63 results about "Rolling contact fatigue" patented technology

The invention relates to the technical field of track structure health monitoring, in particular to a track crack recognition and fatigue life prediction method and system based on deep learning and finite elements, and the method comprises the steps: collecting and preprocessing a track surface crack image, and obtaining crack image data; a deep neural network model is trained, and a corresponding track crack recognition algorithm based on deep learning is determined; identifying and extracting positions and geometric dimensions of the cracks; based on the geometrical characteristics and the material attributes of the track, establishing a corresponding track finite element model, and inputting the position and the geometric size of the crack into the track finite element model to generate and obtain a track model containing crack damage; based on wheel-rail rolling contact fatigue finite element simulation, simulating the mechanical response of a track structure, determining the fatigue life of the track in combination with the stress-strain distribution of the track, and predicting the development trends of cracks under different operation conditions; automatic and efficient identification of track cracks is realized, and the accuracy of fatigue life evaluation is improved.

The invention belongs to the field of prediction of fatigue failure caused by surface defects under rolling contact loads, and particularly relates to a rolling contact fatigue pitting corrosion prediction method considering crystal plasticity, a corresponding computer readable storage medium and electronic equipment. The method comprises the following steps: S1, constructing a crystal plastic constitutive model of a coupling damage accumulation theory; s2, developing the model in the step 1 into a UMAT subprogram by using Fortran, and embedding ABAQUS into the UMAT subprogram; s3, establishing a representative volume element crystal plastic finite element model; s4, applying a periodic boundary condition and a shear load, obtaining a shear stress-strain curve, carrying out a torsional fatigue test, obtaining fatigue damage parameters of the material, and determining constitutive model parameters of the material; s5, establishing a crystal plastic finite element model of the roller and raceway contact pair; s6, applying boundary conditions in two steps; and S7, observing a damage evolution path to the surface, and obtaining the rolling contact fatigue pitting corrosion life. The method can fill the blank of rolling contact fatigue pitting corrosion prediction methods at present.

The present invention relates to the technical field of wheel-rail tribology. Specifically disclosed is a wheel-rail material rolling contact fatigue damage prediction method based on different evaluation indices. The method comprises the following steps: on the basis of a wheel-rail shakedown map, carrying out wheel-rail rolling contact fatigue simulation tests, so as to obtain damage states and shakedown limit curve equations of wheel / rail materials with different shear yield strengths under different contact parameters; on the basis of a rough set theory, calculating the importance and relative weights of different evaluation indices; establishing a comprehensive evaluation index cloud model, respectively calculating comprehensive certainty degrees of an index attribute value to be evaluated belonging to different damage states, and using a maximum-value rule for the comprehensive certainty degrees to evaluate and predict rolling contact fatigue damage states; and using comprehensive evaluation index attribute values to perform validation, so as to finally determine a prediction result of a selected wheel-rail material rolling contact fatigue damage state under a condition to be subjected to prediction. The method in the present invention only depends on existing engineering data, such that the subjectivity of a damage state prediction process can be greatly reduced.

The invention provides a rolling contact fatigue internal crack propagation test method based on additive manufacturing, belongs to the technical field of rolling part near-surface fatigue crack propagation research, and aims to solve the technical problems that the rolling contact fatigue internal crack propagation process is difficult to monitor, the propagation path and the propagation rate are not clear and the like. The method comprises the following steps: preparing a rolling contact fatigue sample containing internal buried defects through additive manufacturing, carrying out a rolling contact fatigue experiment by using a rolling contact fatigue testing machine and changing different experimental parameters, monitoring the expansion behaviors of internal cracks under different cycle times through industrial CT, obtaining an expansion rate curve of the cracks, and researching the crack formation mechanism. According to the method, the expansion behavior of the rolling contact fatigue II-III type composite crack can be reproduced, and technical support is provided for research on engineering problems of railway vehicle rim cracks, steel rail nuclear damage, bearing raceway surface stripping and the like and the rolling contact fatigue theory.

The invention discloses a silicon nitride ceramic formula and a preparation process of a bearing roller matched with the silicon nitride ceramic formula, belongs to the technical field of ceramic materials, and aims to solve the problem of rolling contact fatigue failure caused by insufficient fracture toughness and microscopic crack propagation of an existing silicon nitride bearing roller under high-speed and heavy-load working conditions. The core formula of the invention comprises an alpha-Si3N4 matrix, a composite rare earth additive, a nano TiC modifier and an MgO heat conduction enhancer. The fracture toughness and fatigue resistance of the material are remarkably improved through process nano powder ultrasonic pre-dispersion, closed nitrogen circulation spray granulation, two-step air pressure sintering and cryogenic-thermal tempering gradient stress treatment.

The present application belongs to the field of rail material research and manufacturing, and specifically discloses a rail structure for a subway humid environment. According to the distribution of pearlite lamellar spacing, the rail head cross-section structure can be divided into cap layer 1, cap layer 2, cap layer 3 and base material layer. The pearlite lamellar spacing distribution of cap layer 1 is 130-150 nm, the pearlite lamellar spacing distribution of cap layer 2 is 90-120 nm, the pearlite lamellar spacing distribution of cap layer 3 is 140-170 nm, and the pearlite lamellar spacing distribution of the base material layer is 200-230 nm. The present application designs cap-shaped structures with different depths and different pearlite lamellar spacing in the rail head. By accelerating the cooling speed of the heat treatment of the hot-rolled rail in different stages, the reasonable gradient structure distribution of the pearlite structure of the rail material is realized, the expansion speed of the rolling contact fatigue crack of the rail in the humid environment to the internal material is effectively slowed down, the rolling contact fatigue damage is reduced, and thus the comprehensive performance and service life of the rail are improved.

The invention discloses a safety wheel for a rubber wheel metro vehicle bogie and a preparation method of the safety wheel. The wheel comprises the following chemical components in percentage by mass: 0.52%-0.60% of C, 0.30%-0.40% of Si, 0.70%-0.80% of Mn, less than or equal to 0.015% of P, less than 0.010% of S, 0.20%-0.30% of Cr, 0.05%-0.23% of Ni, 0.04%-0.06% of V, (60-80) * 10 <-4%) of N, less than or equal to 0.012% of Al, less than or equal to 0.005% of Ti and the balance of Fe and inevitable impurities. The composition proportion of N and Al is controlled by adjusting C and adding V, so that the volume fraction of the tread ferrite reaches 5-12%, and the volume fraction of the rim reaches 10-16%; meanwhile, the metallurgical quality is controlled, the proportion of plastic inclusions is larger than or equal to 90%, the proportion of the size below 10 micrometers is larger than 85%, and the wrapping rate is larger than or equal to 80%. And finally, the average value of the fracture toughness of the wheel is larger than or equal to 85 MPam1 / 2, the unit value is larger than or equal to 80 MPam1 / 2, the rolling contact fatigue resistance is remarkably improved, and the cracking risk of large-size inclusions is reduced.

The present invention relates to the technical field of wheel-rail double-disc rolling simulation, and specifically discloses a double-disc rolling rail specimen design method that takes into account the effect of bending stress. The present invention realizes the effect of bending stress on the extension of rail rolling contact fatigue cracks on the double-disc rolling specimen, and combines finite element analysis methods and rolling contact fatigue and wear testing machines, SEM scanning electron microscopes and other equipment to analyze the cross-sectional crack morphology and maximum bending stress value σ of the double-disc rolling rail specimen. simRmax The cross-sectional shapes of the specimens are optimized according to the analysis results until the crack morphology of the specimen cross section is close to the crack morphology of the rail cross section after field service, and the total height H of the simulated beam cross section of the specimen is continuously modified until it meets σ simRmax =σ Rmax , and then combined with the rolling contact fatigue and wear testing machine to verify the rationality of the test structure again, to ensure that the rolling contact fatigue crack damage of the full-size rail under bending stress can be reproduced in the laboratory.

The application discloses a wheel fatigue life prediction method based on a rolling contact fatigue simulation technology, and comprises the following steps: establishing a finite element model of a wheel-axle-rail, performing grid encryption on a wheel-rail contact area, and performing static strength checking to obtain an initial finite element model meeting static force requirements; establishing a wheel-rail rolling contact model based on the initial finite element model, describing rolling motion of the wheel by using a hybrid Lagrangian / Eulerian description or a co-rotating coordinate system, and applying a wheel non-circularity excitation spectrum in explicit dynamics analysis to calculate a dynamic contact stress field under different axle loads and friction coefficients; and based on the dynamic contact stress field, a multi-axle fatigue damage model is used in combination with a linear cumulative damage criterion to calculate fatigue life, and an abrasion correction coefficient and a residual stress correction coefficient are introduced to correct the calculation results. The application significantly improves the prediction accuracy of fatigue defects such as wheel peeling, cracking and polygonization.

The application provides a laser impact combined surface modification method for a bearing raceway surface, a pre-processing raceway region and a retainer matching surface, the raceway region reserving a processing allowance layer; a constraint layer is applied to the raceway region; the raceway region is micro-scale laser impact strengthened for at least 3 times without an absorption protective layer, a deep and uniform plastic strengthening layer is formed; the processing allowance layer is removed; an absorption protective layer is attached to the retainer matching surface; and array-arranged oil storage pits are formed on the retainer matching surface through laser impact forming. The method can form a plastic strengthening layer on the raceway region surface through micro-scale laser impact strengthening, can significantly improve the rolling contact fatigue performance and wear performance of the bearing, and can form oil storage pits on the retainer matching surface through laser impact forming, the oil storage pits can lock lubricating oil through the surface tension of the oil, and the problem of insufficient lubrication of the bearing raceway surface is solved.

This invention discloses a rapid prediction method for rail rolling contact fatigue damage in the field of rail damage prediction technology. The method includes establishing a three-dimensional elastoplastic wheel-rail cyclic rolling contact finite element model, improving the cyclic plastic constitutive model, and simulating the stress-strain evolution of the rail. A rail stress-strain sample library is generated through parametric sampling and batch calculation. A Physically Constrained Generative Adversarial Network (PC-GAN) is constructed, embedding physical constraints such as contact force conservation and energy consistency into the loss function to achieve rapid and high-precision mapping from operating parameters to the stress-strain field. Based on the PC-AN prediction results, cumulative damage and fatigue life are calculated using an incremental multiaxial fatigue damage model, and a damage distribution map of the entire rail line is drawn, identifying high-risk sections. This invention deeply integrates physical modeling with intelligent algorithms, achieving an order-of-magnitude improvement in rail fatigue damage assessment efficiency while ensuring prediction accuracy, providing efficient and reliable technical support for rail life assessment and maintenance decisions across the entire rail line.

The invention provides the application of the test method in testing the rolling contact fatigue performance of the steel rail material in a humid and / or corrosive environment. The invention also provides a test method for testing the rolling contact fatigue performance of the steel rail material, which comprises the following steps: preparing a steel rail test sample, simulating a humid and corrosive environment, and carrying out a double-wheel rolling contact fatigue test according to test requirements; and evaluating the contact fatigue performance of the sample through weightlessness, vibration signals and the surface state of the sample. The test mode better conforms to the actual service condition of the steel rail line in the humid and corrosive environment, and the test result is more accurate and effective. The steel rail material rolling contact fatigue test method provided by the invention can evaluate the contact fatigue performance of multi-steel-grade steel rails in a humid and corrosive environment, and parameters such as corrosive liquid and test pause interval time can be adjusted according to actual requirements. The method is suitable for test evaluation of various service conditions such as coastal, tunnel and plateau, and has a good application prospect.

The invention relates to the technical field of wheel-rail double-disc rolling simulation, and particularly discloses a double-disc rolling steel rail sample design method considering the action of bending stress, which realizes the expansion of the bending stress on the rolling contact fatigue crack of a steel rail on a double-disc rolling sample. A finite element analysis method, a rolling contact fatigue and wear testing machine, an SEM scanning electron microscope and other equipment are combined to analyze the profile crack morphology and the maximum bending stress value sigma simRmax of the double-disc rolling steel rail sample, and different section shapes of the sample are optimized according to analysis results. And continuously correcting the total height H of the simulated beam section of the sample until sigma simRmax is equal to sigma Rmax, and verifying the reasonability of the test structure again by combining a rolling contact fatigue and wear testing machine, and the rolling contact fatigue crack damage of the full-size steel rail under the action of the bending stress can be reproduced in a laboratory.

The invention relates to the field of rolling linear guide rail treatment, and discloses an inertia-driven self-adaptive lubricating rolling linear guide rail which comprises a sliding rail piece, a vertical plate is arranged on the left side of the top of the sliding rail piece, a sliding rod piece is arranged on the right side of the vertical plate, and a sliding block assembly is arranged on the surface of the sliding rod piece. And the sliding block assembly is slidably connected to the surface of the sliding rail piece, a sliding assembly is arranged in the sliding block assembly, and an inertia adjusting assembly is arranged in the sliding block assembly. According to the device, the inertia adjusting assembly is arranged, inertia force generated in the sliding process of the sliding block assembly can push the sliding part to move on the surface of the limiting sliding rod in the sliding direction of the sliding block assembly, the inertia force in the moving process can make oil permeate, and the sliding part and the oil storage part on the front face can transversely move; and the top is provided with an assembly capable of supplementing oil, so that the oil can seep during radial movement, and the wear rate of the raceway is reduced.

A dual-track ball bat fatigue test assembly and a dual-track ball bat fatigue testing machine including the test assembly, which relate to the technical field of ball bat fatigue testing. The present invention solves the problems of low efficiency of single test of ball bat fatigue test, cumbersome installation and disassembly, and inability to accurately evaluate axial load in existing ball bat rolling contact fatigue testing machines. A vertically arranged linear slide is installed at the front end of the slide support frame of the present invention, and the motor is installed on the slide working plate of the linear slide. The motor main shaft is connected to the upper end of the ball bat test piece through a flexible coupling, and the lower end of the ball bat test piece passes through the test cabin cover, the thrust spherical bearing, the upper first loading ring and the second loading ring in sequence. The outer surface of the ball bat test piece contacts the upper and lower test rolling bodies, and the power output end of the loading force mechanism is offset against the ball head pressure head. The present invention is used to test the fatigue life of a ball bat, and can simultaneously meet the requirements of dual tracks, accurately measure the input axial load, and simplify the installation procedure.

The invention discloses a moderate-strength contact-fatigue-resistant bainite steel rail and a preparation method thereof, and belongs to the technical field of steel rail preparation. The steel rail comprises the following chemical components in percentage by weight: 0.22%-0.26% of C, 1.00%-1.20% of Si, 1.25%-1.45% of Mn, 0.25%-0.6% of Cr, 0.2%-0.4% of Mo, 0.025%-0.040% of Nb, less than or equal to 0.015% of P, less than or equal to 0.010% of S and the balance of Fe and inevitable impurities. The moderate-strength contact fatigue-resistant bainite steel rail for the freight railway curve line is prepared by combining low-cost alloy component design with a controlled cooling process, so that the rolling contact fatigue resistance of the steel rail is improved while the strength and the toughness of the steel rail are ensured; and in the using process, abrasion and rolling contact fatigue damage can be effectively controlled, the service life of the steel rail is remarkably prolonged, and the grinding and maintaining cost of the steel rail is reduced.

The present invention discloses an on-line measurement method for the wear amount of a rolling contact surface based on line structured light, which relates to the technical field of rolling contact surface wear detection. The present invention includes constructing a measurement system for the wear amount of a rolling contact surface based on the principle of line structured light; data acquisition and preprocessing, preprocessing the noise points in the original point cloud; designing a wear amount calculation method, and finally obtaining the rolling contact fatigue wear amount of the specimen surface. The present invention collects the point cloud of the specimen surface through a line structured light sensor installed on a rolling contact fatigue testing machine; adopts the k-dimensional tree nearest neighbor search method to perform neighborhood analysis and statistics point by point, and uses a distance threshold to eliminate the outlier points in the point cloud; according to the obtained point cloud data of the specimen surface, designs a wear amount calculation method for plastic material specimens, and performs angle and temperature compensation on the measured height, so as to accurately calculate the rolling contact fatigue wear amount of the specimen.

The invention discloses a double-track ball bat fatigue test assembly and a double-track ball bat fatigue testing machine comprising the same, and relates to the technical field of ball bat fatigue tests. According to the invention, the problems of low single test efficiency, complicated installation and disassembly and incapability of accurately evaluating the axial load of the ball rod fatigue test of the existing ball rod type rolling contact fatigue testing machine are solved. A vertically-arranged linear sliding table is installed at the front end of a sliding table supporting frame, a motor is installed on a sliding table working plate of the linear sliding table, a main shaft of the motor is connected with the upper end of a bat test piece through a flexible coupler, and the lower end of the bat test piece sequentially penetrates through a test cabin cover, a thrust knuckle bearing, an upper-layer first loading ring and a second loading ring. The outer surface of the bat test piece is in contact with the upper and lower layers of test rolling bodies, and the power output end of the loading force mechanism abuts against the ball head pressure head. The device is used for testing the fatigue life of the bat, can simultaneously meet double tracks, accurately measures the input axial load, and simplifies the installation procedure.

The application relates to the field of material service behavior evaluation, in particular to service behavior evaluation of ceramic balls in high-end bearings, and more specifically to a ceramic ball rolling contact fatigue performance testing device and testing method simulating the structure and lubrication of an angular contact ceramic ball bearing. The device comprises a fixing plate, a stand, a limiting plate, an upper thrust bearing, a lower thrust bearing, an upper conical ring base, a lower conical ring base, an upper conical ring, a lower conical ring, a retainer, a bearing steel rod and ceramic balls. According to the diameter size of the ceramic balls to be tested, the geometric relationship of the ball-rod contact is designed and calculated, the rotating speed and the contact stress are determined; according to the selected contact stress and the fatigue cycle of the trial test, the cut-off value of the constant cut-off test is determined; the rolling contact fatigue test is carried out on the ceramic balls to be tested, and the contact fatigue performance of the ceramic balls is evaluated. The application can evaluate ceramic balls of different diameter sizes without special sample preparation, so that the ceramic balls in actual bearings can be directly tested.

The invention provides a method for testing rolling contact fatigue of a steel rail material. The method comprises the following steps: preparing a plurality of steel rail test samples and grinding accompanying samples; carrying out ultrasonic cleaning on the test sample and one accompanying grinding sample by using anhydrous B, airing and then mounting on a rolling contact fatigue testing machine; the grinding accompanying sample rotates at a certain rotating speed, the test sample is fixed and does not rotate, and after the test sample makes contact with the grinding accompanying sample for a certain time under a certain load, the test sample is separated from the grinding accompanying sample, and scratches are made; carrying out ultrasonic cleaning on the test sample and another grinding accompanying sample by using absolute ethyl alcohol, weighing and recording the test sample after airing, and carrying out a rolling contact fatigue test on a rolling contact fatigue testing machine; after the test reaches a required test cycle, stopping the test, recording a vibration signal, and taking down a test sample and an accompanying grinding sample; ultrasonically cleaning the test sample by using anhydrous B, airing, weighing and recording; and subtracting the weight after the test from the weight of the test sample before the test to obtain the weight loss. The method can accurately evaluate the rolling contact fatigue test under the condition that the surface of the steel rail is scratched.

This invention discloses a method for determining the parameters of wheel-rail rolling contact fatigue damage function that considers the microscopic contact solution within the contact patch, is applicable to different railway systems, and has good predictive performance. The method includes the following steps: solving for transient wheel-rail contact state parameters; calculating the macroscopic rolling contact solution and the microscopic contact solution within the contact patch; and solving for the transient wear number Tγ and the total transient damage value D within the contact patch at any given time. t and peak transient damage value h m Solve for the local wear coefficient τγ within the contact patch. L ; with h m As τγ L d L , thus obtaining τγ L with h m The corresponding relationship; by changing the working conditions, Tγ and τγ covering the entire domain of the macroscopic damage function model under different traction coefficients are obtained. L The relationship between them; for τγ at the critical point L The reduction is calculated based on the wear reduction until the total local damage value d within the corresponding contact patch is reached. t Total transient damage value D within the contact patch t Equal to each other, we obtain the reduced τγ L With d L The relationship is as follows: the parameters of the local damage function model are obtained by fitting and / or the parameters of the macroscopic damage function model of another railway system are derived by reverse calculation.

The invention discloses a method for evaluating the dispersion degree of a bearing fatigue life by quantizing an uncertain interference fit parameter, and the method comprises the following steps: 1, analyzing the uncertain interference magnitude in a shaft-hole interference fit model based on a Chebyshev interval method, and obtaining an interpolation point; step 2, combining a quasi-statics model of the angular contact ball bearing based on the no-raceway control hypothesis with a shaft-hole interference fit model, and determining ball-raceway contact forces under different interference magnitudes corresponding to the interpolation points; and Step 3, analyzing the values of the ball-raceway contact forces under different interference magnitudes corresponding to the interpolation points in a ball-raceway rolling contact fatigue life model to obtain the maximum Von-Mises stress and the corresponding position depth, and quantifying the influence of uncertain parameters on the dispersion degree of the bearing life. According to the method, the specific influence of the uncertainty interference fit parameters on the bearing fatigue life dispersion degree under different working condition parameters can be considered.

The invention relates to the technical field of transportation, in particular to a method for establishing a heavy haul railway steel rail rolling contact fatigue damage function, which comprises the following steps of: 1, determining a rolling contact fatigue critical initiation position; 2, determining a fatigue initiation critical abrasion number; step 3, estimating a rolling contact fatigue initiation rate; and step 4, determining a damage function through the linear relation. According to the method, the damage function model can be well established.

The invention relates to a production method of high-carbon bearing steel for a spindle bearing of a high-rotating-speed precision machine tool, and belongs to the field of metallurgy. The process production of KR molten iron pretreatment, converter smelting, converter tapping, LF refining, vacuum degassing and continuous casting is adopted, the whole process collaborative optimization design is adopted, all process control targets are deeply coupled, KR ultra-low sulfur (less than or equal to 0.004%) lays a foundation for low-oxygen and low-sulfur smelting, LF and RH efficient refining is guaranteed through converter accurate end point control (C / P / temperature three elements), and the low-oxygen and low-sulfur low-oxygen and low-sulfur low-oxygen and low-sulfur low-oxygen and low-sulfur low-oxygen and low-sulfur low-oxygen and low-sulfur low-oxygen and low-sulfur low-oxygen The continuous casting electromagnetic stirring and soft reduction technology synergistically improves homogenization, the steel oxygen content is smaller than or equal to 5 ppm, the sulfur content is smaller than or equal to 0.006%, the calcium content is smaller than or equal to 5 ppm, the titanium content is smaller than or equal to 9 ppm, the center porosity is smaller than or equal to 1.0 level, the center segregation is smaller than or equal to 1.0 level, the B fine inclusion is smaller than or equal to 1.0 level, the B coarse inclusion is smaller than or equal to 0.5 level, the DS inclusion is smaller than or equal to 0.5 level, the macroscopic purity is smaller than or equal to 3 mm / dm < 3 >, and the rolling contact fatigue rated life L10 under the contact stress of 4.5 GPa is 2.38 * 107 and is 1.2 times or above that of a die casting material.

The invention relates to a method for screening multiple supporting rollers based on sliding-rolling coupling, belongs to the technical field of performance detection of core parts of wide and thick plate rolling equipment, and solves the problem that the screened supporting rollers are not suitable for application scenes due to the lack of effective evaluation standards of the supporting rollers in the prior art. The screening method comprises the following steps: pretreating a plurality of samples of a plurality of supporting rollers to obtain a first number of sliding test samples and a second number of rolling test samples corresponding to each supporting roller; obtaining sliding wear data of each supporting roller based on a reciprocating sliding friction wear test; based on a ball disc type rolling contact fatigue test, rolling contact fatigue failure data of each supporting roller is obtained; and according to the sliding wear data and the rolling contact fatigue failure data of each type of supporting rollers, screening the multiple types of supporting rollers to obtain the optimal type of supporting rollers. And the scene adaptability of the screened supporting roller is improved.

The invention discloses a determination method for wheel-rail rolling contact fatigue damage function parameters, which considers an intra-spot mesoscopic contact solution, can be suitable for different railway systems and has a good prediction effect. The determination method comprises the following steps: solving transient wheel-rail contact state parameters; calculating a macroscopic rolling contact solution and an intra-spot mesoscopic contact solution; solving a transient abrasion number T gamma, a total transient damage value Dt in a contact spot and a transient damage peak value hm at any moment; solving a local abrasion number tau [gamma] L in the contact spot; hm is used as dL of tau gamma L, and the corresponding relation between tau gamma L and hm is obtained; obtaining a relation between T gamma and tau gamma L covering the whole domain of the macroscopic damage function model under different traction coefficients through working condition changes; the tau gamma L at the critical point is reduced according to the abrasion reduction amount until the local damage total value dt in the corresponding contact spot is equal to the transient damage total value Dt in the contact spot, and the relation between the reduced tau gamma L and dL is obtained; and fitting to obtain local damage function model parameters and / or reversely deducing macroscopic damage function model parameters of another railway system.

The invention discloses a device and method for a rolling contact fatigue corrosion test, and belongs to the technical field of fatigue corrosion tests.The device comprises a liquid corrosion liquid supply mechanism, and the liquid corrosion liquid supply mechanism is installed in a testing machine and used for creating a corrosion environment in the testing machine; the sensor group is arranged in the testing machine and is used for detecting the environment in the testing machine; and the microcontroller is respectively connected with the liquid corrosion liquid supply mechanism and the sensor group. According to the invention, the complex corrosion condition of alternation of wetting and drying in the ring / ring rolling contact fatigue corrosion environment is truly simulated.

The invention discloses a steel rail material for a subway small-radius curve line, and the rail head area of the cross section of a steel rail is divided into three areas according to different microsizes of pearlite structures, namely a surface regulation and control layer, a rail angle hardening area and a core base body area. Aiming at more small-radius curves of the subway line at present, the microstructure of different stressed parts of the steel rail head is reasonably designed and arranged on the basis of the wheel-rail contact relation and stress distribution characteristics of the small-radius curve line, so that the steel rail material rail head is ensured to have the wear and the surface contact fatigue crack cooperative control, and meanwhile, the steel rail material rail head is ensured to have a good anti-fatigue effect. And the generation and development of internal fatigue cracks can be reduced. Meanwhile, gradient distribution and stable control of pearlite structures of different parts of the rail head of the steel rail are achieved by controlling rolling and conducting accelerated cooling at different speeds on the rail head, and generation and development of steel rail abrasion and rolling contact fatigue damage on a small-radius curve line are effectively relieved; the comprehensive use performance and the service life of the steel rail are improved.

The present invention relates to the technical field of wheel-rail tribology and discloses in particular a prediction method for rolling contact fatigue damage of wheel / rail materials based on various evaluation indicators. This method comprises the following steps: performing a wheel-rail rolling contact fatigue simulation test based on a wheel-rail stability diagram to determine the damage state and the stability limit curve equation of wheel / rail materials with different shear yield strengths under different contact parameters; calculating the importance and relative weighting of various evaluation indicators based on roughness quantity theory; and creating an integrated evaluation indicator cloud model to calculate the association of the attribute values ​​of the indicators to be evaluated with different damage states.Evaluating and predicting a rolling contact fatigue damage condition using the maximum value rule; performing a check against the attribute value of the integrated evaluation indicator, and determining the prediction results of the rolling contact fatigue damage condition for selected wheel and rail material under the conditions to be predicted. The method according to the present invention relies solely on existing technical data, which can significantly reduce the subjectivity of the damage condition prediction process.

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.