25 results about "Surface strain" patented technology

The invention relates to the technical field of ultrahigh strength steel delayed cracking performance testing, in particular to an ultrahigh strength steel delayed cracking performance testing device and a testing method thereof.The testing method includes the following steps that firstly, a rectangular strip sample is cut from a to-be-tested ultrahigh strength steel plate, the width of the sample is 10-20 mm, the thickness of the sample is 0.5-6.0 mm, and the thickness of the sample is 10-20 mm; performing oil removal, grinding and ultrasonic cleaning, and recording a surface treatment mode; step II, bending the sample into a bending state according to a U shape, and enabling the surface of the outer layer to generate maximum surface strain, the method can be used for rapid screening and can also be used as a preposed step for threshold and life evaluation, the consistency and comparability of results between different laboratories and engineering units can be improved, and the method is suitable for large-scale popularization and application. And through hydrogen-free contrast, fracture microscopic analysis, diffusible hydrogen detection and finite element check, macroscopic crack behaviors are associated with microscopic fracture characteristics and hydrogen content, so that the capability of judging a fracturing mechanism is enhanced, and a reliable basis is provided for engineering material type selection and process verification.

The application discloses a UHPC anti-bending test initial cracking strength determination method and system based on an image method, and belongs to the technical field of mechanical property testing, and comprises the following steps: spraying random speckles on the surface of a UHPC test piece, pre-embedding an optical fiber Bragg grating sensor array in the test piece, and performing X-ray computed tomography on test pieces in the same batch to establish a fiber-matrix interface transition zone damage evolution model; when three-point anti-bending loading is performed on the test piece, surface speckle images are collected in real time, the DIC algorithm is used to calculate the full-field strain distribution, and the surface initial cracking time and the strain concentration area coordinates are determined in combination with a criterion; meanwhile, the wavelength drift of the optical fiber is monitored, the internal initial cracking time is determined by calculating the coefficient of variation; the interface debonding rate and the interface initial cracking point time are calculated according to the model and the real-time interface stress; a multi-source initial cracking characteristic data set containing the surface strain, the internal strain anomaly and the interface debonding rate is constructed, the weight coefficients are obtained by inputting the neural network model, and the initial cracking anti-bending strength is calculated by weighted summation.

The invention relates to the technical field of data processing, in particular to a quantitative analysis method for mechanical property dispersibility of ceramic matrix composite components, which comprises the following steps: acquiring experimental measured values corresponding to a surface strain field and a stress-strain curve; constructing a data set; constructing a neural network model, and obtaining predicted values corresponding to the surface strain field and the stress-strain curve; obtaining posterior distribution of mechanical property parameters of each test piece; constructing a hierarchical Bayesian inference model and obtaining posterior distribution of hyper-parameters of the hierarchical Bayesian inference model; and obtaining a quantitative analysis result of the mechanical property dispersibility of the components of the ceramic matrix composite material. According to the invention, systematic quantification and consistency evaluation of material performance dispersibility are realized, and effective data support is provided for quality control, reliability design and engineering application of the ceramic matrix composite material.

This invention discloses a real-time inversion method and system for mechanical property parameters of ceramic matrix composites, specifically relating to the field of composite material performance characterization. The method includes: acquiring the surface strain field and stress-strain curve of the ceramic matrix composite to be tested; inverting and identifying the mechanical property parameters of the microscale components with the objective of minimizing the error function to obtain the optimal microscale component mechanical property parameters; inputting the optimal microscale component mechanical property parameters into a macroscale homogenized performance parameter prediction model to obtain the macroscale mechanical property parameters; wherein, the error function is determined based on the predicted surface strain field, the predicted stress-strain curve, and the stress-strain curve; the predicted surface strain field and the predicted stress-strain curve are obtained through a pre-trained response data prediction model, which improves prediction accuracy and thus ensures the accuracy of the characterization of the microscale component mechanical property parameters.

This invention discloses a method for monitoring the surface deformation evolution process of rock undergoing uniaxial compression creep failure, belonging to the field of geotechnical and rock mechanics testing technology. The steps are as follows: Step 1: Set up a test platform, which includes a speckle spraying system, an imaging and illumination module, a test device, and a host computer; Step 2: Fabricate rock test specimens and arrange the imaging and illumination module; Step 3: Obtain the compressive strength and set the graded loading levels; Step 4: Form a white base layer and black speckles on the surface of the rock specimen, meeting the requirements; Step 5: Conduct a uniaxial graded loading creep test on the rock specimen and acquire image data; Step 6: Process the image data to obtain the strain field evolution process on the specimen surface. This invention uses the above method to record the changes of the white base layer and black speckles during compression using an imaging device, thereby obtaining the deformation creep failure characteristics and evolution law of the rock surface.

The application discloses a kind of directional crystal mould shell automatic detection cleaning system.In the application, by transient air pressure excitation and multi-scale wavelet domain digital speckle correlation detection, the micro crack identification ability is identified from surface opening defect to sub-surface strain anomaly stage, which significantly improves the detection sensitivity of hidden cracks and wall thickness thinning defects, and replaces artificial visual experience determination with full-field strain cloud quantification grading, which significantly reduces the missed detection rate and the quality risk caused by human error. Strain-cleanness dual-factor fusion evaluation simultaneously completes the judgment of structural integrity and internal cavity cleanliness at the same station, improving the completeness and automation of defect evaluation, reducing the drag of batch offline sampling and chemical permeation operation on production rhythm, and eliminating the need for fluorescent penetrant immersion and cleaning process with transient pulse excitation method, which improves the single-piece detection rhythm and reduces the cost of hazardous chemicals procurement, storage and waste liquid treatment.

The invention discloses a real-time inversion method and system for mechanical property parameters of a ceramic-based composite material, and particularly relates to the field of performance characterization of composite materials. Comprising the following steps: acquiring a surface strain field and a stress-strain curve of a to-be-measured ceramic-based composite material; performing inversion identification on the mechanical property parameters of the micro-scale components by taking minimization of the error function as a target to obtain optimal mechanical property parameters of the micro-scale components; inputting the optimal micro-scale component mechanical property parameters into a macro-scale homogenization performance parameter prediction model to obtain macro-scale mechanical property parameters; wherein the error function is determined according to the predicted surface strain field, the surface strain field, the predicted stress-strain curve and the stress-strain curve; the predicted surface strain field and the predicted stress-strain curve are obtained through the pre-trained response data prediction model, and the prediction precision can be improved through the model, so that the characterization accuracy of the micro-scale component mechanical property parameters is ensured.

The application discloses a method for evaluating viscoelastic cracking performance of rubber asphalt mixture, and aims at solving the problem that current evaluation of cracking performance of rubber asphalt mixture is limited to brittle cracking at low temperature and does not involve evaluation of viscoelastic cracking performance. The evaluation method comprises the following steps: 1, cutting a Marshall test piece; 2, image recognition; 3, performing an indirect tensile test on the Marshall test piece of the asphalt mixture to determine a control load; 4, collecting photos of the asphalt mixture in a loading process of the indirect tensile test; 5, calculating and obtaining a surface strain field of the Marshall test piece of the asphalt mixture in the indirect tensile test process; 6, calculating a high strain index to determine a high strain area proportion; 7, calculating a viscoelastic protection index; 8, constructing a discrete element test piece model; 9, performing indirect tensile simulation; 10, counting mortar tension chains; 11, calculating a mortar tension chain score; and 12, evaluating. The application combines the image recognition technology and the discrete element modeling, and effectively improves the accuracy of the evaluation result.

To provide a flange strain measuring tool capable of highly accurately and easily measuring the surface strain of a flange functioning as a pipe joint.SOLUTION: The disc-shaped jig body 2 positioned on the flange by the positioning device is provided with a plurality of measurement holes 12a to 12c at intervals in the circumferential direction in the first facing annular portion 22 facing the target surface portion of the flange in the positioned state. The flange strain measuring jig 1 according to the present invention can easily and stably measure surface strain of a target surface portion of a flange by inserting a gauge head of a dial gage into each of the measurement holes 12a to 12c of the jig body 2 in a state where the jig body 2 is positioned on the flange.SELECTED DRAWING: Figure 4

This utility model discloses an auxiliary tool for installing surface strain gauges, used to align and install the surface strain gauge onto a steel pipe support. The surface strain gauge includes a main body and two mounting ends formed on opposite sides of the main body. The auxiliary tool includes two clamping members, two fixing devices, and two guide positioning strips. The clamping members are used to connect to designated positions on the steel pipe support and provide installation space for the surface strain gauge. The fixing devices are used to fix the surface strain gauge to the mounting surfaces provided by the two clamping members. The guide positioning strips are used to connect the two clamping members so that they maintain the same orientation. This utility model has the advantages of convenient installation and reusability.

This invention provides a method for assessing internal failure of orthotropic laminates based on strain measurement, relating to the field of orthotropic composite materials technology. The method includes the following steps: S1, fabricating a strain gauge test model of the laminate; S2, connecting the strain gauge test model to a data acquisition instrument, conducting a working condition test on the structure under test, and using a host computer to calculate the stress in each layer and principal direction of each angle within the laminate; S3, acquiring the strength limit of the orthotropic single-layer laminate material, and based on the strength limit of the orthotropic single-layer laminate material and the stress in each layer and principal direction of each angle within the laminate, performing failure assessment for each ply at different angles. Due to the special characteristics of orthotropic laminates, different ply failures can occur under different stress states. This invention provides a method that can calculate the failure assessment of ply in different directions within the laminate structure based on the surface strain measurement values ​​of the composite laminate.

The invention discloses a shield tunnel convergence deformation monitoring method and device, a medium and a product, and relates to the technical field of shield tunnel structure health monitoring and safety assessment, and the method comprises the steps: constructing an initial hexagonal auxiliary model of a shield pipe ring section; acquiring strain data of the bolt in real time; determining a maximum deflection value and a circular seam opening angle of the bolt based on the inner cambered surface strain and the outer cambered surface strain; determining a deformed hexagonal auxiliary model based on the axial tensile strain, the maximum deflection value and the circular seam opening angle; and determining the vertical convergence deformation and the horizontal convergence deformation of the tunnel pipe ring based on the angle variation of any vertex angle in the hexagonal auxiliary model and the circular seam opening angle of the vertex angle, so as to monitor the convergence deformation of the shield tunnel. According to the method, the accuracy and efficiency of shield tunnel deformation monitoring can be improved, and reliable technical support is provided for tunnel structure safety evaluation.

The invention discloses a temperature compensation correction method for a steel wire type surface strain gauge, and relates to the technical field of engineering monitoring, and the method comprises the following steps: S01, collecting data according to a preset window period; s02, sorting the collected data of the plurality of preset window periods in a preset collection period to obtain a frequency and temperature data sequence under a day and night temperature change period; s03, drawing a frequency square-temperature diagram based on the frequency and temperature data sequence; s04, obtaining a slope of a drawn frequency square-temperature diagram fitting straight line according to a least square method, and calculating a temperature compensation calibration coefficient; and S05, performing temperature compensation on the strain change measurement value of the steel wire type surface strain gauge by using the temperature compensation calibration coefficient, and finally obtaining the strain change measurement value generated by the stress change after temperature compensation. According to the invention, effective temperature compensation calibration of the steel wire type surface strain gauge can be realized by using natural environment temperature change, and the field measurement precision and data reliability of the sensor are effectively improved.

The invention discloses a large thick-wall solid structure layer surface displacement field inversion method based on a virtual layer, and relates to the technical field of large thick-wall solid structure displacement monitoring and inversion, and the method comprises the steps: embedding a geometrically attached and mechanically isolated virtual layer on the outer surface of a large thick-wall solid structure; measuring points are arranged on the single side of the neutral surface of the virtual laying layer to collect entity surface strain as virtual laying layer film strain; constructing a weighted least square functional containing a film strain fitting item and a bending and shearing strain regularization item; calculating the functional variation to obtain virtual layer node displacement; according to the method, high-precision displacement inversion of the large thick-wall solid structure under single-side point distribution is achieved, structural stress is not interfered, inversion numerical stability is improved, and the method adapts to a solid unit model, is suitable for structures such as a pressure container and the like, and has the advantages of being simple in structure, convenient to operate and the like. The method can be used for structural health assessment.

The invention discloses a simple indoor HDD model test hole deformation test method. A device for realizing the method comprises a model soil box and a test plate, the testing plate is of an elastic structure, and the two ends of the testing plate are supported on the side wall of the model soil box through bayonets in a simple supporting mode. The upper surface and the lower surface of the midpoint of the span of the test board are respectively pasted with a strain gauge. And the test plate and the strain gauge are pre-buried in a preset depth in the model soil box before soil filling. HDD drilling is carried out in filling soil of the model soil box, and the linear distribution load enables the test plate to be bent and deformed, so that the strain gauges on the upper surface and the lower surface of the test plate have reading difference. Based on the reading difference, the HDD model test hole deformation and stress test is realized; indirect measurement is achieved, disturbance is small, the principle is rigorous, and the result is reliable; the device disclosed by the invention is simple and low in cost, and the distribution rule of soil deformation and stress along the depth can be conveniently obtained by pre-embedding a plurality of test units at different depths.

The invention relates to the technical field of microscopic analysis of metal materials, in particular to a metal surface strain distribution characterization method. The method comprises the following steps of: (1) etching a square grid on the surface of a metal matrix by adopting a standard photoetching process before deformation of the metal matrix, wherein the side length of the grid is 5-40 microns; (2) depositing a Ni layer with the thickness of 60-80nm on the surface of the metal matrix on which the square grid is positioned by adopting an electron beam evaporation system; (3) stripping the Ni layer outside the square mesh from the metal matrix, and leaving a square mesh consisting of Ni on the surface of the metal matrix; and (4) after the metal matrix is deformed, observing the deformation degree of the square grid through a laser scanning confocal microscope to reflect the real strain of the local area of the surface of the metal matrix. The method solves or partially solves the problem that the metal material is difficult to visually reflect the real strain distribution of the surface on the macroscopic level.

A silk-covered wire hardness change trend prediction and evaluation method belongs to the technical field of material performance evaluation, and comprises the following steps: acquiring a surface strain value and a core strain value of a silk-covered wire in a bending process, calculating a strain difference value, synchronously acquiring bending radius, grain boundary migration distance and microcrack initiation distribution data, and constructing a comprehensive damage data set; a dislocation density cumulant mapping relation is established according to the strain difference value, and the hardening degree grade is determined; the surface damage depth is calculated by combining the grain boundary migration distance and the microcrack initiation distribution data, and the microcrack initiation probability is determined; and performing correlation analysis on the microcrack initiation probability and the bending radius, determining the position of a softening turning point, dynamically adjusting the hardness prediction range, performing bending life simulation, and outputting a residual life evaluation result. The full-chain analysis from microscopic damage to macroscopic life prediction is realized, the reliability evaluation precision of the silk-covered wire in a high-stress environment is remarkably improved, and a scientific basis is provided for preventive maintenance.

The application discloses a kind of non-invasive flange sealing contact state monitoring method and system, method includes: obtaining the mechanical property parameter data of flange sealing ring, and establishes flange sealing state monitoring model according to mechanical property parameter data;Real-time strain distribution data of flange surface is monitored in real time using sealing state monitoring model, when monitoring that real-time strain distribution data reaches monitoring early warning threshold, early warning is carried out.The application establishes flange sealing state monitoring model by the change rule of strain distribution and sealing contact state of flange surface, identifies the sealing contact state in the flange, and combines the comprehensive factors of mechanical property parameters to analyze the rule of strain distribution and sealing contact state of flange surface, realizes the abnormal monitoring of flange sealing contact state of multiple factors, and can realize local abnormal positioning potential leakage risk, discovers flange sealing failure risk in advance, improves the monitoring accuracy and early warning timeliness of sealing contact state.

This invention provides a rapid, non-destructive, and non-contact device and method for measuring strain on silicon surfaces, comprising: a femtosecond laser for generating femtosecond laser pulses; a time-domain stretching component disposed in the output optical path of the femtosecond laser; an optical signal amplification component disposed in the output optical path of the time-domain stretching component; a beam splitter located in the output optical path of the optical signal amplification component, for splitting the femtosecond laser pulses into a test beam and a reference beam with a specific power ratio; a spatial dispersion component disposed in the output optical path of the test beam of the beam splitter; a microscope objective disposed in the output optical path of the spatial dispersion component; a high-speed photodetector located in the output optical path of the reference beam of the beam splitter; a high-speed oscilloscope electrically connected to the high-speed photodetector; and a data processing device electrically connected to the high-speed oscilloscope. This invention addresses the problems of strong dependence on speckle and low detection frame rate in existing technologies.

The invention discloses a UHPC bending test initial crack strength judgment method and system based on an image method, and belongs to the technical field of mechanical property tests.The UHPC bending test initial crack strength judgment method comprises the steps that random speckles are sprayed on the surface of a UHPC test piece, and a fiber bragg grating sensor array is pre-embedded in the UHPC test piece; performing X-ray computed tomography on the same batch of test pieces to establish a fiber-matrix interface transition region damage evolution model; when three-point anti-bending loading is carried out on the test piece, surface speckle images are collected in real time, full-field strain distribution is calculated through a DIC algorithm, and the surface initial cracking time and the coordinates of a strain concentration area are determined in combination with criteria; meanwhile, monitoring an optical fiber wavelength drift distance, and calculating a variable coefficient to determine internal initial cracking time; calculating the interface debonding rate and the interface initial crack point time according to the model and the real-time interface stress; and constructing a multi-source initial crack feature data set containing surface strain, internal strain anomaly and interface debonding rate, inputting the data set into the neural network model to obtain a weight coefficient, and calculating the initial crack breaking strength through weighted summation.

The utility model provides a fixing device for a surface strainmeter. The surface strainmeter comprises a strainmeter sensor body and sensor connectors arranged at the two ends of the strainmeter sensor body respectively. The fixing device comprises a first mounting seat and a second mounting seat, and the first mounting seat and the first sensor are respectively connected with the corresponding sensor connectors; each of the first mounting seat and the second mounting seat comprises a first fixing piece, a second fixing piece and a bolt fixing piece, and a mounting channel penetrating left and right is formed in the second fixing piece; the corresponding sensor connector is inserted into the mounting channel of the corresponding mounting seat and slides left and right in the corresponding mounting channel; the bolt fixing piece penetrates through a first mounting hole which is formed in the first fixing piece and penetrates up and down and extends into the structure so that the first fixing piece can be fixed to the structure. According to the utility model, the problem that the range of the surface strain gauge is shortened due to the fact that the distance between drill holes is inconsistent with the standard caused by inaccurate drilling and the sensor cannot be installed or compressed or stretched can be solved.

This invention discloses a method for testing the transverse crack sensitivity of welded joints through four-point bending loading, relating to the field of welding quality inspection technology. The method includes the following steps: selecting a base material matching the actual welded structure; preparing a welded specimen without pre-existing cracks; creating deformation observation marks in a predetermined area on the surface of the weld and heat-affected zone; simultaneously applying longitudinal four-point bending loads and independent transverse restraint loads to subject the weld and heat-affected zone to multiaxial stress; performing welding operations to generate thermal cycling; dynamically controlling the application sequence and magnitude of at least one load based on real-time temperature signals; simultaneously acquiring temperature field, surface strain, acoustic emission signals, and mechanical load data; calculating initiation and propagation characteristic parameters based on this data to quantitatively evaluate the transverse crack sensitivity of the welded joint. This invention extracts crack characteristic parameters and accurately and quantitatively evaluates the transverse crack sensitivity of welded joints by constructing a multiaxial stress field, dynamically linking welding thermal cycling and load.

The application discloses a kind of asphalt mixture cracking strain threshold determination methods, comprising, preparation multiple asphalt mixture test pieces and carry out fatigue test, collect acoustic emission signal extraction event count, energy count, rise time, peak frequency, amplitude, ringing count and duration seven kinds of indexes;Analysis its time series determines the minimum time data cluster of each kind of index and corresponding threshold;To newly prepared with speckle test piece fatigue test, synchronous collection acoustic emission signal and DIC image;Acoustic emission index normalization, according to cumulative frequency filter out top three indexes, with their first reach threshold time earliest point as damage initiation characteristic moment;Match DIC image at this moment and calculate surface strain field;Crack region of completely cracked state is mapped to the strain field, extract the average value of maximum strain point in the region and be defined as the cracking strain threshold of asphalt mixture;The application provides more reliable quantitative basis for performance evaluation and durability design of asphalt mixture.

The invention discloses a non-intrusive flange sealing contact state monitoring method and system, and the method comprises the steps: obtaining the mechanical property parameter data of a flange sealing ring, and building a flange sealing state monitoring model according to the mechanical property parameter data; and performing real-time monitoring on the real-time strain distribution data of the flange surface by using the sealing state monitoring model, and performing early warning when the real-time strain distribution data is monitored to reach a monitoring early warning threshold value. According to the invention, a flange sealing state monitoring model is established through the strain distribution of the flange surface and the change rule of the sealing contact state, the sealing contact state in the flange is identified, and the flange surface strain distribution and sealing contact state rule analysis is carried out in combination with comprehensive factors of mechanical property parameters. Flange sealing contact state abnormity monitoring influenced by multiple factors is achieved, potential leakage risks can be positioned through local abnormity, flange sealing failure risks can be found in advance, and the monitoring accuracy and early warning timeliness of the sealing contact state are improved.