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226 results about "Displacement field" patented technology

A displacement field is an assignment of displacement vectors for all points in a region or body that is displaced from one state to another. A displacement vector specifies the position of a point or a particle in reference to an origin or to a previous position. For example, a displacement field may be used to describe the effects of deformation on a solid body.

Prefabricated structural surface concrete single-hole blasting test device and test method

The invention provides a prefabricated structural surface concrete single-hole blasting test device and test method. The test method comprises the following steps: preparing a concrete test piece by using a similar material, drilling a hole in the concrete test piece to form a blasting hole, prefabricating a structural surface on the concrete test piece, and putting an energy release head of a CO2phase change cracker into the blasting hole; applying radial pressure and axial pressure to the concrete test piece; arranging strain monitoring points at the end parts of the structural surfaces; connecting the high-speed digital camera synchronously with the exploder, triggering shooting at the same time and continuously collecting image information of the surface of the concrete test piece inthe blasting process; and recording a displacement field and a strain field on the surface of the concrete test piece in the observation area by using a digital image correlation method. The technical scheme provided by the invention has the beneficial effects that the crack propagation behavior of the concrete of the prefabricated structural surface for SC-CO2 phase change gas-action and the change characteristics of the displacement field and the strain field of the moving crack can be obtained, and the crack propagation rule of the concrete of the prefabricated structural surface for SC-CO2 phase change gas-action is disclosed.
Owner:CCCC SECOND HIGHWAY CONSULTANTS CO LTD

Soil landslide monitoring, early warning and evaluating method

ActiveCN111259605AFlexible and diverse monitoring meansAccurately reflect the actual stateDesign optimisation/simulationNeural architecturesSoil scienceLandslide
The invention discloses a soil landslide monitoring, early warning and evaluating method which comprises the following steps: S1, acquiring landslide topography and geological data to be monitored, and acquiring a rock-soil parameter test value through an indoor test; S2, establishing a landslide geologic model, carrying out limit analysis, determining a landslide damage mode and carrying out landslide monitoring; S3, uniformly designing parameter combinations for the rock-soil parameter test values, performing finite element calculation on all the parameter combinations to obtain a displacement field calculated by each parameter combination, and recording the displacement of each monitoring point to obtain a 'parameter combination-displacement' neural network model; S4, according to the landslide real-time cumulative displacement monitoring data and the parameter combination-displacement neural network model, performing rock-soil parameter inversion correction, obtaining rock-soil real-time strength parameters, and performing precision inspection; and S5, performing limit analysis by adopting real-time strength parameters, establishing a 'real-time cumulative displacement-safety coefficient' relation curve, establishing a landslide monitoring three-level early warning grade evaluation system, and evaluating the monitored landslide.
Owner:CHINA RAILWAY ERYUAN ENG GRP CO LTD

Rapid evaluation method for two-dimensional temperature and strength of turbine air cooling blade

The invention belongs to the field of aero-engines, and particularly relates to a rapid evaluation method for two-dimensional temperature and strength of a turbine air cooling blade. The method comprises the steps: 1, acquiring the two-dimensional section of the turbine air cooling blade; 2, constructing a finite element model with a two-dimensional cross section, and performing mesh generation onthe finite element model to obtain node data of meshes; 3, obtaining the material parameters and temperature field calculation boundary conditions of the turbine air cooling blade, calculating the temperature value of each node of the grid, and acquiring the temperature field of the turbine air cooling blade; 4, enabling the temperature field of the turbine air cooling blade to be equivalent to athermal load, applying the thermal load and a preset pressure load to the finite element model at the same time, calculating the displacement value and the stress value of each node of the grid, andacquiring the displacement field and the stress field of the turbine air cooling blade; and adopting the same set of grids in calculation of the temperature field, the displacement field and the stress field. According to the method, the calculation efficiency and the calculation convenience can be improved on the basis of ensuring the calculation accuracy.
Owner:AECC SHENYANG ENGINE RES INST +1

Circular tunnel mechanical calculation method considering interaction between surrounding rock and a supporting structure

ActiveCN109657358AObjectively reflect the deformationObjectively reflect the characteristicsGeometric CADSustainable transportationPrincipal stressMechanical models
The invention relates to a circular tunnel mechanical calculation method considering the interaction between surrounding rock and a supporting structure. The method comprises the following steps that1, establishing a circular tunnel mechanical model; 2, selecting a rock strength criterion: selecting a Dryer-Prager (D-P) criterion in place of Mohr-Culomb (M-C) criterion to consider the influence of the middle main stress; Thirdly, analyzing a surrounding rock secondary stress field and a displacement field caused by tunnel excavation on the basis of an elastic-plastic theory; Fourthly, considering the cubic stress field and displacement field of the surrounding rock considering the interaction of the surrounding rock and the supporting structure, wherein the rigidity of the supporting structure and the timing of the supporting structure are used to reflect the surrounding rock support in the calculation of the supporting force of the supporting structure; The interaction of the structure, and then its influence on the plastic zone of the surrounding rock and the stress field and displacement field. The calculation method comprehensively considers the influence of three factors, such as the intermediate principal stress, the stiffness of the supporting structure and the timing of the application, on the displacement and plastic zone of the surrounding rock of the circular tunnel, which makes the calculation result more in line with the actual situation.
Owner:CHINA UNIV OF GEOSCIENCES (BEIJING)

Deformation and displacement measurement method in model test based on image processing

The invention provides a deformation and displacement measurement method in a model test based on image processing. The method comprises the following steps of: dotting and marking an area, needing deformation and displacement measurement, of a measured model in a model test; meanwhile, arranging a calibration plate in a test scene; shooting pictures, and carrying out distortion correction and perspective transformation on the shot pictures successively to obtain perspective-transformed images; carrying out feature point detection on the perspective-transformed images; performing feature pointmatching on the same mark point by using the perspective-transformed images acquired at two different time points to obtain a plurality of feature point pairs; calculating the displacement of the mark point in the period of time; and calculating a dynamic displacement field or a deformation field of the measured plane area through the displacement combination of all mark points. The problems thatin the prior art, the surface of a measured model needs to have large roughness, irreversible treatment such as speckle spraying needs to be conducted on the surface, a fixed datum point needs to beset, the measurement principle is complex, and measurement equipment and an operation system are expensive are solved.
Owner:CENT SOUTH UNIV

Similar model displacement field measuring system and method based on grid dot matrix

The invention relates to a similar model displacement field measuring system which comprises a grid dot matrix, an image collection device and a computer, wherein the grid dot matrix is arranged on the surface of a similar model, the image collection device is composed of a video camera array or a single video camera with accurate and controllable poses, the computer is used for processing data, and identity codes composed of symbols such as numbers and letters are marked on grid dots. On the basis of the measuring system, the invention further relates to a measuring method. The measuring method comprises the steps of obtaining images of the surface of the similar model in a regionally-collecting mode; extracting the grid dots with the geometrical shapes of the grid dots as characteristics; using the geometrical center of each grid dot as a coordinate of each grid dot; utilizing a pose relation relative to a video camera coordinate system of a measuring coordinate system for converting the coordinates of the grid dots into a uniform coordinate system; recognizing the identity codes inside the areas of the grid dots, and conducting matching on the grid dots on the basis of the identity codes; obtaining a displacement field of the similar model by comparing changes of the coordinates of the grid dots in the measuring coordinate system.
Owner:CHINA UNIV OF MINING & TECH (BEIJING)

Method for measuring plastic strain ratio in metal tensile test process

ActiveCN110779797AReliable Plastic Strain RatioQuick calculation of plastic strain ratioMaterial strength using tensile/compressive forcesContact modeMaterials science
The invention relates to a method for measuring a plastic strain ratio in a metal tensile test process. The method comprises the following steps: arranging speckle points in a scale distance area on the surface of a metal sample to prepare a to-be-measured tensile sample; performing a tensile test on the tensile sample to obtain an image in an initial state as a first image and an image in a uniform plastic deformation stage as a second image; performing correlation matching on gray fields of the first image and the second image to obtain displacement fields of all pixel points of the first image; performing differential calculation on the displacement field to obtain displacement fields of all pixel points of the first image; carrying out differential calculation on the displacement fields to obtain real plastic strains in length and width directions in the scale distance area; and acquiring a plastic strain ratio of the metal sample according to the principle of volume constancy in the stretching process. The method has advantages of having a non-contact mode, low influence on the mechanical performance of the sample, high precision, and reliable result and the like; and a novelconcept and way are provide for accurately measuring the plastic strain ratio (r value) in the metal tensile test process.
Owner:NANJING UNIV OF AERONAUTICS & ASTRONAUTICS

Test device and method for simulating dynamic influence of rainfall on karst tunnel seepage

The invention relates to the field of tunnel seepage model tests and discloses a test device for simulating the dynamic influence of rainfall on karst tunnel seepage. The device comprises a test modelbox device used for simulating a karst area and an internal tunnel of the karst area and is positioned above the test model box device; a rainfall device used for simulating rainfall, a non-contact full-displacement field measuring device used for shooting the test model box device and recording a seepage path, the upper part of the test model box device is connected with the simulated terrain, the simulated terrain is positioned below the rainfall device, and the boundary of the simulated terrain is matched with the boundary above the test model box device. The device is beneficial to improving the accuracy of the model test. The invention further comprises a test method of the device. The test method specifically comprises the following steps: topographic data extraction; determining test parameters; manufacturing a test model; installing a test device; stratum, tunnel and terrain simulation; adding a coloring agent; water level simulation; rainfall simulation; dynamic collection oftest data. The method can obtain the seepage path of the seepage field.
Owner:CENT SOUTH UNIV

Molten iron flow velocity detection device based on polarization characteristics

ActiveCN111413516ASolve the technical problem of low flow rate detection accuracyEasy to installDigital video signal modificationFluid speed measurementEngineeringMechanical engineering
The invention discloses a molten iron flow velocity detection device based on polarization characteristics. The device comprises a high-speed camera video capture unit; a video acquisition unit, a video preprocessing unit, an extremely highlight characteristic displacement field calculation unit and a molten iron flow velocity detection unit which are sequentially connected with the high-speed camera video capture unit; the video preprocessing unit extracts the extremely highlight features of frame images in the frame image group. The extremely highlight characteristic displacement field calculation unit is used for obtaining a sub-pixel-level displacement field according to extremely high light characteristics. The molten iron flow velocity detection unit is used for obtaining flow rate of molten iron flow according to the sub-pixel-level displacement field, thereby solving the technical problem that the existing detection precision of the flow velocity of the molten iron flow with high temperature, high speed and high light is not high. The invention provides the molten iron flow velocity detection device which can detect the flow velocity of the ultrahigh-temperature, high-speedand high-light molten iron in a severe detection environment, and the molten iron flow velocity detection device is convenient to install and simple and flexible to operate, can adapt to a more severe environment, and has a wide application range of detection objects.
Owner:CENT SOUTH UNIV +1

Multi-parameter synchronous measurement method, device and system

The invention relates to a multi-parameter synchronous measurement method, device and system. The method comprises the following steps: obtaining an initial image of the surface of a measured object when the surface of the measured object is not heated, an examination image of the surface of the measured object in the heating process and a reference temperature of a reference point of the surface of the measured object in the heating process; determining the light intensity of each channel of the initial image and the assessment image; determining a temperature field of the surface of the measured object; determining an out-of-plane displacement field of the surface of the measured object; and determining a deformation field of the surface of the measured object according to the light intensity of the blue light channel of the initial image and the light intensity of the blue light channel of the examination image. According to the multi-parameter synchronous measurement method provided by the embodiment of the invention, the problems of error increase and incapability of measuring out-of-plane displacement easily caused by channel crosstalk of an existing multi-channel camera are eliminated, synchronous and accurate measurement of a deformation field, a temperature field and an out-of-plane displacement field of a measured object in a high-temperature environment is realized, and the method has the characteristics of high precision and high efficiency.
Owner:TSINGHUA UNIV

Multi-component layout topological optimization method based on parameterized color level set

ActiveCN111460622AEasy to describe topologicallyCalculate Density FieldDesign optimisation/simulationAlgorithmElement analysis
The invention belongs to the related technical field of multi-component layout topological optimization design, and discloses a multi-component layout topological optimization method based on a parameterized color level set, which comprises the following steps: (1) constructing a level set function of each component, and integrating all the components into one level set function; (2) determining amaterial topology model of a matrix, a component and a cavity; (3) interpolating the elastic modulus of the component embedded into the finite grid of the structural design domain with the elastic modulus of the base material in the structural design domain to obtain the equivalent elastic modulus of the structural design material; (4) constructing a minimum flexibility layout optimization modelof the multi-component integrated system, and performing finite element analysis to obtain a displacement field; then, calculating to obtain a target function; afterwards, conducting sensitivity analysis on the design variables, and updating the design variables so as to determine the optimal position of the assembly layout and the optimal distribution of the base material. The number of design variables is reduced, and the calculation efficiency is improved.
Owner:HUAZHONG UNIV OF SCI & TECH

Optical deformation measurement method based on adaptive mesh and electronic equipment

The invention relates to an optical deformation measurement method based on an adaptive mesh and electronic equipment. The measurement method comprises the following steps: acquiring a speckle image containing a region of interest, dividing uniform meshes in the region of interest, and determining an L-shaped curve in which the condition number of a corresponding coefficient matrix changes with the size of a mesh unit; taking the size corresponding to inflection points of the L-shaped curve as a unit size lower limit, taking the same size as an initial upper limit, and dividing uniform meshesin a second region range of the image, the second region including the region of interest; calculating and updating a displacement field according to the uniform meshes divided in the second region; and determining a strain gradient field of the region of interest according to the updated displacement field, determining unit size upper and lower limits according to the strain gradient field, and determining distribution of the unit size through a mapping relationship between strain gradients and unit sizes. According to the measurement method, the mesh size is selected in a self-adaptive mode,so that errors, caused by shape function mismatching, of the large-strain-gradient position and random errors of the small-strain-gradient position are reduced.
Owner:PEKING UNIV

Test method for researching rock wedge instability failure under high stress

The invention provides a test method for researching rock wedge instability failure under high stress. In the test, a uniaxial testing machine is adopted to load a Y-shaped cross combined structure surface test sample; before an experiment, speckle identification points are sprayed on the surface of the sample, point cloud data of two structure surfaces are obtained through scanning, and JRC values of the two structure surfaces are calculated; in a loading process, a surface displacement field and an acoustic emission signal of the Y-shaped cross combined structure surface test sample are monitored to obtain deformation and acoustic emission precursor characteristics of instability failure of the Y-shaped cross combined structure surface test sample; the sample is loaded until the sample is damaged to obtain peak normal stress of the sample; shear stress components of the two structure surfaces are calculated according to the peak normal stress, and comparative analysis is carried outon the shear stress components and the shear strength of the structure surfaces; and multiple groups of tests are repeatedly carried out under different structural surfaces JRC, included angles and loading modes, and the structural surface shear strength, the displacement field and the acoustic emission signal change rules before the rock sample is damaged are inspected, so that the comprehensivecriterion of rock wedge instability damage is established, and reference is provided for rockburst disaster early warning in rock engineering.
Owner:NORTHEASTERN UNIV

Structure test detection method based on three-dimensional laser scanning technology

The invention discloses a structure test detection method based on a three-dimensional laser scanning technology. The structure test detection method comprises the specific steps of placing a test object, selecting and arranging the position and the number of three-dimensional laser scanner observation stations, setting the position and the number of three-dimensional laser scanning target balls,detecting the test object and processing a detection result. The three-dimensional laser scanning technology is applied to the structure test, and the whole process of the structure test is detected and monitored. According to the structure test detection method based on the three-dimensional laser scanning technology, the full-displacement field of the structure can be tested, the full-deformation field of the structure is obtained, and the cracking, failure and damage modes of the structure can be fed back in all directions and in the whole process. According to the structure test detectionmethod provided by the invention, scientific research personnel can be helped to comprehensively master various changes of the structure in the test process, and the accuracy of understanding, analyzing and mastering the mechanical property of the structure can be greatly improved.
Owner:JIANGSU UNIV OF SCI & TECH

Dam mechanical parameter random inversion method and system based on displacement field monitoring data

The invention discloses a dam mechanics parameter random inversion method and system based on displacement field monitoring data. According to the random inversion method, by combining the displacement monitoring data of multiple measuring points in space, parameter random inversion criteria under the first-order perturbation meaning and the second-order perturbation meaning are given, and real displacement and observation errors of a dam can be separated; the random inversion system comprises a database module, a structure information module, a random inversion module and an information display module; the database module is used for collecting and summarizing dam basic information, geographic space information and monitoring information; the structure information module is used for storing geometric model information and finite element model information of engineering; the random inversion module is used for identifying the mean value and the standard deviation of the dam mechanicalparameters; and the information display module has an engineering model display function, a monitoring information browsing function and an inversion evaluation result output function. According to the invention, the real operation state and the observation error of the dam can be identified.
Owner:HOHAI UNIV

Wing structural mechanics high-fidelity order reduction simulation method, electronic equipment and storage medium

ActiveCN112560167ASolve problems that are no longer cyclicalWell formedGeometric CADSustainable transportationElement analysisFinite elemente analyse
The invention provides a wing structure mechanics high-fidelity order reduction simulation method. The method comprises the steps of finite element grid node pairing and rigid body constraint application, non-shear load loading analysis, shear load loading analysis and equivalent section attribute calculation. The invention relates to electronic equipment and a storage medium, which are used for the method. According to the method, the problem that the internal force of the structure does not have periodicity when the slender structure is under the action of the shearing force is well solved,the shearing force condition is corrected by utilizing the mechanical response of the structure unit cells under the action of the bending load, the disturbance displacement field and the surface force are restrained, the form is simple and clear, and the embeddability is good. According to the method, the equivalent section stiffness matrix of the equivalent reduced-order model can be calculatedby simulating deformation of the wing structure unit cells under different loads, so that a reduced-order model unit is provided for finite element analysis of the aircraft wing, and the analysis efficiency of the aircraft wing model is improved.
Owner:BEIHANG UNIV

Anti-slide pile-transparent soil slope system test device based on PIV and close scene photography technology and deformation measurement method

The invention relates to an anti-slide pile-transparent soil slope system test device based on PIV and a close scene photography technology and a deformation measurement method, and belongs to the technical field of geotechnical engineering. The test device comprises an optical vibration isolation system, a model system, a loading system, a traditional measurement system, a PIV measurement systemand a close scene photogrammetry system. The model system and the loading system are arranged above the optical vibration isolation system; and the PIV measurement system is arranged on the side surface of the model system and used for measuring the internal displacement and deformation of a model, and the close scene photogrammetry system is erected on the upper part of the model system and usedfor performing three-dimensional space displacement and deformation measurement of the external slope surface of the model. According to the test device, through the measurement of displacement and deformation field of slice at any position inside and space displacement field of the external slope, the three-dimensional space deformation and displacement field of anti-slide pile-slope system are obtained; test research of all types of pile-soil systems can be realized; and the measurement effect is superior to that of a traditional displacement meter, and meanwhile, only the combination of close range non measurement camera and scale can be used to measure the displacement of the characteristic points on the slope.
Owner:DALIAN UNIV OF TECH

Fairing part and method for forming thin-wall fairing part through selective laser melting

The invention relates to the technical field of preparation of fairing parts, and provides a fairing part and a method for forming a thin-wall fairing part through selective laser melting. The method comprises the steps that data modeling is conducted on the fairing part; a residual stress field and a displacement field of the fairing part are obtained through process simulation, and a supporting structure is added to an area with displacement and stress exceeding certain values; slicing processing is performed to obtain two-dimensional section data information; the two-dimensional section of the part is scanned layer by layer, and selective laser melting forming manufacturing of the fairing part is completed; heat treatment is conducted; and the support is removed and surface treatment is conducted to obtain a finished product. According to the fairing part and the method, the problems that a thin-wall structural part is prone to warping deformation during forming and the support is difficult to remove can be solved; and the additive manufacturing cost can be reduced, the success of the part is ensured, and an effective supporting design method is provided for the thin-wall fairing part.
Owner:BEIJING AERONAUTIC SCI & TECH RES INST OF COMAC +1

Method for predicting dual-scale creep fatigue life of discontinuous structure

PendingCN112966347AAccurate prediction of creep fatigue lifeGeometric CADDesign optimisation/simulationCrystal plasticityElement model
The invention relates to a method for predicting the dual-scale creep fatigue life of a discontinuous structure. The method comprises the following steps: extracting a displacement field of a finite element model of the discontinuous structure; obtaining crystal plasticity model parameters, and establishing a crystal plasticity finite element model at the dangerous position of the discontinuous structure; taking a displacement field of the finite element model of the discontinuous structure as a boundary condition of a crystal plasticity finite element model, and constructing a dual-scale finite element model of the discontinuous structure; acquiring a creep indication factor and a critical value thereof, and a fatigue indication factor and a critical value thereof; and predicting the creep fatigue life of the discontinuous structure. According to the method, the stress condition of the discontinuous structure on the macro scale can be reflected, the damage evolution of the discontinuous structure on the micro scale can be revealed, the dangerous position of creep fatigue crack initiation can be effectively obtained, and therefore the creep fatigue life of the discontinuous structure can be accurately predicted; and theoretical support is provided for premature failure prevention and life extension of the discontinuous structure.
Owner:EAST CHINA UNIV OF SCI & TECH

Non-contact type displacement field measuring method and system for rotating blade

The invention discloses a non-contact type displacement field measuring method and system for a rotating blade. The method comprises the following steps of establishing a three-dimensional finite element model of a rotating blade to be measured, and extracting the modal parameters of the three-dimensional finite element model; determining the number of blade tip timing sensors and the axial mounting positions; constructing a conversion matrix of the limited measuring point displacement and an integral displacement field; and acquiring the limited position displacement of the blade tip of the rotating blade on the basis of the blade tip timing sensors, wherein the position displacement is subjected to the conversion matrix treatment to obtain the displacement field of any time, any positionand any direction of the rotating blade. According to the method provided by the invention, the displacement field of all nodes of the rotating blade is reconstructed by only utilizing the displacement of the finite measuring point at the blade tip in a reversion mode, the vibration measurement of the blade surface and the internal node can be realized, the calculation process is simple, the measurement precision is high, and the online measurement is easy.
Owner:XI AN JIAOTONG UNIV

Additive and subtractive composite manufacturing part deformation prediction and control method and equipment

The invention discloses an additive and subtractive composite manufacturing part deformation prediction and control method and equipment. The method comprises conducting feature recognition and feature decomposition on a target part model, and determining printing parameters; performing finite element thermal coupling analysis of equivalent loading on the model; performing model reversible deformation optimization design according to a simulation result; and determining an optimized final part structure model in an iteration mode. According to the method, a method of combining unit-by-unit activation and Gaussian moving heat source commonly adopted at present is converted into surface heat flow loading of layer-by-layer life and death unit activation in an energy equivalent mode. In the simulation process, birth and death units are used for simulation, all the units are killed firstly, namely, the rigidity is changed into 0, and then the rigidity is activated to be changed into a'birth 'state. Compared with other current life-death unit analog simulation additive manufacturing methods, the method has the advantages that the calculation process can be simplified, the calculation speed can be increased, overall simulation of large parts can be achieved, and an overall temperature field-stress field-displacement field can be obtained quickly.
Owner:XI AN JIAOTONG UNIV +1

Digital image deformation characterization method and device, electronic equipment and medium

The invention discloses a digital image deformation characterization method and device for image quality and deformation gradient regulation, electronic equipment and a medium. The digital image deformation characterization method comprises the following steps: providing speckle images before and after deformation; aiming at the speckle images before and after deformation, determining the minimumsize value of a unit or a sub-region through the change of the Hessian matrix condition number; roughly calculating a displacement field by searching or appointing initial grid or sub-region distribution through an integer pixel according to the minimum size value of the unit or sub-region; according to a displacement field and a tangent vector correlation function C (r) = (t (s) * t (s + r)) min= C0, determining a unit or sub-region size maximum value; and judging whether a convergence condition is satisfied or i is greater than N according to the determined maximum size value of the unit orthe sub-region, i being the number of iterations and N being the number of cycles, and if so, outputting a current displacement field to realize digital image deformation representation of image quality and deformation gradient regulation and control. The method is suitable for complex deformation conditions and image quality, has higher precision and accuracy, and is easy to use.
Owner:PEKING UNIV
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