642 results about "Strain measurement" patented technology

The invention discloses a global ultra-precision strain measurement method, and relates to the technical field of strain measurement. The method comprises the following steps: continuously shooting moving images of a target area by using a high-frame-rate high-definition camera, and recording accurate time; and carrying out image correction, feature extraction and tracking and data normalization. And after Gaussian white noise is added, singular value decomposition and reconstruction are carried out. And a Lucas-Kanade optical flow method is adopted to calculate the displacement of the feature points in the reconstruction matrix. And a displacement smoothing stage: smoothing the displacement data by using an LOESS method. And carrying out global strain calculation by adopting a window sliding method, and calculating the strain through the spatial derivative of the displacement field. According to the method, the quantization effect can be relieved, the continuity of displacement calculation is improved, low-energy noise and irrelevant features are removed, main motion information is reserved, meanwhile, smoothness is enhanced, local features are captured in a high-precision mode, and measurement sensitivity is improved. The method is suitable for strain measurement of large-scale structures such as bridges and buildings.

The invention discloses a fiber bragg grating strain measurement method and system based on deep learning, designs a double-grating structure and a deep learning analysis module, and separates temperature and strain components in grating wavelengths in real time. The system comprises a fiber grating sensor module, a data acquisition module, a deep learning analysis module and a display module, high-precision separation and real-time compensation of strain and temperature are realized through high-precision data acquisition and deep learning model processing, and the system is widely applied to the field of health monitoring of engineering structures such as bridges and tunnels.

The invention discloses a large workpiece strain measuring point auxiliary positioning system and method, and the system comprises a professional software and automatic control system, and an industrial photogrammetry system, a car lifting system, a laser projection system and a three-dimensional scanning quantitative analysis system which are connected with the professional software and automatic control system. And a positioning target is arranged on the surface of the large workpiece product. According to the system, strain contact auxiliary lineation and laser guide assembly work of a large workpiece and quantitative analysis work of strain gauge pasting are achieved, the system takes a target arranged on a product as a positioning reference, the outline of a product model is extracted in a photogrammetry mode, the product model and a real object are matched and unified to the same coordinate system, and the product model and the real object are obtained. The position contour of the strain gauge needing to be pasted and auxiliary information are projected to the surface of a product through the laser projection technology, the current pasting position information can be efficiently and accurately reflected, and high-efficiency and high-precision assembly of the strain gauge is facilitated.

The invention provides an indoor crustal stress test device and method based on optical strain measurement, the test device comprises a stress simulation device, the stress simulation device can perform real three-dimensional crustal stress environment simulation on a test rock mass as far as possible; the drilling releasing device is provided with a hollow drill bit used for drilling the optical strain measurer installed in the test rock mass, and the drilling hole and the hollow drill bit are coaxially arranged. Thus, according to the method, pressure is applied to the test rock mass from multiple directions through the multiple hydraulic loading columns, the real three-dimensional crustal stress environment can be more accurately simulated, speckle image changes in the speckle coating can be continuously recorded in real time through the optical strain measurer, and hole wall strain data are obtained; and converting the strain data into stress by applying an elastic theoretical formula, and accurately calculating the stress state of the experimental rock mass.

The invention discloses a multi-scale strain measurement method for a metal material at an ultralow temperature, and the method combines a DIC technology and HR-EBSD analysis, and achieves the precise strain measurement from a macro scale to a micro scale. Macroscopic strain distribution on the surface of a sample is accurately captured through a DIC technology, and HR-EBSD analysis is utilized to further go deep into a microscopic level, so that a microscopic deformation mechanism of a material in an ultralow-temperature environment is disclosed. The overall strain of the material is researched from the macroscopic perspective, the specific region of interest in the macroscopic strain state is further deepened, the microscopic strain distribution of the region of interest is explored, and the deformation behavior and the mechanical property of the material at the ultralow temperature can be more comprehensively understood. Besides, a non-direct contact type heat exchange mode is adopted, so that accurate temperature control is realized, and meanwhile, the influence of water mist or condensation and the like generated by evaporation and condensation of a cooling medium on a test result is avoided.

The invention discloses a creep test system of a turbine rotor blade film hole simulation piece and a test method of the creep test system. Comprising a clamping assembly used for fixing a test piece, a loading assembly used for applying a load to the test piece, a strain measuring assembly used for measuring the strain rate of the test piece, a heating assembly used for covering the test piece to form a heating channel, and a cooling assembly used for manufacturing and conveying cooling airflow to flow through the interior of the test piece, the strain measurement assembly is used for measuring the external temperature of the test piece and the internal temperature of the test piece, the control assembly is connected with the strain measurement assembly, the heating assembly, the cooling assembly and the temperature measurement assembly, and the heating assembly is used for manufacturing and conveying high-temperature airflow to flow through the heating channel so as to heat the outside of the test piece to a first set temperature; the cooling assembly is used for cooling the interior of the test piece to a second set temperature, and the heating assembly and the cooling assembly are used for forming a dynamic convection environment around the test piece.

The invention discloses a non-contact monitoring method for the axial force of an end anchoring anchor rod, and relates to the technical field of anchor rod axial force measurement. The monitoring method comprises the steps that firstly, relevant parameters of surrounding rock, relevant parameters of an anchor rod in the anchoring process and relevant parameters of an anchoring agent are obtained; acquiring strain data of an anchor rod tray in the anchoring system by adopting a full-field strain measurement system, transmitting the strain data to a data processing module of the full-field strain measurement system, and acquiring anchor supporting force by virtue of a stress-strain relationship of the anchor rod tray; finally, a calculation analysis formula of the mechanical relation between the anchor supporting force Ft generated by the anchor rod tray and the anchor rod axial force F is constructed in a computer; and inputting the values of the related parameters obtained in the step 1 and the step 2 into a calculation analysis formula, and calculating to obtain the axial force of the end anchoring anchor rod. By means of the method, non-contact measurement of the anchor supporting force of the anchor rod can be achieved, and the integrity of an anchoring system is further protected.

A helicopter blade waving and shimmy decoupling position measuring method based on fiber bragg grating sensors comprises the following steps that a plurality of fiber bragg grating sensors are evenly pasted on the upper surface and the lower surface of a to-be-measured section of a helicopter blade in parallel from the front edge to the rear edge of the blade; flapping and shimmy bending moments are loaded on the blades respectively, and strain values corresponding to the flapping and shimmy bending moments are obtained through measurement; according to the position of the sensor and strain measurement data thereof, adopting a Kriging interpolation method to carry out interpolation on point positions with the same spacing, and obtaining an estimated value of a corresponding spatial position; establishing shimmy / flapping and flapping / shimmy decoupling coefficient evaluation functions; global traversal is carried out on the interpolation result, evaluation function values are calculated and sorted, and finally a decoupling position is determined.

The invention belongs to the field of material mechanical property testing and strain measurement, and particularly relates to a local strain measurement method and system based on a four-point bending and digital image correlation (DIC) technology, and the method specifically comprises the following steps: cutting to prepare a sample, carrying out surface electrolytic polishing, preparing speckles on the surface of the sample to be tested, and carrying out a four-point bending experiment; speckle images of the lower surface of the sample are collected, displacement correction is conducted in combination with bending deflection calculation, the bending load and the strain of the upper surface of the sample are obtained in real time, the stress-strain relation and local strain distribution of the lower surface of the sample are obtained through calculation, and finally deformation and failure mechanism analysis is conducted in combination with surface deformation and crack morphology. The method provided by the invention combines four-point bending and DIC plane strain measurement technologies, can realize stretching, compression and dynamic fatigue loading on the surface of the sample, is suitable for performance test and failure analysis of tension, compression and fatigue deformation of brittle metal materials such as intermetallic compounds and amorphous materials, and has the characteristics of convenience, rapidness and low cost.

The invention provides a multifunctional rock test system under a multi-field coupling condition, which is internally provided with a reaction cabin, a rock sample is placed in the reaction cabin, and the system is internally provided with an axial force loading control system, a confining pressure oil circulation system, a high-temperature heating and control system, an injection pump system and a temperature and strain measurement system. The subsystems are respectively in communication connection with the computer display and control system and are respectively used for controlling the pressure or temperature in the reaction cabin; the test method based on the system comprises the following steps: 1) processing a rock sample; 2) assembling a rock sample; 3) loading the rock sample into a reaction cabin; the method comprises the steps of (1) preparing a rock sample, (2) assembling a reaction cabin, (5) initializing a system and fixing the rock sample, (6) providing a confining pressure environment for the rock sample, (7) providing a high-temperature environment for the rock sample, (8) providing a triaxial high-pressure environment for the rock sample, (9) providing a chemical field and osmotic pressure environment for the rock sample, (10) providing water pressure for the rock sample and monitoring pressure, temperature and strain changes, (11) relieving pressure, cooling and recovering confining pressure oil, and (12) sorting and processing data.

The invention relates to a method for dynamically measuring a composite material under an ultra-high-temperature working condition, which comprises the following steps of: constructing a composite material high-temperature strain dynamic detection platform, and respectively acquiring speckle images of a tested piece under a cold state condition and an ultra-high-temperature working condition as data sets; constructing a supervised network model for eliminating speckle image thermal radiation and thermal disturbance influence, wherein the supervised network model comprises a multi-scale feature extraction module, a dual convolutional neural network and a polarization self-attention mechanism; constructing a joint loss function L for the supervised image restoration network model; training the model to obtain an optimal image restoration network model; an ultra-high-temperature speckle image serves as input, a speckle image restoration result is output through the image restoration network model, and a displacement field is obtained through DIC calculation; according to the invention, the influence of thermal radiation, thermal disturbance and haze phenomena in an ultra-high temperature environment on image quality is effectively eliminated, and the dynamic strain measurement precision of the composite material under an ultra-high temperature working condition is remarkably improved.

The invention relates to the technical field of structural deformation shape reconstruction, in particular to a novel inverse finite element deformation reconstruction method based on virtual deformation field physical constraint. According to the method, a virtual displacement field obtained by sparse strain through inverse finite element reconstruction is used as a strain extrapolation physical constraint; and an iteration thought is adopted, extrapolated strain and measured strain are used for inverse finite element deformation reconstruction again, a new virtual displacement field is obtained, and therefore strain extrapolation can be restrained again. And continuously iteratively reconstructing virtual deformation and extrapolation strain in this way, and finally reconstructing real structural deformation. And determining the accuracy rate of the deformation characterization values based on a plurality of actually measured actual deformation characterization values and a plurality of deformation characterization values determined by the extrapolation strain data, and determining the deformation reconstruction state based on the accuracy rate. According to the method, the strain measurement points are extrapolated through iteration in the deformation reconstruction process, and the virtual displacement field is used as physical constraint, so that the accuracy of deformation reconstruction is improved.

The invention discloses a method for dynamically measuring deformation and strain through digital speckle interference, and relates to the field of optical detection. The method comprises the following steps: firstly, building a speckle interference light path, secondly, selecting a to-be-detected area of a detected object, recording four speckle interference patterns with different phase shifts before and after deformation through a polarization camera, performing four-step phase shift on the recorded speckle interference patterns, and then performing subtraction to obtain a deformation wrapped phase diagram; and carrying out sine and cosine filtering and unwrapping processing on the deformation wrapped phase diagram to obtain a real phase diagram, thereby obtaining the deformation and strain of the measured object. According to the invention, the deformation and strain of the measured object can be dynamically detected in real time, the measurement light path is simplified, and the method is a high-precision full-field nondestructive measurement method.

The invention belongs to the technical field of impact fatigue performance detection, and particularly relates to a Hopkinson rod three-point bending sample-based constant-amplitude impact fatigue device, which comprises a dynamic indentation system, an energy absorption system, a strain measurement system and a pressure data acquisition system, and is characterized in that the dynamic indentation system comprises kinetic energy application equipment, an impact rod, an incident rod and a three-point bending test bed; the strain measurement system comprises a strain gauge and a dynamic strain acquisition instrument which are electrically connected, the pressure data acquisition system comprises a force transducer and a data acquisition instrument which are electrically connected, and the energy absorption system comprises a flange, a sleeve and a mass block. The device depends on the Hopkinson rod technology, the momentum well design is ingeniously fused, the problem of secondary loading is effectively avoided, constant-amplitude impact fatigue loading is achieved, key parameters such as the yield point, the elastic limit and the breaking strength of the material are accurately measured, and the reliability and safety of the material are comprehensively evaluated.

The invention provides a battery chemical stress in-situ monitoring method, which comprises the following steps that: a sensing optical fiber covers the upper surface of an anode plate of a battery in a snakelike routing mode in a first direction, the sensing optical fiber completely covers the anode plate, and every two adjacent first optical fiber sections are connected through a corresponding second optical fiber section; the two ends, located outside the anode plate, of each first optical fiber section are fixed to a protective shell below the anode plate, so that each first optical fiber section is always kept in a stretching state in the monitoring process; connecting the sensing optical fiber with a strain measurement and analysis system, and respectively carrying out pressing test on two ends of each first optical fiber section so as to carry out position calibration on each first optical fiber section; and the strain measurement and analysis system obtains a three-dimensional strain field of the anode plate according to the scattering signals reversely transmitted back by the first optical fiber sections, the calibrated two-end positions of the first optical fiber sections and the arrangement relation between the first optical fiber sections. The strain field monitoring of the whole surface of the anode plate can be realized.

The invention discloses a corrugated steel web bridge deformation monitoring temperature lag compensation method and system, and the method comprises the steps: constructing time sequence data of a corrugated steel web, the time sequence data comprises a time sequence composed of a wave crest temperature, a wave trough temperature, a strain measurement value, a wind speed and solar radiation intensity in any fold period of the corrugated steel web at any moment; according to the time sequence data, calculating the temperature lag time of the temperature to the structure response by using a sliding cross correlation coefficient algorithm of the frequency domain energy weight; time sequence data are reconstructed according to the temperature lag time, and the reconstructed time sequence data are obtained to serve as state vectors of the corrugated steel web; the state vector of the corrugated steel web is input into the strategy network of reinforcement learning, an optimal action instruction of the next step is output and obtained, and the optimal action instruction comprises the step that a compensation signal is applied to time sequence data; according to the optimal action instruction, the predicted state vector of the corrugated steel web at the next moment is obtained; and obtaining a strain prediction value of the corrugated steel web according to the state vector of the corrugated steel web at the next moment. Dynamic and high-precision compensation of the corrugated web bridge temperature hysteresis effect is achieved for the first time.

The invention relates to a winding spray pipe forming process internal temperature strain measurement method and a winding spray pipe, and the method comprises the steps: winding first winding cloth on the surface of a winding core mold, laying a grating fiber sensor between the first winding cloth to form an inner layer structure, and enabling a part of the grating fiber sensor to be located in the inner layer structure, the other part extends out of the inner layer structure; vacuumizing the inner-layer structure, then transferring the inner-layer structure into an autoclave for curing, and carrying out a conduction test on the grating optical fiber sensor; the inner layer structure is taken out of the autoclave, second winding cloth is used for winding the surface of the inner layer structure, a grating optical fiber sensor is laid between the second winding cloth, a spray pipe winding piece is formed, part of the grating optical fiber sensor is located in the second winding cloth, and the other part of the grating optical fiber sensor extends out of the second winding cloth; vacuumizing the spray pipe winding piece, then moving the spray pipe winding piece into an autoclave for curing, and performing a conduction test on the grating fiber sensor; and the spray pipe winding piece is taken out of the autoclave for demolding.

A trailer and vehicle hitching assembly 100 comprising a tongue portion 22 for affixing to a body of the trailer or vehicle, a hitch portion 32 for selectably securing the assembly to the other of the

The invention belongs to the technical field of metamaterial sensors, and particularly relates to a metamaterial multi-parameter sensor for a complex environment, which comprises a dielectric substrate, a temperature sensor, a pressure sensor and a strain sensor, and is characterized in that the dielectric substrate is made of high-temperature co-fired alumina ceramic; the temperature sensor is arranged at the left end of the dielectric substrate; the pressure sensor is arranged in the middle of the medium substrate; and the strain sensor is arranged at the right end of the dielectric substrate and comprises a metal sheet structure capable of generating relative displacement. According to the invention, long-distance signal monitoring is realized by adopting a microwave scattering technology, and the problem that a traditional wired sensing transmission line is damaged at a high temperature is solved; the high-temperature-resistant aluminum oxide HTCC ceramic is used as the dielectric substrate, temperature measurement within the range of 25 DEG C to 1200 DEG C, pressure within the range of 0 kPa to 700 kPa and strain measurement within the range of-400 mu epsilon to + 400 mu epsilon are achieved, the sensor is smaller in size and higher in sensitivity, and application of a traditional sensor in the multi-metal environment is expanded.

The disclosure relates to monitoring blades of a wind turbine rotor shaft. Example embodiments include a computer-implemented method of monitoring blades of a wind5 turbine (100), the wind turbine (100) having a plurality of blades (103a, 103b) mounted to a hub (102), each blade (103a) comprising one or more strain sensors (109a1-3) mounted to the blade (103a) at corresponding respective distances from the hub (102, 201) along the blade (103a), the method comprising: i) recording (1301) strain measurements from the strain sensors (109a1-3) on each of the plurality of blades10 (103a); ii) recording (1302) a rotor speed of the wind turbine (100); iii) calculating (1303) a statistical measure of each of the recorded strain measurements; iv) calculating (1304) a difference in the statistical measure for strain sensors at corresponding positions on each of the plurality of blades over a range of rotor speeds; and v) identifying (1305) the presence or absence of damage in one of the plurality of blades15 based on the calculated difference.

The invention belongs to the technical field of intelligent manufacturing, and discloses a demodulator working temperature drift correction method in aviation tooling optical fiber strain measurement, which aims at strain measurement temperature drift characteristics of different temperature intervals, completes curve segmentation on the basis of temperature change rate, and further applies a proper polynomial function to perform segmentation fitting to obtain a temperature drift correction result. And the temperature drift correction model is established, so that the fitting complexity is reduced, and the temperature drift correction accuracy is improved. And the measurement precision of the fiber bragg grating strain sensor under the condition that the working temperature of the demodulator changes is ensured. The method is suitable for the strain measurement of a tool in the assembly process of aircraft components, and is also suitable for the strain measurement process of any fiber bragg grating. The method has the advantages of wide application range, simple operation, easy popularization and the like.

The invention discloses a rock shear seepage coupling true triaxial test system, which relates to the technical field of rock mechanical tests, and comprises a host, a sigma 1 / sigma 2 direction loading module, a sigma 3 direction confining pressure module, a pressure chamber auxiliary system, a sample clamp, a pore water seepage system, a temperature system, a control module and a data acquisition and processing module, through servo closed-loop linkage double-pump loading in the sigma 1 / sigma 2 direction, synchronous output of the double pumps and coordination of pressure supply of the two oil cylinders by the controller, a strain correction algorithm is combined, stability of a stress loading center is guaranteed, strain measurement accuracy is improved, confining pressure is accurately controlled in the sigma 3 direction through a double-balance pressure chamber and a pressure regulation algorithm, and the stress measurement accuracy is improved. The pressure chamber is in full-automatic operation, manual steps are omitted, errors are reduced, efficiency is improved, a stress-free blank angle clamp eliminates friction interference, a seepage system supports a double-loading mode, a control module achieves multi-control-mode impact-free switching, a data processing module is combined with an elastic modulus calculation algorithm, rock mechanical parameters are accurately obtained, and the multi-field coupling test requirement is met.

An apparatus for digitizing an optical signal comprises: an optical detector to detect an optical signal and to generate an electric signal corresponding to the optical signal; an envelope curve detector to determine the amplitude of the electric signal or a modified electric signal resulting from the electric signal, and to supply an amplitude signal corresponding to the amplitude; an analog to digital converter to digitize the amplitude signal and to supply a corresponding digitized amplitude signal; and a variable voltage source to calibrate the envelope curve detector.

The invention provides an anti-counterfeit label film coating tension control method and system, and relates to the technical field of film coating tension control. The method comprises the following steps: acquiring surface image data of a substrate film; identifying and acquiring real-time coordinates of the feature points; calculating the local strain of the substrate film according to the real-time coordinates of the feature points; calculating to obtain a strain deviation; calculating the time required by the film section corresponding to the strain deviation to reach the film coating station as the adjustment time; calculating a tension compensation amount according to the strain deviation; and within the adjusting time, the tension control unit adjusts the tension applied to the substrate film according to the tension compensation amount. According to the method, through accurate local strain measurement and prospective tension adjustment, it is ensured that each section of film is kept in an ideal strain state at the moment of film coating, so that the integrity and functional effectiveness of optical microstructures such as diffraction gratings are thoroughly protected, and the technical problems in anti-counterfeit label film coating production are effectively solved.

Heart strain determination includes receiving a series of 2D-slice images as input. A pose estimation module estimates a slicing-pose of the inputted series of 2D-slice images in the heart. A 3D deformation estimation module estimates a 3D deformation field from the series of 2D-slice images and the estimated slicing-pose. A strain measurement module computes a heart strain measure from the 3D deformation field and a predefined definition for strain computation.

The invention belongs to the technical field of high-temperature thin film sensors, provides a high-temperature dynamic strain measurement method based on a thin film strain gauge, and is used for solving the problems that a traditional contact strain gauge is difficult to assemble, the surface structure of a part is damaged, and the accuracy is poor. The method comprises the following steps: firstly, arranging a film strain gauge and a temperature sensor on the surface of a test piece, and synchronously acquiring time-domain resistance signals and temperature information in the vibration process of the test piece; then, converting the time-domain resistance signal into a frequency-domain resistance signal by adopting spectral analysis, taking the resistance amplitude at the zero frequency as the initial resistance of the thin film strain gauge, and taking the resistance amplitude at the resonant frequency of the test piece as the resistance response quantity of the thin film strain gauge; and finally, determining a strain factor of the film strain gauge according to the temperature information, and calculating the dynamic strain of the test piece based on the initial resistance, the resistance response amount and the strain factor of the film strain gauge. On the basis, the strain measurement error is remarkably reduced, and the accuracy of dynamic strain measurement is improved.

The invention relates to a static strain measurement method and system based on a grating array, and electronic equipment, and belongs to the technical field of optical fiber sensors, and the method comprises the steps: obtaining a reflection signal obtained through the reflection of a laser pulse signal by a chirp grating array; the laser pulse signal is transmitted by the grating array sound wave demodulator; interference demodulation is carried out on the reflected signal, and the phase of the reflected signal is determined; and performing optical frequency drift compensation and temperature compensation on the phase to obtain a static strain value of the optical fiber. According to the static strain measurement method based on the grating array, signal demodulation is achieved through the grating array sensing unit and an interference mode, a high-speed, high-spatial-resolution and wide-range static strain distribution measurement method can be achieved through temperature decoupling, and when the static strain measurement method is applied to infrastructures, the measurement accuracy is greatly improved. The structure change of the structural body can be rapidly and accurately detected, so that the safety state of the infrastructure structure is obtained.

The invention provides a surgical robot tail end three-dimensional force sensing mechanism and a force measurement method, and relates to the technical field of force measurement, and the surgical robot tail end three-dimensional force sensing mechanism comprises a first connecting end used for connecting a surgical instrument, a second connecting end used for connecting a surgical robot mechanical arm, and a first strain measurement unit arranged between the first connecting end and the second connecting end. The first strain measurement unit comprises a strain structure and a measurement assembly, the strain structure is provided with a first strain part, a second strain part and a third strain part, and the three strain parts are elastically deformed under acting force in a first direction, a second direction and a third direction which are perpendicular to one another; a first strain assembly, a second strain assembly and a third strain assembly of the measuring assembly are correspondingly installed on three strain parts, and the three components are matched to measure acting force borne by the surgical instrument in the first direction, the second direction and the third direction. The measurement limitation of a one-dimensional sensor is broken through, and the measurement of the acting force borne by the surgical instrument in three dimensions is realized.

The invention relates to the technical field of mechanical property testing of metal materials, and provides an unsteady-state in-situ high-temperature forming property testing device and method. A punch constant strain rate loading model is arranged in the device, the punch moving speed is adjusted in real time to realize punch constant strain rate loading, and the rheological behavior of a constant strain rate sensitive material in a complex stress state is accurately tested; a rapid cooling system is arranged, so that accurate simulation of complex unsteady-state forming processes such as actual hot stamping and warm forming is realized, and the unsteady-state in-situ high-temperature forming performance of the material is obtained; in combination with a DIC dynamic strain measurement technology, a strain field and deformation force are collected in real time in a plate high-temperature plane stress bulging test, and local necking strain and main strain and secondary strain change paths are determined. According to the method, the reliability of researching macroscopic rheological behaviors such as strain field distribution, flow behavior, hardening mechanism, forming limit and fracture limit of the plate in a complex stress state can be remarkably improved.