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487 results about "Material fatigue" patented technology

Material fatigue is a phenomenon where structures fail when subjected to a cyclic load. This type of structural damage occurs even when the experienced stress range is far below the static material strength. Fatigue is the most common source behind failures of mechanical structures.

Fatigue acceleration detection method and system for high-fatigue-resistance cast wheel

The invention relates to the technical field of material fatigue performance testing, in particular to a fatigue acceleration detection method and system for a high-fatigue-resistance cast wheel, and the method comprises the steps: generating a dynamic load spectrum containing a multi-axis combined load according to the actual operation condition of a target cast wheel; applying a dynamic load spectrum to the target casting wheel to perform an acceleration test, and monitoring dynamic strain responses on the surface and inside of the target casting wheel in real time based on the distributed sensing array; establishing a damage accumulation calculation model by taking a loading parameter of the dynamic load spectrum as an additional correlation condition, and calculating an equivalent fatigue damage accumulation value based on the dynamic strain response; when the equivalent fatigue damage accumulated value reaches a preset damage threshold value, it is judged that the target cast wheel reaches the fatigue life end point, and the damage evolution rule in the acceleration test is kept consistent with the damage mechanism of the actual operation working condition. According to the invention, the problems of multi-axis load simulation distortion, incomplete damage monitoring, low service life prediction precision and the like in traditional fatigue detection are effectively solved.
Owner:CHANGZHOU TONGTAI HIGH CONDUCTIVITY NEW MATERIALS CO LTD

Natural gas pipeline leakage probability calculation method and system based on genetic algorithm

The invention provides a natural gas pipeline leakage probability calculation method and system based on a genetic algorithm, and relates to the technical field of probability calculation, and the method comprises the steps: collecting pipeline operation parameters, building a pipeline structure dynamic stress model, a material fatigue model and a corrosion damage model, carrying out the coupling analysis of the three models, and obtaining a risk assessment parameter matrix; a leakage risk assessment initial model is constructed as a fitness function, and a leakage probability calculation model is obtained through genetic algorithm optimization. According to the method, the pipeline leakage risk can be accurately predicted, accurate evaluation and early warning of pipeline safety are realized, and the pipeline operation safety is improved.
Owner:BEIJING BODA SHUNYUAN NATURAL GAS CO LTD

Casting detection method and system based on machine vision

The invention discloses a casting detection method and system based on machine vision, and relates to the technical field of intersection of machine vision and material science, and the method comprises the steps: extracting the boundary coordinates of a region with a risk value exceeding a risk threshold according to a defect risk weight map, and forming a dynamic region of interest scanning frame; adjusting the incident angle of a polarized light source according to the track of the dynamic attention area scanning frame, collecting a local image, and obtaining a high-contrast image sequence for eliminating the interference of a surface oxide layer; extracting a defect edge feature map from the high-contrast image sequence through a deformable convolution kernel, and obtaining a defect candidate region mask; the defect candidate region mask is mapped to a von Mises stress field, and a crack germination probability is predicted in combination with a material fatigue limit parameter. According to the method, the accuracy and reliability of detection are improved, and the applicability under complex working conditions is remarkably improved, so that the casting quality control level is effectively improved, and the repair and quality control cost is reduced.
Owner:HUNAN HECHUANG MASCH CASTING CO LTD

Ultrasonic fatigue experiment monitoring method based on digital twinning

The invention belongs to the field of material performance testing of mechanical structure strength, and particularly relates to an ultrasonic fatigue experiment monitoring method based on digital twinning. According to the method, on the basis of an ultrasonic fatigue testing machine platform, an ultrasonic fatigue digital twin model of a tested object is established by collecting frequency, temperature, load and other test data, and real-time online monitoring of ultrasonic fatigue and life prediction are carried out in combination with a fatigue life prediction model. Compared with a traditional test method, the method has the advantages that ultrasonic detection data and a digital twinborn model technology are combined, the fatigue life of the material is predicted and evaluated, the test efficiency is improved, the long-life test cost is reduced, and the accuracy and reliability of test data are improved.
Owner:EAST CHINA UNIV OF SCI & TECH

Method for optimizing air tightness of soft pressurizing cabin

The invention provides an air tightness optimization method for a soft pressurization cabin, and the method comprises the steps: presetting a dynamic sensor array at a specific position where a structure is liable to fail according to a failure risk assessment table, collecting stress concentration data caused by non-uniform pressure distribution in real time, and generating a stress distribution dynamic graph containing a time sequence; the dynamic adjusting device is driven to operate through the homogenized pressure distribution adjusting scheme, pressure field data in the cabin body is updated in real time, whether material fatigue is within the fracture risk range or not is judged, and a fatigue state monitoring report is generated; obtaining a fracture risk index in the fatigue state monitoring report, carrying out iterative adjustment on the fiber weaving density and the elastic modulus of the key area by adopting a material design optimization algorithm, and determining a final structure layout parameter for improving the performance; and extracting a limiting condition of dynamic adjustment difficulty from the final structure layout parameters, simulating a cabin operation state in an extreme environment through a digital twin technology, calculating a boundary value of performance limitation, and obtaining a verification result of performance improvement.
Owner:CHINESE PEOPLES LIBERATION ARMY NAVAL SPECIALTY MEDICAL CENT

Method for simulating and deducing torsion cycles

The invention relates to the field of mechanical fatigue simulation, and discloses a method for simulating and deducing the number of torsion cycles. Comprising the steps that a component three-dimensional parameterized model is constructed, and material fatigue characteristics are defined; applying a periodic torsion load spectrum containing a harmonic component; adopting a stress influence coefficient matrix method to execute quasi-static finite element analysis, and extracting a multi-axis stress state; calculating the maximum alternating shear stress and the average shear stress based on a critical plane recognition technology; converting into a single-axis equivalent stress amplitude through a gradient enhanced multi-axis correction rule; calculating node fatigue damage by combining an S-N curve and a damage accumulation theory; and when the damage reaches a threshold value, outputting a failure cycle number and a position. The innovation points are as follows: the prediction error is controlled within 10% by a critical plane and multi-axis correction technology; a stress matrix method realizes ten thousand times of cycle-level efficient simulation, and the efficiency is improved by 10 times; the risk early warning accuracy rate is improved to 96% by integrating a process correlation defect model; and the research and development period is shortened by 40% through a life cloud picture and an automatic optimization closed loop. The method is suitable for transmission shaft system reliability design.
Owner:NANJING ZHENGCHENG JIAMING INTELLIGENT TECHNOLOGY CO LTD

Self-adaptive constant-force damping mechanism base and robot

The invention discloses a self-adaptive constant-force vibration reduction mechanism base and a robot, and belongs to the technical field of specialized robots. Two sets of buffer units and vibration reduction units are arranged at the front end and the rear end of the base correspondingly; driving wheels are arranged on the buffer unit and the vibration reduction unit; the buffer unit comprises a horizontal buffer structure, a vertical buffer structure and a support; the horizontal buffer structure is slidably connected with the support in the vertical direction; the top of the vertical buffer structure is hinged to the support, and the bottom is fixedly connected with the driving wheel; the support is fixedly connected with the base; the vibration reduction unit comprises a rotating support and a constant force component. According to the self-adaptive constant-force vibration reduction mechanism base and the robot, the problems that in the prior art, a vibration reduction mechanism cannot completely avoid vibration generated by a wheel type moving device in the vertical direction when the wheel type moving device moves on an uneven road surface, and consequently bolt looseness, wire harness interface looseness, material fatigue strain and the like occur can be effectively solved; and therefore, the wheel type moving device has a fault in the operation process and cannot stably operate, and the like.
Owner:CHENGDU HUMANOID ROBOT INNOVATION CENT CO LTD

Method for simulating fatigue small crack propagation of polycrystalline metal material

The invention relates to a method for simulating fatigue small crack propagation of a polycrystalline metal material. The method comprises the following steps: determining a crystal plastic constitutive model and accurate values of all undetermined parameters of the crystal plastic constitutive model; establishing a crack propagation finite element model of the polycrystalline metal material, and embedding the crystal plasticity constitutive model of which each undetermined parameter has a respective accurate value and a pre-obtained crack propagation criterion into the crack propagation finite element model; applying load and boundary conditions to the crack propagation finite element model, and performing crack propagation finite element analysis to obtain a finite element analysis result, including stress-strain data calculated based on the crystal plasticity constitutive model and crack propagation data calculated based on a crack propagation criterion and the stress-strain data. According to the method for simulating the fatigue small crack growth of the polycrystalline metal material, the Hall epicy size effect is introduced into the crystal plasticity constitutive model to consider the influence of the grain size on the sliding resistance, so that the simulation accuracy is improved.
Owner:EAST CHINA UNIV OF SCI & TECH

Pressure vessel health monitoring method based on intelligent algorithm

The invention relates to the technical field of intelligent diagnosis, in particular to a pressure vessel health monitoring method based on an intelligent algorithm, which comprises the following steps: acquiring pressure, stress and temperature data in real time by using a sensor array, calculating a track evolution parameter set, identifying a damaged area, detecting a fault event, and predicting a health state and residual service life. And establishing a damage grade classification framework, and obtaining a damage grade classification result. According to the method, through multi-source data real-time acquisition and spatial gradient refining processing, by using a pressure and stress distribution coupling relation, accurate damage positioning is realized, the anomaly detection sensitivity is improved, damage boundary coordinates are marked, the expansion rate of adjacent damage areas is quantified, and phase delay is judged in combination with a multi-period pressure track; fault recognition stability is enhanced, abnormal event classification precision is optimized, a material fatigue accumulation and pressure uniformity correlation means is adopted, health score attenuation observation is enhanced, health state quantification depth is improved, and life prediction reliability is expanded.
Owner:NANTONG UNIV

Metal fatigue crack initiation simulation method for coupling holes and microstructures

The invention discloses a metal fatigue crack initiation simulation method for coupling holes and microstructures, which comprises the following steps of: firstly, establishing a microscopic scale model by collecting microstructure characteristic data and hole distribution data in a metal material, obtaining basic parameters by combining a mechanical property test result, and deducing and calculating microscopic orthotropic parameters; the method comprises the following steps of: scanning internal defects of an alloy, establishing a hole defect model with the same characteristic information according to the scanned internal defects of the alloy, extracting key holes through finite element simulation to establish a geometric model, introducing a stress concentration coefficient, and replacing a shear stress amplitude calculation mode in a Tanaka-Mura dislocation theoretical formula with a stress amplitude calculation mode. And micro-scale numerical simulation of fatigue crack initiation of the metal material with the hole defect is completed. According to the method, factors such as the microstructure and the internal holes of the material are considered, and the finite element simulation technology is combined, so that accurate prediction of the microscale metal fatigue crack initiation life can be realized.
Owner:NANCHANG UNIV

Aircraft shell surface quality detection method and system

The invention discloses an aircraft shell surface quality detection method. According to the method, a passenger cabin pressure difference curve and a shell outer surface temperature curve are calculated to obtain a pressure difference change node and a temperature difference change node respectively, and then partitioning is carried out to obtain phase thermoelastic coupling partitions; when a temperature difference change node reaches a phase change threshold value, performing beta-phase to alpha-phase transformation on the polyvinylidene fluoride microcapsule premixed in the finish paint, and forming a polarized memory cavity at a defect cementing position; when a voltage difference change node reaches a peak value, triggering a polarized memory hole to release charges, exciting a high-order thin film elastic wave, and performing integer ratio phase locking on the high-order thin film elastic wave and a natural vibration wave of a machine body to obtain a defect harmonic signal; carrying out acoustic-mechanical coupling calculation according to the amplitude of the defect harmonic signal to obtain a virtual work increment, and recording the virtual work increment to a damage matrix; and performing multi-leg accumulation calculation on the virtual work increment, and outputting a defect early warning signal when an accumulation value exceeds a material fatigue critical value. According to the invention, the hidden fatigue defect of the surface of the aircraft shell under the dynamic load can be detected.
Owner:HANZHONG WANLI AVIATION EQUIP MFG CO LTD

Anchoring system life intelligent evaluation method, system, equipment and medium

The invention relates to an anchoring system life intelligent evaluation method, system and device and a medium, and the method comprises the steps: constructing a topological network through the space coordinates of anchoring points and the rigidity of components, and quantifying the mechanical correlation between nodes; the load is monitored in real time and compared with a design value, and the dynamic sensitivity of the node is calculated by fusing material strength characteristics; identifying a set of overload source nodes based on a sensitivity threshold; a Monte Carlo path simulation technology is adopted, a material fatigue accumulation effect is combined to model a failure conduction probability, and a risk conduction path and a strength index are generated; integrating historical degradation data to predict single anchor life, and coupling the maximum path risk and the minimum single anchor life to calculate a system attenuation coefficient; and outputting an evaluation report containing the remaining service life and the position of the high-risk unit. The method breaks through the limitation of traditional single-anchor isolated evaluation, realizes dynamic quantification of the failure conduction effect of the multiple anchoring units, and solves the problem of maintenance decision blindness caused by conduction effect deficiency.
Owner:GUANGXI UNIV +2

Method and device for testing fatigue crack growth rate of metal material based on temperature gradient change

The invention discloses a method and device for testing the fatigue crack growth rate of a metal material based on temperature gradient change, and relates to the technical field of metal material detection. Mounting a constant low-temperature component and a constant high-temperature component close to two ends of the sample respectively; pasting a plurality of thermocouples on the middle surface of the sample; a magnetic powder dynamic moving assembly is installed on the surface of the sample, and a constant-temperature state is given to magnetic powder; loading a bidirectional tension-compression fatigue testing machine along the through hole of the sample; a thermal imager is arranged far away from the parallel sample, and a thermal imaging image is shot; according to the data, the fatigue crack growth rate of the sample at the corresponding temperature is obtained; according to the method, the fatigue crack growth rate of the metal material can be rapidly tested, meanwhile, the temperature gradient is formed in the sample, the influence of the temperature on the crack growth rate can be obtained in different temperature areas, the device required by the whole test is simple in structure, low in cost and convenient to load and disassemble, and the whole efficiency of the test is effectively improved.
Owner:UNIV OF SCI & TECH BEIJING

Method and device for automatically segmenting and quantifying fatigue crack in structural strength test

The invention discloses a fatigue crack automatic segmentation and quantification method and device in a structural strength test, and the method comprises the steps: obtaining a material fatigue crack image, and constructing a material fatigue crack image data set; a fatigue crack segmentation and quantification network CrackDAM-Net is constructed; comprising the following steps: constructing a local feature encoder, a global information encoder, a multi-scale feature fusion module, a decoder module and a crack length automatic quantization module, and training a fatigue crack automatic segmentation and quantization network; and inputting a crack image to be detected into the fatigue crack segmentation and quantization network CrackDAM-Net, and carrying out crack segmentation and length quantization to obtain the fatigue crack length. According to the method, the calculation complexity of the model is reduced by constructing the fatigue crack segmentation and quantification network-CrackDAM-Net; the effective fusion of fine-grained details and coarse-grained information is realized, and the extraction effect of crack global information, the accuracy of crack segmentation and the precision of crack length measurement are improved.
Owner:XIDIAN UNIV +1

Estimation method for fatigue crack growth rate of corrosion-resistant metal composite material

The invention relates to the field of test methods, in particular to a method for estimating the fatigue crack growth rate of a corrosion-resistant metal composite material, which comprises the following specific steps: S1, preparing a sample, and measuring and recording the thickness B, the width W and the machining notch length am of the sample; s2, prefabricating fatigue cracks; s3, selecting test parameters; s4, carrying out a fatigue crack growth rate test; s5, calculating the opening displacement variation (delta delta) of the crack tip; s6, forming a data group, analyzing a distribution rule and establishing a mathematical model; and S7, carrying out damage tolerance design and fatigue life check. According to the method, the crack tip opening displacement variation delta delta is used as a driving parameter to describe the fatigue crack propagation rule of the corrosion-resistant low-strength high-plasticity metal material and the composite material of the high-strength low-plasticity metal material; the method can solve the crack propagation problem that K is only suitable for elastic or small-range yield and r cannot be fully covered under the condition of plastic yield.
Owner:CHINA SHIPBUILDING INDUSTRY CORPORATION NO725 RESEARCH INSTITUTE

Optimal torsion optimization method based on stress model

The invention relates to the field of mechanical transmission control, and discloses a self-adaptive torsion optimization method and system based on a stress model. The method mainly comprises the following steps: acquiring strain, temperature and vibration data of a transmission system in real time through a distributed sensor network; constructing a three-dimensional dynamic stress field model, and marking a high-risk area; dynamically adjusting a safety threshold based on material fatigue characteristics, and generating a torque control curve by adopting an optimization algorithm; and eliminating response delay through a pre-compensation mechanism. The system comprises an edge calculation unit, a millisecond-level actuator and a grading protection module. According to the method, the tooth root stress concentration is successfully inhibited by 35% in the wind power gear box, the impact load is reduced by 52% in the industrial robot joint, the equipment reliability is remarkably improved, and the service life is remarkably prolonged. The device is suitable for transmission systems of wind power, electric automobiles, industrial robots and the like.
Owner:NANJING ZHENGCHENG JIAMING INTELLIGENT TECHNOLOGY CO LTD

Method, system and equipment for predicting fatigue life of composite material patching and repairing structure

The invention belongs to the technical field of computer simulation, and particularly discloses a method, a system and equipment for predicting the fatigue life of a composite material patching and repairing structure. The prediction method comprises the following steps: establishing a composite laminated plate fatigue damage analysis method in combination with an improved Hashin criterion, finite element analysis, a strength degradation model, a rigidity degradation model and a Camanho material parameter degradation model; fatigue life prediction analysis is carried out on the non-porous laminated plate and the porous laminated plate by using the method; and comparing a prediction result with a test result, and verifying the effectiveness of the established composite material laminated plate fatigue damage analysis method. On the basis, a composite material fatigue damage analysis method and a cohesion unit are combined, and a repair structure fatigue life prediction model is established. The fatigue life prediction method for the repair structure is provided by taking the composite material patching and repairing structure as a research object, and has certain engineering practical significance and better practical value.
Owner:CHENGDU AIRCRAFT DESIGN INST OF AVIATION IND CORP OF CHINA +1

Water cooling wall safety monitoring method and combustion adjustment control method based on distributed optical fiber sensing

The invention provides a water-cooled wall safety monitoring method and a combustion adjustment control method based on distributed optical fiber sensing, and the method specifically comprises the following steps: arranging a Bragg grating on a water-cooled wall, and obtaining the Bragg wavelength offset; predicting a temperature value and a strain value at the current moment according to historical temperature and strain data by using a state equation of stress and temperature; the Bragg wavelength prediction offset is obtained by combining the temperature value and the strain value at the current moment with the sensor error; obtaining a wavelength change residual error according to the Bragg wavelength offset and the Bragg wavelength prediction offset, and correcting the temperature value and the strain value at the current moment by using the wavelength change residual error to obtain a real temperature value and a real strain value at the current moment; a real strain value at the current moment is converted into a stress value, a water-cooled wall tearing factor is established by utilizing the stress value, the number of thermal cycles and the fatigue life of a water-cooled wall material, water-cooled wall safety monitoring and combustion adjustment control are realized by utilizing the water-cooled wall tearing factor, and the operation safety of the boiler is improved.
Owner:XIAN THERMAL POWER RES INST CO LTD

Multi-stage turbine rotor blade fatigue life analysis method and device

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.
Owner:AECC HUNAN AVIATION POWERPLANT RES INST

Constant-force damping mechanism and robot

The invention discloses a constant-force vibration reduction mechanism and a robot, and belongs to the technical field of specialized robots, the constant-force vibration reduction mechanism comprises at least two vibration reduction units arranged on a base and a plurality of driving wheels consistent with the vibration reduction units; the vibration reduction unit comprises a rotating support and a constant force component. The rotating bracket is rotatably connected with the base; the rotating bracket is respectively connected with the driving wheel and the constant force component; the constant force component is used for applying counter-acting force to the base, and it is guaranteed that the base and an upper structure of the base are kept stable in the vertical direction in the moving process. According to the constant-force vibration reduction mechanism and the robot, the problems that in the prior art, a vibration reduction mechanism cannot completely avoid vibration generated by a wheel type moving device in the vertical direction when the wheel type moving device moves on an uneven road surface, and consequently bolt looseness, wire harness interface looseness, material fatigue strain and the like occur can be effectively solved; and therefore, the wheel type moving device has a fault in the operation process and cannot stably operate, and the like.
Owner:CHENGDU HUMANOID ROBOT INNOVATION CENT CO LTD

Self-resetting three-dimensional damping rubber support based on SMA (Shape Memory Alloy) tows and damping method

The invention relates to a self-resetting three-dimensional damping rubber support based on SMA tows and a damping method, and belongs to the field of civil engineering structure damping. The support comprises an upper connecting plate, a lower connecting plate and a shock insulation rubber support, I-shaped sliding rails are fixed to the upper connecting plate and the lower connecting plate respectively, sliding pieces are connected to the sliding rails in a buckled mode, and multidirectional displacement is coordinated through sliding piece connecting rods; the SMA tow system is composed of a fixing rod, a push-pull rod and an annular tow, the two ends of the SMA tow system are anchored to the sliding rail and the connecting rod respectively, and energy consumption and self-resetting are achieved by stretching the tow through a sliding piece. When an earthquake causes horizontal deformation of the support, the SMA tows utilize the hyperelastic hysteretic characteristic to efficiently dissipate energy, automatically recover deformation after the earthquake and drive the sliding piece to reset. According to the invention, the vertical tensile function, the horizontal bidirectional free deformation function and the self-resetting function are integrated, the structure is simplified through the sliding rail-sliding piece module, a complex mechanical device is avoided, and the energy consumption efficiency and the engineering applicability are remarkably improved. And the problems of large residual deformation, poor multidirectional coordination and material fatigue are solved.
Owner:CHINA MERCHANTS CHONGQING COMM RES & DESIGN INST

Wind turbine blade crack detection system based on acoustic signature analysis

The present invention relates to the field of wind turbine detection technology, and specifically to a wind turbine blade crack detection system based on acoustic feature analysis, comprising an acoustic signal acquisition module, a material fatigue state monitoring module, a signal separation and identification module, and a crack location module, wherein: the acoustic signal acquisition module acquires acoustic signals generated during blade operation; the material fatigue state monitoring module compares changes in material properties with a material damage database to determine the material fatigue state of the current blade; the signal separation and identification module distinguishes between normal operating acoustic signals and abnormal acoustic signals; and distinguishes crack signals from material fatigue signals; and the crack location module determines the crack location using a triangulation positioning algorithm. The present invention significantly improves the accuracy of abnormal signal separation through the coordinated analysis of material behavior and acoustic signals, thereby more accurately detecting crack signals.
Owner:GUODIAN NANJING ELECTRIC POWER TEST RES CO LTD

Method and system for predicting structural fatigue of unmanned aerial vehicle

The invention relates to the technical field of unmanned aerial vehicle evaluation, in particular to an unmanned aerial vehicle structure fatigue prediction method and system, and the method comprises the steps: obtaining a sensor data set of a key structure part of an unmanned aerial vehicle; dynamically evaluating the data quality of the sensor data set, and dynamically adjusting a data cleaning preprocessing strategy according to an evaluation result; constructing a stress field model reflecting global stress distribution of the structure on the basis of the preprocessed sensor data set in combination with real-time flight environment parameters; and according to the stress field model and material fatigue characteristics, calculating a fatigue damage prediction value of each structural part. The objective of the invention is to improve the prediction precision of the fatigue damage of the unmanned aerial vehicle structure.
Owner:THE SECOND RES INST OF CIVIL AVIATION ADMINISTRATION OF CHINA

Method for predicting residual life of existing asphalt pavement structure

The invention discloses a method for predicting the residual life of an existing asphalt pavement structure, particularly relates to the technical field of computer simulation and data processing, and is used for solving the problem that the existing prediction method cannot efficiently represent the non-uniformity of an existing pavement material and the dynamic environment load influence on the premise of ensuring the precision. Existing damage data of a road surface are acquired to construct a simulation model reflecting a real initial state, material fatigue parameters are acquired in combination with cross-scale analysis, a dynamic environment boundary is driven by utilizing climate time sequence data, and then time-frequency coherence analysis is performed on a damage mode and a climate load to identify a high-threat working condition, so that the high-threat working condition is identified. And finally, preferentially operating high-fidelity thermal-mechanical coupling numerical simulation aiming at a high-threat working condition, and mapping damage evolution data output by simulation to a macroscopic performance degradation process so as to determine the residual fatigue life.
Owner:JIANGXI PROVINCIAL EXPRESSWAY INVESTMENT GRP CO LTD +1

Constant-force buffer mechanism and robot

The invention discloses a constant-force buffering mechanism and a robot, and belongs to the technical field of specialized robots, the constant-force buffering mechanism comprises at least two constant-force buffering assemblies arranged on a base and a plurality of driving wheels consistent with the constant-force buffering assemblies; the constant-force buffering assembly comprises a main support and a constant-force spring piece. The driving wheel is telescopically connected to the main bracket through a constant-force spring piece; the constant-force spring piece exerts counter-acting force on the base through vertical telescopic deformation so as to offset the gravity of the base and the gravity of the upper structure of the base, and it is guaranteed that the base and the upper structure of the base are kept stable in the vertical direction in the moving process. According to the constant-force buffering mechanism and the robot, the problems that in the prior art, a damping mechanism cannot completely avoid vibration generated by a wheel type moving device in the vertical direction when the wheel type moving device moves on an uneven road surface, and consequently bolt looseness, wire harness interface looseness, material fatigue strain and the like occur can be effectively solved; and therefore, the wheel type moving device has a fault in the operation process and cannot stably operate, and the like.
Owner:CHENGDU HUMANOID ROBOT INNOVATION CENT CO LTD

Double-spring frequency conversion lever tuned mass damper device and regulation and control method

The invention relates to the technical field of bridge vibration reduction, in particular to a double-spring frequency conversion lever tuned mass damper device and a regulation and control method. The double-spring frequency conversion lever tuned mass damper device comprises a base, a lever, a mass block, a first spring and a second spring. Wherein the base is used for being connected with a to-be-damped structure; the middle of the lever is rotationally connected with the base; the mass block is arranged on the lever and located on one side of the base. The first spring and the second spring are located on the two sides of the base respectively, connected with the lever or abut against the lever and used for balancing the gravity of the mass block, and the first spring is located between the mass block and the base. The problems that in the prior art, when the spring end stress and the mass block end stress are amplified in a lever proportion, the pin shaft stress is too large, damping is too large, debugging is difficult, the pin shaft and a lever need to be thickened or made of special alloy, the manufacturing cost is increased, and potential safety hazards are possibly caused by material fatigue are solved.
Owner:CHINA RAILWAY BRIDGE RES TECH CO LTD +2

Vibration and conventional fatigue load coupled nonlinear damage accumulation prediction method

The invention discloses a vibration and conventional fatigue load coupled nonlinear damage accumulation prediction method. The method comprises the following steps: analyzing and determining a peak stress at a dangerous point under the loading of a conventional fatigue load according to a finite element model of an engineering component; determining a stress amplitude probability density function at the dangerous point under random vibration loading according to structural dynamics analysis; searching a pre-generated material fatigue life curve; determining equivalent stress at the dangerous point under random vibration loading according to the fatigue life curve; calculating the ratio of the peak stress loaded by the conventional fatigue load at the dangerous point to the random vibration equivalent stress, and establishing a coupling damage parameter according to the vibration and conventional fatigue load coupling series; and establishing a nonlinear damage accumulation model of vibration and conventional fatigue load coupling. According to the nonlinear damage accumulation model provided by the invention, the influence of vibration, a conventional load sequence and a coupling series is considered, the parameter determination is simple, and high-precision prediction of structural damage evolution under complex load coupling can be realized.
Owner:NANJING UNIV OF AERONAUTICS & ASTRONAUTICS

Post-treatment method for improving fatigue performance of additive manufacturing TA15 alloy

The invention relates to the field of metal material fatigue performance optimization, in particular to a post-treatment method for improving the fatigue performance of an additive manufacturing TA15 alloy. The method comprises the following steps that a printing state material of the additive manufacturing TA15 alloy is taken to be subjected to annealing treatment, and a destressing state material of the additive manufacturing TA15 alloy is obtained; then carrying out hot isostatic pressing treatment; carrying out solution treatment on the material subjected to hot isostatic pressing treatment; and then aging treatment is carried out. According to the method, solution aging treatment is combined on the basis of HIP, on the basis of eliminating pores, coarsening of alpha laths is inhibited, the grain boundary alpha enrichment distribution density in the additive manufacturing TA15 alloy is reduced, the microstructure of the alloy is further optimized, the fatigue strength of the additive manufacturing TA15 alloy can be effectively improved, and the process is simple, convenient and reliable.
Owner:INST OF METAL RESEARCH - CHINESE ACAD OF SCI

Material fatigue damage measuring device and method based on Ampere force loading

The invention discloses a material fatigue damage measuring device and method based on Ampere force loading. The device comprises a base support; the circular magnetic field generating device is fixed on a top plate of the base bracket and is connected to the magnetic field controller through a first lead to adjust parameters of a magnetic field; the two sliding contact clamps are installed on the baffles on the two sides of the base support respectively. A to-be-tested material is fixed between the two sliding contact clamps, and the sliding contact clamps clamp the to-be-tested material through a sliding contact structure; the constant current source is connected to the two ends of the to-be-tested material through a second wire to form a closed loop, and ampere force is generated when current passes through the to-be-tested material; the constant current source provides constant current for the to-be-tested material and has an overcurrent protection function; according to the method, the stress and fatigue damage of the material under the action of the Ampere force can be accurately calculated through accurate current and magnetic field control in combination with the calculation formula of the Ampere force.
Owner:SOUTHEAST UNIV CHENGXIAN COLLEGE

Composite cold shrink cable terminal

The utility model relates to the technical field of cold-shrink cable terminals, in particular to a composite cold-shrink cable terminal, which comprises an umbrella skirt, an insulating sleeve is fixedly connected to the inner side of the umbrella skirt, a stress control tube with a high dielectric constant is arranged on the inner side of the insulating sleeve, a sealing sleeve is arranged on the inner side of the stress control tube, and the sealing sleeve is fixedly connected with the umbrella skirt. A group of sealing sleeves are arranged on the base, a stress control sleeve with a high dielectric constant is fixedly connected between the group of sealing sleeves, and plastic spiral supporting strips are arranged on the inner sides of the sealing sleeves. The arc-shaped positioning blocks, the damping rods, the connecting shaft rods and the like are placed on the inner sides of the plastic spiral supporting strips, the supporting effect of the plastic spiral supporting strips can be enhanced through the arc-shaped positioning blocks, materials cannot be rigidly limited through cooperation of the damping rods and the springs, and therefore the situation that shrinkage is not in place due to material fatigue is reduced.
Owner:HUBEI DELE ELECTRIC POWER TECH CO LTD