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104 results about "Fatigue stress" patented technology

While the main symptoms of fatigue are a general feeling of weariness or being tired or drowsy, stress related fatigue is usually accompanied by other symptoms: Sore or aching muscles or feeling of muscle weakness. Headache. Moodiness, irritability or easily agitated. Dizziness and blurred vision.

Bridge structure monitoring system and method combined with active early warning

The invention provides a bridge structure monitoring system and method combined with active early warning, and the method comprises the steps: obtaining dynamic stress data and static stress data of each bridge monitoring point in a bridge section, and constructing a plurality of fatigue stress spectrums according to the dynamic stress data of each bridge monitoring point; determining a damage accumulation coefficient of a bridge structure at each bridge monitoring point according to a stress distribution difference between the fatigue stress spectrums, and extracting a plurality of monitoring key points by combining all the damage accumulation coefficients with dead load characteristics of a bridge section; determining the rigidity of the bridge structure corresponding to each monitoring key point according to the static stress data of each monitoring key point, and determining a confidence interval for performing active early warning on the structural damage of the bridge section according to all the rigidity of the bridge structure; and performing structural damage early warning on the bridge section based on the confidence interval and the current bridge stress at each bridge monitoring point. Accurate early warning of bridge structure damage can be realized under the influence of multi-dimensional load response.
Owner:GUANGZHOU INFORMATION INVESTMENT CO LTD +1

Fatigue analysis method for reactor pressure vessel in marine environment

The invention discloses a reactor pressure vessel fatigue analysis method in a marine environment, which belongs to the technical field of pressure vessel analysis, and comprises the following steps: calculating a transfer function of a structure under the action of a wave load through a spectrum analysis method, and obtaining a stress component power spectrum density function of a node based on a sea condition parameter; converting the frequency domain signal into a time domain signal; calculating a stress time history under the action of the thermal-internal pressure load and carrying out superposition of stress component time histories to obtain a fatigue stress value of the structure; and calculating the fatigue damage value of each stress cycle, obtaining the fatigue damage of each group of time history, and obtaining the total fatigue damage under the working condition. According to the method, the defects of the existing fatigue analysis method can be overcome, and the fatigue damage of the reactor pressure vessel of the nuclear power station under the combined action of multiple loads in heat, internal pressure and marine environment can be accurately evaluated.
Owner:烟台哈尔滨工程大学研究院

Fatigue damage prediction method and system for floating platform based on actually measured sea condition data

InactiveCN119378339AGeometric CADProbability distribution functionsFatigue damagePredictive methods
The invention relates to the technical field of offshore oil engineering, and provides a floating platform fatigue damage prediction method and system based on actually measured sea condition data, and the method comprises the steps: building an overall finite element model of a floating platform; determining a stress transfer function of a local structure of each fatigue sensitive position in the floating platform under different loading conditions under different wave direction angles; combining the stress transfer function with wave spectrums of different short-term actually-measured sea conditions to obtain fatigue stress energy spectrum density functions under different actually-measured sea conditions; determining fatigue damage values under different short-term actual measurement sea conditions according to the fatigue stress energy spectrum density functions under different actual measurement sea conditions and the SN curve, and constructing a fatigue damage array; the fatigue damage array is searched according to the current loading working condition of the floating platform and the short-term actually-measured sea condition data and the wave direction angle of each sea condition duration recorded in real time, the fatigue damage value of the local structure of the fatigue sensitive position in the corresponding short-term actually-measured sea condition recording time period is obtained, and the prediction result is more accurate and reliable.
Owner:OFFSHORE OIL ENG CO LTD

Fatigue reliability self-adaptive evaluation method for wind power gear box under real-time wind condition

The invention relates to the field of reliability design analysis of a transmission system, and discloses a fatigue reliability adaptive evaluation method for a wind power gear box under a real-time wind condition, and the method comprises the steps: obtaining a working condition curve of a wind turbine generator according to a wind energy utilization coefficient Cp; according to the real-time wind speed history, fitting to obtain average wind speed distribution and turbulent flow standard deviation characteristic values of the real-time wind speed history; according to the cut-in wind speed and the cut-out wind speed, generating an input rotating speed and an input torque history according to the working condition curve of the wind turbine generator, and obtaining a fatigue stress history of each failure mode according to external excitation; according to the fatigue stress distribution and the stress cycle index of the part under each working condition, obtaining the fatigue stress distribution of the part under the full wind condition; generating a corresponding equivalent fatigue load spectrum according to the fatigue stress distribution and the stress cycle index of the part under each working condition; obtaining the fatigue damage and residual strength history of the fatigue sample of each part; obtaining a function value of each failure mode of each fatigue sample; and obtaining the fatigue reliability of the wind power gear box according to the reliability of each failure mode.
Owner:XINJIANG UNIVERSITY

Intelligent testing method for fatigue performance of wet brake

The invention belongs to the field of mechanical performance testing, and relates to an intelligent testing method for the fatigue performance of a wet brake, which comprises the following steps of: acquiring real-time operation data of the wet brake under the condition that a load is applied by a loading device in a testing process by deploying a multi-source monitoring array; generating a fatigue stress distribution diagram representing the stress state of a preset test area of the wet brake based on working condition fusion analysis, correspondingly identifying a failure early warning signal representing the current fatigue damage stage so as to dynamically adjust the parameters of a loading device, and adjusting the stress state of the wet brake in the loading intermittent period of a single test cycle period. The fatigue performance response effect of the wet brake under the action of the current loading strategy is analyzed, the correction direction of the loading strategy of a secondary test cycle is determined, test convergence is achieved through iterative optimization, the consistency of a test result and a real fatigue damage rule is improved, meanwhile, the test efficiency and evaluation precision are improved through closed-loop regulation and control and a self-adaptive iterative framework, and the test accuracy is improved. And a reliable basis is provided for fatigue performance evaluation of the wet brake.
Owner:QINGDAO KAMAN TRANSPORTATION EQUIP CO LTD

Non-parametric prediction method for fatigue life of steel-FRP composite bar

The invention discloses a nonparametric prediction method for the fatigue life of a steel-FRP composite bar, and belongs to the field of fatigue performance evaluation of civil engineering materials and structures, and the nonparametric prediction method comprises the following steps: initializing component material attributes, load conditions and initial states of the steel-FRP composite bar, the component materials comprising an inner core steel bar and an FRP layer; according to an equivalent stiffness distribution principle, fatigue stresses of the component materials are calculated respectively; according to the fatigue stress of the component material, theoretical fatigue life of the component material is obtained in combination with the S-N curve relation, and cyclic jumping is executed; calculating accumulated fatigue damage of the component materials respectively based on results after cyclic jumping; and circularly updating the dynamic stiffness and the equivalent cycle number of the component material until the accumulated fatigue damage of any component material reaches a critical threshold value, judging that the component material is invalid, and outputting the fatigue life. According to the method, the fatigue life of the steel-FRP composite rib can be efficiently and accurately predicted, and the test cost is remarkably reduced.
Owner:FOSHAN UNIVERSITY

Vehicle fatigue analysis method based on VPG and modal stress recovery, analysis terminal and storage medium

PendingCN119150448ASpeed ​​up the development processimprove accuracyGeometric CADSustainable transportationVehicle dynamicsElement model
The invention provides a whole vehicle fatigue analysis method based on VPG and modal stress recovery, an analysis terminal and a storage medium, and belongs to the technical field of whole vehicle fatigue analysis. Configuring a vehicle body finite element model, and performing modal analysis to obtain a modal neutral file and a modal result file; coupling the modal neutral file with the vehicle dynamics model to generate a rigid-flexible coupling model; carrying out vehicle dynamics analysis by taking the actual test field virtual road surface as input, and outputting a modal coordinate file; stress recovery and fatigue life prediction are carried out based on a fatigue analysis algorithm, the equivalent fatigue stress of the whole vehicle body is obtained, and fatigue analysis of the vehicle body is completed in combination with an S-N curve. According to the method, the vibration relation between the external load frequency and the inherent frequency of the structure can be effectively considered, the more accurate fatigue life is further obtained, and the method has good application value in engineering.
Owner:HEZHI SHUCHUANG (SHANDONG) TECH DEV CO LTD +1

Real-time balance fatigue stress monitoring method, electronic equipment and storage medium

The invention discloses a balance fatigue stress real-time monitoring method, electronic equipment and a storage medium, and belongs to the technical field of wind tunnel test. In order to solve the problem of real-time monitoring of fatigue stress of a test balance, the method comprises the following steps: constructing a balance model by using ANSYS software, performing finite element mesh division on the constructed balance model, calculating a finite element solution of the balance model after mesh division under a designed pneumatic load, and obtaining a finite element analysis result of the balance model; extracting a stress node close to the yield strength of the balance as a high-risk stress monitoring object, and establishing a stress equation between the aerodynamic load of the balance and the stress node; collecting the aerodynamic load of the balance through data collection equipment, and recording the stress change of the balance in real time; a Goodman straight line graph is used for representing the fatigue characteristic relation of high-risk stress nodes of the balance, and balance fatigue stress real-time monitoring and risk early warning are carried out. The balance can be safely used under the condition of higher load and volume ratio.
Owner:CHINA AVIATION IND CORP HARBIN AERODYNAMICS RESEARCH INSTITUTE

Method for calculating bearing capacity of embedded steel bar beam under fatigue load effect

The invention relates to a method for calculating the bearing capacity of an embedded steel bar beam under the fatigue load effect, and belongs to the technical field of engineering structure reinforcement and transformation. Comprising normal section flexural capacity calculation under the static load effect, normal section fatigue stress calculation, oblique section shear capacity calculation under the static load effect and oblique section fatigue stress calculation. The method for calculating the bearing capacity of the embedded steel bar beam is given by considering the influences of the concrete compressive strength, the section size, the embedded steel bar drilling position, the tensile strength of steel bars in an original component, the external load form and the like. According to the method, the known plane section assumption and the stress equivalent graph are calculated by adopting the bearing capacity of the concrete structure, the balance equation of the bending moment and the force is established, and derivation is performed according to the truss-arch theoretical mechanical model and the fatigue stress damage amount obtained by the test in combination with the component damage form limited by the existing specification, so that the reliability is relatively high; and a new thought can be provided for research on the bending-resistant and shearing-resistant bearing capacity of the embedded steel bar concrete beam.
Owner:NORTH CHINA INST OF AEROSPACE ENG

Passenger car body fatigue life prediction and grading early warning integrating visual and frequency domain data

The invention provides a passenger car body fatigue life prediction and early warning method fusing visual and frequency domain data. The method comprises the following steps: synchronously acquiring a car body vibration time domain signal and a road surface image; converting the time domain signal into a power spectral density curve, extracting frequency domain features, and combining image visual features to jointly identify the grade of the road surface; constructing and dynamically calibrating a digital twin simulation model based on the curve; fusing physical, frequency domain, virtual, visual and knowledge data, and predicting the residual fatigue life through a neural network; on the basis of the power spectral density curve, calculating equivalent fatigue stress through a Miller criterion to carry out fatigue evaluation, and calculating maximum quasi-static stress according to a criterion 3 to carry out static strength evaluation; and dynamically triggering and managing monitoring, early warning and emergency three-level closed-loop early warning according to the road grade, the fatigue damage value and the stress intensity ratio. Accurate sensing of working conditions, fatigue-strength collaborative evaluation and multi-stage dynamic early warning are realized, and the accuracy and practicability of passenger car body safety monitoring are improved.
Owner:XIAMEN UNIV OF TECH

Running part framework fatigue damage assessment method based on motor vibration

The invention discloses a motor vibration-based walking part framework fatigue damage assessment method, which comprises the following steps of: performing vibration test and dynamic stress test at a specified position of a bogie to obtain a motor acceleration signal and dynamic hot spot stress, and preprocessing the motor acceleration signal and the dynamic hot spot stress; a motor acceleration signal is used as input excitation, and the power spectrum density of the dynamic hot spot stress is calculated through a transfer function and the real-time motor acceleration; based on the obtained power spectrum density of the dynamic hot spot stress, reconstructing a stress time history by using fast Fourier inversion; and based on the stress time history obtained by reconstruction, performing fatigue stress estimation by adopting a frequency domain method. The fatigue damage degree of the bogie frame is evaluated through motor vibration, and harm caused by fatigue fracture of the frame is avoided.
Owner:SUZHOU RAIL TRANSIT GROUP CO LTD +1

Harmonic speed reducer bearing retainer

The utility model provides a harmonic speed reducer bearing retainer, which belongs to the field of harmonic transmission flexible bearings and comprises an annular retainer end ring and a plurality of window beams arranged along the circumference of the retainer end ring at equal intervals, one end of each window beam is connected with the retainer end ring, and open pockets for accommodating rolling bodies are formed between the adjacent window beams. The window beam is provided with the turnup fins facing the outer ring face, the structural strength of the window beam is enhanced through the fins arranged on the window beam, and when the retainer is deformed under the action of external force, the fins can absorb part of deformation energy through elastic deformation of the fins. Once the external force disappears, the elastic recovery capability of the fins can promote the retainer to quickly recover to the original shape, so that the risks of accumulated stress and fatigue fracture caused by continuous deformation are reduced, and the retainer can effectively resist fatigue stress caused by continuous deformation in the long-term operation process. The service life of the retainer is prolonged, and faults and maintenance cost caused by fatigue fracture are reduced.
Owner:SHANDONG GOLDEN EMPIRE PRECISION MACHINERY TECH CO LTD

Wing-plate-free steel box girder bridge temperature fatigue load model

A wing-plate-free steel box girder bridge temperature fatigue load model is composed of a vertical temperature gradient fatigue load model and a transverse temperature gradient fatigue load model which are both in a bifold line type. According to the temperature field and temperature stress distribution characteristics of the wing-plate-free steel box girder, a Latin hypercube sampling method and a damage equivalence principle are adopted, and a temperature gradient fatigue load model of the wing-plate-free steel box girder bridge with the designed service life reaching 100 years is constructed. According to the temperature fatigue load model, rapid calculation of the temperature fatigue stress process of the wing-plate-free steel box girder bridge is achieved, and the temperature fatigue load model can be used for anti-fatigue design and fatigue life evaluation of the wing-plate-free steel box girder bridge.
Owner:CCCC FIRST HIGHWAY CONSULTANTS CO LTD +1

Corrosion fatigue life prediction model construction method and process parameter optimization method for milling workpiece

The invention belongs to the field of corrosion fatigue performance, and particularly discloses a milling workpiece corrosion fatigue life prediction model construction method and a process parameter optimization method.The milling workpiece corrosion fatigue life prediction model construction method comprises the steps that a surface quality prediction model is constructed based on process parameters and corresponding workpiece surface states obtained through tests, and the workpiece surface states comprise surface roughness and hardness; introducing a fatigue stress concentration factor and a work hardening ratio into the initial fatigue life model to respectively reflect local stress concentration caused by surface topography and machining surface hardening caused by milling, and performing surface roughness correction and surface hardness correction on the initial fatigue life model; obtaining a fatigue life model related to the surface state of the workpiece and the corresponding corrosion fatigue life; and combining the surface quality prediction model and the fatigue life model to form a corrosion fatigue life prediction model of the milling workpiece. According to the method, corrosion fatigue life prediction and process parameter optimization of the nickel-aluminum bronze milling workpiece can be realized, and important guidance is provided for actual processing.
Owner:HUAZHONG UNIV OF SCI & TECH

Austenitic stainless steel fatigue aging damage prediction and evaluation method, equipment and system

A method for predicting and evaluating the fatigue aging damage of austenitic stainless steel is provided. Based on the Allometricl model calculation method, the fatigue stress-fatigue life relationship corresponding to the low-cycle accelerated fatigue experiment is output, and the coincidence degree is evaluated by establishing the fitting relationship between the stress amplitude and the fatigue life using the Basquin formula; based on the KAM value in EBSD as the characteristic defect parameter, the change curve with the number of cycles is calculated; based on the Vickers hardness as the mechanical characteristic parameter, the fitting relationship between the Vickers hardness and KAM of each stage sample of the fatigue sample under the fatigue stress is obtained; based on the correlation model between the KAM value and the saturation magnetic induction intensity, the fitting relationship between the saturation magnetization intensity and KAM of each stage sample of the fatigue under the stress action is obtained. By combining the evolution of micro-defects and the macroscopic magnetic properties, the present application realizes the in-situ non-destructive detection and life evaluation of the austenitic stainless steel structure, providing a new technical means for the reliability analysis of engineering structures.
Owner:YANGTZE RIVER DELTA RES INST OF NPU TAICANG +1

Electromagnetic reversing valve

According to the electromagnetic reversing valve, the structure of the electromagnetic reversing valve is optimally designed, the concave part is additionally arranged on the transition part of the valve body part, and / or the convex part is arranged on the first plate-shaped part of the valve body part, so that stress generated when a high-temperature and high-pressure medium enters the valve body part is dispersed, fatigue stress generated by the valve body in a high-pressure environment is effectively weakened, and the reliability of the electromagnetic reversing valve is improved.
Owner:ZHEJIANG SANHUA INTELLIGENT CONTROLS CO LTD

Stress gradient absorption type self-toughening high-bearing phosphogypsum pavement structure

This invention discloses a stress gradient absorbing, self-toughening, high-load-bearing phosphogypsum pavement structure, relating to the field of road construction materials technology. From top to bottom, it comprises a high-strength load-bearing layer, a stress transmission layer, and a stress dispersion layer. The raw materials for the high-strength load-bearing layer, stress transmission layer, and stress dispersion layer include modified phosphogypsum, cement, admixtures, a complexing water-resistant crosslinking agent, a water-reducing agent, and water. The modified phosphogypsum is prepared by adjusting the pH value of phosphogypsum waste to 7-8. The admixtures are blast furnace slag and / or metakaolin. The pavement structure provided by this invention achieves improved base layer strength and modulus, as well as gradient distribution, effectively transferring pavement stress to the underlying layer while reducing fatigue stress in the base layer material and increasing the fatigue life of the pavement base layer.
Owner:WUHAN UNIV OF TECH

Movable flap for the leading edge of an aircraft wing, having a curved nominal shape in order to adapt to the bending of the wing in flight

PCT designated stageWO2026002807A1Aircraft controlLeading edgeClassical mechanics
The invention relates to a movable flap (16) for the leading edge of an aircraft wing, the flap being intended to be mounted on a fixed part (8) of the wing and comprising two flap ends (16a, 16b) positioned opposite one another along the span (17) of the flap, the flap defining a leading edge zone from which a lower surface and an upper surface extend, the surfaces being spaced apart from one another over the height (21) of the flap. According to the invention, the flap has a generally upwardly concave shape in its nominal state in order to limit fatigue stresses on the flap during flight.
Owner:SONACA SA

Method, device and electronic equipment for predicting fatigue life of a gfrp-rc beam

The present application relates to a kind of method, device and electronic equipment for predicting GFRP-RC beam fatigue life, method includes: obtaining the limit bearing capacity before the destruction of GFRP-RC beam and the maximum deflection before the destruction of the GFRP-RC beam, the limit bearing capacity and the maximum deflection are by the GFRP-RC beam is obtained by three-point bending static loading test, obtain the initial fatigue deflection value of the GFRP-RC beam, the initial fatigue deflection value is by the GFRP-RC beam is carried out fatigue stress level cyclic loading test, and the test result is carried out initial deflection identification and obtains, based on the maximum deflection and the initial fatigue deflection value, input to the preset CEB-FIP fatigue life prediction model, obtain the GFRP-RC beam fatigue life.
Owner:HUBEI JIAOTONG EXPRESSWAY CONSTR MANAGEMENT CO LTD +5

Ballastless track concrete dynamic fatigue life prediction method and system

The invention provides a ballastless track concrete dynamic fatigue life prediction method and system, and relates to the technical field of high speed railway ballastless track performance evaluation.The method comprises the steps that a load spectrum of a ballastless track is obtained, and the load spectrum comprises a train dynamic load spectrum and an environment temperature change spectrum; based on the load spectrum, a fatigue stress spectrum of the track slab is calculated through a track fatigue stress calculation model, and the fatigue stress spectrum comprises a stress amplitude, a stress base value and an action frequency; dividing stress grades according to the fatigue stress spectrum, determining stress parameters of each grade in combination with concrete tension and compression characteristics, and calling a corrected fatigue life equation to calculate the fatigue life under the current stress grade; based on the fatigue life, a damage variable increment is calculated through a nonlinear damage accumulation criterion, and a total damage variable is obtained through accumulation; and judging a fatigue failure state according to the total damage variable, and if the fatigue failure state does not occur, updating material parameters and carrying out iterative calculation until the fatigue failure is judged.
Owner:TAIZHOU UNIV +1

Method and apparatus for testing coating performance of engine hot section components

The application discloses a method and device for testing coating performance of an engine hot-end component, and the method comprises the following steps: obtaining working condition data of an engine, wherein the working condition data comprises task profile data, simulation data and measured data of the engine; establishing a temperature model, a corrosion load model and a fatigue stress model based on the working condition data; determining an environment spectrum of the engine based on the working condition data, the temperature model, the corrosion load model and the fatigue stress model, wherein the environment spectrum comprises a time sequence of multiple working conditions of the engine and corresponding environment test parameters in the multiple working conditions; and testing a coating sample of the engine based on the environment spectrum to obtain a test result of the coating sample. The application establishes a mapping relationship between test environment parameters and actual working conditions, and overcomes the simulation distortion problem caused by using fixed environment parameters for testing in the prior art.
Owner:AERO ENGINE ACAD OF CHINA

Rapid time domain fatigue calculation method for floating type fan foundation structure

The invention discloses a rapid time-domain fatigue calculation method for a floating type wind turbine foundation structure. The rapid time-domain fatigue calculation method for the floating type wind turbine foundation structure comprises the following steps: S1, selecting an easily fatigue position in a floating type wind turbine foundation; s2, building a finite element model of an isolator in the floating fan foundation; s3, determining the main cyclic load and the acting position of the isolator; s4, independently applying a force of 1000N or 1000Nm to the position Li of the isolator model, and determining the maximum principal stress sigma 1000 of the isolator; s5, obtaining a fatigue stress factor ki corresponding to the external load cycle fi of the isolator model; s6, obtaining a stress time history curve sigma i generated by the external load cycle fi; s7, calculating a stress amplitude sigma a; s8, calculating the number of cycles; s9, obtaining a corresponding accumulated fatigue damage value D; and S10, determining the fatigue life of the key structure of the floating fan. According to the rapid time domain fatigue calculation method for the floating type wind turbine foundation structure, the calculation efficiency is improved, and calculation resources are reduced.
Owner:OFFSHORE OIL ENG CO LTD

CFRP reinforcing device for fatigue crack of steel bridge

The utility model relates to a CFRP reinforcing device for a fatigue crack of a steel bridge. The steel bridge fatigue crack CFRP reinforcing device relates to the technical field of steel bridge fatigue cracks. The CFRP reinforcing device for the fatigue crack of the steel bridge comprises telescopic shells, telescopic blocks and deformed steel bars, the telescopic shells and the telescopic blocks are symmetrically arranged, the situation that new cracks appear on a steel member is reduced by means of high temperature resistance, mechanical stability and small thermal expansion coefficient of CFRP plates, the CFRP plates are of a Z-shaped plate-shaped structure bent back and forth, the number of the CFRP plates is two, and the number of the CFRP plates is two. The two CFRP plates are arranged between the telescopic shells and the telescopic blocks correspondingly, so that when the two telescopic shells are pulled by stress, the CFRP plates are compressed and released, the stress pulling effect is further reduced, the connection stability between the steel members is improved, fatigue stress is well reduced, and new cracks are reduced.
Owner:ZHEJIANG UNIV CITY COLLEGE

A high mileage all-steel radial truck tire tread pattern and tire suitable for all wheel positions

ActiveCN224490542UTruckMechanical engineering
The utility model provides a kind of high mileage all-steel load radial tire tread pattern suitable for full wheel position and tire, the design of the pattern groove of the present application can prevent the pattern groove from clamping stone, and can effectively reduce the damage of groove bottom crack caused by groove bottom fatigue stress;The design of U-shaped groove improves the drainage property while ensuring the self-cleaning performance of the tire;Moreover, the angle of the normal direction of the sidewall of the central pattern groove and the sidewall above the tread is the same, which can also make the stress on both sides of the entire tread pattern more uniform.
Owner:AEOLUS TIRE

Method and device for testing performance of engine hot end component coating

The invention discloses an engine hot end component coating performance testing method and device, and the method comprises the steps: obtaining the working condition data of an engine, and the working condition data comprises the mission profile data, simulation data and actual measurement data of the engine; establishing a temperature model, a corrosion load model and a fatigue stress model based on the working condition data; based on the working condition data, the temperature model, the corrosion load model and the fatigue stress model, an environment spectrum of the engine is determined, and the environment spectrum comprises time sequences of multiple working conditions of the engine and environment test parameters corresponding to the multiple working conditions; and testing the coating sample of the engine based on the environment spectrum to obtain a test result of the coating sample. By establishing the mapping relation between the test environment parameters and the actual working conditions, the problem of simulation distortion caused by adopting fixed environment parameters for testing in the prior art is solved.
Owner:AERO ENGINE ACAD OF CHINA

Nickel-based single crystal alloy fatigue life forecasting method considering second orientation and recrystallization defect

The invention relates to the technical field of single crystal alloy fatigue life prediction, in particular to a nickel-based single crystal alloy fatigue life prediction method considering second orientation and recrystallization defects. The specific method comprises the following steps: obtaining a plurality of nickel-based single crystal alloys as single crystal alloy samples which have different second orientations and have recrystallization defects partially; establishing a crystal plastic model; acquiring fatigue life and fatigue stress parameters; inputting the fatigue stress parameter into a crystal plastic model to calculate the accumulated plastic shear strain of the dangerous point; 1 / 2 of the product of the cumulative plastic cutting strain and the fatigue load in the crystal plasticity or the cumulative plastic cutting strain is used as a fatigue indication factor; and fitting by taking the fatigue indication factor as a vertical coordinate and the fatigue life as a horizontal coordinate to obtain a fatigue life prediction model. According to the method, the recrystallization defect and the influence of different second orientations are considered, the related fatigue indication factors are introduced to construct the fatigue life prediction model between the fatigue indication factors and the fatigue life, and the accuracy and reliability of the prediction result are improved.
Owner:SUN YAT SEN UNIV

Method for establishing influence of fatigue stress concentration coefficient and temperature on fatigue performance of alloy material and application

The invention provides a method for establishing the influence of a fatigue stress concentration coefficient and temperature on the fatigue performance of an alloy material, and the method comprises the following steps: S1) defining the given fatigue life of an alloy, and obtaining a fatigue stress concentration coefficient Kf, N; under the condition that the stress concentration coefficient Kt, the stress ratio and the temperature of the alloy are determined, a two-parameter stress fatigue life model of the alloy is obtained; s2) if the stress concentration coefficient Kt is equal to 1, obtaining the fatigue limit of the given fatigue life of the smooth sample on the basis of the given fatigue life; s3) on the basis of the given fatigue life, obtaining a fatigue limit and Kf, N when Kt is not equal to 1 of the given fatigue life; and S4) establishing a relationship with the given fatigue life according to the Kf, N of the given fatigue life and the temperature in the step S1). According to the establishment method provided by the invention, the influence of the combined action of two factors of Kf, N and temperature on the fatigue performance can be analyzed.
Owner:AVIC BEIJING INST OF AERONAUTICAL MATERIALS +1

A steel strand with excellent fatigue resistance and its production method

ActiveCN118996262BWire rodHigh stress
The present invention relates to a steel strand with excellent fatigue resistance and a production method thereof. By making full use of existing equipment conditions, optimizing the ratio of alloy elements, and combining the following production methods, including heating in a heating furnace, continuous rolling on multiple stands, cooling by flow control in different water tanks after finish rolling, Stelmor phase transformation cooling, coiling to form wire rods, drawing the wire rods and twisting the steel wires to form steel strands, and stabilizing and coiling the steel strands, the plasticity of the wire rods is improved under the existing production level, and the residual stress state of the steel wire is improved to increase the fatigue stress amplitude of the steel strand, thereby meeting the high stress amplitude fatigue requirement of 2000MPa-grade steel strands.
Owner:INST OF RES OF IRON & STEEL JIANGSU PROVINCE +1

A method and system for calculating fatigue life of road assembled box culvert

The present invention provides a method and system for calculating the fatigue life of a prefabricated box culvert on a road, relating to the fields of material mechanics and civil engineering technology. The method establishes a three-dimensional finite element model of the box culvert, screens fatigue hotspots, and, based on fatigue stress analysis, installs strain sensors at the fatigue hotspots to measure stress values. Calibration coefficients are generated using vehicle weight and speed data to correct the stress values. Temperature sensors are deployed for real-time monitoring, and a temperature compensation model is established to correct the stress data. Ultimately, after calibration and compensation, the true stress values of the fatigue hotspots are obtained, the cumulative damage degree is defined, and the fatigue life of each hotspot is calculated based on Miner's law. By establishing a three-dimensional finite element model and implementing stress and temperature monitoring and calibration, the present invention accurately assesses the fatigue performance and service life of the box culvert.
Owner:CHINA RAILWAY 19 BUREAU GRP CO LTD +4

Fatigue simulation method for local stress ratio change caused by nonlinear deformation

The invention discloses a fatigue simulation method for local stress ratio change caused by nonlinear deformation, and belongs to the technical field of composite material fatigue performance research. The method comprises the following steps: determining a fatigue load peak-valley value and calculating a fatigue stress ratio; the fatigue loading process is divided into two stages; calculating the equivalent fatigue life under the current fatigue cyclic loading; calculating a stress ratio under current fatigue cyclic loading; calculating the equivalent fatigue life of the current unit; establishing a uniaxial fatigue rigidity degradation model and a uniaxial fatigue strength degradation model of the composite material, and calculating the overall fatigue life of the models. By considering the influence of local stress ratio change on the fatigue life of the composite material in the fatigue process and based on the equal-life model, the rigidity degradation model, the strength degradation model and the fatigue failure criterion, a more accurate composite material fatigue simulation analysis method is established, the prediction precision of a traditional model is optimized, and the prediction efficiency is improved. And the blank in the field of composite material fatigue simulation calculation is filled.
Owner:HARBIN INST OF TECH