85 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 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 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 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 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.

The invention discloses a method for determining size-effect-free fracture parameters of an MGPCC material and a method for evaluating the performance of the MGPCC material, and belongs to the technical field of material performance evaluation. The method specifically comprises the following steps: firstly, preparing MGPCC test pieces with different sizes, seam height ratios and span-height ratios, and carrying out a three-point bending fracture test to obtain related data; then calculating the equivalent crack length and the virtual crack propagation amount, and further determining fracture parameters, such as fracture toughness KIC and tensile strength ft; and a mean value and a standard deviation are obtained through normal distribution statistical analysis, and finally the size-effect-free fracture parameters are determined. According to the method, the influence of various factors on fracture parameters is comprehensively considered, the normal distribution hypothesis is verified by adopting K-S verification, and the reliability of data is ensured. The fracture failure curve is constructed based on the determined fracture parameters, the fracture failure type of the MGPCC material can be accurately evaluated, and a scientific basis is provided for engineering design.

The application belongs to the technical field of fracture toughness evaluation, and specifically discloses a small-size fracture toughness testing method for metal materials based on fracture cross-section characteristics, which utilizes the fracture cross-section shape of a test sample, considers the elastic energy distribution of a normal fracture zone dominated by I-type fracture and a shear fracture zone dominated by II-type fracture, establishes a linear relationship between G and J, carries out a fracture test by using a multi-sample method with different thicknesses, determines different groups of data, obtains and estimates values by combining a least square method, forms a new method for evaluating the small-size fracture toughness of metal materials based on fracture cross-section characteristics, and avoids the difficulty of directly using standard pieces for evaluation for materials such as high-strength steel, and has significant engineering application value.

The invention relates to a shale gas horizontal well fracture pressure prediction method. The method comprises the steps of 1, multi-source data acquisition and intelligent depth correction, wherein logging data, element logging data, logging-while-drilling data, drilling engineering parameters and shaft track data of a target horizontal well section are acquired; 2, multi-scale feature enhancement: generating a high-dimensional feature sequence; step 3, nonlinear feature screening and mixed crustal stress prediction: screening out a key element combination, calculating an initial crustal stress profile through a traditional physical model based on sound wave and density logging data, and training a machine learning residual prediction model by taking the key element combination and other logging features as input to obtain a mixed crustal stress prediction model; adding the initial crustal stress profile and a residual error predicted value by predicting a residual error between a calculated value and an actual measured value of the physical model to obtain final predicted crustal stress data; and 4, calculating and verifying the fracture pressure: deducing the fracture pressure, and verifying a prediction result by using actual fracture test data.

The invention discloses a strap tension testing device, and particularly relates to the technical field of strap testing, the strap tension testing device comprises a mounting plate, and a support frame is arranged above the mounting plate; a cutter and a friction block are arranged below the support frame, a switching test piece is arranged between the cutter and the friction block, and a strap is arranged on one side of the cutter; the positioning cutting piece is mounted on the other side of the outer wall of the support frame; and a tension test piece is mounted on the mounting plate. By arranging the switching test piece, the cutter moves leftwards to cut and break the strap, when the friction block is selected, the stepping motor drives the friction block to drive the friction strip to make contact with the strap and rotate forwards and backwards at a small angle, the test in the abrasion state is simulated, the fracture test or the abrasion test can be flexibly selected according to needs, and the test efficiency is improved. The adjustability and applicability of the test are effectively improved, and the problems that the test is carried out under the problem that abrasion or breakage is difficult to switch, and the applicability of the test adjustability is poor are solved.

The invention discloses an ultra-deep fault control fracture-vug type condensate gas reservoir classification transformation mode determination technology. The technology comprises the following steps that reservoir transformation layer sections are determined; according to the commissioned well and the data of the corresponding reservoir transformation, parameters for determining the classification transformation mode and threshold values of the parameters are obtained; and determining a transformation mode of the reservoir transformation interval. The defect that an existing reservoir transformation mode depends on human influence factors is overcome, engineering investment can be reduced, and single well benefits are improved; specifically, in actual production, the technical scheme is applied to 12 exploratory wells in the 6 #, 8 # and 12 # fault zones in the North of Chenou Kuller region of the Tarim Basin, the high yield is obtained through a conventional test of 3 wells, the high yield is obtained through an acidification test of 6 wells, the high yield is obtained through an acid fracturing test of 3 wells, and the exploration investment is saved by hundreds of million yuan.

The invention discloses a multi-angle rotating ultra-high core wall dam gravel-doped clay tensile-fracture test device which comprises a mold assembly, two groups of adjusting assemblies and two groups of loading assemblies, a dumbbell-shaped cavity is formed in the mold assembly body and is used for preparing and bearing a test soil test piece; the two sets of adjusting assembly bodies are distributed on the two sides of the mold assembly body in a central symmetry mode, each adjusting assembly body comprises a rotatable semicircular disc and a semicircular disc track, the rotatable semicircular discs are coaxially embedded in the inner sides of the semicircular disc tracks, and the semicircular disc tracks are movably connected with the rotatable semicircular discs; and the end part of the mold assembly body is embedded into the inner side of the semicircular disc track and is detachably connected through a mold fixing bolt. The front loading assembly, the front assembly body, the rear loading assembly, the rear assembly body and the mold assembly body are used in cooperation, the operation process is convenient and rapid, the device can be suitable for a uniaxial tensile test, a tensile fracture test, a shear fracture test, a tension-shear fracture test and a compression-shear fracture test at the same time, and the application range is remarkably widened.

The application discloses a high core wall dam mixed clay tensile-shear fracture test method without friction influence, which comprises the following steps: S1, collecting soil samples and determining the optimal water content and the maximum dry density; S2, designing various test conditions; S3, combining a front half of a mold and a rear half of the mold; S4, assembling a compaction fracture mold; S5, preparing and compacting the mixed clay soil sample; S6, transferring the compaction fracture mold to a hollow test tank; S7, removing a Z-shaped compaction plate and a rectangular ring wall; S8, suspending the test part of the compaction fracture mold; and S9, carrying out the tensile fracture test or the shear fracture test of the mixed clay of the core wall. In the application, the tensile fracture and the shear fracture characteristics of the mixed clay can be studied on the same test device, and the friction does not need to be considered. The application fundamentally solves the problem that the existing soil body fracture test method cannot be used for determining the fracture characteristics of the mixed clay of the high core wall dam, and fills the blank of the test method of the mixed clay of the high core wall dam.

The invention provides a horizontal well fracturing simulation method, device and equipment and a storage medium, and belongs to the technical field of oil and gas reservoir development. The method comprises the following steps: controlling true triaxial fracturing equipment to pressurize a fracturing test piece through a hydraulic fracturing pump; the crack flow value of each crack is collected through a flowmeter; calculating a flow distribution coefficient of the fracturing test piece based on the fracture flow value, wherein the flow distribution coefficient is used for indicating the stress interference degree between the fractures; and based on the flow distribution coefficient, the morphological characteristics of the crack, the acoustic emission signal and the pumping pressure curve, performing crack stress interference evaluation on the fracturing test piece. According to the method, the real-time non-uniform distribution characteristic of each crack flow in the multi-crack synchronous expansion process can be obtained, the dynamic quantization parameter of the stress interference intensity is increased, in addition, the influence rule of the pressure in the fractured section crack on the expansion of the lower section crack during the multi-crack sequence expansion can be obtained, and the expansion efficiency is improved. And a foundation is laid for mechanical mechanism research of multi-fracture interaction in the horizontal well multi-stage fracturing process.

The invention discloses a testing device and method for a rock dynamic I-type fracture test, and belongs to the technical field of detection of rocks and rock materials under dynamic loading in rock engineering, the testing device comprises a shell, and the inner wall of the shell is provided with a plurality of wire grooves; the sample is arranged in the shell; the end part of the incident rod penetrates through the shell and extends into the shell; the end part of the transmission rod penetrates through the shell and is matched with the incident rod to clamp a sample, and stress waves are transmitted to the sample; the telescopic assembly is arranged in the shell and corresponds to the sample so as to adjust the position of the sample; the plurality of acoustic emission sensor assemblies are arranged in the shell and are connected with the test sample so as to detect the test sample; the plurality of acoustic emission sensor assemblies are arranged in one-to-one correspondence with the plurality of wire slots; the acoustic emission sensor assembly is connected with the data acquisition line; and the data acquisition wire is arranged in the wire slot.

The application relates to a photoelectricity-assisted complex shearing path fracture test fixture and a detection method, which comprises a motion unit, a clamping unit and a data detection unit; the motion unit comprises a motion cover plate and a fixed cover plate, both of which are fixedly connected with a testing machine, and the clamping unit and the data detection unit are fixed on the motion unit; the clamping unit comprises a motion back plate and a fixed back plate, and the whole structure is symmetrically distributed in the middle part of the motion unit; the data detection unit comprises a pulse sensor and an industrial camera, and the whole structure is distributed on both sides of the motion unit and is fixedly connected with the lower end of the motion unit. The bidirectional clamping is realized through the combined design of the back plate and the cover plate, the fastening force of the test piece is stronger, the photoelectricity-assisted detection method is adopted, the strain path of the complex shearing path fracture can be obtained, the detection precision is improved, the accurate prediction of the damage and unstable fracture behavior is realized, and the method has the functions of high reliability, high efficiency, powerful function and convenient operation.