56 results about "Full field strain" patented technology

The invention provides a three-dimensional deformation measuring method of a non-contact wind power blade whole field. The three-dimensional deformation measuring method of the non-contact wind power blade whole field comprises spraying black and white lusterless paint on the surface of a wind power blade to be measured to form into random scattering spots; performing partition on the whole surface of the wind power blade, calculating three dimensional coordinates of every point of the wind power blade before deformation and calculating three dimensional coordinates of the whole wind power blade under an overall coordination system; and calculating three dimensional displacement of the wind power blade whole field according to differential values of the wind power blade before and after the deformation to obtain a strain value of the wind power blade whole field further. The three-dimensional deformation measuring method of the non-contact wind power blade whole field has the advantages of being whole-field, non-contact and three-dimensional, being capable of obtaining the three dimensional displacement and the strain of the wind power plant whole filed, solving the difficulties and overcoming the disadvantages of contact measuring method and providing technical support for research of wind power blade damage mechanism.

A sensor for visualizing stress includes a medium and a plurality of mechanoluminescence assemblies dispersed therein. A mechanoluminescence assembly can include a mechanoluminescence material and a coating material, where the mechanoluminescence material is at least partially coated with the coating material. A method of using the sensor can include applying the medium to a substrate and allowing the medium to form a solid film on the substrate. Methods of using the mechanoluminescence assemblies are also provided.

The invention discloses a three-dimensional grid strain measurement method, which comprises the following steps of: step 1, grid preparation; step 2, sampling and shooting; step 3, picture orientation; step 4, grid node matching; step 5, grid node rebuilding; step 6, grid connection, step 7, grid optimization; and step 8, strain calculation. Through the operation steps, the method can be used for measuring the three-dimensional full field strain information in the metal plate material forming process, and the metal plate material forming performance and the advantages and disadvantages of the mold process design scheme can be evaluated, so the metal plate material forming quality is improved, the manufacture precision is improved, and the production cost is reduced. The three-dimensional grid strain measurement method has the characteristics that the measurement operation is convenient, the automation degree is high, the result is accurate and reliable, the measurement information is rich, the efficiency is high, and in addition, the non-contact measurement is realized.

The invention, which belongs to the technical field of test measurement of a helicopter, relates to a method for measuring a motion parameter of a large-size rotor wing. Motion track image data of a large-size rotor blade in high-speed rotation are collected at different azimuthal angles by a calibrated multi-camera motion attitude video measurement and dynamic characteristic analyzer; after calculation, three-dimensional coordinates of the rotor blade at different azimuthal angles are reconstructed; and then according to definitions of all motion parameters, all motion parameters of the bladeare calculated. According to the method provided by the invention, with the employed feature marking point generation plan and process, defects of marking point shedding, low image definition, and poor measuring effect and the like during the high-speed rotation of the large-size rotor blade are overcome. And the full-field strain of the large-size blade can be measured effectively; measurement becomes flexible; and on-line measurement of the motion parameter of the rotor blade is realized.

The invention discloses a thermal fatigue testing system for a ceramic-based composite material structural part. The system comprises a thermal radiation part and a high-frequency sensitive heating furnace, wherein the high-frequency sensitive heating furnace comprises a sensitive heating copper tube which is arranged around the thermal radiation part, an industrial cooling water machine, an air compressor, a PLC (Programmed Logic Controller), a temperature measuring device and a full-field strain gauge. By adopting the technical scheme of the invention, the ceramic-based composite material structural part is indirectly heated through high-frequency sensitivity, and the heating speed, the heat-preservation temperature and the cooling time of the testing process are automatically controlled.

The invention discloses an ultraviolet illumination DIC (digital image correction)-based mechanical property loading measuring system and method for a high-temperature material. The measuring system is characterized by comprising the following steps: projecting an ultraviolet light source on the surface of a to-be-measured sample which is in a set temperature environment and in a set loaded state; and collecting images of the surface of the to-be-measured sample by using an ultraviolet sensitive image collection module to acquire collection images on the surface of the to-be-measured sample, corresponding to different temperatures, moments and loading forces, and carrying out DIC image processing on the collected images to acquire full-field thermal deformation information of the surface of the to-be-measured sample. The system and the method disclosed by the invention can be used for effectively achieving the non-contacted measurement of full-field strain of the material with the temperature being over 1000 DEG C.

The invention provides a combined tension-torsion multi-axis fracture experimental system. The experimental system comprises a dynamic tension-torsion testing machine and a control device connected with the dynamic tension-torsion testing machine. The dynamic tension-torsion testing machine has an upper chuck, a lower chuck and a force sensor, and is clamped with a sample through the upper chuck and the lower chuck. The sample is a thin-walled tube with a notch, and is provided with a speckle. A deformation measurement system comprises a non-contact three-dimensional strain optical measurementsystem connected with the control device through a synchronous trigger device which comprises two cameras connected with the synchronous trigger device and an image acquisition and data processing device connected with the two cameras respectively. The invention also provides a combined tension-torsion multi-axis fracture experimental method. The invention adopts a sample of a thin-walled tube with a notch, which can obtain a low-stress triaxial level and different Rhodes parameter levels by changing different combined tension-torsion loading ratios. In addition, since the experimental systemcomprises a non-contact three-dimensional strain optical measurement system, measurement of full field strain can be achieved.

The invention discloses a non-contact experimental method for measuring a heat constant of a high-temperature material, and belongs to the technical field of experimental mechanics and high-temperature test. An elastic modulus, a poisson ratio and a thermal expansion coefficient of the material under a high temperature are measured by combining a high-temperature digital speckle technology, a three-point bending technology and a virtual field technology. By the method, a charge coupled device (CCD) is used for recording speckle maps of a three-point bent test sample before and after thermal load; a full-field strain before and after the thermal load is calculated by a digital speckle method; the elastic modulus, the poisson ratio and the thermal expansion coefficient of the material under high temperature are calculated; and the elastic modulus, the poisson ratio and the thermal expansion coefficient of the material under high temperature can be measured at the same time.

The invention discloses a method for determining a rock crack stress threshold value based on full-field strain measurement. The method comprises the following steps: manufacturing a rock sample; performing speckle treatment on the surface of the rock sample; carrying out test loading and collecting an image of a speckle surface of the rock sample in the test loading process; calculating the full-field displacement of the speckle surface of the rock sample; calculating the full-field strain of the speckle surface of the rock sample; calculating a volume strain, an elastic volume strain and a crack volume strain of the rock sample; acquiring a rock sample volume strain-axial strain curve, a crack volume strain-axial strain curve and an axial stress-axial strain curve, and drawing the curvesin the same subgraph; and determining changing rules of the volume strain of the rock sample and the crack volume strain and determining threshold values of the four crack stresses including the crack closing stress, the crack initiation stress, the crack damage stress and the peak stress of the rock sample. The method has the advantages of low requirement on test environment, more convenience inapplication, high result reliability, and higher representativeness and universality.

The invention discloses a seismic oscillation simulation testing machine for macroscopic and microscopic damage joint tracking of rock mass and a method thereof. The testing machine provided by the invention is suitable for real-time tracking measurement of macroscopic deformation and microscopic damage under the action of different seismic oscillations. The testing machine comprises an MTS vertical press machine, a door-type supporting frame, a vertical pressure-bearing platform, a rigid working platform, a rigid indenter, an MTS lateral press machine, a sealed anti-radiation test chamber, a test chamber supporting rod, a macroscopic optical camera, a microscopic optical camera, a CT scanning machine, a strong spotlight, a locating rod, a data processor, a terminal server and several lines. Under the action of different seismic oscillations, full-field strain measurement of rock mass in different scales can be realized, thus providing laboratory testing technical support for determination of macroscopic and microscopic mechanical parameters and identification of dynamic damage of rock mass.

The invention relates to a welding strain measurement system and method based on a three-dimensional digital image correlation method. The system comprises a first camera and a second camera which arerespectively mounted at two ends of a support holder in a translational manner, wherein a dimmer and a filter are respectively arranged in front of imaging lenses of the first camera and the second camera, a laser light source is arranged on the support holder between the first camera and the second camera, the first camera, the second camera and the laser light source are respectively connectedwith a control box, and the first camera and the second camera are respectively connected with a computer. Compared with the prior art, a digital image correlation method and a binocular stereoscopicvision technology are combined, full-field three-dimensional strain measurement is carried out in the welding process, the system can meet the requirements for welding three-dimensional full-field strain non-contact and high-precision measurement, and compared with a traditional method, the method has the advantages of being high in measurement precision, convenient to use, simple and compact in system structure and the like.

The invention provides a composite material elastic property variability identification method based on strain full-field measurement. The method is combined with a finite element for inverse problem analysis, and full-field strain information is obtained in an experiment; a strain field is divided into a limited number of subareas, and average strain information is obtained; then the initial material property of each subarea is obtained; a simulation model of a sample test experiment is built; the material properties obtained from last time of calculation are substituted into the simulation model, and new subarea material elastic properties are calculated through iteration till iteration meets a convergence criterion; the material property of each subarea serves as a sample, a statistical parameter mean value and a standard deviation for representing material property discreteness are calculated, multiple material properties are obtained through one time of experiment, and accordingly composite material variability identification is achieved. The method can reduce experiment cost and is low in requirement of test and simulation means.

The invention discloses a dynamic strain measurement method for drawing mechanical property tests of a film material. The method comprises the following steps: rectangular grid drawing; camera positioning; shooting sampling; extraction of grid nodes; calculation of 3D coordinates of the nodes and reconstruction of grid point cloud; division of a triangular unit; calculation of side length of the triangular unit; strain calculation. According to the operation steps, dynamic full-field strain distribution information of the film material in uniaxial drawing and biaxial drawing mechanical property tests can be measured, deformation rules of the film material can be obtained precisely, mechanical properties of the film material can be mastered accurately, important material parameters are provided for design and analysis of a film structure, and design precision and use safety of the film structure are guaranteed. The dynamic strain measurement method has the advantages of being non-contact, non-damage, simple to operate, high in automation degree, efficiency and measurement precision, low in cost and the like.

A method for measuring corrosion-expansion force during cracking of concrete due to corrosion and expansion of reinforcing steel; wherein, deformation on a surface of reinforced concrete is photographed based on a digital image correlation (DIC) method, a full-field displacement and a full-field strain on a surface of the concrete are analyzed and calculated, a relationship between corrosion-expansion force and the strain on the surface of the concrete is found through an established theoretical model, and corrosion-expansion force of reinforcing steel and a change rule of the corrosion-expansion force are calculated. Therefore, the method is simple and includes with safe and reliable operations, scientific principles, and low costs, so that a change in corrosion-expansion force during corrosion and expansion of reinforced concrete can be monitored in real time.

The invention relates to a method for measuring the strain of the connecting piece of a pull rod linkage mechanism. The method captures a sensed image of a connection position by using double cameras, may measure the strain gradient of the curved connecting piece, and comprises a step 1 of establishing a non-contact measurement coordinate system; a step 2 of discretizing a curved structure to be measured in order to divide the curved structure to be measured into a plurality of area units, observing the area units by using the double cameras at two different points of sight in order to obtain the sensed images, and obtaining the 3D morphological information of the surface of an object by computing and analyzing the parallax of the area units in different sensed images; a step 3 of computing the spatial positions, in the measurement coordinate system, of measuring points in the curved surface to be measured; and a step 4 of performing subarea point-by-point fitting on a displacement field by using a fitting process to obtain full-field strain. The method for measuring the strain of the connecting piece of a pull rod linkage mechanism overcomes the defects of a conventional strain gage measurement method, shortens a development period, and reduces development cost.

The invention provides a strain field reconstruction visualization method and system based on load strain linear superposition. The method comprises the following steps: acquiring beam parameter data and beam surface strain data; obtaining a full-field strain value according to the obtained data, and mapping the full-field strain value to a unit grid node of the beam finite element model, wherein the calculation of the full-field strain value comprises the following steps: obtaining a strain response column vector according to the surface strain data of the cross beam; obtaining a strain response matrix of finite element nodes and a structural full-field strain response matrix according to the obtained beam parameter data; obtaining a strain weight according to the strain response column vector and the strain response matrix of the finite element node; and obtaining a full-field strain value under the static load working condition according to the full-field strain response matrix and the strain weight. According to the method, a load and strain reconstruction model is established by extracting mechanical parameters such as strain on the basis of an elastic mechanics principle by applying a linear superposition means, and accurate reconstruction of the cross beam structure is realized.

The invention discloses a dynamic loading platform for an in-vitro knee joint, and an application method thereof. The dynamic loading platform comprises an experiment table, a mechanical arm system, amotion capture system, a non-contact full-field strain measurement system and an industrial personal computer; the motion capture system establishes a three-dimensional space coordinate system of a knee joint sample by setting mark points, and acquires space position data of the mark points in real time when the knee joint sample performs continuous functional motion; the non-contact full-field strain measurement system obtains displacement data and strain distribution of speckles on the surface of a knee joint sample by using a digital image correlation technology based on a binocular visionprinciple; MATLAB software is arranged in the industrial personal computer, and the tail end of a mechanical arm is controlled to drive the knee joint sample to perform functional action; spatial position data of the mark points are received, and a stability evaluation report of the knee joint sample is obtained; and speckle displacement data are received, and a strain analysis report is obtainedthrough a digital image related technology. According to the invention, mechanical test and motion function test requirements are met, the experiment time cost and learning cost are reduced, and theexperiment efficiency is improved.

The invention provides a strain impulse response covariance damage identification method based on DIC technology. The method comprises the following steps: constructing an analysis object experiment system, and acquiring a plurality of deformation process images before and after structural damages; processing the images, acquiring the displacement field of a to-be-measured surface of a component,and obtaining corners of the two ends of the unit through cubic polynomial fitting; calculating a unit strain response to obtain a strain unit impulse response function, thereby obtaining a unit strain unit impulse response covariance; and judging the variation value of the unit strain unit impulse response covariance to complete the damage condition identification of the component. According to the strain impulse response covariance damage identification method based on DIC technology, the DIC technology and the strain impulse response covariance identification method are combined, so that full field strain response information of the structure can be obtained, the identification speed is accelerated, and the identification precision is improved when the method is applied to an actual engineering.

The invention discloses a rapid testing technology for an internal deformation field of a lithium ion battery structure. According to the rapid testing technology for the internal deformation field ofthe lithium ion battery structure, firstly, an electrode sheet is obtained by coating a sizing agent on a positive and negative anode current collector; then, micron size internal marking points areadded to the surface of the electrode sheet after first coating is carried out; second coating of the sizing agent is carried out on the two surfaces of the electrode sheet, and then the prepared electrode sheet with the internal marking points is made into a lithium ion battery; then, by adjusting parameters of a CT imaging system, the exposure time of single projection is shortened as far as possible under the better voxel characteristic contrast of the internal marking points, and fast imaging is achieved; and combining a digital volume correlation internal deformation measurement method, the internal three-dimensional full-field displacement and full-field strain of the lithium ion battery are obtained. The rapid testing technology for the internal deformation field of the lithium ionbattery structure is used for solving the problem of in-situ rapid measurement of the internal deformation field of the lithium ion battery in different charging and discharging stages and in the multi-cycle cyclic process. Compared with the prior art, the exposure time of the single projection and the CT imaging time are shortened, and the radiation damage is greatly reduced.

The invention discloses a non-contact underwater full-field strain measurement method. The method includes the steps that firstly, a speckle pattern is designed through MATLAB or Adobe Photoshop CS, and the speckle pattern is printed on a water transfer printing paper pattern; secondly, the speckle pattern is transferred to the surface of a to-be-measured object through the water transfer printing paper pattern; thirdly, speckle images generated before and after deformation of an underwater object are shot through an underwater camera shooting system; finally, a computer is used for processing the speckle images through digital speckle software, and a full-field deformation diagram of the underwater object is obtained. Full-field strain of the underwater object can be obtained without making contact with the underwater object; the designed underwater speckle pattern is transferred to the surface of the to-be-measured object, so that testing is more convenient and cheaper, and the method can be widely applied to underwater mechanical experiments and online strain monitoring in the fields of underwater aircrafts, underwater concrete and the like.

The invention discloses a method, a system and a device for detecting an anisotropic elastic constant of a material, and a storage medium. The method comprises the steps of obtaining deformation displacement and strain information of the material through the full-field strain measurement technology, establishing multiple groups of different virtual fields based on a characteristic function virtualfield method, and analyzing the deformation displacement and the strain information based on the virtual fields to finally detect the anisotropic elastic constant of the material. The system comprises a measurement module, an obtaining module, a detection module, a processing module and a display module. The device comprises a memory for storing programs, and a processor for loading the programsto perform the method. By using the method disclosed by the invention, multiple mechanical parameters of the material can be obtained at one time, thereby greatly reducing the input of the cost of a mechanical test of the material, and improving the analysis working efficiency of the material by workers. The method, the system and the device disclosed by the invention can be widely applied to thetechnical field of material detection.

The invention discloses a ridge regression strain measurement method with an initial value in digital image correlation, and belongs to the fields of experimental mechanics, non-contact full-field strain measurement and digital image correlation, and the method comprises the steps: firstly, building a digital image correlation measurement system, and obtaining digital images before and after deformation of a test piece; dividing grid units and nodes of the image, selecting feature points in the units, and obtaining displacement and strain of the feature points through a digital image correlation method; calculating the average value of the strain of each feature point in the unit; selecting a displacement function type in the unit, performing ridge regression on the displacement field in the unit by taking the strain average value as an initial value, and fitting to obtain the displacement field in the unit; and interpolating the strain of each unit to obtain full-field strain. According to the invention, the strain measurement precision and robustness of a digital image correlation method can be improved.

The present invention relates to a test system for determination of visible light light-cured resin full-field strain. The system comprises an image generation module, an image collection module and an image analysis module; the image generation module comprises visual light, a support and a digital micro-mirror chip, a planar reflector, a focusing lens and a resin slide which are installed on thesupport in order from bottom to top, and the visual light horizontally illuminates the planar reflector; the image collection module comprises a support rack, an industrial camera clamping device installed on the support rack and an industrial camera clamped on the industrial camera clamping device; and the image analysis module is a computer based on Ncorr software, wherein the industrial camerais located above the resin slide, and the digital micro-mirror chip is electrically connected with the computer. The test system is simple in structure, and can accurately achieve non-contact measurement of the full-field strain of the light-cured resin in the light curing process in real time. The present invention further provides a test system for determination of visible light light-cured resin full-field strain, belonging to the technical field of test measurement material parameters.

The present disclosure relates to a method for measuring full-field strain of an ultra-high temperature (UHT) object based on a digital image correlation method. The temperature range is from normal temperature to 3500 degrees Celsius. The method includes the steps of selecting a proper high-temperature-resistant speckle material, tantalum carbide powder, according to the characteristics of the object to be measured. First, polishing a to-be-measured surface of a tungsten test piece to remove an oxide layer, then mixing the tantalum carbide (TaC) powder and absolute ethanol to form a paste according to a mass ratio of 1:2. Making randomly distributed speckles from the mixture on the to-be-measured surface of the test piece which has been processed. In order to improve firmness and stability of the newly made speckles, performing curing treatment to the speckles.