56 results about "Full field strain" patented technology

The invention relates to the technical field of rock mechanical tests and safety monitoring, and discloses a rock fracture prediction method based on acoustic emission and surface strain cooperative monitoring, and the method comprises the steps: building a monitoring system comprising acoustic emission and an industrial camera array, and building a unified timestamp of each subsystem through a GPS time service module; through load triggering logic, a synchronous trigger is utilized to synchronously acquire an acoustic emission signal and a sample surface image sequence, and evolution characteristics of three-dimensional coordinates of an acoustic emission source and surface full-field strain data are solved. And on the basis, calculating a main strain field variation coefficient, and performing cross-correlation analysis on the resampled energy rate and strain rate. And finally, according to multi-parameter coupling criteria of acoustic emission time sequence parameters, positioning events and surface strain, identifying rock fracture precursor types, and predicting fracture moments and areas by combining a Voight model inverse velocity method and a seismic source projection technology.

The invention relates to the technical field of intelligent control of heavy equipment, in particular to a hydraulic synchronous intelligent control system for segmented turnover of an overweight steel structure, and discloses the hydraulic synchronous intelligent control system for segmented turnover of the overweight steel structure. According to the system, full-field strain data of a structure surface is acquired by deploying a flexible grid sensor array, and a deformation gradient topological graph is constructed to identify an instability risk area. And a dynamic fluid network model of the hydraulic system is established, fluid-solid coupling simulation is carried out in combination with deformation characteristics, and pressure pulsation transmission paths under different control instructions are predicted. And the system dynamically optimizes a data sampling strategy and network model parameters according to a prediction path, generates a hydraulic cylinder coordination action instruction subjected to pressure balance verification, and finally drives an execution mechanism to complete turnover operation. According to the scheme, full-field real-time sensing of structural deformation and dynamic coupling prediction control of hydraulic fluid are achieved, and the safety and control precision of the overweight component in the turnover process are improved.

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

The invention relates to the technical field of strain measurement, in particular to a three-dimensional full-field strain measurement method and system based on multi-view collaboration, and the method comprises the steps: constructing a sparse topology skeleton model of a measured target under a global coordinate system, and building a bidirectional projection mapping relation between the global situation and each local situation; the method comprises the following steps: synchronously acquiring a time sequence texture feature image of a measured target, calculating a luminosity geometric coupling confidence tensor of each pixel point and extracting an initial texture feature field under each view angle; utilizing a skeleton model to guide the initial texture feature field to perform limited local matching, and resolving to obtain a local independent displacement field and residual energy distribution of each view angle; performing multi-view weighted fusion based on a bidirectional projection mapping relation, and reconstructing a global three-dimensional displacement field; and performing differential calculation on the global three-dimensional displacement field to obtain a deformation gradient tensor and generate three-dimensional full-field strain distribution. According to the method, gradient mutation caused by view field splicing errors can be effectively inhibited, and physically real and full-field continuous three-dimensional strain distribution is obtained.

The invention discloses a transparent fractured rock mass stress-seepage-dissolution coupling dynamic visualization test device and method. The device comprises a sample fixing and adjusting platform, a pair of opposite transparent plates are arranged, a transparent soluble fracture sample can be fixed, and an adjustable mechanism is arranged to change and lock the fracture opening degree; the seepage pressure control and measurement device can inject fluid into the fracture, control the flow velocity and monitor the pressure; the confining pressure loading device is provided with a closed pressure gas cavity, an inert gas injection device and a gas pressure sensor and is positioned on the outer side of a transparent plate, and after inert gas is injected into the cavity, uniform confining pressure is applied to a transparent fracture surface through the transparent plate and is monitored; the visual observation device comprises a CCD camera, a light source and a three-dimensional XT-DIC full-field strain measurement system, and the CCD camera and the light source are arranged on the observable side of the sample and can dynamically observe and record the corrosion form, displacement and full-field strain of the fracture wall surface in real time. According to the invention, direct observation of the seepage behavior, the deformation damage change and the corrosion form in the hydraulic coupling process of the soluble rock mass fracture can be realized.

The invention relates to the technical field of vibration monitoring, and provides a vibration monitoring method and system for an oil-immersed transformer, and the method comprises the steps: judging whether the pressing force of laminations is attenuated or not based on the vibration energy data between the laminations, based on strain data obtained by carrying out full-field strain analysis on the displacement data of the winding, judging whether the winding has a deformation or displacement risk or not; based on the strain data of the welding seam of the box body, predicting the fatigue crack risk of the welding seam, and based on the pre-tightening force data of the bolt of the box body, judging whether the bolt is loosened; based on acoustic emission signal data generated by oil flow impact, the abrasion state of the insulation structure is evaluated, and based on vibration mode data of the cooling fins, whether the cooling fins resonate or not is judged; and when any judgment result or evaluation result has an abnormal state, generating an early warning signal.

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 provides a frozen soil full-field deformation self-adaptive measurement method, system and equipment, and relates to the technical field of frozen soil deformation. The method comprises the following steps: acquiring multi-modal data of a tested frozen soil environment to obtain initial data; marking ROI (Region of Interest) for sequence image data in the initial data, obtaining an ROI mask and a confidence map of the tested frozen soil environment, inputting the constructed reinforcement learning intelligent agent, and outputting linkage action data; wherein the reward function of the reinforcement learning agent is coupled with a plurality of physical consistency indexes obtained based on DIC calculation; the action space of the reinforcement learning agent comprises ROI mask form editing, multi-level ROI gating and DIC parameter adjustment; and updating the ROI mask and the DIC parameters based on the linkage action data to perform full-field deformation calculation, outputting a full-field displacement field and a full-field strain field, calculating a quality index, and when the quality index is degraded, performing optimization updating on the reinforcement learning agent. According to the invention, the whole-field deformation self-adaptive measurement of frozen soil is realized, and the long-term measurement stability is improved.

The invention relates to the technical field of mechanical property testing, in particular to a laminated plate mechanical property evaluation method and system based on strain data. The method comprises the following steps: performing a biaxial tensile experiment on a laminated plate sample, synchronously acquiring load time-history data and a full-field speckle image, constructing a full-field strain matrix through a mapping algorithm, dispersing the full-field strain matrix into nodes, dividing a core pure shear region and a stress diffusion region, and then obtaining first principal strain through principal component analysis; a load transmission efficiency attenuation spectrum and full-field strain energy entropy density are calculated respectively, a dynamic correction model is constructed in combination with weighted coupling of preset shape characteristic parameters, and a real constitutive curve is obtained by using the model to calculate correction coefficient inversion nominal stress; the thermodynamic entropy characteristic is introduced, so that the problem that the stress field distortion at the nonlinear damage stage of the material is difficult to sense by a traditional method is solved, and the biaxial mechanical property test precision of the laminated plate is effectively improved.

The invention relates to the field of strain detection, in particular to a self-adaptive strain detection method and system and a medium. The method comprises the following steps: inputting grid point coordinates, noisy displacement data and a maximum smooth half window; calculating the overall noise level sigma through local linear regression analysis; extracting local strain curvature characteristic quantity through cubic polynomial regression; establishing a noise and curvature balance relation based on the sigma and the curvature characteristic quantity, and calculating an adaptive smooth half window; obtaining the strain estimation value of each grid point through linear polynomial regression, and finally obtaining the strain distribution of the whole field. According to the method, the optimal smooth window can be automatically adjusted without manual intervention, balance is achieved between noise suppression and detail reservation, the problem that a traditional fixed window method is insufficient in precision in a non-uniform deformation area is solved, high-precision full-field strain detection of a noise-containing displacement field is achieved, and the detection precision is improved. The method is suitable for derivative calculation of digital image related systems and various noisy continuous signals.

The invention relates to a material in-situ strain DIC analysis method and system based on CT imaging, and the method comprises the steps: preparing speckles having significant X-ray absorption difference with a matrix, directly tracking speckle displacement through a CT image while carrying out the defect change of a sample in a deformation process through CT, and replacing a conventional camera to achieve speckle collection for DIC strain analysis. According to the method, synchronous analysis of defect expansion and a strain field in a material loading process is realized through staged CT scanning and image post-processing, and an integrated solution is provided for research on mechanical properties of materials. The space limitation of CT equipment is broken through, internal defect evolution and surface full-field strain data of the material are synchronously obtained, and the method is suitable for multi-scale mechanical behavior research of metal, ceramic, polymer and composite materials thereof.

The invention belongs to the technical field of experimental mechanics and precision optical measurement, and particularly relates to a magneto-rheological shock absorber full-surface deformation monitoring system, which comprises an annular multiplexing image acquisition array unit, which comprises six high-speed industrial cameras uniformly arranged on an annular rigid bracket, and the optical axes of the high-speed industrial cameras point to the center of a measured object; the stereoscopic vision measurement unit chain is used for enabling the six high-speed industrial cameras to form six stereoscopic vision measurement units which are connected end to end through multiplexing of adjacent view fields; the synchronous control unit is used for controlling the high-speed industrial camera to perform synchronous exposure acquisition in a microsecond error range; the calculation processing unit is used for executing closed-loop global calibration, three-dimensional point cloud reconstruction, coordinate system unification and full-field strain calculation; on the basis, the limitation that independent binocular systems need to be stacked in traditional annular detection is broken through, 360-degree full coverage of binocular stereoscopic vision can be achieved only through six cameras by means of adjacent multiplexing topological structures, and the hardware cost is remarkably reduced.

The invention discloses a method, a device and equipment for determining displacement and strain of a composite material framework, and relates to the field of measurement, and the method comprises the following steps: carrying out analogue simulation on the composite material framework by using a simulation model; correcting the displacement distribution and the full-field strain of the simulation measuring points according to the displacement distribution and the full-field strain of the actual measuring points in one-to-one correspondence with the positions of the simulation measuring points in the actual composite material framework; reducing the number of data in the corrected displacement distribution and the corrected full-field strain to a preset number; and after verifying the accuracy of the dimension reduction displacement distribution and the dimension reduction full-field strain, determining the displacement and the strain of the dimension reduction displacement distribution and the dimension reduction full-field strain characterization composite material framework. And the data obtained after simulation of the composite material framework is simulated by using actual data, so that the obtained result is more accurate. And the data is verified after dimension reduction, so that the data can be ensured to be more simplified without distortion.

The application discloses a kind of based on digital speckle's fiber winding gas cylinder defect detection method and system, high contrast speckle pattern is made on the surface of gas cylinder;Controllable load is applied to gas cylinder, and the image sequence of the surface of gas cylinder before and after load is collected;Based on the image sequence of the surface of gas cylinder, the full-field displacement field data of the surface of gas cylinder is calculated by digital speckle correlation method;The full-field displacement field data of the surface of gas cylinder is corrected by surface coordinate transformation;According to the full-field displacement field data of the surface of gas cylinder after correction, the full-field strain distribution image set of the surface of gas cylinder is calculated using difference method;The full-field strain distribution image set of the surface of gas cylinder is processed by image enhancement;Based on the full-field strain distribution image set of the surface of gas cylinder after enhancement, extract quantitative feature parameters, and utilize machine learning model to automatically identify and classify gas cylinder defect.By surface coordinate transformation correction, small microdefects can be identified, detection efficiency is improved, and detection cost is reduced.

The invention discloses a piezoelectric transducer surface micro-deformation detection method and system based on high-speed camera shooting, and belongs to the field of piezoelectric material dynamic deformation detection. According to the method, a non-contact, full-field and high-temporal-spatial-resolution detection scheme is provided for solving the problems of low frame rate of single-point measurement of a laser Doppler vibration meter and common optical measurement. According to the system, a binocular high-speed camera is adopted, a digital speckle correlation method (DIC) is combined, and accurate measurement of three-dimensional coordinates, micrometric displacement and a strain field of the transducer is achieved by synchronously collecting working images of the transducer underwater or in the air. The method comprises the key steps of binocular camera calibration, speckle marking, image preprocessing, obtaining of a sub-pixel displacement field through a DIC algorithm, and reconstruction of a three-dimensional shape and full-field strain distribution. According to the method, the surface vibration mode can be identified, three-dimensional vibration modeling and vibration-sound field data fusion are supported, the analysis capability on the resonance characteristic and the energy conversion efficiency of the transducer is effectively improved, and the method is suitable for scenes such as ocean exploration, underwater search and rescue, transducer optimization and the like.

The present application relates to the field of strain detection, and particularly to a self-adaptive strain detection method, system and medium. The method comprises: inputting grid point coordinates, noisy displacement data and a maximum smoothing half window; calculating an overall noise level sigma through local linear regression analysis; extracting a local strain curvature characteristic quantity through cubic polynomial regression; establishing a noise and curvature balance relationship based on sigma and the curvature characteristic quantity, and calculating an adaptive smoothing half window; obtaining strain estimation values of each grid point through linear polynomial regression, and finally obtaining overall strain distribution. The method can automatically adjust the optimal smoothing window without manual intervention, balances between noise suppression and detail preservation, solves the problem of insufficient accuracy of traditional fixed window methods in non-uniform deformation areas, realizes high-precision full-field strain detection of noisy displacement fields, and is suitable for derivative calculation of digital image correlation systems and various noisy continuous signals.

The invention belongs to the technical field of tunnel model tests, and particularly discloses a tunnel model test earthquake response testing device and method, and the device comprises a vibration table which is used for applying an earthquake load to a tunnel model; the model box is fixed on the vibration table, filled with soil and provided with a tunnel supporting structure; the speckles are pasted on the surface of the inner wall of the tunnel supporting structure and used for image recognition; the camera array is fixedly arranged relative to the tunnel supporting structure and is used for continuously shooting deformation images of the speckles; and the image processing unit is in communication connection with the camera array and is used for receiving, splicing and analyzing the deformation images to obtain full-field strain, displacement, deformation and acceleration data of the tunnel supporting structure under the action of the earthquake load. The testing device and method have the advantages of non-contact measurement, full-field continuous deformation monitoring, synchronous acquisition of multi-dimensional parameters and the like, and non-contact high-density seismic response data measurement of the tunnel model supporting structure can be realized.

1. The name of the design product: three-dimensional deformation measurement sensor. 2. The use of the design product: suitable for displacement and strain online measurement of various material deformation and structural deformation, and its small and integrated design greatly improves the usability of visual measurement instruments. High-precision measurement of key mechanical parameters such as three-dimensional displacement, full-field strain, dynamic vibration, fatigue damage and fracture behavior of materials and structures can be achieved. 3. The design points of the design product: in shape. 4. The picture or photo that best indicates the design points: perspective view 1.

The utility model provides a torque test device of a cylindrical shell, which integrates a deformation measurement system based on a digital image correlation technology and a stereo camera tracking measurement technology into a high-temperature buckling test device of a thin-wall cylindrical shell structure. And the three-dimensional displacement and the full-field strain of the thin-wall cylindrical shell structure in the test process are dynamically monitored and displayed in real time. And processing the captured image by combining a digital image related technology to obtain the cylindrical shell structure modality at initial buckling, over-buckling and buckling failure moments in the whole buckling process. The thermal infrared imager integrated in the test device can realize the non-contact global monitoring of the temperature change condition of the thin-wall cylindrical shell structure, and can reliably realize the dynamic monitoring and real-time display of the temperature of the thin-wall cylindrical shell through the data acquisition-transmission-computer terminal. Therefore, the buckling performance and modal change of the thin-wall cylindrical shell under the coupling action of the thermal load and the mechanical load are explored, and the bearing capacity of the thin-wall cylindrical shell at high temperature is fully explored.

This invention relates to the field of bridge displacement and stress field measurement technology, specifically to an existing bridge deflection and stress monitoring method based on digital image correlation technology. It includes deploying a speckle field on the surface of a key cross-section of the bridge to be monitored, setting up a high-speed camera to acquire time-series image sequences, processing the image data using a digital image correlation algorithm to calculate the full-field displacement field and full-field strain field of the key cross-section surface, verifying the full-field strain field to generate full-field deformation data, and using a physical driving model to invert the full-field deformation data into the stress distribution of the key cross-section, identifying stress concentration areas, and providing dynamic early warning based on a preset safety threshold. This invention provides full-field, dynamic observation of key areas of the bridge, avoiding the damage and long-term maintenance problems caused by drilling holes and attaching sensors to the structure. Theoretically, the measurement point density is only limited by the camera resolution, enabling seamless coverage of the entire monitoring area and ensuring that local damage is detected.

The invention discloses a simulation test method for an asymmetric support effect of a weakly-cemented and strongly-expansive soft rock roadway, and belongs to the technical field of coal mining. The method aims at solving the problems that in the prior art, it is difficult to truly reproduce roadway asymmetric large deformation under the weak cementing-strong expansion-rich water multi-field coupling effect, and the effectiveness of an asymmetric supporting scheme cannot be rapidly and quantitatively evaluated. According to the technical scheme, real rock mass parameters are obtained through on-site rock core sampling; similar materials are prepared based on the similarity theory, a physical model is constructed, and the surrounding rock deformation environment is reproduced in a high-fidelity mode; designing a plurality of asymmetric support schemes for simulation comparison; a non-contact full-field strain measurement system is adopted to monitor surrounding rock deformation, and an optimal supporting scheme is optimized and applied to field verification. According to the method, complex field problems are solved to a controllable laboratory environment, rapid and accurate optimization of a supporting scheme is achieved, and a scientific and reliable basis is provided for soft rock roadway supporting design.

The invention relates to the technical field of stress testing, and discloses a residual stress testing device and a residual stress testing method.The residual stress testing device comprises a support, a moving assembly arranged on the support, a drilling assembly and an image acquisition assembly, the drilling assembly and the image acquisition assembly are jointly arranged on the moving assembly, and an environment sensor used for detecting environment parameters is arranged on the image acquisition assembly; and the control assembly is electrically connected with the moving assembly, the drilling assembly, the image acquisition assembly and the environment sensor, and is configured to compensate a first full-field strain obtained by comparing the images before and after drilling based on the environment parameters, and input the compensated first full-field strain into a neural network model to obtain the corresponding residual stress. According to the residual stress test device and test method provided by the invention, errors caused by environmental factors to full-field strain calculation can be compensated; the residual stress is calculated in the neural network, the environmental adaptability is high, and the measurement result is accurate.

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 present application belongs to the technical field of rock mechanics, and specifically discloses a rock damage cooperative monitoring and constitutive model construction method, which comprises: uniaxial compression loading on a rock sample, synchronous acquisition of acoustic emission signals and full-field strain data, extraction of cumulative acoustic emission ringing counts and cumulative strain counts, and construction of internal damage variables and apparent damage variables respectively. First and second rock damage constitutive models are established based on the two types of damage variables, a compaction coefficient is introduced to correct the crack compaction stage, and an adaptive model is selected according to the uniaxial compressive strength and failure mode of the rock. The present application realizes double-dimension cooperative monitoring and characterization of internal rock damage and apparent deformation, solves the problems of one-sided damage characterization and low modeling accuracy of traditional methods, and has strong adaptability and high fitting accuracy. The model is in line with the actual mechanical behavior of rock, and can be used for stability analysis and damage evolution prediction of surrounding rock of underground engineering, and has strong engineering practicality.

The invention provides a global mechanical state cloud picture construction method and system for key components of a high-speed train, and relates to the technical field of train state monitoring, and the method comprises the steps: constructing a finite element model of the key components of the high-speed train; extracting geometric information of the finite element model, and reconstructing a three-dimensional contour of the finite element model to obtain a geometric model of the key component; reconstructing full-field strain and deformation data based on a full-field strain and deformation matrix obtained through finite element model simulation and a directly measured local strain value, and establishing a mapping relation between the strain and deformation data and colors; and coloring the geometric model according to the mapping relation between the full-field strain and the deformation data and the color to obtain a global mechanical state cloud picture. The method focuses on the global strain field and the deformation field of the key component of the high-speed train, and realizes efficient and accurate construction of the global mechanical state cloud picture of the key component of the high-speed train based on a global strain / deformation field reconstruction algorithm and a color mapping algorithm.

The application relates to the technical field of a thermoelectric material performance detection system based on a thermoelectric textile, and particularly discloses a thermoelectric material performance detection system based on a thermoelectric textile. The system comprises a temperature control loading platform, an electric heating signal acquisition unit, a computer vision strain sensing unit, an adaptive deformation compensation module and a central processing unit; the temperature control loading platform applies a controllable temperature gradient and contact pressure, the electric heating signal acquisition unit synchronously acquires voltage and current signals, the computer vision unit analyzes full-field strain through image sequences, the adaptive deformation compensation module dynamically corrects the electric heating signal in combination with a physical information neural network, and accurate Seebeck coefficients and electric conductivities are output. Through multi-modal sensing and physical constraint model fusion, the application realizes high-fidelity characterization of the performance of the easily-deformable thermoelectric textile under dynamic load, and improves test accuracy and repeatability.

The present application relates to the technical field of mechanical property testing, and more particularly to a method and system for evaluating the mechanical properties of a laminate based on strain data. The method comprises the following steps: performing a biaxial tensile test on a laminate sample, simultaneously collecting load time history data and full-field speckle images, constructing a full-field strain matrix and discretizing it into nodes using a mapping algorithm, dividing the core pure shear zone and stress diffusion zone, obtaining the first principal strain through principal component analysis, calculating the load transfer efficiency attenuation spectrum and the full-field strain energy entropy density, respectively, combining the preset shape feature parameters to construct a dynamic correction model, and using the model to calculate the correction coefficient to obtain the true constitutive curve by inverting the nominal stress. The introduction of thermodynamic entropy characteristics solves the problem of stress field distortion in the nonlinear damage stage that is difficult to perceive by traditional methods, effectively improving the accuracy of biaxial mechanical property testing of laminates.

The invention discloses a shrinkage detection method of a sheath-core type composite fiber fabric. The method comprises the following steps: acquiring an image and measuring an initial distance; carrying out damp-heat circulation treatment; calculating the shrinkage rate; calibrating a skin-core coupling coefficient; analyzing theoretical shrinkage and deviation; and evaluating the cyclic stability for multiple times. The method overcomes the technical limitation that the existing general detection method can only measure the overall size change and cannot analyze the complex interaction effect of the skin-core structure, realizes the non-contact accurate measurement of the fabric shrinkage rate by introducing the high-precision image marking and full-field strain analysis technology, can identify the local deformation abnormity, and has the advantages of high accuracy and high accuracy. An effective means is provided for positioning potential defects of the skin-core interface; according to the method, a dimensional stability evaluation system oriented to an actual use scene is constructed through multiple times of damp-heat cyclic treatment and combination of variation coefficient evaluation, and the repeated damp-heat stress process of the fabric in the wearing and washing process is effectively simulated.

The application provides a method and a test device suitable for tunnel surrounding rock energy test, wherein the method comprises: performing a loading test on a tunnel surrounding rock test piece, obtaining a stress-strain curve, and determining a mapping relationship between strain and total energy density, elastic strain energy density and plastic dissipation energy density; based on the mapping relationship, a data set is constructed; a strain-energy mapping model is obtained by using a BP neural network; strain characteristic data corresponding to each pixel point in a continuous strain cloud image is input into the trained strain-energy mapping model, and corresponding total energy density values, elastic strain energy density values and plastic dissipation energy density values are output pixel by pixel by the model and are respectively mapped into color values to generate a total strain energy density cloud image, an elastic strain energy density cloud image and a plastic dissipation energy density cloud image. By combining the digital image correlation technology with the strain-energy mapping model, the full-field strain cloud image is converted into an energy cloud image, and direct test support is provided for the energy theory.