19 results about "Residual strain" patented technology

The invention discloses a stress detection method and device for a pipeline and a medium, and relates to the technical field of structural health monitoring, and the method comprises the steps: collecting the geometric dimensions and material parameters of the pipeline, building a digital twin model, completing the zero calibration and residual strain baseline setting, and obtaining a parameter baseline set; performing synchronization, noise filtering and restoration on the multi-source observation data by using the parameter baseline set to generate a data frame with a quality mark; the initial calculation stress is obtained based on temperature compensation and residual correction, the initial calculation stress is compared with a digital twin model to recognize the load and disturbance, corrected stress is obtained, the corrected stress and the initial calculation stress are subjected to fusion estimation, and a fusion stress result and uncertainty are output; risk indexes are calculated and graded according to the stress anomaly and the acoustic emission event, residual life and maintenance suggestions are given, and an audit record is formed. According to the invention, synchronization, noise filtering and deletion repairing are carried out on the multi-source observation data based on the parameter baseline set, so that high reliability of stress detection data and improvement of anti-interference capability are realized.

The invention discloses a cross-fault-zone subsea tunnel structure non-uniform deformation identification and positioning method, which comprises the following steps: firstly, acquiring cross-fault-zone subsea tunnel BOTDA strain data, and respectively carrying out abnormal value processing, fitting and tidal residual strain separation on the strain data to obtain strain data with fault zone spatial characteristics; secondly, the strain data of the fault zone and the adjacent non-fault zone are clustered based on a Gaussian mixture model, a clustering strain mean value is extracted, and a strain mean value difference feature vector is constructed; a PSO algorithm is adopted to optimize an RF model to recognize a strain mean value difference time-varying curve, an LDSA algorithm is adopted to generate a high-resolution three-dimensional feature thermodynamic diagram for a non-uniform deformation region, and therefore the non-uniform deformation region is accurately positioned. According to the method, solid data support can be provided for identification, evaluation and disposal of uneven deformation of the tunnel structure, so that a more scientific management and maintenance decision is made, and subway operation safety is effectively guaranteed.

This invention discloses a method, apparatus, and equipment for evaluating the clamping force variation of exhaust manifold mounting bolts, relating to the field of fastener testing technology. The method includes measuring the axial force-strain relationship curves of the exhaust manifold mounting bolts at different temperatures, and the strain elongation of the bolt shank at operating temperature; combining the axial force-strain relationship curves to obtain the axial clamping force of the mounting bolt in the bolted connection at room temperature; measuring the strain elongation of the bolt shank in the bolted connection at operating temperature to obtain the residual strain elongation; and based on the residual strain elongation and the axial force-strain relationship curves, obtaining the residual axial clamping force and comparing it with the axial clamping force of the mounting bolt in the bolted connection at room temperature to evaluate the clamping force variation. This application can accurately reflect the clamping force attenuation of exhaust manifold mounting bolts under actual working conditions, improving the reliability and accuracy of measurement results.

The application discloses a kind of combustion chamber component residual strain measurement method and device, it is related to gas turbine technical field.The method includes: preparing speckle pattern on the surface of combustion chamber component test piece;Reference image is collected before test, and the space pose of image collection module and ambient light parameter are recorded;The thermal test is carried out to test piece;After test, the recorded parameters are strictly reproduced, and deformation image is collected;Based on digital image correlation algorithm, reference image and deformation image are compared and analyzed, and surface residual strain distribution is obtained.The application solves the technical problems that residual strain is difficult to separate and full-field quantitative measurement after thermal test, realizes non-contact, high-precision, repeatable residual strain measurement, and provides key data support for evaluating combustion chamber component life and reliability.

The present application relates to the technical field of tunnel construction, and particularly relates to a pile foundation response test method under a double-line tunnel shield side-penetration working condition. Residual strain is obtained after the first tunneling body passes and rests until the end, and the stiffness attenuation rate at each depth is calculated according to the attenuation linkage ratio; when the second tunneling body passes from the other side, the cumulative axial strain and the cumulative hoop strain are obtained by merging the stiffness attenuation rate as the weight, the real-time axial and hoop strain and the residual strain at each depth, and the cumulative plastic strain, the cumulative settlement and the bottom interface stiffness are calculated accordingly, so that the quantitative characterization of the pile body deformation and the internal force distribution evolution law in the whole double-line construction process is realized.

The invention relates to a preparation method of an ultrahigh-strength martensitic steel EBSD sample, and belongs to the technical field of metallurgical detection. The process comprises the following steps: 1) cutting; 2) grinding and polishing; (3) fine polishing; 4) ion grinding; and 5) detecting. According to the method, through sample preparation optimization, mechanical polishing and ion grinding are combined, so that a clear Kikuchi line pattern can be obtained in any area of martensitic steel, and residual strain and stress caused by surface mechanical sample preparation are removed at subsequent repeated erosion positions in the final stage of mechanical polishing, so that the Kikuchi line pattern can be obtained. The ion grinding time is greatly shortened; and the calibration rate during EBSD sample detection is improved. And the calibration rate of the collected sample reaches 90% or above.

This invention belongs to the field of tumbling finishing technology and aims to solve the problem that current residual stress simulations struggle to simulate workpiece surface material deformation. It provides a method for predicting residual stress in tumbling finishing based on elastoplastic deformation theory, comprising the following steps: equating a blank three-dimensional array to the workpiece's target region; constructing an EDEM simulation model and extracting contact information between the particulate medium and the workpiece; calculating the maximum overlap based on the contact information and dividing the collision into stages; calculating the contact stress distribution corresponding to the overlap at different collision stages; calculating the elastic stress field distribution of the target region at different collision stages based on the contact stress distribution and converting it into elastic loading stress for plastic correction; after loading, calculating the internal stress distribution under the cumulative action of all activated units in the blank three-dimensional array to obtain the residual strain and residual stress of the target region. This invention can simulate the deformation of workpiece surface materials, improving the accuracy of the simulation.

The invention discloses a method and a device for modifying a sensitized metal active material through lossless impact. According to the method, accumulated dislocation and other defects are formed in the high-entropy alloy metal active material through pre-impact, stress concentration is generated, high-pressure and high-temperature hot spots are generated at the stress concentration position in the application process of the material, the hot spots induce the material to have a chemical reaction, and therefore the reaction threshold value of the high-entropy alloy metal active material is reduced. By designing the controllable pre-impact loading device, residual strain and structural damage caused by the fact that sparse waves and reflected waves are transmitted into a sample are avoided, and almost-nondestructive pre-impact modification is achieved.

The application discloses a kind of aluminum alloy surface corrosion process prediction methods considering residual strain, specifically related to the field of aero-engine protection.It includes: obtaining the composition of the oxide film on the surface of aluminum alloy and the corresponding crystal structure under the corrosion environment, extracting the corrosion medium ions, and constructing a surface model; Determine the tensile and compressive strength of the surface model; Build multiple adsorption configurations; According to the tensile and compressive strength, determine the residual strain range; Within the residual strain range, apply tension or compression strain to any adsorption configuration, determine the adsorption energy of the current corrosion medium ions in the adsorption configuration under different strains; Determine the diffusion barrier of the corrosion medium ions in the oxide film under different strains; Determine the adsorption energy-diffusion barrier ratio of the corrosion medium ions in the adsorption configuration under each strain; According to the adsorption energy-diffusion barrier ratio under each strain, predict the corrosion process of the aluminum alloy surface. Through the above method, the corrosion behavior under complex working conditions can be accurately predicted.

This invention relates to a method for calculating rock fatigue damage under constant amplitude increasing average stress, comprising the following steps: designing loading parameters and calculating rock fatigue damage variables defined by residual strain; establishing a nonlinear fatigue damage evolution model for constant amplitude and continuously increasing average stress; fitting the data of rock fatigue damage variables defined by residual strain as a function of the number of cycles to the nonlinear fatigue damage evolution model to obtain coefficients; fitting each coefficient to the loading parameters to obtain the relationship between each coefficient and the loading parameters; substituting the relationship of the loading parameters into the nonlinear fatigue damage evolution model to obtain a fatigue damage evolution model of lithological rock under cyclic loading with a constant amplitude linearly increasing average stress, calculating rock fatigue damage under constant amplitude increasing average stress, and predicting the evolution characteristics of rock fatigue damage. This invention can reduce the number of cyclic loading experiments and the cost, and can accurately describe the evolution of rock damage variables.

The invention relates to the technical field of real-time monitoring of engine structures, and discloses a solid propellant grain solidification residual strain-stress embedded monitoring method, which comprises the following steps: grain structure solidification simulation analysis; on the basis of a grain structure curing simulation analysis result, curing residual stress is determined, the position of a measuring point where a flexible strain gauge is embedded is determined, and then an online in-situ monitoring network is arranged; a flexible strain gauge is implanted in the determined measuring point position, and packaging is completed; processing bridging and lead wires of the flexible strain gauge test network, and fixing a connection tool required by the test; testing network signals and setting a co-located temperature compensation sensor; pouring and curing the grain structure, and carrying out grain residual strain in-situ online monitoring in the synchronous curing process; after solidification of the grain structure is completed, strain test data are extracted, and corresponding solidification residual stress is obtained. The device can accurately monitor the locally concentrated curing residual stress of the solid propellant grain in situ under the high-temperature and high-pressure environment of grain curing.

The invention belongs to the technical field of barreling finishing machining, and aims to solve the problem that deformation of a workpiece surface material is difficult to simulate by current residual stress simulation. The invention provides a barreling finishing residual stress prediction method based on an elasticoplastic deformation theory. The method comprises the following steps: enabling a blank three-dimensional array to be equivalent to a to-be-predicted area of a workpiece; constructing an EDEM simulation model, and extracting contact information between the granular medium and the workpiece; calculating a collision maximum overlap amount based on the contact information, and dividing collision stages; calculating contact stress distribution corresponding to the overlapping amount in different collision stages; calculating elastic stress field distribution of the to-be-predicted areas in different collision stages based on the contact stress distribution, converting the elastic stress field distribution into elastic loading stress, and performing plastic correction; after loading is completed, internal stress distribution of all activated units in the blank three-dimensional array under the accumulation effect is calculated, and residual strain and residual stress of the to-be-predicted area are obtained. The deformation condition of the workpiece surface material can be simulated, and the simulation accuracy is improved.

This invention belongs to the field of facility monitoring technology, specifically relating to a method and system for health monitoring of highway infrastructure based on an intelligent sensing network. The method includes: real-time acquisition and preprocessing of raw strain field and temperature field data of highway infrastructure using pre-embedded sensors to obtain a stable strain field sequence and a stable temperature field sequence; separation of low-frequency periodic components caused by environmental temperature fluctuations from the stable temperature field sequence, combined with the stable strain field sequence to obtain a temperature-compensated strain field sequence; separation of the reference drift component from the temperature-compensated strain field sequence, and elimination of vehicle load influence factors to obtain a residual strain field sequence; obtaining a set of abnormal deviation points based on the residual strain field sequence; and obtaining the location and degree of damage based on the set of abnormal deviation points. This invention can automatically complete damage identification and safety level assessment of highway infrastructure.

The present application relates to engine structure real-time monitoring technical field, disclose a kind of solid propellant grain curing residual strain-stress embedded monitoring method, comprising the following steps: grain structure curing simulation analysis;Based on the grain structure curing simulation analysis result, determine the curing residual stress, and determine the measuring point position of flexible strain gauge embedding, and then layout online in-situ monitoring network;Flexible strain gauge is implanted in the measuring point position determined, and packaging is completed;Bridge and lead wire of flexible strain gauge test network are handled, and the connecting tooling required for testing is fixed;Test network signal is verified and co-site temperature compensation sensor is set;Grain structure casting and curing are carried out, and the residual strain in-situ online monitoring of grain during synchronous curing process is carried out;Grain structure curing is completed, strain test data is extracted, and corresponding curing residual stress is obtained.Can accurately monitor the local concentrated curing residual stress of solid propellant grain in-situ under the high temperature and high pressure environment of grain curing.

This invention relates to the field of bridge testing and inspection technology, specifically disclosing a test method for damage identification of precast assembled beam bridges based on strain curves. The method includes: arranging multiple strain test points on the precast assembled beam bridge to be tested; applying a moving load and collecting strain data from the strain sections; extracting the strain data from each strain section and performing noise reduction processing on the strain data to obtain the strain influence lines for each strain section; determining the longitudinal damage location: determining the longitudinal damage location based on the changes in the intersection positions of strain influence lines at different spans. This invention uses strain influence lines at different spans of the longitudinal beams of the precast assembled beam bridge to correct errors caused by residual strain influence and reduce noise in the test data, reducing errors caused by equipment and environmental factors. Changes in the intersection points of the strain influence lines enable longitudinal damage identification of the precast assembled beam bridge. The test is short, has minimal impact on bridge traffic, reduces test costs, and improves economic efficiency.

The present application relates to the technical field of tunnel construction, and particularly relates to a pile foundation response test method under a double-line tunnel shield side-penetration working condition. Residual strain is obtained after the first tunneling body passes and rests until the end, and the stiffness attenuation rate at each depth is calculated according to the attenuation linkage ratio; when the second tunneling body passes from the other side, the cumulative axial strain and the cumulative hoop strain are obtained by merging the stiffness attenuation rate as the weight, the real-time axial and hoop strain and the residual strain at each depth, and the cumulative plastic strain, the cumulative settlement and the bottom interface stiffness are calculated accordingly, so that the quantitative characterization of the pile body deformation and the internal force distribution evolution law in the whole double-line construction process is realized.

The invention discloses a monocular detection method, device and system for residual deformation and residual stress. The method comprises the following steps: firstly, judging whether a periodic structure exists on the surface of a measured object, if so, using the periodic structure as a grating; and if not, manufacturing the grating on the surface. Grating images before and after assembly, welding, heat treatment and the like of a measured object are acquired by using a camera or a microscope, and the phase change of the measured object is analyzed based on a phase analysis method, so that the deformation conditions before and after the measured object are obtained, and finally the residual strain, stress and the like of the measured object are calculated. The method is suitable for full-field rapid, high-precision and non-contact detection of residual deformation and residual stress in industrial production, and has the advantages of high efficiency and accuracy.

The invention discloses an arch bridge nonlinear critical load approximate analysis method considering a pier anti-pushing effect. The method comprises the following steps: S1, establishing a nonlinear strain-displacement expression of an arch bridge-pier combined system; s2, deducing a nonlinear equilibrium differential equation in a geometric plane by adopting a layered potential energy decomposition framework in combination with a virtual work principle; s3, solving the vertical displacement of the arch bridge and the horizontal displacement of the bridge pier in combination with the multi-dimensional coordination relationship and the boundary condition; s4, establishing a relational expression between the dimensionless load parameter and the dimensionless axial force parameter; s5, deriving a nonlinear branch point buckling equilibrium differential equation, and solving an antisymmetric branch point buckling critical load; and S6, adopting a differential extreme value analysis method to obtain a nonlinear critical load approximate analytical expression. According to the method, parameters such as the arch pier bidirectional coupling coefficient, the shear deformation correction item and the initial residual strain item are introduced, a multi-dimensional coordination mechanism is formed, and the workload of engineering technicians is reduced while the accuracy of the obtained critical load is guaranteed.

The invention provides a quantitative evaluation method and device for a damage factor of a tubular column under a complex load and a storage medium, and belongs to the field of oil-gas field development. Establishing a tubular column wear model and a wear depth prediction model, predicting the wear depth in the running process of the tubular column, and calculating to obtain a tubular column damage factor in the well completion casing running process; calculating and analyzing the residual strain of the pipe column under the action of the multi-stage cyclic load in each stage of fracturing and the crushing strength of the pipe column under the dynamic pipe diameter-pipe thickness ratio, and calculating the damage factor of the pipe column under the action of the multi-stage cyclic load in each stage of fracturing; analyzing well periphery crustal stress changes caused by all stages of platform well zipper type fracturing and tubular column anti-extrusion strength under non-uniform crustal stress distribution, and calculating tubular column damage factors under the condition of non-uniform crustal stress distribution; and calculating to obtain a tubular column damage factor under a complex load condition based on the result. Factors such as pipe column abrasion, internal pressure circulation and non-uniform external extrusion in the whole process are fully considered in damage factors, and quantitative evaluation is carried out.