23 results about "In plane strain" patented technology

The invention relates to the technical field of coal mining and rock mechanics numerical simulation, and discloses a stress field reconstruction method of a plane strain numerical simulation model for coal mining, and the method comprises the following steps: firstly, obtaining an actually measured vertical stress increment and an actually measured bearing pressure peak value position of a stope face; then, an initial plane strain numerical simulation model is constructed, the space error between the peak position of the simulated bearing pressure and the actual measurement position meets a preset threshold value by adjusting the excavation step pitch, and therefore the numerical simulation calculation state is locked to eliminate space-time dislocation; a simulation strain increment is extracted in a locked state, a theoretical vertical stress difference equation is constructed based on an elastic mechanics plane strain constitutive relation, and a parameter inversion equation set is established in combination with multi-measurement-point data; and solving the corrected elastic modulus and Poisson's ratio by using a least square optimization algorithm. According to the method, through physical state locking and incremental theory inversion, system errors are effectively eliminated, and the reconstruction precision and mechanical preciseness of the mining-induced stress field are improved.

The application discloses a strip filling body damage mode plane strain testing device and method. The testing device comprises a container (10), a containing cavity (101) with an open end, and at least one end face of the container (10) is a transparent face; a test piece (20) provided with a speckle on the surface and arranged in the containing cavity (101); a loader (30) comprising a pressing column (31) and arranged at the open end of the container (10) and configured to apply a load to the test piece (20); and a digital speckle device (40) comprising a high-definition camera (41) arranged at the transparent face of the container (10) and configured to acquire deformation image information of the test piece (20), analyze and calculate the image information to obtain stress and strain values of the test piece (20), and combine the stress and strain values with the image to analyze and obtain a damage mode of the test piece (20).

The application discloses a hydraulic fracture translayer extension simulation method based on DDM-perturbation iteration coupling, belongs to the field of oil and gas field development engineering, and aims to solve the problem of insufficient simulation precision of asymmetric translayer extension of a horizontal well hydraulic fracture in stratified non-uniform rock mass. The method is based on a plane strain assumption, constructs a stratified rock mass model containing stratified fracture toughness, establishes a mechanical equation through a displacement discontinuity method (DDM), introduces a perturbation iteration method to dynamically adjust flow distribution, automatically adapts to new rock layer fracture toughness to update and expand criteria during translayer, and outputs vertical extension form and parameters. The method can be used for simulating translayer behavior of a horizontal well vertical fracture, improving calculation precision and efficiency, and providing a reliable tool for fracturing design of shale gas reservoirs and the like.

A rolling load distribution calculation method for a rolling mill (10) comprises the steps of: calculating the rolling load distribution of a rolling mill (10) on the basis of the Hooke's law of the plane strain state of a material to be rolled (1) and the balance of the force in the roll gap of the rolling mill (10) by using a rolling direction stress distribution approximated by a function dependent on the position coordinates of the rolling direction of the rolling mill (10); calculating the contact arc length of at least one of the elastic recovery area and the elastic depressed area; and calculating a rolling load distribution of at least one of the elastic recovery region and the elastic depression region on the basis of the contact arc length.

The present invention provides a method and system for predicting the fracture toughness of a steel material, a device, and a medium. The method comprises: acquiring carbon content distribution data of a steel material under test, selecting a carbon content from the carbon content distribution data and designating same as a target carbon content; calculating upper shelf impact energy and a temperature offset of the target carbon content by means of a first calculation model; generating a fracture toughness curve for the target carbon content on the basis of the upper shelf impact energy and the temperature offset; calculating tensile strength corresponding to the target carbon content by means of a second calculation model, and calculating yield strength corresponding to the target carbon content by means of a third calculation model; generating a blunting line equation for the target carbon content on the basis of the tensile strength and the yield strength; on the basis of the fracture toughness curve and the blunting line equation, generating plane-strain fracture toughness corresponding to the target carbon content; and collecting statistics about the plane-strain fracture toughness corresponding to each target carbon content to generate fracture toughness data of the steel material under test. The present invention can provide input for assessment of the ductile tearing failure of carbon-segregated structures.

The application provides a microcapsule self-repairing material constitutive curve prediction method and device, and relates to the technical field of tunnel and underground engineering materials, and aims to solve the problem that the mesoscopic mechanics model cannot reflect and predict the softening stage after the peak value of a cement-based material in the prior art. The method comprises the following steps: if the self-repairing concrete material is a conventional concrete material, calculating the constitutive curve of the conventional concrete material under tensile load in a plane strain condition; if the self-repairing concrete material is a microcapsule self-repairing concrete material containing a strong healing agent, calculating the constitutive curve of the microcapsule self-repairing concrete material containing the strong healing agent under tensile load in a plane strain condition; and if the self-repairing concrete material is a microcapsule self-repairing concrete material containing a weak healing agent, calculating the constitutive curve of the microcapsule self-repairing concrete material containing the weak healing agent under tensile load in a plane strain condition. The microcapsule self-repairing material constitutive curve prediction device is applied to the microcapsule self-repairing material constitutive curve prediction method.

The invention provides a GISSMO model parameter calibration method and system based on a local formability characterization test. The method comprises the steps that fracture strain data and a load-displacement curve of a material in four stress states of shearing, plane strain, uniaxial stretching and equal biaxial stretching are obtained through the local formability test; based on the obtained fracture strain data and the corresponding stress three-axis degree, fitting to obtain a stress three-axis degree-fracture strain curve of the material; inputting the obtained stress triaxial-fracture strain curve and a large deformation equivalent stress-strain curve obtained through a shear test into a material model of finite element simulation software; and taking the obtained load-displacement curve as a target curve for simulation optimization, and calibrating damage parameters of the GISSMO model by using an optimization algorithm to obtain GISSMO damage model parameters. According to the method, a complete solution is formed through process optimization, and finally, the accuracy, reliability and efficiency of parameter calibration of the GISSMO model are comprehensively improved.

The invention provides a special-shaped grouting anchor rod supporting system and a model selection construction method, and belongs to the technical field of underground engineering. The method comprises the steps that firstly, physical and mechanical parameters of surrounding rock, grouting and a supporting structure are obtained; then a plane strain mechanical analysis model of the tunnel-grouting body-surrounding rock-supporting structure is established; a finite element numerical simulation calculation model is established based on the model, and mechanical responses of various special-shaped grouting body sections under the same grouting amount are analyzed; comprehensively evaluating and preferably selecting an optimal grouting body section form by taking mechanical response data as a judgment index and adopting a multi-index decision-making method such as an analytic hierarchy process; and finally, anchor rod arrangement and grouting parameters are determined according to the optimized section for construction, and a closed special-shaped grouting body is formed. According to the special-shaped grouting anchor rod supporting system and the model selection construction method, active optimization of surrounding rock stress distribution is achieved, plastic zone development and tunnel deformation are effectively controlled, and the supporting effect and economical efficiency are improved.

The invention discloses a method for calculating the working resistance of a temporary support unit bracket for gob-side entry retaining. The method comprises the following steps: S1, acquiring roof related parameters, coal body related parameters, roadside support body related parameters and unit bracket arrangement parameters; s2, simplifying the basic roof into a plane strain beam structure, and constructing a basic roof bending moment calculation formula; s3, determining an X0 coordinate corresponding to the maximum bending moment position according to the basic top bending moment calculation formula constructed in the S2 in combination with related parameters of the top plate, and defining the position corresponding to the X0 as a basic top fracture position; s4, establishing a mechanical equilibrium formula according to the fracture position of the basic roof, the relevant parameters of the roadside support, the arrangement parameters of the unit bracket and the relevant parameters of the coal body to calculate the supporting force of the unit bracket on the roof; and S5, correcting the supporting force of the unit brackets on the top plate according to the center distance between two adjacent unit brackets and the utilization rate of the working resistance of the unit brackets to obtain the minimum value of the working resistance of the unit brackets. And related personnel can be helped to quickly estimate the temporary support resistance requirement beside the roadway.

The application provides a special-shaped grouting anchor rod supporting system and a selection construction method, and belongs to the technical field of underground engineering. The method first acquires physical and mechanical parameters of surrounding rock, a grouting body and a supporting structure; then a plane strain mechanical analysis model of a tunnel-grouting body-surrounding rock-supporting structure is established; based on the model, a finite element numerical simulation calculation model is established to analyze the mechanical response of various special-shaped grouting body sections under the same grouting amount; then, the mechanical response data are used as a judgment index, a multi-index decision method such as an analytic hierarchy process is adopted, and the optimal grouting body section form is comprehensively evaluated and optimized; finally, according to the optimized section, the anchor rod arrangement and grouting parameters are determined for construction to form a closed special-shaped grouting body. The application adopts the special-shaped grouting anchor rod supporting system and the selection construction method, realizes active optimization of the stress distribution of the surrounding rock, effectively controls the development of the plastic zone and the tunnel deformation, and improves the supporting effect and economy.

The invention relates to the technical field of geotechnical engineering and road engineering, in particular to a calculation method suitable for bag pipe method grouting lifting roadbed soil body additional stress. A soil body stress field caused by bag pipe grouting is decomposed into a classical Lame solution (field B) of internal pressure borne by a drill hole in an infinite body and a correction stress field (field C) introduced for eliminating free surface stress; the method comprises the following steps of: establishing a rectangular coordinate system, converting a stress component under polar coordinates into a rectangular coordinate form, and respectively calculating stress fields caused by vertical and shear distribution loads by utilizing a Flamant solution and a horizontal point load influence function under a plane strain condition; and finally, the additional stress distribution caused by the bag pipe grouting in the semi-infinite soil body is obtained through the stress solution of the superposition field B and the field C. The method has the advantages that the coupling effect of the drill hole boundary and the free surface is considered, the method is suitable for stress prediction and control in roadbed lifting engineering, and the method is rigorous in theory and high in calculation precision.

The application discloses a pipeline structure health monitoring and landslide early warning method and system, and the method comprises the following steps: S1, a centrifugal simulation test platform is built; S2, strain data collected by the centrifugal simulation test platform is acquired; S3, based on plane strain theory, the collected strain data is pretreated, including main strain calculation, azimuth calculation and data denoising; S4, data analysis is carried out on the pretreated data, including coupling law analysis and parameter influence quantitative analysis, and key influence laws are obtained; and S5, based on the key influence laws, early warning criteria are customized, and finally, a two-level early warning system is built, so that the real-time calculation and early warning of the azimuth and the main strain are realized. The application combines the main strain amplitude and the spatial azimuth, makes up for the defects that the traditional method only analyzes the strain size and ignores the direction, and realizes the accurate quantitative analysis of the mechanical response under the three-dimensional multi-axial stress of the pipeline.

The present application relates to geotechnical engineering and road engineering technical field, especially a kind of additional stress calculation method suitable for capsule pipe method grouting lifting roadbed soil body, based on the superposition principle in elasticity, the soil stress field caused by capsule pipe grouting is decomposed into the classic Lame solution (field B) of the borehole under internal pressure in infinite body and the correction stress field (field C) introduced to eliminate the stress of free surface;By establishing rectangular coordinate system, the stress component under polar coordinates is converted into rectangular coordinate form, and the stress field caused by vertical and shear distribution load is calculated respectively by using Flamant solution and horizontal point load influence function under plane strain condition;Finally, the additional stress distribution caused by capsule pipe grouting in semi-infinite soil body is obtained by superimposing the stress solution of field B and field C.The present application has the advantages that the coupling effect of borehole boundary and free surface is considered, it is suitable for stress prediction and control in roadbed lifting engineering, and it has the advantages of rigorous theory and high calculation precision.

The application provides a method for determining displacement-related earth pressure of a pile wall type foundation pit support structure in a sandy soil layer. The method can determine the pore ratio and relative density of each layer of soil in the foundation pit support by sampling, carry out a plane strain loading / unloading test, draw a stress-strain curve, calculate the internal friction angle, initial modulus and failure ratio of the soil, and finally obtain the active and passive earth pressure at any depth of the support structure. The method can calculate the active and passive earth pressure of the pile wall type foundation pit support structure in the sandy soil layer under any displacement, and can consider the influence of the layering of the soil, is more in line with the actual situation, has clear technical scheme steps, and has a simple calculation method. The method can be used in actual engineering to reduce the manpower and material resources, reduce the waste of support materials, and has good popularization and application value.

The application provides a Hill48 yield criterion parameter calibration method based on metal pipes, wherein the axial yield stress sigma0 is obtained through an axial tensile test, the circumferential yield stress sigma is obtained through a circumferential tensile test, the axial yield stress sigma of a plane strain state is obtained through a plane strain state tensile test, the values of Hill48 yield criterion parameters F, G and H are obtained by substituting sigma0, sigma and sigma into an equation group, the value of Hill48 yield criterion parameter N is inversely calculated based on a GA genetic optimization algorithm through the axial tensile test and finite element simulation, and the accurate calibration of the Hill48 yield criterion parameters F, G, H and N is completed. 90 p 90 p The method can provide accurate parameters for metal pipe plastic forming process simulation, and further more accurately simulate plastic deformation behaviors of the metal pipe in a bending process, including wall thickness change rate, cross section distortion and springback and the like.​​​

A method for calculating the rolling load distribution of a rolling mill 10, comprising: calculating the contact arc length of at least one of the elastic recovery and elastic reduction regions based on Hooke's law under the plane strain condition of a rolled material 1, the force balance within the belt-roll contact of the rolling mill 10, and the stress distribution in the rolling direction approximated by a function that depends on the position coordinate in the rolling direction of the rolling mill 10; and calculating the rolling load distribution of at least one of the elastic recovery and elastic reduction regions based on the contact arc length.

The application discloses a design method of a horizontal variable stiffness foundation pit supporting structure, which comprises the following steps: three-dimensional modeling of the foundation pit supporting structure; analysis of lateral displacement of the supporting structure and calculation of a plane strain ratio; for a region with a plane strain ratio less than 1, the structure stiffness is redundant, the corner effect of the foundation pit is considered, the row piles are connected with the concrete support, and stiffness adjustment is performed according to an optimized expression of the plane strain ratio; for a region with a plane strain ratio equal to 1, two groups of row piles are arranged and connected with the concrete support through an active stiffness adjusting device. The application further discloses the horizontal variable stiffness foundation pit supporting structure obtained by the design method. The corner effect of the foundation pit (restraint of the foundation pit deformation by a reentrant corner) is utilized, the stiffness of the supporting structure is divided into regions by introducing the plane strain ratio, and variable stiffness design is performed, so that the cost can be effectively reduced, large deformation of the middle section of the supporting structure can be reduced, and the influence of the foundation pit construction on the surrounding environment can be reduced.

The application discloses a kind of composite film-base structure's sliding failure evaluation method, first, by modeling composite film as no traction model, the mechanical parameters of composite film are obtained analytically, parameter establishes new constitutive relation, subsequently using new constitutive relation gets the equilibrium equation and control equation of composite beam-soft base structure before sliding, finally by solving equation can obtain the interface sliding failure judgment criterion suitable for composite film-soft base structure model.Through analysis model, it can be concluded that the composite film-soft base structure model can be degraded to the single-layer film-soft base structure model under the plane strain assumption, and the risk of introducing error by the plane strain model is eliminated.The sliding failure evaluation method of composite film-base structure can determine whether the interface of flexible electronic device of composite film-soft base structure has sliding failure, which is closer to the actual engineering situation and eliminates the limitations of existing methods.

The application discloses a clamping mechanism for a hot simulation test device and a sample compression method, relates to the technical field of metal material thermal deformation, and discloses a clamping mechanism for a hot simulation test device, which is used for clamping a sample, and the hot simulation test device comprises a driving piece and two clamping grooves. According to the technical scheme, the clamping mechanism is used for clamping the sample, the hot simulation test device comprises the driving piece and the two clamping grooves, clamping components are arranged on both sides of the thickness direction of the sample, and the plane of the sample is contacted with the conductive element, so that the plane strain state of the sample in the hot compression test simulation plate rolling process is realized, stress concentration and bending effect caused by uneven contact of the traditional knurled side are avoided, the simulation of the plane strain state is more accurate and reliable, and the accuracy and repeatability of test data are improved; the driving piece is used for controlling the movement of the clamping grooves, the clamping components can be flexibly adjusted in position, and stress distribution of the sample in the hot simulation test is closer to the actual rolling state.

The application discloses a kind of high magnesium aluminum alloy of marine high temperature temperature control rolling parameter optimization method.This method is: from the square block sample of plane strain hot simulation in aluminium alloy;Hot simulation plane strain compression is carried out, and the orthogonal experimental data of high temperature hot simulation true stress-true strain is obtained;Based on the theory of irreversible thermodynamics, power dissipation diagram and plastic instability diagram are constructed;Power dissipation diagram and plastic instability diagram are superimposed to obtain the hot processing diagram of the aluminium alloy at the set temperature, and the safe area and instability area are divided, and the process parameters in the process of high temperature temperature control rolling are determined according to the safe area under different strains, to obtain the rolling piece that meets the requirements of size accuracy and mechanical properties.In the technical scheme of the application, three-dimensional processing diagram reflects the influence of deformation temperature, strain and strain rate on the hot deformation processability of material, and can comprehensively reflect the processability of material, and perfectly process design and optimization for high temperature temperature control rolling.

Method for identifying a plastic deformation of material of an object in situ using strain sensors operating on the principle of electrical resistive strain gauging, fibre optic measurements using fibre Bragg gratings (FBG), vibrating wire sensors ( )VW, distributed fibre optic sensors (DFOS), inductive, capacitive, or piezoresistive sensors, in which in the monitored area (W) subjected to any load condition, there are placed at least four strain sensors (εs) constituting at least two rosettes (I), (II) turned with respect to each other by any angle (α) other than zero and freely shifted with respect to each other by a vector (V) for measuring any plane strain condition, the rotation angle and the displacement of the rosettes (I), (II) are chosen so that no more than two sensors (εs) between the rosettes are parallel to each other or lie on the same straight line, at least two principal strain states (ε1, ε2) and principal stresses (σ1, σ2) respectively are determined for the monitored area (A), and by monitoring the object, increments of principal strains (Δε1), (Δε2) and / or increments of principal stresses (Δσï), (Δσ2) are calculated, in successive moments of time, for each separated rosette, which below the yield point of the monitored area are proportional between the rosettes, on this basis, the plastic deformation of material indices are determined, and by monitoring the area the yield point is detected at the moment of disappearance of the proportionality of the increments, i.e. a sudden change in the value of the determined yield indices normal to the state below the yield point of a given area.

The embodiment of the invention provides a method for controlling the shape of a hyperelastic plane strain plate in a gravity environment and related equipment, and belongs to the technical field of flexible materials and intelligent structures. The method comprises the following steps: firstly, establishing a hyperelastic plate control equation considering physical strength based on a finite strain theory, and deducing a dimensionality reduction plate equation through asymptotic analysis; secondly, innovatively analyzing and inversely solving an explicit expression of a growth function required for realizing any given target curved surface, and establishing an analytic relationship among a growth field, target shape geometric characteristics and physical power; and finally, preparing a pre-strain sample by designing a mold corresponding to the target configuration, and physically realizing a growth field. The gravity is converted into a design variable from an interference factor, the influence of the gravity is compensated through growth deformation, so that the plane strain plate structure with one side clamped and supported accurately keeps the expected shape under the gravity, and the method has the advantages of being high in control precision, high in design efficiency and easy to implement and can be applied to the fields of soft robots, space deployable structures and the like.

The invention discloses a method for calculating bearing deformation of a plastic drainage plate foundation. The method includes the steps of setting the distance between drain boards in a plane strain model, selecting a proper unit type to simulate the drain boards, calculating and setting the equivalent width of the drain boards in the plane strain model, calculating and setting the equivalent horizontal permeability coefficient of foundation soil in the plane strain model, setting boundary conditions of the plane strain model and executing calculation. According to the method, the principle that the displacement per unit volume in a plane strain model and the displacement per unit volume in an axial symmetry model are equal is followed, the hydraulic gradient changing along with the consolidation process and the smearing effect and the well resistance effect of the drainage plate are considered, and a certain average consolidation degree does not need to be empirically selected in advance to serve as the requirement for matching conversion of the plane strain model; and a reasonable selection basis of the type of the drain board unit is given, modeling calculation of the drain board foundation can be rapidly completed, and a more accurate and reliable numerical simulation tool is provided for related design and calculation analysis of the drain board foundation.