42 results about "Stress cycle" patented technology

The invention relates to the technical field of aero-engines, and discloses a stress determination method and system for wheel disc fatigue damage evaluation in a working process, and the method comprises the steps: uniformly converting the stress of a wheel disc examination part at each time point into the stress at the temperature of the time point with the minimum fatigue life, thereby determining the equivalent stress process of the wheel disc examination part, and determining the fatigue damage of the wheel disc. And a rain flow counting method is adopted to obtain the peak-valley value stress of the first, third and fourth types of stress cycles of the wheel disc examination part in the working process. According to the method, the stress for fatigue damage evaluation in the working process of the wheel disc can be reasonably determined, and support is provided for accurate identification of the maximum fatigue damage in the working process of the wheel disc; the problem that the determined fatigue life damage of the wheel disc is unreasonable due to the fact that the maximum fatigue damage of the wheel disc with the material tensile strength and fatigue performance greatly different along with the temperature change rule cannot be effectively recognized in the prior art is solved, and the risk of fatigue failure of the wheel disc in advance in the life period is reduced.

The invention provides a shock absorber valve system fatigue life prediction method and system, and the method comprises the steps: building a shock absorber valve system fatigue life parameterized model through a fluid mechanics and finite element analysis method, and inputting related parameters which affect the damping force as the characteristic variables of the model; the effectiveness of a shock absorber indicator diagram and a damping force rapid verification model is analyzed through simulation, parameters are examined in time, optimization is made, and meanwhile preloading-valve opening-valve closing stress serves as a cycle period; and the vibration damper valve system stress change is used as a single stress cycle of fatigue analysis stress to quickly and efficiently analyze the fatigue life of the vibration damper valve system combination. According to the method for predicting the fatigue life of the valve system, the fatigue life of the damper valve system combination can be rapidly and efficiently analyzed, and simulation and test error precision obtained through a large number of actual measurement benchmarks can be controlled within 10%.

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.

The invention discloses a wind turbine generator blade root bolt fatigue strength analysis method and system. The method comprises the following steps that a three-dimensional model for blade root bolt fatigue strength analysis is established and simplified; the model is converted into a finite element model, and contact setting, boundary condition setting and loading setting of all the components are carried out; carrying out finite element calculation to obtain corresponding stresses of key nodes under different load conditions, and drawing a load-stress curve; adopting a rain flow counting method to obtain an amplitude value, a mean value and a cycle index required by fatigue calculation; interpolation is carried out in the load-stress curve, and the amplitude, the mean value and the cycle index of stress are obtained; accumulating the damage quantity values obtained in each stress cycle to obtain the total fatigue damage of the blade root bolt; generating a wind turbine generator blade root bolt fatigue strength checking report; according to the method, the initial gap and the gap judgment radius between the components are adjusted through contact setting, so that the penetration influence caused by large deformation of the model is reduced, and the problem that convergence is not easy due to improvement of the model precision is solved.

The invention provides a method, a system and equipment for evaluating fatigue performance of an inner ring rib steel pipe concrete joint. The method comprises the following steps: calculating structural geometric parameters of the jacket foundation according to an ultimate load condition; obtaining a fatigue load time history curve through load simulation based on the parameters; a node hot spot stress cycle amplitude is obtained through finite element analysis; and finally, calculating fatigue accumulated damage through an S-N curve specially fitted for the inner ring rib steel pipe concrete node, and performing evaluation. The method can solve the technical problems that an existing fatigue evaluation method does not consider the specific structure, material and process characteristics of the inner ring rib steel pipe concrete joint, so that the evaluation result discreteness is large, the accuracy is insufficient, and the requirement for accurate evaluation of the fatigue life of the complex space joint of the offshore wind turbine generator is difficult to meet.

The embodiment of the invention discloses a steel cable whole-process life prediction method considering corrosion-fatigue coupling. The method comprises the steps that the initial stress of a to-be-predicted steel cable is acquired; randomly generating an initial crack depth x0 and a critical crack depth xc of each segment; according to the diffusion coefficient of steel wire metal ions to the corrosion solution, the saturated ion concentration of the metal solution in the pit, and the delta Kth and stress distribution of each section, calculating the time tc for the corrosion pit of each section to reach the critical corrosion pit depth; starting from the subsection with the shortest tc, sequentially executing the following operations according to time steps: determining a target subsection in a crack propagation stage in the current time step; loading a stress cycle with a set step length on the basis of x0 of each target segment, and calculating a crack propagation depth x after loading of each target segment; and judging whether x of each target segment reaches xc of each target segment or not, judging whether the steel wire is invalid or not, and finally obtaining the service life of the steel cable. The embodiment of the invention can improve the accuracy of steel cable life prediction.

The invention discloses a tunnel time-delay rock burst dynamic stress and geology comprehensive discrimination method and system, and relates to the technical field of tunnel engineering. By analyzing the magnitude of disturbance stress, the relationship between a disturbance stress source and the spatial position of a tunnel, the circulation frequency of the disturbance stress, the superposition condition of the disturbance stress, the condition of a tunnel face, the spatial relationship between a structural plane and a joint and the tunnel and the characteristics of the structural plane and the joint, the risk of disturbance-induced time-delay rock burst after excavation of the current tunnel face is judged. The judgment of disturbance-induced time-delay rockburst is combined with the actual working condition on site, the time-delay rockburst can be comprehensively evaluated, and the judgment of the time-delay rockburst can be better and more accurately carried out. Targeted supporting and prevention and control measures are taken according to different disturbance stress and geological defect conditions, the engineering construction risk can be reduced to a certain degree, economic damage is reduced, the safety of constructors is guaranteed, and the method has good application value for underground engineering with frequent rock burst disasters, frequent excavation disturbance, active earthquakes and complex geological structures.

The application provides a ship structure fatigue strength analysis method and system, which calculates the main engine vibration load and the wave load received by the ship structure based on the ship data, the characteristic data of the ship structure and the global sea state data, then calculates the stress response process under the combined action of the wave load and the main engine vibration load, the spectral density function of the stress response process, each order spectral moment of the stress response process and the zero-crossing rate of the stress response process, then calculates the stress response and the stress response peak of the ship structure under the action of the sinusoidal vibration load, calculates the stress cycle number of the ship structure based on the stress response and in combination with the fatigue life S-N curve, further calculates the fatigue damage under the action of the main engine vibration load, and finally calculates the total coupling fatigue damage under the long-term sea state, and further calculates the fatigue damage of the ship structure under the combined action of the high and low frequency loads, which effectively improves the accuracy and reliability of the ship structure fatigue strength calculation.

The invention relates to a life prediction method for an automobile differential system, which comprises the following steps of: 1) dividing working conditions according to a motion relation between a planetary gear and a half axle gear of the automobile differential system, and constructing a differential system finite element model; 2) performing stress analysis on the plurality of working conditions to obtain a stress matrix table of each torque and stress parameter under different working conditions; 3) acquiring a durability load spectrum in a whole vehicle durability test and stress cycle times under different torques; and 4) combining the S-N curve of each part of the differential system to obtain the safety coefficient of each part, and predicting the service life. According to the method, a differential system finite element model is established by distinguishing two types of working conditions, a stress matrix table is generated through targeted stress analysis, the number of stress cycles is obtained in combination with a load spectrum, the safety coefficient is calculated by means of a part S-N curve and a Miner rule, the stress rule of the real working condition can be accurately captured, and the service life prediction precision is improved. The high reliability requirement of a new energy automobile differential system is met, and key technical support is provided for research and development and reliability guarantee of the new energy automobile differential system.

This application discloses a fatigue design method for high-strength bolts used in aircraft wheels, specifically relating to the field of aircraft components. The method includes: determining the bolt preload and preload torque based on the bolt's nominal diameter, the bolt material's yield strength, and a first preset relationship, combined with the bolt's application environment; determining the minimum and maximum stresses on a single bolt; determining the stress cycle ratio of a single bolt; when the stress cycle ratio reaches a preset value, determining the equivalent stress based on the minimum and maximum stresses on a single bolt; determining the bolt's cycle life based on the equivalent stress, and combining the product of the tire's rolling circumference and the aircraft's takeoff and landing distance to determine the bolt's takeoff and landing life. Based on the above method, the service life of high-strength bolts under fatigue cyclic loading can be improved.

The present invention belongs to the technical field of surface treatment of rail reinforcement layers and provides a high-energy-density irradiation process for treating rail reinforcement layers. The high-energy-density irradiation process for treating rail reinforcement layers includes inspecting the rails, irradiating the reinforcement layer surface with high-density energy, heat preservation, and testing. This process can eliminate or reduce the tensile stress on the surface of the rail reinforcement layer and refine the coarse-grained structure on the surface of the rail reinforcement layer, thereby improving the toughness and fatigue resistance of the reinforcement layer structure, preventing the reinforcement layer from peeling off due to internal cracks during the external compressive stress cycle, and greatly extending the service life of the rails after being treated with high-energy instant quenching technology. This process plays a vital role in ensuring the quality and safety of the entire high-energy beam reinforced rail.

The technology is generally directed to determining fatigue damages to an electronic component or a hardware system caused by the transport or movement of the electronic component or hardware system. The electronic components may be, for example, data center hardware components. The electronic components are susceptible to fatigue damage resulting from thermal, shock and vibration events. The thermal, shock, and vibration events may occur, for example, during transport or movement of the electronic components. To fully characterize fatigue, the acceleration and stress cycles may be tracked, which correlate with natural phenomena in the global supply chain and data center environment.

The utility model belongs to the field of electronic component detection, and provides environment temperature stress circulation equipment, which comprises a box body, a conveying module and a control module, and is characterized in that the interior of the box body is divided into a normal-temperature area, a low-temperature area, a water vapor area and a high-temperature area which are independent from one another; the conveying module is arranged in the box body, penetrates through the normal-temperature area, the low-temperature area, the water vapor area and the high-temperature area and is used for conveying a to-be-detected piece; the control module is electrically connected with the conveying module and controls the conveying module to transfer the to-be-detected piece among the normal temperature area, the low temperature area, the water vapor area and the high temperature area. According to the utility model, the detection efficiency of the to-be-detected member is improved.

The invention discloses a filter backwashing system, relates to the technical field of filter backwashing, and aims to solve the technical problems that metal fatigue is accelerated by thermal stress circulation and crystals are difficult to wash and clean. The anti-thermal-stress pipe is of a composite structure, thermal stress generated by temperature shock is effectively relieved through cooperation of the low-expansion inner layer, the shape memory middle layer and the high-expansion outer layer, the service life of equipment is prolonged, the air suction outer sleeve forms air-liquid mixed flow according to the Venturi principle, impact force generated by bubble breakage can strengthen crystal removal, and the service life of the equipment is prolonged. The deformation flow channel mechanism achieves two-section type washing, impurities easy to wash are removed in a large-flow mode in the initial stage, gas-liquid mixing needles are used for stubborn crystals in the later stage, pulse flow is generated through cooperation of a pulse pressing sleeve and a pressing piece, and the cleaning effect is enhanced through instantaneous high-pressure shock waves. In addition, a corrugated pipe head adapts to thermal expansion and cold contraction, and the washing distance can be shortened through the multi-section sleeve design of a back-flushing spraying cover; and the recoil performance is optimized, and stable operation of the system under complex working conditions is ensured.

This invention discloses a method, system, equipment, and medium for dynamic operation and maintenance of distribution networks based on point cloud technology, belonging to the field of distribution network operation and maintenance technology. It includes: inferring the connection stiffness of obstructed insulators from deformation correlation data to construct a stress topology map; identifying modally abnormal devices and calculating stress redistribution results, which are then transmitted to the distribution network equipment; constructing a fault evolution map and detecting stress cycle structures; iteratively executing stress correction values ​​until convergence; calculating bifurcation risk values ​​based on the stress distribution dispersion and maximum propagation depth of bifurcation state nodes; simulating the impact of stiffness enhancement on the number of faulty nodes in insulators; and outputting priority reinforcement equipment. This invention enables all insulators to obtain connection stiffness, eliminates accumulated deviations on the cycle path using stress correction values, comprehensively quantifies the unevenness of stress distribution and propagation depth using bifurcation risk values, and prioritizes reinforcement equipment located at critical bifurcation nodes.

This invention relates to the field of building material structural testing technology, specifically a system and method for testing the impact resistance performance of railings and handrails. The system includes: launching a standard test impactor at a preset impact point using a controllable electromagnetic launcher; acquiring a sequence of transient deformation images from multiple perspectives using a high-speed camera; extracting the spatial coordinates of structural feature points through image enhancement and feature point calibration; and calculating the dynamic displacement field and dynamic strain field. An elastoplastic dynamics inversion algorithm is used to calculate the stress distribution time history and local plastic deformation within the impact contact area, identifying stress concentration areas and determining the stress peak and stress cycle number. Combined with the degree of residual deformation, the impact resistance performance level of the railing and handrail is quantitatively assessed, achieving standardization of the testing process and quantification of the results. This method enables controllable impact process and multi-dimensional deformation acquisition, accurately obtaining the internal mechanical response parameters of the component.

The embodiment of the invention provides a thermal fatigue failure diagnosis method and device and a medium, and the method comprises the steps: determining the hardness gradient of a to-be-tested piece, and marking an area, with the hardness gradient greater than a first preset threshold value and the temperature change rate greater than a second preset threshold value, on the to-be-tested piece as a high-risk area; determining the equivalent stress amplitude of the high-risk area according to the fatigue arc spacing of the high-risk area; determining a thermal stress cycle correction coefficient according to the sulfur element enrichment concentration of the high-risk area; and determining the residual life of the to-be-tested piece based on the equivalent stress amplitude of the high-risk area and the thermal stress cycle correction coefficient. According to the invention, the accuracy of positioning a high-risk area with thermal fatigue failure can be improved, and the residual life prediction error can be reduced.

The invention discloses a steel rail welded joint damage failure early warning method and device, electronic equipment and a storage medium, and the method comprises the steps: collecting the current stress distribution data of a steel rail welded joint under the current load effect, determining a damage index vector corresponding to the steel rail welded joint according to the current stress distribution data, and determining the damage failure of the steel rail welded joint according to the damage index vector; the method comprises the steps of determining crack geometric parameters corresponding to a steel rail welded joint, determining the number of stress cycles according to the crack geometric parameters on the basis of a maximum circumferential stress criterion and a crack propagation rule, and determining failure prediction time corresponding to the steel rail welded joint according to the number of stress cycles and steel rail train operation information. And performing damage failure early warning according to the failure prediction time. According to the invention, damage failure early warning of the steel rail welded joint can be realized, early damage in the steel rail welded joint is identified, the damage detection efficiency and accuracy of the steel rail welded joint are improved, and the method can be widely applied to the technical field of rail engineering.

The application provides a kind of fan power scheduling optimization method and system, based on the operating characteristics of fan key components and external environmental factors, the stress characteristic model of key components is constructed;Based on the stress characteristic model of the key components, combined with four-point rain flow counting method and residual wave series method, the stress cycle in the operation of fan is identified and corrected, based on fatigue damage theory, the cumulative fatigue damage of fan key components is calculated;A power scheduling model is constructed to minimize the fatigue damage of the fan, the objective function is defined as the weighted minimum value of the main shaft and tower fatigue damage, and all aspects of constraints are considered comprehensively;The power scheduling model is solved by nonlinear programming method, and the optimal power scheduling strategy of each wind turbine generator is generated.The application can effectively reduce the cumulative speed of fan fatigue damage, prolong the service life of fan key components, and realize the comprehensive improvement of wind farm operation economy and equipment reliability through optimizing power scheduling strategy.

The invention discloses bilateral welding sealing equipment for vacuum packaging of a nickel-based alloy composite board, relates to the technical field of welding, and aims to solve the technical problem that the welding quality and efficiency of the composite board are poor. According to the method, the welding quality is improved from multiple dimensions, the efficiency is optimized, local overheating or insufficient penetration is avoided through bilateral synchronous welding sealing and symmetrical heating, argon full-coverage anti-oxidation is matched, weld defects are reduced, and the vacuum packaging sealing performance is guaranteed; self-adaptive heat conduction and stress dispersion are carried out in the plastic stage, local stress is uniformly dispersed, heat conduction is broken in the non-plastic stage, weld joint instability is prevented, and weld joint cracking and plate body warping are prevented; the elastic elastic pressing piece absorbs thermal expansion displacement of the plate body, so that weld joints are prevented from being damaged due to excessive extrusion, and uniform stress of each area is ensured; dynamic stress dispersion in the whole process is achieved through a stress circulation adjusting mechanism, and the cracking risk is reduced; and meanwhile, the equipment adaptability is high, operation is convenient and fast, the problems that traditional welding is poor in quality and low in efficiency are solved comprehensively, and the strict requirement for vacuum packaging is met.

The application relates to the field of service behavior research of machine tool bearing materials, in particular to a method for testing the rolling contact fatigue performance of GCr15 bearing steel used for manufacturing high-speed ceramic hybrid bearings. The testing method simulates the actual high-speed ceramic hybrid bearing material, and corresponding GCr15 bearing steel and ceramic rolling body material are selected. The bearing steel to be tested is processed into a bearing steel rod sample with a diameter of 12 mm and a length of 120 mm, and the ceramic rolling body material is processed into a ceramic ball with a diameter of 12.7 mm. A ball-rod type rolling contact fatigue test is carried out, and the contact fatigue life of the bearing steel is estimated by using the fixed number of cut-off method. The contact stress cycle cut-off value can be set as 2*10 8 , the contact stress value is 5 GPa, and the rotating speed of the bearing steel rod is 5000 rpm. The testing method of the application is close to the service working condition of the actual machine tool ceramic hybrid bearing, and can more reliably evaluate the rolling contact fatigue life of the bearing steel.

The present application relates to the field of air conditioning control technology and discloses a method for controlling an air conditioner, comprising: determining the number of stress cycles of the piping and the average number of stress impacts during each piping shutdown; calculating the shutdown limit number based on the number of stress cycles and the average number of stress impacts; determining the life extension strategy for the air conditioner based on the number of shutdowns of the air conditioner outdoor unit and the shutdown limit number; and controlling the air conditioner to execute the life extension strategy. This solution allows for a reasonable prediction of the fatigue condition of the air conditioner piping based on the number of shutdowns of the air conditioner outdoor unit and the calculated shutdown limit number, thereby selecting an appropriate life extension strategy for the different fatigue conditions of the air conditioner piping. This extends the service life of the air conditioner piping while controlling the air conditioner to execute the life extension strategy, thereby improving the reliability of the air conditioner while reducing the probability of failure of the air conditioner system. The present application also discloses a device for controlling an air conditioner and an air conditioner.

The invention provides a shield hobbing cutter replacement prediction method and system under complex geological conditions, and relates to the technical field of shield hobbing cutters, and the method comprises the steps: collecting the installation position, the stress parameter, the cutterhead rotation speed and the propulsion speed of a cutterhead hobbing cutter of a shield tunneling machine; dividing the stress parameters into a plurality of stress cycles according to the rotation period of the cutterhead to obtain the peak-valley ratio and the time ratio of each cycle; generating a stress characteristic trajectory curve according to the peak-valley ratio and the time ratio, and determining soil property mutation points according to the change rate of the envelope area of the stress characteristic trajectory curve; the hob soil body cutting volume is determined through the time interval of two continuous stress cycles, a characteristic coefficient curve is constructed according to the projection area of the volume on a cutterhead rotation plane, and the characteristic coefficient curve and the stress characteristic track curve are mapped to obtain stress characteristic coefficients; and taking a section between adjacent soil mass property mutation points as a stable interval, and determining the hobbing cutter changing time according to an internal stress characteristic coefficient accumulated value and a change rate in the stable interval. The technical problem that the prediction accuracy of shield hob abrasion under complex geological conditions is low is solved.

The present invention belongs to the technical field of suspension system durability simulation, and specifically relates to a method for improving the durability simulation accuracy of the strength of the lateral stabilizer bar cover plate; establishing a multi-body dynamics model of the suspension system, applying reverse displacements at the wheel centers on both sides, and calculating the loads at the rubber bushings; modeling the cover plate, fixing bolts, and subframe, restricting the 1-6 degrees of freedom of the connection points between the subframe and the vehicle body, and applying bolt pre-tightening forces; applying uniform loads to distinguish between vertical cover plates and flat-laying cover plates, and calculating the stress results based on the FEMFAT software as the upper and lower limits of the stress cycle, inputting the number of cycles, calculating the damage of the lateral stabilizer bar cover plate, and compiling a calculation and analysis report on the strength and durability of the lateral stabilizer bar cover plate; this method can more accurately calculate the stress, strain, and damage of the lateral stabilizer bar cover plate under the two layout modes, correctly guide the design of various types of lateral stabilizer bar cover plates, and enable their strength and durability performance to meet the standards at one time.

The invention discloses a digital twinborn evaluation method for measuring a wear state of a switch contact. The method comprises the following steps: collecting current waveform data in a switch opening and closing process as an input source; identifying and quantitatively extracting key feature parameters from the preprocessed waveform data; based on fatigue characteristics of the contact material, considering operation stress circulation, quantifying damage increment, and establishing a material fatigue accumulated damage model; inputting key characteristic parameters extracted from the waveform data and a material fatigue accumulated damage model into a digital twin frame, creating a virtual mirror image of the contact, simulating a wear process of the physical contact, and iteratively predicting a future wear trend; based on a digital twinborn simulation result, life prediction is carried out by adopting an accumulated damage threshold method; the accuracy of the model is verified through historical data, and deviation is fed back to model parameter optimization. According to the invention, the digital twinborn model of contact wear can be constructed, and accurate prediction of the residual mechanical life of the contact is realized.

The invention discloses a diaphragm compressor diaphragm head fatigue life prediction simulation method, which comprises the following steps: S1, establishing a fluid-solid-thermal coupling model of a to-be-predicted diaphragm head according to structural parameters of a diaphragm compressor; s2, based on the fluid-solid-thermal coupling model, performing simulation analysis on air pressure distribution, diaphragm dynamic and stress-strain characteristics in the diaphragm compressor under different working conditions to obtain simulation data including pressure load, diaphragm displacement amplitude, a stress cycle curve and temperature distribution; and S3, based on the simulation data, calculating the fatigue life of the to-be-predicted film head. Through a pure simulation means, a fluid-solid-thermal coupling model is established, the flow characteristic and the structure stress state are dynamically corrected by using real-time simulation data, and aiming at the problem that the opening and closing state of the hydrogen compressor valve is difficult to directly monitor, the opening time point and the duration of the valve are accurately determined by monitoring the state parameters of the gas cavity in real time, so that the hydrogen compressor valve opening and closing state is accurately monitored. Indirect and accurate judgment of the working state of the valve is achieved, and the simulation accuracy and reliability are improved.

The application discloses a tunnel time-lag type rock burst dynamic stress and geology comprehensive discrimination method and system, and relates to the technical field of tunnel engineering. The application discriminates the risk of current disturbance-induced time-lag type rock burst after the excavation of a working face by analyzing the disturbance stress size, the spatial relationship between the disturbance stress source and the tunnel, the disturbance stress cycle frequency, the disturbance stress superposition condition, the working face condition, the spatial relationship between the structural plane and joint and the tunnel, and the self characteristics of the structural plane and joint. The judgment of disturbance-induced time-lag type rock burst is combined with the actual working condition, the time-lag type rock burst can be comprehensively evaluated, and the time-lag type rock burst can be better and more accurately judged. Targeted support and prevention and control measures are taken according to different disturbance stresses and geological defect conditions, the engineering construction risk can be reduced to a certain extent, the economic damage can be reduced, the safety of construction personnel can be ensured, and the application has good application value for underground engineering with frequent rock burst disasters, frequent excavation disturbance, frequent earthquakes and complex geological structure.

The invention relates to the technical field of digital twinning, in particular to a digital twinning-based wind turbine generator full life cycle management system, which comprises a deformation parameter resolving module, a skeleton driving reconstruction module, a load damage calculation module, a health difference evaluation module and a balance control decision module. According to the method, the instantaneous curvature and the torsion rate are calculated by collecting cross section wavelength drift data, the dynamic bending posture of the flexible part in the space is reconstructed in real time, continuous tracking of stress circulation and a closed lag loop is achieved by combining pneumatic simulation and the residual peak-valley sequence stack technology, the accumulated damage degree of the part in the whole service cycle is accurately quantified, and the reliability of the part is improved. By analyzing the discrete deviation of individual damage relative to a group mean value, an asymmetric load distribution mechanism based on health state difference is established, the fatigue extension trend of high-damage parts is effectively relieved, premature failure caused by uneven load distribution is avoided, and life balance and collaborative life extension of key parts of a unit in the whole life cycle are achieved.

The application discloses an improved step counting method based on hip gait stress data, and is characterized in that stress step range and stress step number of the improved step counting method are preset based on hip gait stress data characteristics; stress steps crossed by gait stress data are sequentially judged according to a counting principle of the improved step counting method, and the number of the crossed stress steps is counted; and the crossed stress steps are combined into a stress cycle according to a stress cycle determination method of the improved step counting method, so that the amplitude and the average of the stress cycle are obtained. The method overcomes the problems of poor real-time performance and loss of time sequence information in the data counting process of the traditional fatigue counting method, effectively saves the time sequence information of femoral structure gait stress, and improves the accuracy of the artificial hip joint structure fatigue life analysis result.

The invention relates to the technical field of aviation turbine shaft engines, and discloses a power turbine disc stress cycle calculation and engine life management method and system.The method comprises the steps that the rotating speed of a power turbine rotor and the temperature of a gas turbine outlet are obtained and converted into regular cycle data, and pulsation stress cycle data are extracted; calculating the stress of the key part of the power turbine rotor at the rated rotating speed according to the pulsating stress cycle data of the rotating speed of the power turbine rotor; calculating the stress caused by the temperature field of the key part of the power turbine rotor at different rotating speeds except the rated rotating speed by combining the rotating speed of the power turbine rotor and the pulsating stress cycle data of the outlet temperature of the gas turbine; and calculating centrifugal stress and temperature stress of the power turbine rotor at the maximum rotating speed to obtain resultant stress, calculating maximum equivalent stress according to the resultant stress, and performing service life management. According to the method, the calculation efficiency can be improved while the calculation precision of the stress of the power turbine disc is ensured, and the service life of an aviation turbine shaft engine is prolonged.