17 results about "Strain difference" patented technology

The invention provides a concrete normal section reinforcement design method and system, electronic equipment and a storage medium. The method comprises the following steps: establishing a section stress model containing multi-layer reinforcement strain distribution based on plane section assumption; the stress state of the whole process of the section from axle center compression to axle center tension is simulated by setting strain proportion parameters of the strain of the outermost reinforcing steel bar on the tension side and the limit pressure strain of the concrete; aiming at a plurality of set strain state control points, calculating stress of each steel bar layer position, contribution of the stress to axial force and bending moment and contribution of the stress to a concrete compression area; and based on the section static balance condition, the optimal reinforcement area meeting the design load requirement is determined through iterative calculation, and the configuration constraint of multiple layers of steel bars is considered in the iterative calculation. The method overcomes the defects that a traditional method overestimates the effect of the pressed steel bars and ignores the strain difference of multiple layers of steel bars, and the accuracy and safety of reinforcement design of high-performance concrete structures such as nuclear islands are remarkably improved.

The invention provides a gravity angle sensor, a calibration method thereof and a gravity compensation method applying the gravity angle sensor, and belongs to the technical field of sensors and intelligent control. The sensor comprises a sensor frame, a flexible spring piece assembly, a mass block and a differential strain measurement unit, the flexible spring piece assembly is symmetrically connected with the mass block and the sensor frame, and the flexible spring piece assembly is configured to generate bending deformation perpendicular to the axial direction of the flexible spring piece assembly under the action of a gravity component; the differential strain measurement units are arranged on the convex side and the concave side when the flexible spring piece is bent and used for detecting the bending strain difference perpendicular to the axial direction. High-precision and real-time gravity compensation under a dynamic working condition is realized by calibrating a maximum strain difference value, measuring a current strain difference in real time, calculating a specific value and directly generating a gravity compensation amount without resolving an attitude angle and breaking through range limitation of a cosine function. According to the scheme, mechanical friction is eliminated, sensitivity and stability are improved, and the method is suitable for high-dynamic force control systems such as robots and precision platforms.

The application provides a somatosensory method and system based on an intervertebral fusion cage with an optical fiber inside, and relates to the technical field of intervertebral fusion cages. The method comprises arranging four cascaded optical fiber units arranged in the same direction and in a quadrangular distribution inside four support crossbeams of the intervertebral fusion cage respectively. When the intervertebral fusion cage is pressed, the support crossbeam arranged above the bone window is elastically deformed, four fiber gratings generate corresponding strains, the total pressure received by the intervertebral fusion cage is calculated according to the total strain generated by the four fiber gratings; the moment Mx in the X direction received by the intervertebral fusion cage is calculated according to the strain difference generated by the left two fiber gratings and the right two fiber gratings; the moment My in the Y direction received by the intervertebral fusion cage is calculated according to the strain difference generated by the front two fiber gratings and the back two fiber gratings; the motion state of the lumbar vertebrae is judged through the total pressure, the moment Mx and the moment My, and then the intervertebral fusion condition is evaluated.

This invention discloses a method for analyzing long-distance strain data of distributed fixed-point strain optical cables, comprising the following steps: S1, acquiring a set of first data and a set of second data for the effective detection segment of the optical cable, and subtracting them to obtain a set of strain difference values; S2, generating a first position-strain difference curve; S3, dividing the first position-strain difference curve into multiple sequentially connected intervals based on peak noise points; S4, dividing each interval of the optical cable into multiple sequentially connected sub-segments based on the fixed-point spacing; S5, acquiring a set of strain difference values ​​for each sub-segment of the optical cable, and selecting the average value of the strain difference values ​​at the non-endpoint positions of the sub-segment; S6, generating a second position-strain difference curve, and further generating the distance-displacement curve of the optical cable based on this. This invention employs a step-by-step screening mechanism to extract effective points, preserving true strain information while eliminating sampling bias, achieving data denoising, and overcoming the limitation of not being able to comprehensively denoise.

The present invention provides a method and system for detecting the anti-slip performance of a cable clamp based on multi-point stress and strain monitoring, which relates to the technical field of cable net structural components. The method includes: applying graded loads to the target cable body through a hydraulic tensioning module to perform strain monitoring and obtain a dynamic strain data set; calculating the strain difference between the contact surface of the cable clamp and the main cable to obtain strain difference accumulation data, performing change identification calculation to obtain a local strain parameter set, including local strain gradient distribution parameters and local slip parameters; identifying the slip starting position and determining the anti-slip safety factor interval; performing cable clamp slip analysis, generating a slip distribution diagram for safety assessment, performing cable clamp anti-slip performance testing, and constructing a performance test report. The present invention solves the technical problem that the prior art often evaluates the anti-slip performance of the cable clamp by applying static loads to the cable clamp and recording its displacement, which cannot fully grasp the evolution process of the cable clamp's anti-slip performance, thus affecting the reliability assessment of the cable clamp.

The application discloses a three-dimensional in-situ stress measuring method based on core diameter radial strain observation, first obtains the maximum and minimum directions of the core diameter and the axial direction, marks and establishes X, Y and Z axis coordinate systems, then arranges six strain gauges on the core side walls corresponding to the X axis and the Y axis and the 45-degree line between the X axis and the Y axis, obtains the inelastic strain of the core on the X, Y and Z axes through the data of the strain gauges, and finally calculates the main stress size corresponding to the three-dimensional X, Y and Z axis directions according to the inelastic strain difference. The method is simple, economical and accurate, and only six strain gauges are needed to measure the in-situ stress, so that the test process is greatly simplified and convenient.

This invention provides a method for adaptive and coordinated tension control in cable stranding processes, comprising: deploying a high-sampling-rate distributed fiber optic strain sensor array at key equipment nodes to acquire multi-point micro-strain signals in real time; performing sliding window phase space reconstruction and persistent cohomology calculation on the strain difference sequence through topological data analysis to dynamically generate a topological perturbation index characterizing structural disturbances; employing an adaptive threshold determination method to promptly detect potential instability; and utilizing a feedforward compensation algorithm based on graph attention networks to generate and project compensation commands to the servo driver. The method also includes a topological consistency verification and online fine-tuning mechanism to improve response robustness and adaptability. This invention enables early warning, accurate identification, and effective intervention of tension field structural instability during cable stranding, improving product processing stability and equipment operational reliability.

A method and an apparatus monitor the physical state of a suspension means that is connected to an elevator car and can move the same. The support means has markings along its length that divide the support means into segments. The strain difference of the suspension means is monitored segment by segment using a first strain at a first load and a second strain at a second load being determined by a signal processing unit from a distance between two selected markings detected by a detection device, and a strain difference representing the elastic behavior of the segment is calculated from the two strains, wherein the load acting on the suspension means between the two selected markings is measured by a load measuring device.

The invention relates to a tunnel surrounding rock crustal stress rapid determination and verification method based on secant modulus, and belongs to the technical field of geotechnical engineering testing. The method comprises the following steps: firstly, sampling from a drill hole, sampling a directional thick rock core, and drilling cylindrical rock samples in all directions in the thick rock core; then preloading the rock sample for specified time; the method comprises the following steps: performing uniaxial compression on a sample at a higher level, synchronously acquiring axial and radial strain data by using a strain gauge in the compression process, and drawing a stress-strain curve; obtaining a strain value of a corresponding stress increment by using a secant modulus; calculating a strain difference by using a strain difference function to obtain a characteristic SMM curve; determining a normal stress through a strain difference function, establishing a simultaneous equation to solve a stress tensor, and obtaining the size and direction of a principal stress through eigenvalue analysis; the crustal stress measured by the secant modulus method is substituted into the calculated displacement, and degradation correction is carried out by considering the influence of construction disturbance; and comparing the actually measured displacement with a theoretical calculation value for verification.

The invention discloses an analysis method for long-distance strain data of a distributed fixed-point strain optical cable, and the method comprises the following steps: S1, obtaining a group of first data and a group of second data of an effective detection section of the optical cable, and carrying out the subtraction, thereby obtaining a group of strain difference values; s2, generating a first position-strain difference curve; s3, dividing the first position-strain difference curve into a plurality of interval sections which are connected in sequence according to the peak noisy points; s4, averagely dividing each interval section of the optical cable into a plurality of sub-sections which are connected in sequence according to the fixed-point spacing; s5, acquiring a group of strain difference values of each sub-segment of the optical cable, and selecting an average value of the strain difference values of the non-endpoint positions of the sub-segments; and S6, generating a second position-strain difference curve, and further generating a distance-displacement curve of the optical cable according to the second position-strain difference curve. According to the method, a step-by-step screening mechanism is adopted, effective points are extracted, real strain information is reserved, sampling deviation is eliminated, data denoising is achieved, and the limitation that comprehensive denoising cannot be achieved is overcome.

The invention provides a plate two-way stretching stress instability judgment method based on load control, and relates to the technical field of two-way stretching. Comprising the following steps: determining a biaxial tensile test proportion of a material and preparing a sample; determining that the contour shape of the overlapping area of the two stretching axis directions of the sample is a rectangle or a regularized shape, and forming an inner rectangular contour shape and an outer rectangular contour shape in the overlapping area of the sample; sticking mark points on inner and outer contour side lines and a central point; starting a two-way tensile test in a load or stress control mode, and outputting a strain-time curve of outer and inner contour side lines in a tensile direction; calculating the strain difference value of the inner contour side line and the outer contour side line, and judging an instability moment when the strain difference value reaches 0.8-1.2% of the maximum strain of the inner contour side line and the strain of the inner contour side line reaches 9.5-10.5% of the maximum strain of the inner contour side line; comparing the instability moments in all the stretching directions, and taking the stress corresponding to the stretching axis which is unstable at the earliest as the instability stress of the material in the current stretching proportion; and inputting the instability stress into finite element software, and judging the forming safety of the plate.

The invention relates to the technical field of material parameter measurement, in particular to a finite element analysis method for accurately characterizing material characteristics, which comprises the following steps: establishing a finite element model with the same size as a uniaxial tensile sample, endowing the test with a stress-strain curve, and performing uniaxial tensile simulation on the finite element model; selecting a calculation area in the finite element model after simulation is completed, extracting stress of at least two analysis moments in the area, calculating stress difference, selecting an area with the stress difference smaller than 5% as a determined correction area, and calculating the length of the correction area; carrying out a uniaxial tensile test on the sample with the same size as the uniaxial tensile sample; the corrected stress-strain curve is endowed to a finite element model, and uniaxial stretching simulation is carried out; and obtaining a stress-strain curve of the finite element according to the corrected area and by respectively calculating the stress and the strain until the maximum strain difference value between the corrected stress-strain curve and the stress-strain curve of the finite element is smaller than a preset value. According to the method, the working efficiency and the analysis precision can be greatly improved.

The invention provides a pile lateral displacement determination method based on distributed optical fiber strain sensing, which comprises the following steps: acquiring strain data of each node of a pile body acquired by distributed optical fibers, at least one distributed optical fiber being arranged on the side wall of the pile body along the axial direction of the pile body so as to measure the strain data of each node position uniformly spaced along the axial direction of the pile body; and according to the strain difference value collected by the two adjacent nodes of the pile body, the direction factor of each segment of the pile body is determined, and the total displacement of the pile body in the horizontal direction is calculated based on the strain data of the nodes and the direction factor of each segment of the pile body. According to the method, the direction factor is calculated through the strain difference value between the two adjacent nodes, the lateral displacement of the pile body is dynamically corrected by introducing the direction factor and a nonlinear pattern conversion mechanism, accurate synthesis and direction dynamic calibration of the deep displacement of the pile body are achieved, and therefore the calculation precision of the lateral displacement of the pile body is improved.

A silk-covered wire hardness change trend prediction and evaluation method belongs to the technical field of material performance evaluation, and comprises the following steps: acquiring a surface strain value and a core strain value of a silk-covered wire in a bending process, calculating a strain difference value, synchronously acquiring bending radius, grain boundary migration distance and microcrack initiation distribution data, and constructing a comprehensive damage data set; a dislocation density cumulant mapping relation is established according to the strain difference value, and the hardening degree grade is determined; the surface damage depth is calculated by combining the grain boundary migration distance and the microcrack initiation distribution data, and the microcrack initiation probability is determined; and performing correlation analysis on the microcrack initiation probability and the bending radius, determining the position of a softening turning point, dynamically adjusting the hardness prediction range, performing bending life simulation, and outputting a residual life evaluation result. The full-chain analysis from microscopic damage to macroscopic life prediction is realized, the reliability evaluation precision of the silk-covered wire in a high-stress environment is remarkably improved, and a scientific basis is provided for preventive maintenance.

The application is suitable for the field of nuclear power technology, and provides a strain gauge fault analysis method and device and electronic equipment, including: obtaining a plurality of first measured strain values of a to-be-analyzed strain gauge in a target time length, the to-be-analyzed strain gauge being a strain gauge pre-buried in a containment; for any one of the plurality of first measured strain values, adjusting the first measured strain value according to a temperature value corresponding to the to-be-analyzed strain gauge and / or a temperature value of an environment where the to-be-analyzed strain gauge is located; determining a strain difference according to a plurality of adjusted first measured strain values; if the strain difference is greater than a preset first strain difference threshold, it is determined that the to-be-analyzed strain gauge is suspected to have a wiring error. Through the above method, the troubleshooting efficiency of finding a strain gauge suspected to have a wiring error can be improved.

The application discloses a combined estimation method for tire vertical force and side force based on in-utero strain analysis, and comprises the following steps: S1, establishing a tire finite element three-dimensional model; S2, calculating a tire grounding angle φ and a grounding length L based on the tire finite element three-dimensional model established in the step S1 according to in-utero strain; S3, estimating a tire vertical force F based on the tire grounding angle φ and the grounding length L calculated in the step S2 by using a support vector regression machine; S4, simulating and calculating a tire side deflection working condition by using the tire finite element three-dimensional model, taking a last valley value h2 of a side deflection circumferential strain difference curve as a characteristic of a side deflection force F ; S5, establishing a combined estimation model for the vertical force and the side deflection force based on the characteristic h2 of the tire vertical force F and the side deflection force F, and estimating an actual side deflection force of the tire. c c z y z y The application is applicable to static load, rolling and side deflection working conditions, can accurately estimate the vertical force and the side deflection force, and the error between an estimated value and a finite element simulation value is less than 3%.​​​​​

The invention discloses a composite material in-situ equivalent performance inversion method and system, and relates to the field of engineering and material science, and the method comprises the steps: obtaining the strain field data of a to-be-inverted region; based on the strain field data and the physical information neural network, under soft constraints and hard constraints, determining a trace of a stiffness matrix corresponding to the minimum loss function; determining a non-uniform modulus field of the composite material sample according to the trace of the stiffness matrix, and performing FEM simulation based on the non-uniform modulus field to obtain an FEM simulation result; according to the stress value of FEM simulation, updating the boundary constraint, and iteratively executing the above steps until the strain difference value reaches a convergence threshold value; and determining a non-uniform modulus field based on a trace of a stiffness matrix output by the physical information neural network when the strain difference value reaches a convergence threshold, and completing in-situ equivalent performance inversion of the composite material sample. According to the method, in-situ equivalent performance inversion can be carried out on the non-uniform composite material, and the overall implementation mode is relatively simple.