368 results about "Crack initiation" patented technology

The invention belongs to the technical field of nondestructive testing, and particularly relates to a detection method for quantitatively evaluating fatigue damage in a pipeline through a nonlinear ultrasonic technology. 316 stainless steel and SA335GRP-11 ferrite steel samples are adopted, a welding seam area is formed through V-shaped groove welding, fatigue loading is conducted, and actual pipeline fatigue damage is simulated; for the samples with different fatigue cycles, nonlinear response signals of the samples are obtained; fourier transform is carried out on the obtained signal to obtain an energy spectrum of the signal, and energy changes of the signal on a fundamental frequency band and a second harmonic frequency band are analyzed; and calculating a nonlinear coefficient, and analyzing a change rule of the nonlinear coefficient along with fatigue cycles, so that the evolution process of fatigue damage in the pipeline is evaluated. According to the method, energy is used for replacing the amplitude value, on the basis of the formula principle, integration is used for replacing the amplitude value to improve the intensity of the characterization nonlinear ultrasonic signal, the early stage of damage and the later stage of crack initiation are detected, and reliable guarantee is provided for safe operation of an industrial pipeline system.

The invention relates to the technical field of machine vision structure health monitoring, and discloses a steel structure weld fatigue cracking real-time monitoring system based on machine vision. The system comprises a space-time registration and fusion module, a multi-scale feature analysis module, a health monitoring module, a crack deduction calculation module and a regulation and control strategy generation module. Performing space-time registration and pixel-level fusion through the visual data of the plurality of image sensors to generate a synchronous multi-source image stream; a multi-level welding seam characteristic spectrum is constructed through multi-scale characteristic analysis, and a welding seam structure knowledge base is dynamically updated; the knowledge base and the real-time characteristic spectrum are used for monitoring the welding seam health state, and abnormity is recognized; deducing a crack initiation position and an evolution path in combination with historical damage data; and real-time load information is fused to pre-estimate the remaining service life, and a structural integrity regulation and control strategy is generated online. According to the invention, high-precision fusion of the multi-source visual data and active prediction of the crack trend are realized, and the monitoring accuracy and the early warning capability are improved.

The invention discloses a rock crack evolution numerical simulation method based on data analysis, and relates to the technical field of rock mechanics engineering numerical simulation, and the method comprises the following steps: S1, obtaining microstructure data of a target rock, including a CT scanning image, an SEM image and mineral energy spectrum data; and S2, constructing a spatial distribution dynamic mechanical parameter field based on the microstructure data. According to the rock crack evolution numerical simulation method based on data analysis, a dynamic mechanical parameter field driven by a microstructure is constructed, so that the inherent defect that rock is simplified into a homogeneous material in a traditional method is overcome; microscopic characteristics such as mineral hardness gradient, grain boundary strength distribution and pore morphology are effectively quantified into an elastic modulus field, a tensile strength field and a fracture energy field which are spatially distributed, so that the numerical prediction of crack initiation and expansion truly reflects the inherent heterogeneity of the rock for the first time.

The invention provides a method for evaluating the crack resistance of tunnel body concrete, and belongs to the technical field of wind tunnels, and the method comprises the steps: uniformly arranging multiple types of sensors on the surface of a tunnel body concrete structure to form a high-density monitoring network, employing a concrete circular ring constraint test piece to establish an anti-crack reference database, and constructing a multi-working-condition temperature stress database; acquiring multi-dimensional data such as strain, temperature and acoustic emission in real time, inputting the monitoring data into a liquid adaptive neural network model to predict crack initiation probability and expansion risk, establishing a crack risk assessment function, formulating a corresponding processing strategy according to a risk coefficient range, and starting an intelligent spray maintenance system; a closed-loop control system from monitoring perception to risk early warning to active protection is formed, and the technical problem that crack initiation and expansion risks of a hole body concrete structure cannot be accurately predicted under complex working conditions is solved.

The invention discloses a concrete anti-cracking method and system based on fiber reinforcement, and belongs to the technical field of concrete anti-cracking. The method comprises the following steps: acquiring real-time strain data in concrete through a distributed optical fiber sensor; analyzing the data to obtain a three-dimensional crack propagation path containing a crack initiation position, a propagation angle and a tip position; identifying the dominant development direction of the crack and a fan-shaped potential expansion interval which extends at an expansion angle by taking the tip as a vertex based on the path data; in the potential expansion interval of the to-be-poured area, a fiber distribution layer arranged in the dominant development direction is formed through directional arrangement equipment; and the fiber-reinforced anti-cracking structure is formed through vibrating and compacting treatment. According to the invention, directional blocking of fibers to crack expansion is realized, the problem of disordered expansion of cracks is effectively solved, and the anti-cracking efficiency of concrete is improved.

The invention relates to the technical field of intelligent scheduling, in particular to a steel structure weld fatigue cracking real-time monitoring system based on machine vision, which is characterized in that an image acquisition module acquires a high-stability image sequence in a strong vibration environment; the displacement field reconstruction module adopts a frequency domain-space domain combined decomposition technology to isolate environmental noise and material non-uniformity interference in a breakthrough manner, and an anti-noise deformation field and a stress distribution diagram are synchronously output through dual-channel parallel processing; a damage response module accurately locks sub-pixel-level crack initiation coordinates based on strain energy accumulation rate mutation, and dynamically predicts a yield risk area in combination with a displacement gradient diffusion model; the early warning module intelligently triggers graded response according to the crack position and the space coupling state of the risk area, performs positioning maintenance in a low risk area and automatic strengthening in a high risk area, and outputs heat treatment scheme coordinates when no crack exists; the system solves the problems of false detection caused by vibration noise and lagging response of single-parameter monitoring, and active protection from damage initiation to failure blocking is realized.

The invention provides a rock porosity adaptive modeling and blasting crack expansion calculation method based on key-type near-field dynamics, and the method comprises the steps: constructing a unified near-field dynamics model containing pore adaptive generation and blasting dynamic response; dynamic simulation of the rock blasting process is realized through pore distribution control, blasting load time history application and crack evolution judgment, and crack initiation, expansion and penetration rules can be accurately reproduced while the calculation stability is ensured. By introducing a pore adaptive discrete algorithm, the construction of rock models under different porosity conditions is automatically realized, and the initiation, expansion and penetration processes of cracks in the rock mass are accurately predicted in combination with near-field dynamics mechanical calculation under the action of an explosion load. According to the method, the heterogeneous characteristic of the rock and the discontinuous effect of the blasting load can be considered at the same time under a unified dynamic framework.

The invention discloses an ejector pin anti-fatigue strengthening method based on multi-section variable-temperature treatment, and relates to the technical field of ejector pin anti-fatigue strengthening, and the ejector pin anti-fatigue strengthening method comprises the following steps: austenitizing high-temperature quenching: heating an ejector pin to an austenitizing temperature, and then carrying out zoned cooling on the ejector pin; medium-temperature tempering and thermal-state mechanical strengthening are conducted, specifically, the ejector pin is tempered at the medium-temperature tempering temperature, and thermal-state shot blasting or laser shock is conducted on the ejector pin in the heat preservation period or after heat preservation is completed; intermediate low-temperature plasma nitriding: carrying out plasma nitriding in a nitrogen-hydrogen gas environment; subzero treatment: placing the ejector pin in liquid nitrogen; and finally, low-temperature tempering and cold-state mechanical strengthening are conducted. Through multi-section temperature gradient treatment, phase change distribution control over different temperature sections is achieved, too high internal stress and brittleness generated by one-time quenching are avoided, sudden size change and hot cracks induced by phase change are prevented, a controllable surface-core hardness and toughness gradient is formed, the surface crack initiation tendency is reduced, and the surface quality is improved. And the consistency and controllability of anti-fatigue basic conditions are improved.

The invention provides an anti-cracking performance evaluation method and system based on a concrete shrinkage rate. The method comprises the following steps: firstly, collecting shrinkage rate real-time sequence data and an acoustic emission signal flow of a concrete sample in a curing process, separating a high-frequency elastic wave energy attenuation characteristic value from the acoustic emission signal flow, and carrying out space-time coupling on the high-frequency elastic wave energy attenuation characteristic value and a shrinkage rate jump point in the shrinkage rate real-time sequence data to generate a crack initiation tendency index; then obtaining a calibrated crack initiation tendency index based on an ambient temperature hysteresis effect and a temperature drift error of the calibrated crack initiation tendency index, and then outputting an anti-crack performance grade according to a grading deviation degree between a pre-designed grading parameter and a fluctuation range of the calibrated crack initiation tendency index; according to the technical scheme provided by the invention, the essential defect that a traditional method cannot correlate material characteristics with environmental response is overcome, direct quantitative mapping of material structure performance and damage evolution is also realized, and a traceable material-level basis is provided for engineering anti-crack design.

The invention discloses a method for evaluating damage evolution of an underground structure under the action of a sudden explosion load, and relates to the technical field of civil engineering and engineering disaster prevention, and the method is characterized by comprising the following steps: S1, simulating the underground structure based on an explosion load, a geometric boundary and material parameters, and constructing a unified constitutive model; and S2, introducing a pressure-related strength criterion of a Dwark-Prasugrel criterion into the unified constitutive model so as to describe the influence of confining pressure on the shear strength. The technical problem to be solved by the invention is to provide the method for evaluating the damage evolution of the underground structure under the action of the burst explosion load, so that the key pain points such as pressure correlation, high strain rate effect, material random discreteness, damage softening energy consistency and the like are difficult to consider at the same time in the existing analysis method. A set of damage evolution evaluation method and implementation system which can be implemented from the material level to the structure level is established, and quantitative prediction and engineering grading judgment of the whole process of crack initiation, expansion to instability failure of the underground structure are supported.

The application discloses a super-soft austenitic stainless steel and a preparation method thereof. The super-soft austenitic stainless steel is composed of carbon C, nitrogen N, silicon Si, manganese Mn, chromium Cr, nickel Ni, copper Cu and iron Fe. The mass percentage of each component in the super-soft austenitic stainless steel is as follows: C: 0.005%-0.02%, N: 0.05%-0.2%, Si: 0.01%-0.1%, Mn: 1.5%-6.5%, Cr: 15.5%-19.6%, Ni: 7.5%-13.5%, Cu: 1.8%-5.3%, and the balance is iron. The super-soft austenitic stainless steel has the characteristics of low tensile strength and hardness, low strain-induced martensite in the bending process, low crack initiation rate and low failure fracture.

The invention relates to the technical field of material science, and discloses a slurry valve erosion-resistant multi-layer coating with gradient function design and a preparation method thereof.The coating comprises a bonding layer, a gradient function layer and an erosion-resistant surface layer which are sequentially arranged from inside to outside, the bonding layer is composed of nickel-based alloy or cobalt-based alloy, the thickness of the bonding layer is 50-100 micrometers, and the thickness of the gradient function layer is 50-100 micrometers. The gradient functional layer is made of composite powder of metal and ceramic, the metal is nickel or cobalt, the ceramic is tungsten carbide or chromium carbide, and the components of the gradient functional layer are from the bonding layer side to the erosion-resistant surface layer side; the bonding layer is arranged and forms firm metallurgical bonding with the matrix, the interface stress is reduced, the basic reliability of bonding of the coating and the matrix is guaranteed, meanwhile, the gradient functional layer with the metal and ceramic volume fraction gradually changing continuously is adopted, the problem that the thermal expansion coefficients of the coating and the matrix are not matched is solved, and the service life of the coating is prolonged. And the crack initiation and expansion risk caused by internal stress concentration is reduced, so that the long-term stability of the coating structure is ensured.

The invention discloses a tight-lock coupler intelligent tensile testing machine and a testing method thereof, and belongs to the technical field of tight-lock coupler test.The tight-lock coupler intelligent tensile testing machine comprises a mounting bottom plate and an electric control cabinet, and a support for supporting a tight-lock coupler to be detected is mounted on the surface of the mounting bottom plate; a tensile connecting frame for connecting the tight-lock coupler is mounted on the surface of the bottom plate on one side of the support, an integrated design of'tensile force detection and visual detection 'is innovatively adopted, mechanical parameter acquisition and visual deformation observation are combined, traditional mechanical data such as tensile force and displacement are obtained, and visual characteristics such as fine deformation and crack initiation are captured; precise synchronization of pulling force application, displacement collection and camera shooting is achieved through the synchronous controller, the real-time corresponding relation of pulling force-displacement-visual deformation is established, the problems that an existing device is single in detection dimension and poor in data relevance are solved, and the potential quality hazard checking capacity and the persuasion of a detection result are improved.

The invention relates to the technical field of equal-strength design, and provides a high-reliability equal-strength design method and system for an intelligent cubic press, which considers structural characteristics of the cubic press, performs physical field analysis, modeling and simulation, determines deformation, temperature, stress distribution and stress concentration areas of key components, predicts structural crack initiation of the key components, and provides a high-reliability equal-strength design method and system for an intelligent cubic press. Crack propagation simulation is carried out; establishing a fatigue strength life prediction model based on deep learning and a simulation data set; constructing a fatigue strength reliability model, and establishing a mathematical association relationship among fatigue life, fatigue damage and reliability; a reliability calculation index is introduced into multi-objective optimization of the structure, a high-precision numerical solution of reliability robustness optimization design based on structure simulation is developed, and equal-strength design of the cubic press is achieved. According to the method, the optimal combination of design parameters can be obtained, the equal-strength design of parts and the whole machine structure is formed, and development of intelligent, high-precision and large-scale cubic press equipment is promoted.

The invention discloses a research method for a crack evolution law of fractured rock under thermal-mechanical coupling, and belongs to the technical field of rock mechanics. Aiming at the problem that most indoor tests and numerical simulation at present still lack systematic research on crack initiation, polymerization and failure behaviors of cracks in a multi-crack rock mass under the action of high temperature-stress coupling, the method comprises the following steps: defining an interaction coefficient and a thermal damage influence coefficient between the cracks on the basis of a tangential stress distribution theory around the cracks; establishing a tangential stress model sum of the inner and outer surfaces of the crack comprehensively considering the coupling effect of the two to predict a potential crack initiation position; based on a crack mode displacement decomposition method, defining a displacement ratio coefficient gamma, and quantifying a displacement field of rock material cracks; on the basis, the rock sample is subjected to mechanical test and PCF numerical simulation, and the crack evolution law of the rock sample containing the prefabricated crack under thermal-mechanical coupling is researched. Theoretical support and experimental basis can be provided for stability evaluation and safety control of deep high-temperature rock mass engineering.

The invention discloses a method for evaluating a fatigue weak area of a welded joint based on crystal plasticity, which aims at the problem of fatigue failure of the welded joint caused by complex microstructures such as grain orientation difference and uneven grain size distribution, establishes a quantitative correlation model of grain orientation and size evolution through CPFEM, and combines a macro-micro cross-scale analysis method to evaluate the fatigue weak area of the welded joint. And precise prediction of local stress concentration and crack initiation behaviors of the welding joint under a real fatigue load working condition is realized, so that scientific evaluation of a fatigue weak region is completed. According to the method, an innovative framework of fatigue weak area evaluation is constructed through load working condition reduction and grain characteristic multi-scale coupling, so that excessive simplification of a traditional method on real load conditions is made up, the limitation that a traditional model is difficult to couple a microstructure and a real load is overcome, and the fatigue weakening quantization precision is remarkably improved; and a high-precision analysis technology is provided for anti-fatigue design, process optimization and service life evaluation of the engineering welding structure.

The invention discloses a consequence simulation method based on water electrolysis hydrogen production, which comprises the following steps: constructing a multi-physical field coupling simulation model comprising an electric field, a thermal field, a flow field and a stress field, and setting and calibrating a geometric structure, physical property parameters, boundary conditions and a numerical strategy to obtain base field distribution of an electrode system. A bubble dynamics whole-process model is introduced, nucleation, diffusion growth and separation of bubbles are simulated, gas-liquid two-phase dynamic feedback is achieved through a volume fraction method, bubble interface force and a thermal expansion effect are coupled, and micro-crack formation of the electrode is judged by utilizing a stress criterion and a crack initiation threshold. And carrying out curing treatment on crack evolution by adopting a virtual crack unit or a phase field method. A crack propagation process is simulated in combination with a Miner criterion and a Paris law, an acoustic source item is introduced, an acoustic wave equation is solved, and the effects of full-link prediction, early warning, reliability evaluation and life optimization of electrode damage and hydrogen production performance are achieved in the operation process of the water electrolysis hydrogen production system.

The invention relates to the technical field of composite film strength detection, and discloses a composite film peel strength testing device which comprises a testing platform, two pulling sliding plates slidably mounted in the two extending parts respectively and capable of being synchronously and mutually close to or away from each other for adjustment, and the two pulling sliding plates are arranged on the testing platform. The opposite ends of the two pulling sliding plates are each provided with a clamp used for clamping a single-layer film of a composite film separation section. The clamping assembly is arranged in the test platform and is used for clamping and limiting the fitting section of the composite membrane and enabling the separation section and the fitting section of the composite membrane to form a Y-shaped state; and two groups of test assemblies. Through the Y-shaped constant-angle stripping design, the stripping surface of the composite film is uniquely locked, the stripping angle is kept unchanged in the whole testing process, and the effects that stripping cracks are stably limited to a specified unique interface, crack initiation is controllable and deviation is avoided are achieved.

The invention relates to a blade root fatigue load prediction and inversion system for an offshore wind turbine, and the system comprises a data collection assembly which obtains a circumferential strain gradient, and synchronously collects wave spectrum energy distribution, leading edge erosion degree and three-dimensional wind field data to establish a joint input spectrum; the hybrid calculation component is used for generating an adversarial network, reconstructing strain distribution of a bolt hole in a non-degraded state, and comparing a circumferential strain gradient to obtain an abnormal blade root dangerous point; and the control output assembly is used for superposing the damage accumulation cloud picture of the blade root dangerous point, displaying the fatigue life consumption rate and calling an equivalent load spectrum duration curve, and generating an independent variable pitch angle instruction according to the combination of asymmetric load distribution and the combined input spectrum. According to the method, quantitative identification and positioning of early-stage micro-damage can be realized, the hysteresis limitation of traditional threshold alarm is broken through, complex fatigue analysis is converted into engineering interpretable indexes, and a fault backtracking technical support is provided; load active compensation control is achieved through an independent variable pitch instruction, and fatigue crack initiation and expansion are effectively restrained.

The invention relates to the technical field of state monitoring, in particular to a ship main transmission device wear state real-time monitoring and maintenance system which comprises a load path recognition module, an abrasive particle distribution monitoring module, a thermal field response judgment module, a crack evolution tracking module and a maintenance adjustment module. According to the method, the strain data of the front end and the rear end of the main shaft are subjected to time sequence comparison, so that the strain transfer trend in a transmission path can be dynamically captured, and path parts in an abnormal abrasive particle peak value state can be screened out in combination with the mapping relation between the number of particulate matters and the particle size grade; according to the method, a potential thermal response imbalance area in a local structure is identified by combining the change trend of the difference between the axial temperature rise rate and the radial temperature rise rate, meanwhile, pre-judgment of a crack initiation section is completed by combining the peak sudden change characteristic of the number of structural node strain fluctuation times, and real-time identification, trend study and judgment and risk early warning of the running state of the main transmission device are achieved. And timeliness and accuracy of maintenance response are improved.

The application provides a ferrite bainite steel and a preparation method thereof, and belongs to the field of steel preparation. The chemical composition of the ferrite bainite steel includes, in mass fraction, C: 0.18% to 0.22%, Si: 1.3% to 1.8%, Mn: 2.0% to 2.5%, P: less than or equal to 0.01%, S: less than or equal to 0.01%, N: less than or equal to 0.004%, and the balance of Fe and inevitable impurities. The metallographic structure of the ferrite bainite steel includes, in volume fraction, ferrite bainite: 50% to 65%, tempered martensite: 25% to 30%, MA island: 1% to 3%, and residual austenite: 7% to 10%. By reducing the coarse MA island and unstable blocky residual austenite, the crack initiation source is avoided, and the technical problems of poor hole expansion and elongation of the ferrite bainite steel in the prior art are solved.

The invention relates to the technical field of engineering finite element simulation, in particular to an Ansys-based method for predicting the fatigue performance of a cutterhead under a composite stratum. According to the method, the finite element model of the shield tunneling machine cutterhead under the composite stratum is established, the dynamic stress states (such as cutting force, propulsive force and torque) of the cutterhead under alternation of soft soil and hard rock are accurately simulated, and stress amplitudes and equivalent alternating stress under different working conditions are quantified in combination with an S-N curve and a Goodman criterion. According to the method, the crack initiation position coordinates and the fatigue life distribution can be efficiently and precisely predicted, and a reliable scheme is provided for cutter head maintenance.

The invention provides a thermal response glass ceramic repairing agent based on microcapsule packaging, a preparation method of the thermal response glass ceramic repairing agent, an application of the thermal response glass ceramic repairing agent in self-repairing of an SOFC electrolyte and a solid oxide fuel cell. The repairing agent comprises a nano-porous Al2O3 microcapsule and a glass ceramic repairing agent packaged in the nano-porous Al2O3 microcapsule, the glass ceramic repairing agent comprises a low-temperature flowing glass phase and an ionic conductive ceramic phase, when the electrolyte crack expands, the microcapsule is broken to release the repairing agent; the glass phase melts and flows at the running temperature of the SOFC to fill cracks, and then is crystallized to form MgAl2O4-CeO2 composite ceramic compatible with electrolyte, and a compact structure is recovered. Compared with the prior art, the repairing agent disclosed by the invention is compatible with an SOFC electrolyte material, can trigger repairing at an operating temperature, adopts a microcrack self-repairing technology which does not damage an electrode layer, can realize real-time repairing without shutdown, and can automatically trigger repairing after cracks are generated.

The invention discloses a CO2 directional fracturing target layer crack propagation simulation control method based on flow regulation and control. The method comprises the steps that a plurality of experimental coal samples are manufactured, and drill holes are formed; the fracturing pump inputs CO2 with set flow into the coal sample through the CO2 injection pipeline; the high-frequency dynamic pressure sensor collects fluid pressure data in the coal sample crack; the acoustic emission sensor monitors and obtains the crack initiation moment and crack initiation pressure of the coal sample; the method comprises the following steps: carrying out cracking and crack width monitoring on a coal sample, calculating a theoretical value of crack initiation pressure and a theoretical value of CO2 injection flow of the coal sample, injecting supercritical CO2 fluid into the coal sample, obtaining a first-stage correction coefficient and a second-stage correction coefficient of the CO2 injection flow, and calculating a corrected CO2 injection flow value. According to the method, under the multi-physical-field coupling environment, the crack initiation pressure of the coal body can be accurately measured and calculated, the correlation between the CO2 injection flow and the crack width of the coal body is established, and the CO2 injection flow better meets the actual requirements of field operation through a CO2 injection flow grading correction mechanism.

The invention relates to the technical field of mechanical fatigue testing, in particular to rotary bending fatigue testing equipment for a rotor shaft, which comprises a base, a rotary driving module, a loading module, a dynamic balance module, a crack monitoring module and an adjusting module, and is characterized in that the rotary driving module drives the rotor shaft to rotate through a belt transmission assembly; the loading module adopts a lever type force reversing mechanism to realize accurate bending moment loading; the dynamic balance module automatically counteracts eccentric vibration through a free disc and a symmetrical bearing seat; the crack monitoring module captures vibration abnormity and internal crack initiation in real time; and the adjusting module is automatically adapted to different shaft lengths by driving a threaded screw rod through a motor. Anti-slip lines are arranged on the inner sides of the clamps at the two ends to ensure stable clamping; the levers are symmetrically arranged and matched with the locking nuts, so that switching of translation force or bending force applied by the levers is facilitated, the equipment realizes high-precision and full-period fatigue test, and the device is suitable for reliability evaluation of key rotor parts of aero-engines and steam turbines.

The invention discloses an equivalence evaluation method for testing the fracture behavior of an irradiation metal material based on a small sample, belongs to the field of mechanical property testing, and deeply researches the size effect problems of non-uniform deformation and crack initiation of the metal material under the irradiation condition through three research means of experiments, theories and simulation. And a powerful basis is provided for performance evaluation of the metal material under the irradiation condition. In the aspect of experiments, micro-stretching and micro-cantilever beam experiments of samples with different sizes under irradiation conditions are carried out, and a correlation mechanism between irradiation material crack initiation and sample sizes is analyzed. On the theoretical aspect, a dislocation channel-grain boundary interaction model is established, and prediction of fracture toughness of irradiation samples of different sizes is achieved. In the aspect of simulation, a finite element simulation system for non-uniform deformation, crack initiation and size effect of the metal material under the irradiation condition is established, and the influence of irradiation and sample size on microstructure evolution and macroscopic fracture behavior of the material is explored.

The invention discloses a method for optimizing residual stress distribution of a high-speed steel punch based on a spheroidizing annealing process, and belongs to the technical field of metal material heat treatment. The method for optimizing the residual stress distribution of the high-speed steel punch based on the spheroidizing annealing process comprises a circulating spheroidizing annealing process, a quenching process, a subzero treatment process and a multi-stage tempering process, and aims at achieving the following purposes that punch machining residual stress is remarkably released, especially compressive stress concentration of geometric mutation areas (such as the root and the head), and the crack initiation risk is reduced; the microstructure uniformity is optimized, and the comprehensive mechanical property of the material is improved through carbide refining and dispersion distribution; the stress evolution rule under the synergistic effect of multiple processes is quantified, and accurate guidance is provided for process optimization.

The invention discloses coal rock hydraulic fracturing crack dynamic evolution monitoring equipment and method, and the method comprises the steps: firstly applying three-way independent stress to a coal rock test piece through a true triaxial loading module, and simulating an underground true stress environment; then an ultrasonic excitation module is started, an ultrasonic physical field excitation environment is applied to the coal rock test piece, and development of microcosmic fractures in the coal body is promoted; and the high-pressure pump injection module is started, high-pressure water is injected into the coal rock test piece at constant flow or constant pressure, and more efficient hydraulic fracturing is achieved under excitation of the ultrasonic physical field. In the whole process, the acoustic emission monitoring module captures an elastic wave signal generated by coal rock fracture in real time, and the microcrack initiation position is accurately positioned; the CT scanning module obtains the three-dimensional expansion morphology of the macroscopic crack through scanning; and finally, through a multi-physical field cooperative loading and multi-scale monitoring technology, the whole-process dynamic representation from microcrack initiation to macroscopic crack penetration is realized, and a theoretical support and a technical means are provided for efficient development of coal bed gas.

The invention discloses a non-contact uniaxial compression test infrared strain meter and a use method thereof, and belongs to the field of rock mechanics and engineering testing. The objective of the invention is to solve the prominent problems of low measurement precision, easy influence by characteristics of a test object, difficulty in comprehensively and accurately reflecting full-field strain distribution and the like of a traditional contact type strain measurement device in a uniaxial compression test. A non-contact infrared imaging measurement technology is adopted, a high-speed infrared camera is matched with a DIC algorithm, real-time mapping of full-field strain distribution is accurately achieved, transient behaviors such as crack initiation and expansion are clearly captured, strain field data and temperature field data can be synchronously obtained, measurement of the strain field data and the temperature field data are organically combined, and by means of the infrared technology and an environment control device, the measurement accuracy is improved. The device can stably work in severe environments such as high temperature and corrosivity, and is suitable for various complex samples; according to the method, the accuracy and comprehensiveness of measurement are effectively improved, the test efficiency is greatly improved, the method can be widely expanded to multiple fields of civil engineering, aerospace and the like, and powerful support is provided for research on mechanical properties of materials.

The invention provides an FDEM-based rock blasting process simulation method and system considering blasting gas, and the method comprises the steps: building a jointed rock blasting numerical model comprising a blast hole, a rock mass and a joint network based on a finite element-discrete element coupling method; setting a static-dynamic unified boundary condition for the jointed rock mass blasting numerical model, and applying a blasting stress wave load; constructing an explosion gas action model, and dynamically calculating a transient explosion cavity area and transient gas pressure; transient gas pressure is coupled and applied to the boundary of the crack and the surface of the isolated rock; and operating the solver, simulating the whole process from stress wave propagation, joint attenuation effect, crack initiation and propagation to blasting gas driven crushing and throwing, and analyzing the result. The method provided by the invention overcomes the defect that the existing method is difficult to simultaneously and accurately characterize the joint effect and the action of the blasting gas, obviously improves the authenticity and reliability of the simulation of the blasting rupture process of the jointed rock mass, and provides an effective tool for blasting mechanism research and engineering optimization design.