107 results about "Fracture test" patented technology

The invention relates to the technical field of data acquisition and data analysis, in particular to a hydraulic fracturing test crack propagation monitoring system which comprises a monitoring system and is used for monitoring crack propagation behaviors in the hydraulic fracturing process in real time. Constant or dynamically changing confining pressure and axial pressure are provided; the pore pressure dynamic regulation and control unit is used for accurately controlling the injection pressure, flow and saturation of fracturing fluid and simulating fracture propagation behaviors under different seepage conditions; the multi-physics field sensing monitoring network unit is used for collecting strain, sound wave signals and a surface displacement field in the crack expansion process in real time; full-scale monitoring of rock fracture propagation is realized, an influence mechanism of pore pressure and time effect on fracture evolution is disclosed, an accurate prediction means is provided for shale gas development and deep engineering, and the fracturing effect and engineering safety are remarkably improved.

The invention discloses a coal rock full-time-space fracture field inversion method and system based on an interpretable graph neural network. The inversion method comprises the following steps: obtaining staged time CT detection and full-time-space acoustic emission monitoring information through a loaded fracture test of a testing machine, and constructing a data set; training the graph neural network to extract data features to obtain a full space-time fracture parameter real-time quantitative inversion model; inputting acoustic emission scalar parameter data of a test set into the model to obtain a full space-time fracture parameter inversion result; and obtaining an influence factor of the acoustic emission scalar parameter on a fracture parameter inversion result through a Bayesian interpreter, and revealing an inversion mechanism model. The inversion model can realize the inversion of the whole space-time fracture field through the whole space-time acoustic emission monitoring data in the loading process, and fracture parameters can be accurately inverted in real time. Meanwhile, a mechanism model of fracture parameter inversion is disclosed.

The invention discloses an MGPCC fracture damage monitoring method based on AE and DIC, and relates to the technical field of building material fracture damage monitoring, the method comprises the following steps: preparing an MGPCC fracture test piece, arranging an acoustic emission probe, installing the test piece on a 3-P-B fracture test device, carrying out displacement control loading, collecting AE signals and shooting images in real time during loading, and determining the fracture damage of the MGPCC. Then analyzing characteristic parameters, images and the like to determine FPZ related conditions, and finally establishing a fracture damage evolution model in combination with a monitoring result. Spatial distribution and characteristic parameters of a damage source are monitored in real time through the AE technology, a strain cloud picture and a displacement field are accurately obtained in combination with the DIC technology, microcrack propagation and FPZ formation and evolution laws in the MGPCC fracture process are revealed, multi-dimensional quantitative characterization of the fracture damage process is achieved, and the method is suitable for mass production. A more comprehensive and accurate technical means is provided for building material fracture damage monitoring, and the blank of MGPCC multi-scale crack resistance and damage evolution research is filled.

The invention relates to the technical field of oil field reservoir research, in particular to a fracturing fracture imaging physical simulation method and system combined with non-uniform contact electrodes, and the method comprises the steps: carrying out the resistance modal detection at the current time step through a low-frequency excitation signal in the fracture propagation simulation process, and obtaining a corresponding electric signal; obtaining a conductive fluid distribution result of the rock core fracturing test piece at the current time step by using the conductive fluid distribution inversion model; and fitting and comparing the electric field distribution result of the current time step with the conductive fluid distribution result of the current time step, and outputting the fracture parameters and the conductive fluid distribution result of the rock core fracturing test piece at the current time step based on the fitting and comparison result. According to the method, the electrical property change caused by the natural fracture and the fluid contained in the natural fracture is directly sensed in situ, the electrical signal is acquired, the response delay is reduced, the conductive fluid distribution inversion model is constructed by combining prior knowledge and deep learning, and the precision and reliability of conductive fluid distribution inversion are effectively improved.

The invention provides a hydraulic fracturing pilot test method, electronic equipment, a storage medium and a program product, and relates to the technical field of hydraulic fracturing test. The method comprises the following steps: determining a fractured well in a to-be-tested site and a plurality of test wells meeting a preset position relationship with the fractured well; determining the crustal stress state of the target test well; according to the crustal stress state and preset hydraulic fracturing process parameters, fracturing testing is conducted on the fractured well, and collected data of the detection equipment is obtained; based on the rock mass sectioning image of the preset position of the to-be-tested site, crack network characterization information is determined, and the crack network characterization information is used for indicating the shape of a crack formed by fracturing and the distribution condition of a propping agent; according to the collected data, the fracturing test process is inverted, and fracturing dynamic process information is obtained; and generating a hydraulic fracturing process optimization scheme according to a comparison result between the fracturing dynamic process information and the fracture network characterization information. According to the method, the accuracy and practicability of a hydraulic fracturing test result are improved.

The utility model discloses a guide wire fracture test tool, and belongs to the technical field of guide wire testing. The device comprises a base, one side of which is rotatably provided with a handle; the rotating shaft is rotationally installed on the base, the rotating shaft is in transmission connection with the handle, the rotating shaft comprises a plurality of winding shafts which are different in diameter and are coaxially arranged, and through holes are formed in the winding shafts. The rotating shaft directly comprises a plurality of winding shafts with different diameters, so that when different guide wires are replaced or fracture tests with different bending degrees are carried out on the same guide wire, the guide wires are directly wound on the winding shafts with different diameters, and the rotating shaft or a tool does not need to be replaced; therefore, fracture tests of different bending degrees can be carried out on the guide wire very conveniently, and the efficiency of the fracture tests of the guide wire is improved.

The invention relates to the technical field of metal material fracture resistance testing, in particular to a prediction method for interface fracture toughness of a polar region ship composite steel plate, which comprises the following steps: S1, preparing a composite steel plate; s2, carrying out a three-point bending fracture test; s3, performing an interfacial shear strength test; s4, data analysis and model construction: performing fitting analysis on the obtained fracture toughness data of the large-size sample and the obtained shear strength data of the small-size sample, determining undetermined parameters, and constructing a mathematical model between the interface fracture toughness and the interface shear strength of the composite steel plate; and S5, verifying the accuracy of the model. According to the method, the mathematical model is established by analyzing the correlation between the shear strength measured by the small-size interface shear sample and the fracture toughness measured by the large-size fracture sample, and the model has the advantages of simplicity in construction, rapidness in use and the like, so that rapid prediction and evaluation of the fracture toughness of the composite steel plate are realized, the test process is greatly simplified, and the test efficiency is improved. And the research and production efficiency is improved.

The invention relates to a true triaxial fracturing test magnetofluid monitoring system and method, and belongs to the field of coal bed gas exploration and development. The system comprises a magnetic fluid mixing device, an injection device, a 4 * 4 magnetic induction sensor array, a data acquisition device, a high-pressure water pump device and a true triaxial experiment device. The method comprises the following steps: mixing magnetic fluid and adjusting viscosity; injecting a test piece; applying three-dimensional stress; monitoring magnetic field change in real time; millimeter-level positioning and three-dimensional visualization of crack expansion are achieved through magnetofluid dynamic response and data collected by a magnetic induction sensor array in combination with differential analysis, edge detection and a finite element inversion algorithm, and the magnetofluid recovery rate is larger than 95%. The method solves the problems that traditional monitoring is low in precision and poor in real-time performance, and is suitable for dynamic analysis of coal bed gas and shale gas fracturing cracks.

The invention relates to the technical field of metal material fracture resistance testing, in particular to a prediction method for fracture toughness of a polar region ship composite steel plate under different thicknesses, and the method comprises the following specific steps: S1, material selection and performance testing; s2, carrying out a fracture test; s3, modeling and simulation: performing modeling on the composite steel plate samples with different composite layer thicknesses, and performing fracture behavior simulation; s4, model establishment and parameter fitting; and S5, model verification and application. According to the method, the layer thickness ratio Rt is used as a key research parameter, the fracture toughness change rule of the polar ship composite steel plate under different composite layer thicknesses can be systematically represented, and the fracture toughness prediction model based on the layer thickness ratio is established, so that the problems of complexity and high cost caused by one-by-one test on all the composite layer thicknesses in a traditional method are effectively solved; therefore, the actual engineering requirements of rapid fracture resistance design and economic evaluation of the polar ship composite steel plate are met, the test quantity is small, the period is short, and the cost is low.

The invention provides a high-cycle fatigue strength evaluation method based on damage influence, and belongs to the technical field of aero-engines. The method comprises the following steps: performing a high-cycle fatigue test on a to-be-tested material to obtain first high-cycle fatigue strength, and performing a damage fracture test corresponding to a damage type to obtain a damage life, the damage type comprising creep damage and low-cycle damage; determining interruption time on the basis of the damage life, performing a damage fracture test on the basis of different interruption time, then performing a high-cycle fatigue strength test to obtain second high-cycle fatigue strength, and constructing a damage model; constructing a crystal plasticity constitutive model based on the damage model to perform simulation calculation on the to-be-tested material to obtain a simulation damage value; and correcting the first high-cycle fatigue strength based on the second high-cycle fatigue strength and the simulated damage value to obtain an evaluation result of the to-be-tested material. According to the method, deformation mechanisms of different damage types are clearly distinguished, the method is more flexible, interruption time setting refers to influences of different damage degrees, and the method is more accurate, safer and more reliable.

The invention relates to the technical field of concrete fracture tests, in particular to a preparation method of a transparent resin-based imitation concrete material. Comprising the following steps: S1, weighing raw materials: weighing epoxy resin and a curing agent according to a mass ratio of 20: 1; s2, material mixing: pouring the epoxy resin and the curing agent into a stirring cup, placing the stirring cup in a planetary gravity stirrer, and performing high-speed mixing under a vacuum condition; s3, water bath cooling: putting the mixed liquid subjected to vacuum defoaming into cold water for water bath cooling; s4, pouring and forming: slowly pouring the cooled mixed solution into a mold, and standing and primarily curing at room temperature to form an initial setting body; s5, constant-temperature curing: transferring the mold containing the initial setting body into a constant-temperature drying oven, and continuously curing; and S6, demolding the test piece: after curing is completed, removing the mold to obtain the transparent imitation concrete resin test piece with a smooth surface and no bubbles inside. By adopting the transparent resin-based imitation concrete material, the damage characteristic can be directly observed, and an experimental basis is provided for high-pressure water jet stress wave cracking concrete.

The invention provides a design method for improving effectiveness of a biaxial tensile sample, which comprises the following steps: S1, establishing a finite element model, and performing a simulation test; s2, judging whether the biaxial tensile sample needs to be adjusted or not according to the simulation result of the biaxial tensile test working condition; if the deformation of the biaxial tensile sample mainly occurs in a non-central area, entering S3; s3 comprises the following steps: (1) increasing the lengths of four stretching arms of the biaxial stretching sample and the width of the widest part according to the proportion of 5-20% of the side length of the central region; (2) 1-3 grooves are additionally formed in the four stretching arms respectively; (3) the width of the groove formed in each stretching arm is adjusted to be not larger than 0.2 mm; (4) increasing the length of the groove according to the proportion of 10-50% of the width of the widest part of the stretching arm; and S4, verifying the effectiveness of the biaxial tensile sample after each round of adjustment. The problems that an existing sample design mode is high in machining complexity, the sample is prone to deformation and fracture in a non-central area, and stability is poor in the testing process are solved.

The invention relates to the technical field of natural fracture distribution rules and geological exploration and development, and discloses a high-precision inversion method for natural fractures of hot dry rock based on geology-engineering integration, which comprises the following steps: (1) field data acquisition and preliminary geological modeling: constructing an initial fracture model based on geological data of a hot dry rock reservoir; (2) fracturing experiment and engineering inversion correction: on the basis of the preliminary fracture model, engineering inversion is carried out by using field fracturing test data and micro-seismic information, and inversion correction is carried out on the model; and (3) multi-time iteration closed-loop feedback optimization: performing multi-time mutual feedback correction on a geological modeling result and engineering inversion data to obtain a high-precision fracture distribution model of the hot dry rock reservoir. According to the scheme, geological modeling and engineering inversion are organically combined, a closed-loop feedback mechanism is constructed, and high-precision inversion of fracture distribution is achieved through multiple times of iterative optimization.

The utility model relates to a device for testing hydrogen-induced delayed fracture of high-strength steel, which comprises an upper pressing cake, a lower pressing cake, an upper pressing block, a lower pressing block and a screw rod, a plurality of clamping grooves are uniformly distributed on the upper pressing block along the circumferential direction, the upper pressing block and the lower pressing block have the same structure, and the upper pressing cake and the lower pressing cake are connected on the screw rod in a penetrating manner; the upper pressing block and the lower pressing block are also connected to the threaded rod in a penetrating mode and are symmetrically arranged between the upper pressing cake and the lower pressing cake, a plurality of hydrogen-induced delayed fracture samples are arranged on corresponding clamping grooves of the upper pressing block and the lower pressing block respectively, the upper pressing cake and the upper pressing block can be locked and fixed to the threaded rod through nuts, and the lower pressing cake and the lower pressing block can be locked and fixed to the threaded rod through nuts. The hydrogen-induced delayed fracture experiment requirement of the high-strength steel with the pressure ranging from 1000 MPa to 2 GPa can be met, and reliable analysis data can be obtained when the hydrogen-induced delayed fracture experiment is carried out on the high-strength steel. Positioning and fixing holes are not required to be punched during sample preparation, a plurality of samples can be prepared by one clamp, and a bending test of a plurality of metal test pieces is allowed to be performed in one test.

The invention provides a high-low temperature composite environment sensitive fracture test system. The high-low temperature composite environment sensitive fracture test system comprises a fracture testing machine, a high-low temperature composite salt spray test box and a host control cabinet, a test cavity of the high and low temperature composite salt spray test box is arranged in the environment sensitive fracture testing machine; a test piece is located in a test cavity of the high-low-temperature composite salt spray test box, and a high-low-temperature alternating corrosion environment is achieved through the damp and hot module, the low-temperature module and the spraying device. Salt mist, damp and hot, dry and low-temperature test sections are set through a control system, the time and the cycle index of each test section are adjusted, a high-low temperature composite salt mist environment is formed, and an environment sensitive fracture test in a multi-factor coupling environment can be achieved in cooperation with an environment sensitive fracture testing machine. The device is flexible in structure, large in adjustable range and high in test efficiency, test space is saved, and according to service environments of material test pieces under different working conditions, the environment sensitive fracture performance of materials can be examined in a multi-level mode by compositing multiple test environments, adjusting environment test parameters and simulating a real service environment.

The invention provides a polyester fiber asphalt mortar in-situ tensile fracture test device which comprises a base, a pressure test wheel is arranged between a placement block and a fixing plate, two placement racks are symmetrically arranged on the inner side of a fixing rack, pressure test balls are correspondingly arranged at the upper ends of the placement racks, anti-skid racks are arranged on the inner sides of the placement racks, and the anti-skid racks are arranged on the inner sides of the placement racks. And two sides of the connecting piece are symmetrically provided with two elastic force dynamometers. A pressure test wheel is rotatably connected to the outer side of a rotating shaft, and a clamping groove is formed in the inner side of a placement block, so that the device facilitates rapid, simple and uniform pressure test tensile fracture, a connecting piece is fixedly connected to the upper end of a sliding pressing rod, two connecting plates are symmetrically and fixedly connected to the two sides of the connecting piece, and third electric push rods are fixedly connected to the lower ends of the connecting plates; the lower end of the third electric push rod is fixedly connected to the upper end of the fixing frame, and an elastic force dynamometer is correspondingly arranged on one side of the connecting plate, so that the device is convenient to quickly and accurately measure force and test pressure and is not easy to slide randomly in a tensile fracture test process.

The invention discloses hydraulic fracturing test equipment for a hard top plate of a mine, and belongs to the technical field of hydraulic fracturing, the output end of an inner drilling driving motor is provided with an inner drilling shaft, the rear end of the inner drilling shaft is provided with an inner drilling bit, and the rear end of a mounting frame is connected with the head end of a water conveying pipe, and the invention further discloses a using method of the hydraulic fracturing test equipment for the hard top plate of the mine. According to the technical method, an electromagnetic clamping shaft is installed to be conveniently linked with a detection module, meanwhile, seismic waves emitted after rock mass stress deformation and damage are used for detecting the stability of engineering rock mass, information such as the rock mass fracture occurrence time, position and energy distribution is inversed by collecting waveforms, and through two sets of drilling equipment including a drilling head and an inner drill bit, the stability of the engineering rock mass is detected. The effects of forming a fracturing hole channel in a hard roof and reversely recycling drilling equipment are conveniently achieved, multiple leaking stoppage layers are formed in one fracturing hole channel so as to conduct multi-time staged fracturing, sufficient fracturing is achieved, the roof weakening effect is improved, hydraulic fracturing can be conducted at the same time, and the operation efficiency is improved.

The application discloses a method for determining the allowable damage scale of concrete based on a fracture extremum theory, which comprises the following steps: S1, carrying out a fracture test to obtain a peak load; S2, calculating a stress intensity factor generated by an external load and cohesive force according to a stress intensity factor manual; S3, establishing a crack tip stress intensity factor balance equation according to a crack propagation criterion, and then deducing an expression of the external load; S4, determining a critical effective crack length of the concrete according to the fracture extremum theory; and S5, calculating the allowable damage scale according to the critical effective crack length. The method for determining the allowable damage scale of concrete based on the fracture extremum theory is adopted, the fracture extremum characteristics of the concrete are fully considered, the peak load of the fracture test needs to be measured only when the method is applied to analyze the crack propagation of the concrete, the test operation is simple, the calculation result is high in accuracy, and the method is suitable for test pieces of different sizes and types.

The invention discloses a test device and method for simulating fracture of a mine earthquake source. The method comprises the following steps: putting a rock sample into the test device and mounting the test device to a triaxial testing machine; a loading method is determined according to the fracture type of the mine earthquake source needing to be simulated, a triaxial testing machine is used for applying load, and if pressure or tension needs to be applied to the rock sample, the tension or pressure is applied to the inner frame to drive the upper clamping part and the lower clamping part to apply required stress to the rock sample; when shear force needs to be applied to the rock sample, pressure is applied to the two shear stress loading parts at the same time, then the lower clamping part is driven to move along the horizontal sliding groove relative to the upper clamping part, the needed shear force is applied to the rock sample, and a compression-shear composite fracture or tension-shear composite fracture test is achieved. The fracture processes of different mine earthquake sources are effectively simulated, so that the acoustic emission data corresponding to the fracture processes of the different mine earthquake sources are obtained, and data support is provided for revealing fracture evolution mechanisms of the different earthquake sources and disaster source early warning.

The invention relates to the technical field of crustal stress monitoring, in particular to a crustal stress monitoring method based on a hydraulic fracturing test principle of any two holes, which comprises the following steps of: constructing a crustal stress calculation model for hydraulic fracturing test of any two holes on the basis of a crustal stress hydraulic fracturing test principle; two arbitrary ground stress test holes which are not vertical and not parallel in space are formed in a test site, three stress values sigma x, sigma z and tau xz represented by the first test hole are obtained, and the rest three unknown stress values sigma y, tau xy and tau yz are obtained through an equation set established after three times of stress equivalent conversion on the stress values sigma x ', sigma z' and tau x'z 'determined by the second test hole. According to the method, any stratigraphic geological parameters are not needed, the special requirements of orthogonal holes, vertical holes and the like of a conventional test method for the test drill holes do not exist, the crustal stress is calculated only through stress equivalent conversion between any two holes, the test principle is simple, the calculation result is accurate, and the processing result can be applied to the technical field of coal mine geological exploration engineering.

The application discloses a fracturing stress and fracturing fluid action range analysis method based on post-press coring, and the method is as follows: obtaining a pre-press rock contrast sample; obtaining a core through post-press coring after a fracturing test, and constructing a spatial hydraulic fracture three-dimensional model; obtaining a rock sample; obtaining a microstructure and mechanical parameters of the rock sample; comparing the microstructure and mechanical parameters of the rock sample with those of the pre-press rock contrast sample corresponding to the sampling position, and determining whether the sampling position of the rock sample is subjected to liquid spread and stress spread; and obtaining a hydraulic fracture liquid and stress spread range diagram. The method has the beneficial effects that the parameters involved in the method are objective and accurate, the limitations of indirect monitoring and simulation of the fracture network through microseismic and numerical simulation methods are avoided, the result accuracy is greatly improved, and the method provides a reference for actual construction.

The invention relates to a preparation method of a micro-cantilever sample with pre-cracks for testing the fracture toughness of a micro-nano material, and belongs to the technical field of micro-nano materials. The specific morphology of the crack is represented through the tip radius of the crack, the opening of the crack and the depth of the crack, then ion beam parameters are changed to regulate and control the morphology of the prefabricated crack, and the crack morphology and the sample characteristics of the repeated test and the verified test are similar. The fracture toughness value obtained by a micro-cantilever fracture test has relatively high repeatability; and the repeatability of the micro-cantilever prefabricated crack morphology and the reliability of a test result are remarkably improved.

The application provides a high-low temperature composite environment sensitive fracture test system, which comprises a fracture testing machine, a high-low temperature composite salt spray test box and a main control cabinet; the test cavity of the high-low temperature composite salt spray test box is arranged in the environment sensitive fracture testing machine; a test piece is in the test cavity of the high-low temperature composite salt spray test box, a high-low temperature alternating corrosion environment is realized through a wet heat module, a low temperature module and a spraying device; a salt spray, a wet heat, a drying and a low temperature test section are set through a control system, the time and the cycle number of each test section are adjusted, a high-low temperature composite salt spray environment is formed, and the environment sensitive fracture test under a multi-factor coupling environment can be realized in cooperation with the environment sensitive fracture testing machine. The application has a flexible structure, a large adjustable range, high test efficiency, saves test space, can simulate the real service environment according to the service environment of the material test piece under different working conditions, adjust the environment test parameters, simulate the real service environment, and multi-levelly examine the environment sensitive fracture performance of the material.

This invention relates to the technical field of deep well mining, and particularly to a real-time analysis and early warning method for true triaxial hydraulic fracturing test data. The method includes the following steps: acquiring multi-source monitoring data during the true triaxial hydraulic fracturing test, wherein the multi-source monitoring data includes mechanical property data, fluid parameter data, deformation monitoring data, and fracture evolution correlation data; assigning verification weights matching the test conditions based on the heterogeneous attributes of the mechanical property data, fluid parameter data, deformation monitoring data, and fracture evolution correlation data; and verifying the acquisition timestamps and range matching of each data point using the verification weights to generate a standard dataset. The real-time analysis and early warning method for true triaxial hydraulic fracturing test data provided by this invention can simultaneously capture the stress field, fluid transport, deformation state, and internal fracture evolution characteristics of rock samples, improving the comprehensiveness of rock sample condition characterization and solving the problem of one-sided condition perception.

The invention provides a high-strength high-toughness hydrogen-induced delayed fracture-resistant oil casing material, and belongs to the field of oil exploitation equipment. The contents of Mn, Mo and V are optimized, and other components are matched, so that the material has good hydrogen-induced delayed fracture resistance while having high strength and high toughness. Experimental results show that the mechanical properties of the casing material provided by the invention are as follows: the tensile strength is not less than 1260Mpa, the yield strength is not less than 1200Mpa, the longitudinal impact energy at 0 DEG C is not less than 100J, and the transverse impact energy is not less than 70J; a notch constant-load delayed fracture test is carried out, the notch constant-load critical fracture stress ratio n is not smaller than 0.8, and fracture does not occur after more than 100 h.

The invention relates to a method for predicting fracture properties of composite materials with different fiber orientations based on a composite trilinear cohesion model. The method comprises the following steps: 1) preparing a sample; 2) performing a fracture test and recording data; 3) calculating fracture toughness; 4) performing finite element modeling on the cohesion constitutive model; 5) performing grid division; and 6) fracture performance prediction based on different fiber orientation angles. According to the method, the composite cohesion model which is suitable for different fiber directions and has relatively high description capability and easily acquired parameters is provided, and the relationship between the key parameters of the composite trilinear cohesion model and the orientation angle is established, so that rapid and accurate prediction of the fracture toughness under different orientations is developed; the method has important engineering significance for improving FRPC fracture performance prediction efficiency and precision.

To provide an inclusion evaluation method capable of making a grip part hard to break in a breaking test even when there is almost no change in diameter between the grip part and an effective part.SOLUTION: Provided is an inclusion evaluation method in which hydrogen is charged to a test piece 1 made of a metallic material that gripping portions 3 at both ends and an effective portion 5 provided in an intermediate portion 2 between the gripping portions 3, a destructive test is performed on the hydrogen-charged test piece 1, and the dimensions of a non-metallic inclusion 6 that is the origin of the fracture are measured. The test piece 1 is cut out from a wire and has an outer surface 7 that is formed by an outer surface of the wire, and in the intermediate portion 2, a surface layer 8 is removed from the outer surface 7, and masking 11 is applied to at least the outer surface 7 at the gripping portions 3 to suppress hydrogen penetration, and at least a part of the intermediate portion 2 from which the surface layer 8 has been removed is made into the effective portion 5 without performing the masking 11.SELECTED DRAWING: Figure 1

The application relates to a simulation method and platform dummy of a hub central piece crack acoustic emission signal, and the simulation method comprises the following steps: (1) preparing a standard fatigue test piece; (2) acquiring acoustic emission signals of a whole process of fatigue fracture of the standard fatigue test piece; (3) performing filtering and noise reduction pretreatment on the acquired acoustic emission signals; (4) generating simulation acoustic emission signals; (5) installing a hub central piece platform dummy on a model rotor test bed; (6) operating the model rotor test bed to complete rotor system hub central piece crack damage monitoring test verification; the waveform and spectrum characteristics of the crack acoustic emission signals are determined through fatigue fracture test of the hub central piece test piece made of the same material; the crack acoustic emission signals are simulated by using an acoustic emission signal waveform generator and a driver; finally, the simulation of the hub central piece crack acoustic emission signals is completed on the model rotor test bed, and the rotor system hub central piece crack damage monitoring test verification is realized.

This invention relates to a method for predicting fracture pressure in layered shale wells with extended reach based on a machine learning model. S1: Acquire drilled well data and collect downhole core samples, conduct anisotropic tensile mechanical experiments on shale along the bedding direction, and construct shale fracture criteria based on the experimental results; S2: Construct a fracture pressure model for layered shale wells with extended reach, and correct and integrate the calculated fracture pressure values ​​with field fracture test data; S3: Calculate the fracture pressure using a mechanical model based on the wellbore structure conditions of highly deviated wells, verify it using field low-pressure data, and form a fracture pressure calculation and analysis database; S4: Train the prediction model based on machine learning methods, determine the WT-LSTM model structure, set hidden layers, and train it; S5: Optimize the machine learning-based fracture pressure model through hyperparameter adjustment, feature selection, and importance assessment. This invention comprehensively improves the accuracy of fracture pressure prediction in highly deviated wells by integrating multiple factors, provides data support for the design of fracturing engineering in complex layered shale, helps to rationally select parameters for extended reach well construction, improves adaptability and safety, and provides data support for the development of layered shale oil and gas resources.

The invention relates to a method for testing a fracture track of a metal material under a multi-field coupling effect. The method comprises the steps of sample preparation, high-temperature speckle preparation, sample loading, strain field acquisition, fracture morphology observation, data processing and fracture model establishment. By constructing a new fracture test method under the action of multi-field coupling, the problems of lack of physical field coupling factors, non-uniform test systems, limitation of fracture models and the like at present are effectively solved. A coupling loading test system capable of synchronously applying complex stress, high strain rate and transient high temperature is established, and real simulation of the multi-physical field coupling effect under the actual disaster working condition is achieved; a metal material fracture test system with universality and comparability is formed; key data support is provided for building a fracture model comprehensively considering the stress three-dimensional degree, the strain rate effect and temperature softening, the accuracy and reliability of fracture track prediction of the steel structure under the extreme disaster are remarkably improved, and an important basis is provided for engineering disaster resistance design and safety evaluation.