatigue loads and ultimate loads equivalent to those of a complete blade, thereby improving the mechanical properties of the blade.

This invention discloses a low-pressure casting and heat treatment process for high-strength and high-toughness aluminum alloy used in contact wire ratchet, belonging to the field of rail transit component manufacturing technology. The process uses AlSi7Mg0.3 alloy, obtaining high-purity aluminum liquid through two refining and modification treatments. In the low-pressure casting stage, a three-stage pressure control is adopted: the first stage is the liquid-raising stage, the second stage is the mold-filling stage, the third stage is the pressure-increasing and shrinkage-compensating stage, and finally, pressure holding and cooling are performed; followed by T6 heat treatment. This invention solves the casting problems of easy air entrapment in ratchet teeth and easy shrinkage porosity in the hub. The casting has a tensile strength ≥275MPa and a breaking load ≥94.5kN, meeting the requirements for a 2×10 contact wire ratchet. 5 Secondary fatigue load requirements.

The present invention provides a method for preparing a weld specimen with a crack, which relates to the technical field of weld specimen preparation. The method comprises the following steps: S1: Process the bevels at the welding ends of two base metals. The main weld is located between the two bevels, and the two base metals are welded at the main weld; S2: Process a first groove on the outer side wall of the base metal, and the first groove penetrates through the main weld; S3: Weld in the first groove to form an induced layer; S4: Process a second groove on the surface of the induced layer, and perform welding in the second groove by means of fusion welding. After welding, perform a cooling treatment to generate cracks; S5: Complete the welding of the cover layer of the main weld, and cover the crack inside the welding material during welding. By adopting the present invention, the crack morphology is realistic, and the position and depth of the crack are easy to control during the preparation process. It can be detected and verified in ultrasonic testing to ensure the reliability of the simulation test results. Compared with the fatigue loading method, this method effectively saves the production cost and time of cracks.

The application discloses a kind of concrete asymmetric fatigue test systems based on ultrasonic vibration loading, including universal testing machine, ultrasonic frequency generator, ultrasonic transducer, upper displacement amplifier and lower displacement amplifier and for reducing system loading eccentric moment ball hinge mechanism, the ball hinge mechanism is connected with lower displacement amplifier bottom by clamping connecting disc.This application also provides a kind of concrete asymmetric fatigue test method based on ultrasonic vibration loading, fix the concrete test piece of equal cross section cylinder between upper displacement amplifier and lower displacement amplifier, then open universal testing machine, ultrasonic frequency generator and ultrasonic transducer, realize the ultrasonic vibration asymmetric compression-compression fatigue cycle loading of concrete test piece.The application can realize the asymmetric compression-compression fatigue loading of concrete test piece by ultrasonic fatigue test technology, solve the problem of high time cost in the super-long life fatigue test of traditional concrete fatigue test system.

This application provides a method and system for predicting the fatigue performance of composite materials based on infrared thermal imaging, belonging to the field of material mechanical property testing technology. The method includes determining the fatigue performance characterization parameters and corresponding static strength values ​​of the composite material to be predicted; constructing a fatigue performance testing system for the composite material; determining the progressively increasing fatigue loading stress and load; applying progressively increasing stress levels of fatigue cyclic loading to the composite material under a given cycle to obtain a temperature field sequence and extracting temperature characteristic parameters characterizing the material's energy dissipation state; based on the temperature characteristic parameters and a composite material damage infrared characteristic library, obtaining the temperature-damage characteristic-stress relationship of the composite material under each cyclic loading level; based on this relationship, obtaining the critical transformation stress of the composite material to be predicted, determining the fatigue limit, and obtaining the fatigue life-stress relationship for fatigue performance prediction. This scheme improves prediction efficiency and accuracy, and avoids misjudgment based on a single parameter.

This invention relates to a method for evaluating service damage of aero-engine compressor blades, solving the problem that current blade performance testing cannot obtain test values ​​'d' through direct sampling from the blade. The method comprises the following steps: S1: Design the dimensions of the blade simulator; S2: Select a base material consistent with the blade; S3: Calculate the maximum temperature and maximum stress of the blade under different service conditions, based on the blade's design status; S4: Statistically count the number of Category I low-cycle cycles, Category III flight takeoff cycles, and Category IV powered takeoff cycles for at least 10 engines, and calculate the conversion factors for each type of cycle using the temperature and stress calculation values ​​under different service conditions to obtain the equivalent number of cycles for different service times; S5: Apply low-cycle fatigue loading, fixing and clamping the simulator, and performing low-cycle cyclic loading according to the stated temperature, stress, and number of cycles; S6: Take samples from the low-cycle fatigue-treated specimen and perform tensile and high-cycle fatigue mechanical property tests. This invention significantly reduces the need for collecting blade service conditions and parameters, greatly reducing workload.

This invention relates to the field of building material testing technology, specifically a method for testing the mechanical properties of corn stalk laminated timber. The method includes: planning a grid of testing points on the laminated timber; measuring the elastic modulus and local compressive strength of each testing point in both the longitudinal and transverse directions to form a measurement distribution matrix; based on the differences in values ​​of the measurement distribution matrix in each direction, performing multi-directional feature calibration on the laminated timber to delineate preliminarily identified performance defect areas; based on the performance defect areas under multi-cycle fatigue loading, using the residual elastic modulus under multi-directional cyclic testing, performing residual performance calibration to establish performance distribution weights for each testing point; based on the performance distribution weights configured for the testing points, performing spatial autocorrelation analysis to determine the spatial correlation data of performance defects; and interpreting the spatial correlation data in relation to the distribution of testing points to generate mechanical testing results. This method improves the accuracy and efficiency of laminated timber testing.

The present application relates to a kind of fatigue limit fast prediction method based on infrared thermal image energy dissipation characteristics, containing sample preparation and pretreatment, fatigue loading stress level upper limit determination, infrared fatigue test and temperature rise data acquisition, thermal image data processing and temperature rise feature extraction, energy dissipation model construction, fatigue limit value prediction, error analysis and method verification.Steady temperature rise rate under different stresses is monitored by infrared thermal imager, the relationship curve of dissipation rate and stress amplitude is established, the fatigue limit is predicted based on least square method, and compared with S N Test results are compared and verified.Compared with traditional method, the method has the advantages of high prediction accuracy, high response sensitivity, low loss, short test cycle, etc., and is especially suitable for fatigue limit fast prediction and strengthening effect determination of high-temperature alloy material after laser-assisted ultrasonic roll strengthening.​

This invention provides a fatigue testing device and system for a front axle assembly. The front axle assembly fatigue testing device includes a leaf spring surface fixing mechanism for fixing the leaf spring surface of the front axle assembly; a steering knuckle fixing mechanism for fixing the steering knuckle flange surface of the front axle assembly; a simulated tire fixture mounted on the wheel hub flange surface of the front axle assembly to simulate a vehicle tire; and a loading assembly whose loading end acts on the tire contact point of the simulated tire fixture to apply fatigue loads simulating actual vehicle driving conditions to the front axle assembly. The steering knuckle fixing mechanism is configured to fix the steering knuckle flange surface when the front axle assembly is in a steering limit state, and the loading assembly is configured to apply lateral fatigue loads and / or steering fatigue loads, thereby improving the accuracy and adequacy of verification during the front axle assembly development and design phase.

This disclosure provides a method and system for collaborative compensation of yaw error in a pitch control system. It acquires the blade's bending moment matrix, azimuth angle, and macroscopic yaw error, and uses asymmetric load decoupling and quantization techniques to convert the blade load into fixed d-axis tilting moment and q-axis yaw moment components. Subsequently, these moment components are subjected to dual-channel PI control to generate d-axis and q-axis pitch compensation commands, and the yaw feedforward signal is cleverly extracted from the q-axis integral term. Finally, based on the azimuth angle, the d-axis and q-axis pitch compensation commands are fused with the collective pitch command to obtain independent pitch commands for each blade. These commands are then combined with the yaw feedforward signal and macroscopic yaw error for collaborative control and execution, thereby achieving deep collaboration between the pitch control and yaw systems. This approach more accurately reflects the rotor's stress state and enables refined compensation, effectively reducing fatigue loads on the blades and tower base.

This invention discloses a method and system for predicting fatigue loads of wind turbines based on dynamic Weibull parameter optimization and edge computing. The method includes collecting multi-source sensor data from the wind turbine; dynamically adjusting the shape and scale parameters of the Weibull distribution based on real-time wind speed data using an optimization algorithm; cleaning, aligning, and weighting the multi-source data to construct a feature set containing dynamic Weibull parameters; predicting fatigue loads using an LSTM neural network model with integrated attention mechanism and hierarchical structure on edge computing nodes deployed at the turbine site; training the model using self-supervised learning and transfer learning strategies to improve generalization ability; and finally, combining real-time wind conditions and Weibull parameters to output the load prediction result. This invention achieves high-precision, real-time dynamic prediction of fatigue loads of wind turbines, effectively supporting turbine health management and operation and maintenance decisions.

This invention discloses a statistical damage constitutive modeling method considering multi-stage fatigue loading of rock, comprising the following steps: describing the damage of rock micro-element based on the Weibull probability distribution and establishing the relationship between damage variables and strain; dividing the constitutive model into a compaction stage and a post-compaction stage according to the initial compaction characteristics of the rock stress-strain curve, and establishing damage constitutive equations for each stage; establishing constitutive relations for loading, unloading, and secondary loading processes for multi-stage fatigue loading, and considering the cumulative effect of fatigue strain; solving the model parameters using the extreme point method to achieve theoretical modeling of the multi-stage fatigue constitutive curve of rock. This method fully considers the fatigue strain behavior generated during secondary loading, and the model parameters are all explicit, reflecting the nonlinear mechanical behavior under multi-stage fatigue loading well, and has high prediction accuracy and practical application value.

The application is suitable for the technical field of fatigue test of new energy automobile structural parts, and provides a hydraulic fatigue test method and system for automobile structural parts based on loading curve control, which comprises the following steps: acquiring a current sealing indentation continuity characteristic value, and generating a loading curve correction factor according to the deviation between the two when the value is lower than a reference value, so as to weaken the sealing pre-press simulation loading curve of the correction preset; superimposing the corrected sealing pre-press simulation loading curve and a road fatigue loading curve to perform hydraulic fatigue test on a current to-be-tested battery pack lower shell. The application avoids the test deviation caused by the same pre-press curve used in different production batches of workpieces, makes the corrected sealing pre-press simulation loading curve more suitable for the actual sealing indentation state of the current workpiece, thereby improving the consistency between the flange sealing test response and the actual vehicle service sealing reference, and enhancing the authenticity and reliability of the hydraulic fatigue test result.

The application discloses a wind turbine load adaptive load reduction method and system for complex wind fields, and relates to the technical field of wind turbine control. The method comprises the following steps: acquiring unit operation state data and environment data in real time; estimating equivalent aerodynamic load acting on a wind wheel on line according to wind wheel dynamics relation through a parameter identification algorithm based on the data; calculating generator torque compensation according to the equivalent aerodynamic load and a load reference value, and calculating pitch angle compensation according to the equivalent aerodynamic load and a cut-off frequency; superimposing the two compensation amounts on original control instructions of the wind turbine to generate and execute load reduction instructions. Through the above method, real-time on-line estimation and active feed-forward compensation of random time-varying aerodynamic load are realized, dynamic load fluctuation under complex wind fields can be adaptively reduced, fatigue load of key components can be effectively reduced, and operation safety and service life of the unit are improved.

This invention provides a multifunctional impact and fatigue testing system and method based on electromagnetic drive, belonging to the field of materials and structural mechanical property testing technology. It includes an electromagnetic track; a modular testing platform disposed at both ends of the electromagnetic track; an electromagnetic drive assembly disposed at both ends of the electromagnetic track; a multifunctional mover electrically connected to the electromagnetic drive assembly and moving along the electromagnetic track; a fatigue loading assembly disposed on the modular testing platform for applying cyclic loads to the specimen; and a measurement and control subsystem electrically connected to the electromagnetic drive assembly and the fatigue loading assembly for controlling the testing process and acquiring data. The measurement and control subsystem is configured to: control the output pulse current of the electromagnetic drive assembly to drive the multifunctional mover to accelerate in impact mode; control the electromagnetic drive assembly to drive the fatigue loading assembly to apply cyclic loads to the specimen in fatigue mode; and realize continuous or alternating execution of impact and fatigue tests in a combined mode.

The present disclosure relates to methods and systems for determining fatigue loads in wind turbines. Such methods can include obtaining operational metadata representative of an operating condition, and determining whether the operational metadata corresponds to operational metadata from a plurality of previously defined operating conditions for which fatigue loads are known, the plurality of previously defined operating conditions being stored in an operating condition database. If the operational metadata representative of the operating condition substantially corresponds to operational metadata from a stored previous operating condition, the fatigue load for the stored previous defined operating condition is aggregated to a historical cumulative fatigue load to determine a total cumulative fatigue load. Methods for registering operating conditions in a wind turbine are also provided.

This invention discloses a test bench and method for evaluating the structural optimization of a loader boom based on the Digital Image Correlation (DIC) method, belonging to the field of engineering machinery structural design optimization technology. The test bench includes a fatigue testing machine, a reconfigurable fixture, a scaled-down model of the loader boom, a high-speed camera, and an image processing system. The reconfigurable fixture simulates boundary conditions under two typical working conditions of loader propulsion and lifting by switching the linkage connection positions and component configurations. A speckle pattern is prepared on the surface of the scaled-down model, and images are continuously acquired by the high-speed camera during fatigue loading. This invention utilizes the DIC algorithm to obtain the full-field strain distribution of the boom, converts it into stress amplitude using Hooke's Law, and quantitatively evaluates the structural optimization effect by comparing the stress cloud map, maximum stress value, and fatigue life prediction results of the model before and after optimization. This invention solves the problems of traditional strain gauges having few measurement points, failing to reflect global stress concentration, and the high cost and long experimental cycle of full-scale tests, providing a low-cost, high-precision verification method for rapid iterative optimization of boom structures.

This invention provides a fatigue testing method and system for a front axle assembly. The method includes fixing the leaf spring surface of the front axle assembly to a test bench and fixing the steering knuckle flange surface of the front axle assembly according to preset test conditions, so that the front axle assembly is under the constraint state simulating the actual load of the vehicle. A fixture simulating the tire of the vehicle is installed and fixed at the wheel hub flange surface of the front axle assembly. The fixture is provided with a load application interface simulating the tire contact point. A fatigue load is applied at the load application interface of the fixture through a loading component to simulate the actual input load applied to the front axle assembly by the road surface through the tire during vehicle operation. A cyclic loading test is completed according to a preset fatigue load spectrum. The fatigue response data of the front axle assembly is recorded, and its design reliability is evaluated to determine whether it meets the load-bearing and driving requirements of the vehicle. This significantly improves the accuracy and sufficiency of the verification during the development and design stage of the front axle assembly.

This invention discloses a fatigue testing device and method for large composite material power blades. The testing device includes: a blade to be tested, a fixing fixture, an aerodynamic / aerodynamic torque loading system, a clamping loading fixture, and a centrifugal force loading system. The blade shank and support ring are connected to the fixing fixture, and the blade body is connected to the clamping loading fixture. The clamping loading fixture is connected to both the aerodynamic / aerodynamic torque loading system and the centrifugal force loading system, with the aerodynamic / aerodynamic torque loading system perpendicular to the centrifugal force loading system, to simultaneously apply the axial centrifugal force, aerodynamic bending load, and aerodynamic torque load of the blade rotation. This invention features a compact structure, convenient operation, and high reliability. It enables the development of a fatigue load spectrum based on the blade's operating conditions, fully verifying the blade's fatigue performance and solving the problem of high-reliability verification of blade fatigue life.

The application provides a SEM in-situ single-lap interface push-shear fatigue test device and method, and belongs to the technical field of mechanical testing. The device comprises a base, a loading mechanism installed on the base, an outer clamping mechanism for fixing one end of a second material in a single-lap sample, an inner clamping mechanism connected with an output end of the loading mechanism and used for clamping one end of a first material in the single-lap sample, wherein the end of the first material is lap-jointed with the other end of the second material, and a force sensor arranged between the outer clamping mechanism and the base. The loading mechanism, the inner clamping mechanism, the lap-jointed interface of the single-lap sample and the clamping point of the outer clamping mechanism are arranged in line in sequence. The application geometrically eliminates the secondary bending moment of the single-lap sample through a unique push-shear guide structure, and realizes high-stability in-situ fatigue loading by using a motor-piezoelectric series hybrid driving strategy.

The application discloses a fatigue load spectrum construction method of a superconducting magnet and related products. The method comprises the following steps: acquiring measured data of a preset superconducting maglev train scaled test line in each physical field; the physical field comprises an electromagnetic field, a temperature field, a structure field and an aerodynamic pressure field; and fatigue load spectrum construction of the superconducting magnet is realized by using the measured data corresponding to each physical field, so that the fatigue load spectrum is used for fatigue durability design of the superconducting magnet, thereby improving the pertinence and rationality of superconducting magnet design, improving the design reliability of a core component of a high-speed maglev train, and promoting the engineering process of a superconducting high-speed maglev train.

This invention belongs to the field of fatigue life prediction technology for automotive components, specifically involving a wheel fatigue life prediction method based on impact damage transmission. This method obtains plastic strain and stress results through explicit dynamics module simulation of impact tests; extracts residual stress tensors and node numbers; imports these damage states as initial conditions into a static analysis module and maps them to the deformed nodes to establish a wheel model containing impact damage; then applies fatigue loads for static solution; finally, imports the stress results into nCode for fatigue life prediction and comparison. This invention solves the problem of fatigue life prediction for wheels after impact damage during service, constructs a simulation analysis process for wheel "fatigue life prediction after impact damage," realizes fatigue life prediction for accident-damaged wheels, and provides a reliable basis for wheel structure optimization.

The application discloses a kind of quantitative test method and system of robot joint module peak stall torque, it is related to robot joint performance evaluation technical field, comprising: extracting the torque time history curve of joint module, peak stall torque is defined as controlled low-frequency fatigue loading process, the mapping model of torque amplitude and failure cycle number is established;Test system is constructed, torque-current static calibration is carried out;Specific excitation function is embedded in servo driver current loop;Bus voltage and rotational speed change rate are monitored in real time, using back electromotive force compensation algorithm and combining energy dissipation discharge loop, the voltage and current impact of unloading moment is inhibited;Repeatedly loaded until structure is damaged, cycle number is recorded, peak torque-life curve is drawn, as whole machine life prediction basis.The application realizes the quantitative correlation of peak stall torque and fatigue life, realizes the quantitative evaluation from static index to dynamic life, provides basis for robot whole machine life prediction, improves test precision.