120 results about "Low-cycle fatigue" patented technology

The invention discloses a water turbine runner fatigue life prediction method based on multi-physics-field coupling calculation, and belongs to the technical field of water turbine runners, and the method comprises the steps: collecting the operation condition data of a water turbine set, carrying out the iterative solving of a residual vector based on a multi-physics-field coupling model, enabling the residual to approach zero, and outputting a time sequence result; extracting a vibration stress amplitude and a strain time history based on a time sequence result; accumulating the high-cycle fatigue damage and the low-cycle fatigue damage to obtain total accumulated damage of each runner unit, and performing weighted calculation by counting critical damage and operation duration to obtain the residual life of the hydraulic turbine set; and constructing a training data set containing historical working condition parameters, historical residual life and time sequence results of the hydraulic turbine set, training a Transform network, and generating a residual life prediction curve of the hydraulic turbine set under all working conditions. The method solves the problem that a traditional method is difficult to quantify coupling damage of the turbine runner temperature and the alternating load to predict the fatigue life of the turbine runner.

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

The invention relates to the technical field of aero-engine turbine rotor blade fatigue life design, in particular to a multistage turbine rotor blade fatigue life analysis method and device. The method comprises the following steps: based on material fatigue performance data of turbine rotor blades and a three-dimensional finite element model of the turbine rotor blades, obtaining a target test temperature and a target test rotating speed of a multi-stage turbine rotor blade group in a low-cycle fatigue test and a stress coefficient of each assessment part of each stage of turbine rotor blades; and obtaining an actual fatigue test cycle number analysis result of each stage of turbine rotor blade based on the target test temperature and the target test rotating speed of the low cycle fatigue test of the multi-stage turbine rotor blade group and the stress coefficient of each assessment part of each stage of turbine rotor blade. According to the method, the function of carrying out fatigue life test on multiple groups of turbine rotor blades is realized, the test efficiency is effectively improved, the test period is shortened, and the economic cost is reduced.

The utility model relates to the technical field of low-cycle fatigue tests, and discloses an anti-buckling tool for a low-cycle fatigue test sheet metal structure, which comprises a fixing assembly and a guide assembly, the fixing assembly comprises an upper fixing piece I, an upper fixing piece II, a lower fixing piece I and a lower fixing piece II, two screws are connected between the first upper fixing piece and the second upper fixing piece, two screws are connected between the first lower fixing piece and the second lower fixing piece, and cushion blocks are arranged on the inner side faces of the first upper fixing piece, the second upper fixing piece, the first lower fixing piece and the second lower fixing piece. Through the fixing assembly, the sample can be conveniently and quickly assembled, the low-cycle fatigue test requirement of the sheet metal structure can be met, and the lateral buckling instability phenomenon between a clamping part of equipment and the buckling-restrained tool can be reduced; through the guide assembly, when the sample bears a tension and compression cyclic load, the lateral buckling instability phenomenon in the thickness direction is prevented, and the stability of the sample is further enhanced.

The invention relates to the technical field of hydrogen storage cylinder state detection, in particular to a hydrogen storage cylinder damage characteristic identification method and system, and the method comprises the steps: S1, collecting and storing a damage data threshold value of a hydrogen storage cylinder sample, and a low-cycle fatigue data threshold value of each different region on the hydrogen storage cylinder; s2, arranging a sensor network for detection in each area of the target hydrogen storage cylinder, and collecting structural response data of the target hydrogen storage cylinder in real time; s3, if the structural response data is not lower than a damage data threshold value, judging that the target hydrogen storage cylinder is subjected to structural damage; s4, if the structural damage is not detected, acquiring a target position where the fatigue structural crack occurs in the area; and S5, predicting the fatigue life of the target hydrogen storage cylinder according to the fatigue structure crack degree of the target position. According to the invention, whether the hydrogen storage cylinder is damaged or not can be accurately and rapidly identified.

The invention provides a clamping device for a thin-wall whole pipe fatigue test and a test method, and belongs to the technical field of clamping devices. The device comprises clamping cushion blocks which are fixedly connected to two ends of a thin-wall whole tube sample main body and are used for transmitting test force; the high polymer material film adhesive tape is wound on a transition area of the clamping cushion block and the thin-wall whole pipe sample main body; the chock plugs are used for being plugged into the two ends of the thin-wall whole-tube sample main body, and packing paper is installed between the chock plugs and the inner wall of the thin-wall whole-tube sample main body and used for supporting the inner wall of the sample and evenly transmitting test force. The clamping cushion blocks are fixedly connected to the two ends of the sample and matched with the high polymer material film adhesive tape to reduce friction, the chock plugs are wound around the packing paper to support the inner wall, a stable clamping structure is formed, and it is ensured that fatigue fracture occurs in the working section. The problems of clamping stress concentration and fracture of a non-working section can be effectively avoided, the accuracy of a fatigue life evaluation result of the whole thin-wall pipe is improved, and the method can be widely applied to high-cycle and low-cycle fatigue performance tests under different conditions.

The invention discloses a wall type Z-shaped metal torsion tube damper anti-seismic system and method. The wall type Z-shaped metal torsion tube damper anti-seismic system comprises a frame beam, a frame column, a cantilever wall and a Z-shaped metal torsion tube damper. The frame beams and the frame columns are connected with a building, the cantilever walls are connected with the frame beams, and the Z-shaped metal torsion tube dampers are arranged between the paired cantilever walls and connected with the cantilever walls so as to dissipate energy transmitted by the cantilever walls. According to the damper anti-seismic system, the Z-shaped metal torsion tube damper is arranged to replace a traditional mild steel metal damper and a viscous damper to conduct damping design of a building structure, the problem that the low-cycle fatigue performance of the traditional metal damper is poor is solved, the oil leakage risk of the viscous damper is avoided, and the anti-seismic performance of the building structure is improved. Moreover, due to the structural design in the damper, the influence of the bending and shearing effect on the deformation of the torsion tube under the action of an axial load is eliminated, so that the section of the torsion tube is always kept a stable circular section in the hysteresis energy consumption period of the torsion tube, and the energy consumption efficiency is ensured.

The invention discloses a data-physical hybrid driven hydrogen-induced fatigue life prediction method, which comprises the following steps: S1, selecting different hydrogen storage steel lining materials, respectively carrying out a tensile test and a low-cycle fatigue test before and after hydrogen charging, collecting mechanical property parameter data, fatigue parameter data and fatigue life, and calculating the fatigue life of the hydrogen storage steel lining materials according to the mechanical property parameter data, the fatigue parameter data and the fatigue life; carrying out normalization processing on the collected data; s2, constructing a cascade PINN model composed of a BP model and a PINN model; s3, the non-hydrogen-filled mechanical property parameters serve as input, the hydrogen-filled mechanical property parameters serve as output, and a BP model is constructed; the hydrogen charging mechanical property parameters output by the BP model and the fatigue parameters serve as input of a PINN model together, the fatigue life under the hydrogen charging working condition serves as output, and the PINN model is constructed; and taking a prediction result finally output by the PINN model as the fatigue life under the hydrogen charging working condition. According to the method, the fatigue life of the hydrogen storage steel lining material stored for a long time can be rapidly predicted.

The invention relates to the technical field of aero-engines, and discloses a wheel disc low-cycle fatigue test load coefficient determination method, a wheel disc low-cycle fatigue test load coefficient determination device and application of the wheel disc low-cycle fatigue test load coefficient determination method. Based on stress characteristics and temperature characteristics of key parts of a wheel disc in an engine state, reasonable determination of a low-cycle fatigue test load coefficient of the wheel disc and conversion of the fatigue life of the wheel disc are realized by comprehensively considering the influence of a peak-valley value stress ratio of the wheel disc in a working state on the fatigue life of the wheel disc and a change rule of material performance along with temperature. The safety risk caused by the fact that the load coefficient deviates from the reality is reduced, and the design and use of the wheel disc are safer and more reliable; by correcting the load coefficient, the fatigue damage of the engine in the test state can be truly reflected, so that the safe life of the wheel disc is effectively determined, and support is provided for the life management of the wheel disc.

The invention relates to a fatigue life prediction method based on a physical failure mechanism in a liquid lead bismuth environment, and the method comprises the following steps: building a representative volume element model, and defining elements belonging to a slip band; defining a crystal plasticity constitutive equation; determining parameters in the crystal plasticity constitutive equation; calculating the average shear strain range of the slip band; carrying out a fracture toughness test to obtain specific fracture energy; establishing a fatigue life prediction model based on a physical failure mechanism; carrying out a symmetrically cyclic low-cycle fatigue test on the metal material in a predicted-temperature high-oxygen liquid lead bismuth environment to determine the thickness of an oxide film; and establishing a fatigue life prediction model in the high-oxygen-concentration liquid lead bismuth environment, and predicting the fatigue life of the metal material in the high-oxygen-concentration liquid lead bismuth environment. According to the method, the fatigue life in the liquid lead-bismuth environment can be predicted by carrying out a low-cycle fatigue test for calibrating crystal plasticity constitutive equation parameters in the air at the predicted temperature and a fracture toughness test in the air and liquid lead-bismuth environment.

The present invention discloses a cyclic viscoplastic constitutive model with coupled damage, combining viscoplastic flow laws, kinematic hardening, isotropic hardening, and damage variable evolution. Based on continuous damage mechanics, the damage variable is combined with the constitutive model to accurately simulate the cyclic deformation behavior of the entire life cycle, with high-precision life prediction capabilities. The present invention conducts strain-controlled low-cycle fatigue tests and tensile load-holding creep fatigue tests to obtain the test data required to construct the cyclic viscoplastic constitutive model, and uses a genetic algorithm to obtain a set of optimal model parameters, which can predict the cyclic deformation behavior and fatigue failure life under various cyclic loading waveforms, such as different strain amplitudes, different strain frequencies, and different load-holding times. The constitutive model ultimately obtained by the present invention has high accuracy, strong universality, and life prediction capabilities.

The invention relates to an aviation supercharger turbine case high-low cycle composite fatigue life prediction method, which comprises the following steps: firstly, determining the working state parameters of a supercharger under the start-stop cycle of an aviation piston engine, then calculating the stress strain of dangerous parts of the supercharger turbine case under different working conditions through a simulation model, decomposing the high-low cycle fatigue load spectrum of the supercharger, and calculating the fatigue life of the supercharger; determining parameters of an S-N curve and an epsilon-N curve of a turbine box material, and predicting the high-low cycle composite fatigue life of the turbine box on the basis. The method can scientifically determine the high-low cycle composite fatigue life of the turbocharger turbine box in the design stage or the use process of the turbocharger turbine box, can be used for reliability analysis and life evaluation of the turbocharger turbine box, guides the structure optimization design and reasonable use of the turbocharger turbine box, and has a good application prospect. And therefore, the reliability and the safety of the aviation turbocharger in the working process are ensured.

The application discloses a kind of prediction model establishment methods of exhaust heat end low cycle fatigue life, comprising the following steps: according to engine at different power, set different exhaust heat end model thermal boundary condition;According to each boundary condition respectively to exhaust heat end model is carried out stress field analysis, obtains the strain table of the maximum equivalent plastic strain increment of exhaust heat end and the temperature table of the maximum equivalent plastic strain increment corresponding node;According to the maximum equivalent plastic strain increment of exhaust heat end determines exhaust heat end life check component;Based on the temperature value in temperature table respectively to check component carries out high temperature tensile test and cold thermal shock cycle test, obtains the static tensile table of the material of life check component under corresponding temperature and test life table;According to static tensile table, test life table and strain table determine the prediction model of exhaust heat end, to predict the fatigue life of exhaust heat end, it is convenient to set up reasonably for the overhaul and replacement cycle of exhaust heat end.

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

The present invention discloses a method for compiling an acceleration task test load spectrum taking heating and pressurization into consideration, taking a long-term life test spectrum without considering heating and pressurization as basic compilation data, and calculating and analyzing the corresponding turbine front inlet temperature when the engine speed reaches the maximum speed under the conditions of increasing the inlet total temperature and total pressure according to the engine performance model; according to the engine temperature limit condition, the corresponding inlet total temperature and total pressure when the turbine front inlet temperature reaches the temperature limit value are used as the final determined single-stage total temperature spectrum and single-stage total pressure spectrum; then, according to the engine performance model, the speed of the long-term life test spectrum with heating and pressurization is corrected, so that the damage of the long-term life test spectrum taking heating and pressurization into consideration is equivalent to that of the long-term life test spectrum without considering heating and pressurization; then, based on the characteristic load damage acceleration method such as low-cycle fatigue, creep, thermal fatigue, etc., the acceleration task test spectrum is compiled under the premise of damage equivalence, and finally the whole machine test is carried out.

The present application relates to the field of material science and engineering application technology, specifically to a kind of metal material thermal mechanical fatigue life fast prediction method based on hysteresis energy density.First, hysteresis curve is used to calculate hysteresis energy density, then the quantitative relationship between shape coefficient, stress variation range and plastic strain range between low cycle fatigue and thermal mechanical fatigue is used, to achieve the purpose of predicting thermal mechanical fatigue hysteresis energy density under the same mechanical strain amplitude by low cycle fatigue, finally, energy accumulation damage model is used to predict thermal mechanical fatigue life.The method carries out two groups of experiments for low cycle fatigue and thermal mechanical fatigue respectively, realizes the prediction of thermal mechanical fatigue life under different mechanical strain amplitudes by low cycle fatigue, establishes the correlation between low cycle fatigue and thermal mechanical fatigue by using the similarity between them in the process of cyclic loading, effectively reduces the experimental amount required for thermal mechanical fatigue life evaluation, and is applied to the thermal mechanical fatigue life prediction of high-temperature alloy and vermicular cast iron and other metal materials.

The invention relates to the technical field of metal material processing and forming, in particular to a metal plate gradient structure construction method. The method comprises the following steps that (1) a metal cast ingot is subjected to hot forging to form a cylindrical forging material, and the diameter of the forging material is 20-40 mm; (2) the forged material is subjected to solid solution treatment, the solid solution temperature ranges from 500 DEG C to 1250 DEG C, and the heat preservation time is longer than or equal to 30 min; (3) carrying out rolling treatment on the forged material subjected to solid solution treatment, and rolling the forged material into a small cylindrical rod with the diameter of 4-16 mm; (4) axially rolling the rolled cylindrical small rod into a plate shape, wherein the pressing amount is 50-80%; and (5) the rolled metal plate is subjected to recrystallization annealing, the annealing temperature ranges from 600 DEG C to 800 DEG C, and the annealing time ranges from 10 min to 60 min. The problems that a large-range gradient structure is difficult to prepare and low in efficiency are solved or partially solved, the obdurability and high / low cycle fatigue performance of the metal material are synchronously improved, and therefore a new thought is provided for developing and manufacturing metal materials and components with high strength, high toughness and high fatigue performance.

The invention discloses a transient characteristic-containing maneuvering and pneumatic extreme value load combination probability distribution research method for a multi-duct casing system, and relates to the technical field of aero-engines, and the method comprises the steps: processing an original maneuvering load spectrum through employing a filtering method based on rain flow counting, extracting a typical task segment, and completing distribution fitting; acquiring basic data of a maneuvering load and an aerodynamic load; a turning point sequence of the basic data of the maneuvering load and the aerodynamic load is extracted, time domain reconstruction is carried out, and rain flow counting and low-cycle fatigue damage verification are carried out; carrying out mass sampling on the reconstructed load spectrum, and analyzing maneuvering and pneumatic extreme value load distribution characteristics; and calculating the correlation coefficient of the dynamic load and the aerodynamic load by adopting a rain flow method to obtain the joint probability density of the maneuvering load and the aerodynamic load. According to the method, the transient load analysis precision and efficiency of the multi-duct casing are improved, and theoretical support and data basis are provided for structural design and fatigue life prediction.

The invention provides a unified damage low-cycle fatigue life prediction method and system, and relates to the technical field of material tests.The method comprises the steps that stress and strain information of current and adjacent moment increment steps of a crack expansion area is obtained, damage opening displacement is constructed according to the stress and strain information, and the damage opening displacement is input into a unified cohesive force model; monotonic and cyclic fatigue damage evolution quantities are output; uniformly representing the two damage evolution quantities, determining a total damage accumulation value of cohesion unit nodes, sequentially judging monotonous and cyclic fatigue damage failure, deleting the nodes and recording moments if the monotonous and cyclic fatigue damage failure is failed, and updating cohesion rigidity if the monotonous and cyclic fatigue damage failure is not failed; and updating the boundary conditions of the model, performing iterative execution until a preset time increment step number is reached, extracting crack length change information to construct a life curve, and finally determining a low-cycle fatigue crack propagation life prediction result.

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

The invention relates to a friction stir welding method for strengthening the low cycle fatigue performance of a high-strength aluminum alloy joint. The friction stir welding method comprises the steps that a copper base plate with the heat conductivity being 300-500 W / m.K is laid in a tool groove used for friction stir welding; a pair of high-strength aluminum alloy plates to be welded are fixed in a tool groove, butt joint friction stir welding is conducted under the welding conditions that a stirring head rotates anticlockwise, the dip angle ranges from 2 degrees to 3 degrees, the rotating speed ranges from 300 rpm to 400 rpm, and the welding speed ranges from 60 mm / min to 120 mm / min, and the friction stir welding direction is consistent with the rolling direction of the high-strength aluminum alloy plates to be welded; in the friction stir welding process, the bottoms of butt welding seams of a pair of high-strength aluminum alloy plates to be welded are placed on a copper base plate, and the cooling rate during friction stir welding reaches 20-100 DEG C / s; the non-uniformity of the structure of the cross section of the welding seam is greatly reduced, namely, the strength and the low-cycle fatigue performance of the welding seam are improved.

The application provides a fatigue test load debugging method for a main hub central part of an unmanned helicopter, comprising the following steps: establishing a mechanical model according to a preset test loading scheme, and calculating theoretical values of a flapping force and a pitching force required to be applied to reach a target load; performing parameter configuration and parameter debugging on each load channel of a coordinated loading control system; performing static load and dynamic load working condition debugging on the main hub central part, so that the static load and the dynamic load meet test requirements; and on the basis of the static load and the dynamic load debugging of the main hub central part, performing low-cycle fatigue test load and high-cycle fatigue test load debugging on the main hub central part, so as to obtain input loads of a flapping force actuator and a pitching force actuator meeting test requirements. The technical scheme of the application solves the problem that the existing fatigue test mode of the main hub central part cannot guarantee that the loads of the hub center and the butt joint surface of the arm of the main hub central part meet test requirements at the same time.

The application belongs to the technical field of magnesium alloy solid-phase connection, and discloses a double-sided friction stir welding joint and a welding method and application thereof, which comprises the following steps: first friction stir welding is performed on pretreated magnesium alloy plates; the magnesium alloy plates after the first friction stir welding are turned over by 180 DEG, coaxially centered, and then second friction stir welding is performed symmetrically to obtain the double-sided friction stir welding joint. The application realizes the improvement of the low-cycle fatigue performance of the magnesium alloy joint, the improvement of the deformation coordination and the weakening of the basal texture induced by multidirectional plastic flow, the synergistic effect of the uniform and refined structure, the defect elimination and the texture weakening, the direct change of the macro-mechanical response of the joint under the low-cycle fatigue load, and the systematic and substantial improvement of the low-cycle fatigue life of the magnesium alloy double-sided friction stir welding joint.

The present invention discloses a method and system for evaluating the seismic effect of high-rise shear wall structures, specifically relating to the technical field of high-rise shear walls. By accurately collecting low-cycle fatigue parameters, a concrete and steel degradation model considering fatigue effects is constructed, which is applied to the seismic analysis of shear wall structures, simulating the influence of main earthquake and multiple aftershock loading on structural performance, drawing a bearing capacity degradation curve through multiple loading results, analyzing the abnormal state of degradation rate, combining the changes in residual stiffness and bearing capacity, judging the risk of abnormal structural stiffness and bearing capacity, and dividing the risk into high, medium and low levels, and proposing appropriate reinforcement or preventive measures for different risk levels, effectively making up for the deficiency of existing seismic evaluation that does not fully consider material fatigue effects, and being able to more accurately predict the damage accumulation of high-rise shear wall structures in frequent aftershocks, thereby reducing the risk of premature structural failure and improving the durability and safety of buildings in earthquakes.

The method for predicting the service life of the coiled tubing under the cooperation of plasticity and damage is characterized in that the fatigue service life and the strain amplitude under the specific curvature radius are obtained through a full-size bending fatigue test, and the fatigue service life and the strain amplitude are substituted into a Manson-Coffin model to invert an unknown coefficient; the method comprises the following steps: determining mechanical parameters of a material in combination with a uniaxial tensile test, constructing a finite element mechanical model, carrying out finite element simulation on bending working conditions of a damaged coiled tubing on a roller and a guider, extracting strain amplitudes, and further establishing strain amplitude calculation models under different working conditions by adopting a Levenberg-Marquardt algorithm; coupling the model with a Manson-Coffin equation, and respectively constructing fatigue life prediction models of the roller and the guider; and on the basis of the Miner theory, three times of bending cycles with different curvatures in one trip are regarded as complete load cycles, an accumulated damage value is calculated, a correction coefficient is determined through low-cycle fatigue finite element simulation, a calculation model of the number of remaining trip times is established, and quantitative prediction of the remaining life is achieved. The method is suitable for the technical field of petroleum and natural gas drilling engineering.

The invention belongs to the technical field of heat-resistant steel life prediction, and discloses a heat-resistant steel life prediction method and system based on low-cycle fatigue crack evolution and fracture, and the method comprises the steps: collecting the original structure morphology of austenitic heat-resistant steel, and obtaining the average grain size and grain orientation characteristics; and calculating the maximum Schmidt factor and the minimum Schmidt factor of each crystal grain by traversing a crystal grain slippage system. Meanwhile, a dislocation slippage theory is taken as a core, a low-cycle fatigue test is combined, shear stress, friction stress, Poisson's ratio and a plastic strain range are introduced, a low-cycle fatigue slippage zone length c and a crack tip fatigue slippage length increment delta CTSD are calculated, elastic and plastic strain tensors and a fatigue hysteretic curve are fused, and a crack tip fatigue slippage zone length delta CTSD is calculated. The crack growth rate and the crack length change rule under different circulation cycles can be accurately obtained, and the prediction error of a general model is reduced. The prediction accuracy of the fracture life of the austenitic heat-resistant steel can be greatly improved, potential safety hazards and resource waste are reduced, and stable operation of equipment under the high-temperature working condition is guaranteed.

The application discloses a kind of probability low-cycle fatigue life prediction methods of turbine blade, it is related to blade life prediction technical field.Acquire the multiple groups of sample working condition data of turbine blade to be predicted, and the low-cycle fatigue life of turbine blade to be predicted under each group of sample working condition data is calculated respectively by fatigue life prediction model based on critical plane method;Through multiple groups of sample working condition data and corresponding low-cycle fatigue life, neural network is trained, and low-cycle fatigue life prediction model is obtained;Through Monte Carlo method, the multiple groups of candidate working condition data of turbine blade to be predicted are generated, and the life prediction result corresponding to each group of candidate working condition data is predicted by low-cycle fatigue life prediction model;According to multiple life prediction results, the probability low-cycle fatigue life prediction result of turbine blade to be predicted is determined.The method can improve the accuracy of probability low-cycle fatigue life prediction while improving the efficiency of blade probability low-cycle fatigue life prediction.

Provided is a high-strength steel plate for hydrogen transport steel pipes that has excellent fatigue crack propagation resistance, little deterioration in strength and elongation, excellent low-cycle fatigue properties, and excellent resistance to ground movement in a high-pressure hydrogen environment. The present invention provides a steel sheet having a predetermined component composition and a tensile strength (TS) in air. A ) and tensile strength in hydrogen gas environment (TS H ) is 535 MPa or more, and the tensile strength in air (TS A ) and tensile strength in hydrogen gas environment, elongation in air (EL A ) and elongation in hydrogen gas environment (EL H ), the yield ratio (YR), which is the ratio of the yield strength to the tensile strength of the steel plate in air and hydrogen gas environments, the minimum grain size of the top 20% of the largest grains at the center of the plate thickness, the number of repeated fractures in a low-cycle fatigue test with a strain amplitude of 3%, and the stress intensity factor range ΔK are all within specified ranges.

The invention discloses a submodel-based complex component creep-low cycle fatigue life rapid prediction method, which comprises the following steps of: firstly, establishing a global simplified model of a complex component to carry out macroscopic response analysis; then, based on the stable cycle response characteristic shown by the specific high-temperature alloy under the creep-low cycle fatigue combined load, the boundary condition of the dangerous point sub-model is accurately defined; finally, through efficient and high-resolution sub-model analysis, rapid and accurate evaluation of the service life of the complex component under the creep-low cycle fatigue coupling effect is realized.