157 results about "Axial strain" patented technology

The invention discloses an inversion method of fracturing fracture parameters based on distributed optical fiber strain. The method comprises the following steps: firstly, acquiring a horizontal well distance and a vertical well distance in an adjacent well monitoring scene, a distributed optical fiber scale distance Lg and axial strain observation data epsilon acquired by a low-frequency DAS system, and initializing an inversion model; on the premise that a fracturing crack meets an optical fiber, a crack height H0 is preset, a constraint matrix A is adjusted to be an A1 matrix constraint inversion model (1), w in the inversion model (1) is w1, and w1 is solved through a hybrid-LSQR iterative algorithm; according to the solved w1, the constraint matrix A is adjusted to be A0, the crack propagation boundary is not constrained, w in the inversion model (1) is w0, and w0 is solved through a hybrid-LSQR iterative algorithm; iterative optimization is carried out, the fracture height with the error between the fracture width w0 obtained through A0 constraint inversion and the fracture width w1 obtained through A1 constraint inversion being smaller than a threshold value delta is solved, and in this way, fracturing fracture parameters are quantificationally inverted through distributed optical fiber strain data.

The invention relates to the technical field of safety management, in particular to a mine safety production risk prevention and control method based on multi-source data fusion, and the method comprises the following steps: constructing a coupling parameter set through a micro-seismic sensor and a temperature and humidity sensor, detecting and extracting displacement points through Bayesian regression, and drawing a deformation diagram; determining a displacement area, counting an airflow velocity gradient, extracting a main fracture direction, generating an airflow path diagram, calculating a curvature change rate, positioning a sudden change area, extracting a thermal strain rate and an axial strain rate, generating a smooth curve, identifying a risk point, and expanding a boundary when the overlapping rate exceeds 60%, and redrawing a mine thermal-mechanical coupling risk map. According to the method, a multi-parameter analysis framework is constructed through micro-seismic and temperature and humidity data coupling to extract a deformation active band, difference statistics airflow velocity gradient is combined with a crack direction to correct an airflow path, a sudden change area is positioned based on a curvature change rate mean threshold, and thermal strain and axial strain are extracted to screen risk points. And constructing thermal variable amplitude mapping to represent the rock mass instability risk.

The invention is suitable for the technical field of automobile fuel injection nozzle forging, and particularly relates to an automobile fuel injection nozzle forge piece forging method and equipment. The method comprises the steps that metal flow resistance, metal flow speed, forging vibration data and lateral force are obtained; determining a target flow velocity based on the metal flow resistance, the metal flow velocity and the forging vibration data; determining an axial strain coefficient and a radial strain coefficient based on the metal flow resistance, the metal flow velocity, the forging vibration data and the lateral force; based on the axial strain coefficient and the target flow velocity, generating a sliding block control instruction, and based on the radial strain coefficient, generating an ejector rod control instruction; and according to the sliding block control instruction and the ejector rod control instruction, a forging and pressing device and a hydraulic device are controlled to forge the automobile oil nozzle forge piece. According to the method, the forge piece forming precision, the production efficiency and the intelligence and automation level of the forging process can be remarkably improved.

The invention discloses an optical fiber three-dimensional shape sensor based on an optical frequency domain reflection technology and an application method of the optical fiber three-dimensional shape sensor, the optical fiber three-dimensional shape sensor comprises a base material and more than three optical fibers, and all the optical fibers are spirally wound and fixed on the surface of the base material at equal intervals and constant screw pitches to form distributed sensing units; according to the application method, measurement signals of all the optical fibers are obtained, and axial strain and strain are calculated; calculating the total curvature vector of the reconstruction curve of the measured object; calculating a bending direction angle and a curvature of the reconstruction curve of the measured object; performing differential calculation on the bending direction angle to obtain the torsion rate of the reconstructed curve of the measured object; and reconstructing the three-dimensional shape of the measured object according to the curvature and the torsion of the reconstructed curve of the measured object. The invention aims to realize synchronous measurement of bending, torsion and axial strain by using a distributed sensing unit formed by a multi-fiber structure which is spirally wound at the same interval and at a constant screw pitch.

The invention discloses a method and system for analyzing the rolling resistance of a concrete-filled steel tube combined pier column, and the method comprises the steps: applying an axial compression load to the concrete-filled steel tube combined pier column, and dividing the cross section of the concrete-filled steel tube combined pier column into three layers of regions along a radial material change part; according to corresponding total cross-section average axial strain generated by the steel pipe concrete combined pier column when different axial compression loads are applied, equivalent stress corresponding to each layer of area is calculated, total axial force corresponding to each total cross-section average axial strain is calculated, and a total cross-section average axial strain-total axial force curve is formed; searching a first total cross-section average axial strain corresponding to the maximum value of the total axial force in the total cross-section average axial strain-total axial force curve and a second total cross-section average axial strain corresponding to a first obvious inflection point of the total cross-section average axial strain-total axial force curve, and calculating a ductility coefficient, and judging whether the concrete-filled steel tube composite pier column meets the ductility design requirement or not.

The invention discloses a roadway roof damage time prediction method and system, and belongs to the technical field of mine rock mechanics and safety engineering. Comprising the following steps: recognizing a roof rock stratum structure and lithology of each layer through drilling peeping, and drilling a representative rock sample; determining the crack initiation strength and peak strength of the rock sample through a uniaxial compression test; selecting a plurality of stress levels between the axial strain and the acoustic emission signal to carry out a creep test, synchronously monitoring the axial strain and the acoustic emission signal, and determining an accelerated creep starting moment as the damage time under the stress according to the abrupt change characteristics of the axial strain and the acoustic emission signal; establishing a stress-failure time relation model of each lithology; finally, selecting a corresponding model to predict the damage time of rocks at different layers of the roof according to the actual rock stratum structure and ground stress state of the roadway; according to the method, accurate and reliable time prediction of the progressive damage process of the roadway roof is realized.

Provided are a method and apparatus for calibrating contact parameters of electrode materials, and a computer storage medium. The method includes the following operations. A discrete element simulation test is performed on an electrode material based on a calibration model and calibration ranges of contact parameters of the electrode material when an axial force-displacement curve of a target pellet of the electrode material meets an adaption condition of the contact model; then a simulated axial pressure-axial strain relationship of the electrode material is acquired based on a target discrete element simulation parameter of the electrode material; whether the contact parameters are calibrated successfully is judged based on this relationship; and when the contact parameters are calibrated successfully, calibration results of the contact parameters are determined.

The invention discloses a rock triaxial statistical damage constitutive model construction method based on an energy dissipation theory. The method comprises the following steps: step 1, defining a function relationship between an energy dissipation ratio and an axial strain corresponding to a rock test piece; 2, obtaining a rock damage evolution equation; 3, constructing a rock damage constitutive model; and 4, obtaining stress-axial and radial strain relation curves of the rock through an indoor test, determining mechanical strength parameters and energy parameters of the rock sample according to test data, identifying model parameters according to a test result, and determining a damage threshold value according to an energy dissipation ratio-axial strain relation curve stagnation point. According to the rock triaxial statistical damage constitutive model construction method based on the energy dissipation theory provided by the invention, the problem in the prior art that the rock damage evolution process cannot be represented for a rock material showing obvious nonlinear characteristics in a compaction stage and a residual deformation stage is solved.

The invention provides a sequential network land subsidence detection method and device based on a distributed optical fiber phase signal. The detection method comprises the following steps: acquiring an axial strain signal and a radial strain signal of a distributed optical fiber of a pre-detection land subsidence band; performing noise reduction processing on the axial strain signal to obtain a first strain signal; enhancing the radial strain signal to obtain a second strain signal; performing multi-dimensional feature extraction on the first strain signal and the second strain signal to obtain first feature data and second feature data; performing multi-scale time sequence feature extraction on the first feature data to obtain time sequence feature data; performing spatial dimension feature mining on the second feature data to obtain feature mining data; performing fusion processing on the time sequence feature data and the feature mining data to obtain a fusion processing result; and performing surface collapse detection according to a fusion processing result to obtain a surface collapse detection result. According to the embodiment of the invention, the precursor information of the surface collapse can be more accurately captured.

The invention relates to the technical field of nickel alloy pipe water pressure detection, and discloses a thin-wall nickel alloy pipe inner wall water pressure test detection system and method. The method comprises the steps that a closed water pressure environment is established in a pipe, a preset pressure gradient is applied, and pipe wall deformation response data are collected through a distributed sensing array; and generating a composite feature matrix containing axial strain, circumferential stress and radial displacement features through multi-dimensional feature extraction, inputting the composite feature matrix into a material performance degradation evaluation model, and simulating microstructure change to output a potential defect distribution map. Dynamically adjusting the water pressure gradient and the pressure maintaining time according to the map, executing a secondary water pressure test, and capturing a microscopic deformation sequence image through high-frequency imaging; comparing the image with a model prediction result identification deviation value, and iteratively updating a model parameter to optimize a detection threshold value; the test is completed by optimizing the threshold value, qualified pipe section marks and defective pipe section positioning coordinates are output, and the comprehensiveness and accuracy of thin-wall nickel alloy pipe inner wall defect detection are improved.

The invention relates to the technical field of geotechnical engineering and geomechanics, in particular to a round gravel soil constitutive model construction method and system. The method comprises the following steps: performing a triaxial consolidation drainage experiment on round gravel soil to obtain mechanical test data of the round gravel soil; according to the mechanical test data, the Duncan-Chang model is improved; and based on the improved Duncan-Chang model, constructing a roundstone soil constitutive model. According to the method, by improving the curvilinear relation between the axial strain and the lateral strain of the Duncan-Chang model, the volume strain and the tangent Poisson's ratio, the applicability of the Duncan-Chang model to the round gravel soil is improved, and the problem that under the combined action of mountainous area alluviation and lacustrine facies deposition on the rushing-lacustrine round gravel soil, the model is difficult to deform is solved. The problem that an existing constitutive model cannot accurately describe the mechanical behavior of round gravel soil is solved.

The invention provides a steel truss arch bridge suspender fatigue damage engineering evaluation method considering a bending effect, which comprises the following steps: firstly, distinguishing load working conditions according to a lane where a train is located and the number of carriages, comprehensively considering the influence of the bending effect, and simplifying the evaluation method by analyzing the influence degree of the transverse position of the train on suspender fatigue damage; then, axial strain epsilon < axial > and bending strain epsilon < bending > data of the shortest suspender under various working conditions are extracted and checked with health monitoring data, the influence of train bending behaviors, lanes where the train is located and the number of carriages on fatigue damage of the shortest suspender is determined, and the fatigue damage of the shortest suspender is determined based on a finite element model; evaluating fatigue damage of all suspenders of the full bridge under various load conditions when the bending effect is considered; finally, according to the accumulated fatigue damage rate, the fatigue damage grade and the maintenance period of the suspender are proposed, the fatigue performance of the steel truss arch bridge suspender is evaluated based on health data and numerical simulation, and a reference basis is provided for daily maintenance of the rigid suspender of the bridge.

The invention discloses a construction method of a water-containing rock damage statistical constitutive model considering compaction deformation, which comprises the following steps: carrying out a uniaxial compression test on a rock sample to obtain an axial stress-axial strain curve and a demarcation point in a compaction stage and a linear elasticity stage in the axial stress-axial strain curve; a sigmoid function is introduced, and the constitutive relation of the water-containing rock in the microfracture compaction stage is constructed; acquiring a damage variable after coupling of rainfall damage and stress damage caused by rock moisture infiltration; based on a damage statistical theory, constructing a constitutive relationship between a linear elasticity stage and a damage softening stage after a microfracture compaction stage of the water-containing rock; and constructing a damage statistical constitutive model of the water-containing rock considering compaction deformation. The constitutive curve corresponding to the constitutive model well reflects the compaction characteristic, the elastic characteristic, the damage softening characteristic and other deformation characteristics of the rock mass, and high prediction precision and practical application value are shown.

The invention provides a calculation method for the elastic modulus of a soil-rock mixture based on a mesoscopic structure model, relevant to the field of meso-numerical simulation of geotechnical materials. It includes the following steps: obtaining the gradation curve of soil-rock mixture particles through a screening test and constructing a two-dimensional random meso-structure model of the mixture with varying stone contents. Using the finite element method, a biaxial compression numerical test is conducted on the model under different stone contents and confining pressures. The equivalent elastic modulus of the mixture is determined by the corresponding secant elastic modulus at an axial strain of 1%. This macro-equivalent elastic modulus, considering stone content and confining pressure, is then fitted. This method effectively addresses the challenge of presenting accurate physical and mechanical parameters in engineering design and construction, making it directly applicable to practical engineering involving soil-rock mixture materials.

The utility model discloses a novel three-dimensional force sensor, which comprises an elastic sensor main body with a cylindrical structure, the upper part of the elastic sensor main body is provided with a first annular groove, the lower part of the elastic sensor main body is provided with a second annular groove, and four mounting positions are arranged in the second annular groove; an axial strain gauge is attached to the first annular groove, and three of the four installation positions are each provided with a transverse strain gauge. Thus, axial pressure information is received through the axial strain gauge in the first annular groove, transverse pressure information is received through the three transverse strain gauges, and the application scene of the sensor is improved.

The invention belongs to the field of superconducting material measurement, and discloses an external field critical current test sample rod under axial strain of a superconducting tape, which comprises a mechanical transmission device, a worm vertical to a left-right rotation trapezoidal screw rod, and a worm gear connected with the middle part of the left-right rotation trapezoidal screw rod through an optical axis key; the axial strain loading platform and the nut seat are respectively screwed into a left thread part and a right thread part of the left-handed and right-handed trapezoidal screw rod, the sample holder is supported and fixed through convex parts at two sides of the nut seat, the copper current terminals are respectively fixed at two ends of a platform part of the sample holder, and the strain gauge is used for being fixed on a middle shaft in the middle of a superconducting tape to be tested; and the electric signal transmission device is electrically connected with the strain gauge. According to the invention, the left-handed and right-handed trapezoidal screw rods are driven to rotate, so that the pair of nut seats with opposite threads are linearly opened and closed, the superconducting tape to be measured on the sample holder tape welding platform is driven to generate axial strain, and the critical current of the superconducting tape under the axial strain in a background magnetic field is measured.

The invention discloses a deformation monitoring system for a vertical supporting body of a foundation pit in a hydraulic reclamation area, which relates to the technical field of deformation monitoring and comprises a multi-source signal acquisition module, a dynamic environment acquisition module, a fusion identification module, a dynamic analysis module and a dynamic early warning module. Millisecond-level deformation signal capture is achieved, five key parameters including axial strain, lateral displacement, soil pressure, pore water pressure and water level are synchronously collected, the blind area problem of single-index monitoring is solved, the safety coefficient K is corrected by calculating a comprehensive deformation value Q and then introducing a pore water pressure change rate U3 and a water level change rate W3, the data fusion efficiency is improved, and the data fusion precision is improved. The problem of data islands is solved, multi-stage response is triggered according to the K value, regulation and control equipment and personnel evacuation are linked, the early warning response efficiency is improved, and the engineering defense value of the deformation monitoring system under the complex working condition of the hydraulic reclamation area is improved.

This application relates to the field of automotive fuel injector forging technology, and particularly to a forging method and equipment for automotive fuel injector forgings. The method includes: acquiring metal flow resistance, metal flow velocity, forging vibration data, and lateral force; determining a target flow velocity based on the metal flow resistance, metal flow velocity, and forging vibration data; determining axial strain coefficient and radial strain coefficient based on the metal flow resistance, metal flow velocity, forging vibration data, and lateral force; generating a slider control command based on the axial strain coefficient and the target flow velocity, and generating a push rod control command based on the radial strain coefficient; and controlling a forging device and a hydraulic device to forge the automotive fuel injector forging according to the slider control command and the push rod control command, respectively. This method can significantly improve the forging accuracy, production efficiency, and the level of intelligence and automation in the forging process.

The invention provides a rock strain softening constitutive model construction method, and relates to the field of rock mechanics, the method comprises the following steps: determining an actually measured rock axial stress-axial strain curve to be fitted; dividing a post-peak strain softening curve of the axial stress-axial strain curve of the rock into j sections according to engineering requirements; the axial stress and the axial strain of the peak intensity are recorded as the sum, and the axial stress and the axial strain at the right end point of each segment divided into the j segments are recorded as the sum; calculating to obtain axial cumulative plastic strain corresponding to each point; calculating cohesion corresponding to each point; and importing the axial cumulative plastic strain corresponding to each point and the cohesive force corresponding to each point into FLAC3D software in a table form to complete the construction of the rock strain softening constitutive model. According to the method, the problems that a conventional strain softening model is complex in parameter, poor in fitting with an actual test result and difficult to construct in numerical software are solved to a certain extent.

The present application relates to the field of testing and numerical analysis control technology, and in particular to a simulation method, apparatus, equipment, medium, and program for a true triaxial test. The method comprises: obtaining a test target for the true triaxial test; determining a specimen based on the test target and applying a preset axial strain increment to the specimen; collecting the true axial stress value, the true longitudinal stress value, the true transverse stress value, and the axial strain of the specimen; identifying a stress control target and a drainage control target within the test target, calculating a transverse stress target based on the true longitudinal stress value and the true axial stress value, generating a strain control matrix based on the stress control target, the drainage control target, the true axial stress value, the true longitudinal stress value, and the axial strain; and controlling the specimen to apply strain increments in three directions based on the strain control matrix to obtain simulation results of the true triaxial test. This method solves the problem in related arts that the simulation model for true triaxial testing cannot meet the requirements of various drainage conditions, resulting in low applicability and practicality.

The invention relates to the technical field of combined machining, in particular to a special-shaped ring rolling process method for tooth blank die forging forming, which comprises the following steps: circularly adjusting the rotating speed of a main roller and the feeding speed of a core roller of a ring rolling device in real time according to the actual rotating angle of an annular blank, and correcting the eccentric degree of the annular blank; reflecting the matching condition of the radial strain rate and the axial strain rate according to the change of the convex part of the annular blank, adjusting a correction parameter for correcting the eccentricity degree of the annular blank, and adjusting the holding roller compression rate of the rolling ring device to make up the change of the length of the convex part; estimating the required torque of the main roller and the maximum static friction, and judging whether the eccentricity of the corrected annular blank can cause the required torque of the main roller to exceed the limit or not; when the required torque of the main roller exceeds the limit, the adjusting amplitude of the rotating speed of the main roller and the feeding speed of the core roller is reduced, and the judgment standard for judging whether the eccentricity degree of the annular blank can be corrected or not is called back. The forming uniformity of the non-standard annular special-shaped tooth blank is improved by combining die forging with ring rolling.

The application relates to a kind of high strain rate under fiber concrete material dynamic axial tensile performance test method, comprising: setting Hopkinson tensile rod device, using the verified Hopkinson tensile rod device to pulse wave is applied to test piece, and the deformation of resistance strain gauge is collected;The deformation is converted into voltage signal, for calculating the strain of resistance strain gauge and the average compressive stress of test piece;Based on strain and average compressive stress, determine the dynamic tensile stress-strain relationship of test piece, according to the dynamic tensile stress-strain relationship of test piece, the dynamic tensile stress time history and dynamic axial strain time history are point by point corresponding pairing on time axis, and the dynamic tensile stress-strain curve of test piece under high strain rate is obtained.The application can make the performance test of fiber concrete and other materials under high strain rate more easily realized, provide the basis for the dynamic performance characterization of material, help the application and popularization of high-performance materials under extreme working conditions such as explosion impact.

The present invention discloses a pipeline leakage prediction method and system, belonging to the technical field of pipeline leakage monitoring. The present invention predicts leakage for buried pipelines that have not yet leaked. By establishing a corresponding relationship between the depth of the corrosion pit and the axial strain of the pipeline outer wall, and with the monitoring cooperation of an optical fiber measurement system, the present invention can effectively predict the leakage location and the time when a leak will occur in the buried pipeline that has not yet leaked, thereby preventing problems before they occur, eliminating the need to wait until the pipeline leaks before taking measures, greatly reducing the risk of explosions and the like caused by pipeline leakage, and facilitating its application in pipeline transportation in the fields of oil and natural gas.

The present invention provides a state monitoring method for an ultra-high pressure cylinder, comprising monitoring the ultra-high pressure cylinder through finite strain monitoring, temperature monitoring, key phase monitoring and plunger strain test calibration; polishing the symmetrical outer surface of a pipeline near the inlet and exhaust ports of the ultra-high pressure cylinder and pasting a temperature self-compensating strain gauge to test the axial strain and axial strain of the pipeline respectively; pasting a resistive temperature sensor near the strain gauge to test the temperature change of the inlet and exhaust pipelines, calculating the increased axial strain of the pipeline after the pipeline is heated and expanded according to the temperature change of the inlet and exhaust pipelines and the equivalent material linear expansion coefficient of the ultra-high pressure pipeline, thereby obtaining the pressure change in the inlet and exhaust pipelines; pasting a temperature self-compensating strain gauge on the symmetrical outer surface of the plunger tail end to test the axial strain of the plunger when the ultra-high pressure cylinder is working; accurately identifying the PV diagram of the working process of the ultra-high pressure cylinder, and realizing online monitoring of the ultra-high pressure compressor.

The invention relates to the technical field of marine flexible riser monitoring, in particular to a marine flexible riser axial strain monitoring and verification method. The strain monitoring device comprises a corrosion-resistant pipe clamp and a stepped shaft type strain rod, a fiber bragg grating sensor is packaged on the strain rod and is fixed on a vertical pipe through a metal pipe clamp, and the strain value of the vertical pipe is calculated through the change of the central wavelength of the fiber bragg grating sensor. The strain relation between the strain of the vertical pipe and the strain rod is obtained; finite element models of the riser and the strain monitoring device are established by adopting Ansys finite element analysis software, theoretical values of riser strain are calculated, the theoretical values are compared with simulation values, the strain monitoring device shows high accuracy, the actual monitoring accuracy is as high as 90%, the actual monitoring accuracy is remarkably improved compared with a traditional mode, and the reliability of monitoring data is ensured.

The present application provides a kind of microwave rock volume change measurement system and method thereof, including test cavity, microwave control device, strain measurement device, measurement circuit and resistance strain gauge;Test cavity is sealed cavity structure, and rock test piece is placed in test cavity;Microwave control device is set to the inside of test cavity;Strain measurement device includes hoop strain gauge and axial strain gauge, and strain measurement device is attached to rock test piece surface;Measurement circuit is connected with multiple strain measurement devices by lead, and resistance strain gauge is connected with measurement circuit.In the microwave emitted by microwave control device acts on rock test piece, data acquisition is carried out to rock test piece by multiple hoop strain gauges and axial strain gauges attached to rock test piece surface, and the volume change of rock test piece can be obtained by combining measurement circuit and resistance strain gauge, so as to exclude the volume change of liquid or gas caused by temperature change, and more accurately measure the size of the influence of microwave on rock volume.

A medical probe is presented including an expandable basket assembly coupled to a distal end of a tubular shaft. The basket assembly includes a cloverleaf cutout structure at its distal end and spines extending proximally from the cloverleaf structure and coupling to the tubular shaft. The cloverleaf structure includes a sinusoidal-like member extending from one spine to an adjacent spine in a direction around the longitudinal axis. Dimensions of the sinusoidal-like member can be configured to provide a lateral stiffness of the expandable basket assembly within a predetermined range and a maximum peak stress during retraction of the expandable basket assembly into an intermediate catheter such that the maximum peak stress is less than a predetermined threshold.

The application particularly relates to a cast stainless steel multiaxial low-cycle fatigue prediction method, which comprises the following steps: measuring or calculating the axial strain amplitude and the corresponding axial stress, the shear strain amplitude and the corresponding shear stress, and the phase difference between the axial strain amplitude and the shear strain amplitude of a cast stainless steel concerned part; calculating the equivalent axial strain amplitude and the equivalent shear strain amplitude of the cast stainless steel concerned part after correction and containing the influence of thermal aging; and substituting the equivalent axial strain amplitude and the equivalent shear strain amplitude of the cast stainless steel concerned part after correction and containing the influence of thermal aging and the phase difference therebetween into a cast stainless steel multiaxial low-cycle fatigue prediction model containing the influence of thermal aging to calculate the multiaxial low-cycle fatigue life and the fatigue crack direction of the cast stainless steel after thermal aging. The cast stainless steel multiaxial low-cycle fatigue prediction method can accurately predict the fatigue life of the cast stainless steel under multiaxial low-cycle fatigue loading and the direction of fatigue crack initiation and initial propagation.

The application discloses a kind of cavity-containing bolt pre-tightening force and temperature compound sensing optical fiber sensor and method, including bolt, glue and fiber grating, the cavity, longitudinal hole and transverse through hole are equipped in bolt, two transverse through holes are arranged in the cavity both sides, longitudinal hole sequentially passes through transverse through hole and internal cavity along bolt length direction, longitudinal hole is used to lay optical fiber, one half grating area of fiber grating is suspended and arranged at the cavity, the other half grating area surface is attached with metal plating layer and then is pasted in longitudinal hole by glue, since the cavity and longitudinal hole are different in bolt cross-sectional area, when bolt is subjected to axial stretching, two sections grating area will have different axial strain;Simultaneously after metal plating layer, there will be no chirp phenomenon, and metal plating layer can change the response coefficient of grating area to temperature.The application realizes the simultaneous monitoring of bolt temperature and force signal, and obtains accurate bolt temperature and force signal according to the different sensing coefficients of two parts of fiber grating to temperature and force.

The invention provides an optical fiber shape sensing system, method, medium and equipment, in the system, a sensing unit comprises a multi-core optical fiber, the multi-core optical fiber is provided with at least three eccentrically distributed sensing cores and a central core, each sensing core is inscribed with a fiber bragg grating used for sensing axial strain caused by bending and torsion, and the central core is provided with a fiber bragg grating used for sensing the axial strain caused by bending and torsion. The central core is used for providing temperature compensation reference; the signal processing unit is used for receiving the original wavelength and strain data acquired by the sensing unit and executing filtering, temperature compensation and curvature and torsion calculation processing; and the shape reconstruction and display unit reconstructs a three-dimensional space curve through numerical integration based on the geometric parameters output by the signal processing unit, and realizes real-time visual display of a three-dimensional shape. According to the invention, high-precision and high-stability optical fiber shape sensing can be realized in a complex dynamic scene, and application requirements of complex scenes such as medical catheter navigation and flexible robot control can be met.