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16 results about "Strain softening" patented technology

• Strain softening is referred to as a behaviour where the shear resistance (or shear stress) reduces with continuous development of plastic shear strains. • So we cannot use stress path tests to study strain softening.

Wheel disc tenon and groove broaching force regulation method and system

ActiveCN120715288BBroaching machinesFlow stressBroaching
The present application relates to the turbine disc and compressor disc processing and manufacturing technical field of aero-engine, gas turbine, etc., and discloses a wheel disc mortise broaching force regulation and control method and system, the method comprises the following steps: obtaining broach geometric parameters, broaching process parameters and workpiece material physical properties; based on the broach geometric parameters, the broaching process parameters and the workpiece material physical properties, the shear flow stress on the main shear surface in the cutting process is calculated, and the cutting force considering the strain softening and temperature-strain rate coupling effect is further calculated; based on the broach geometric parameters and the shear flow stress, the edge extrusion force caused by the broach edge roundness radius is calculated; the broaching force and the edge extrusion force are superimposed to obtain the wheel disc mortise broaching force; according to the wheel disc mortise broaching force, the broach geometric parameters and the broaching process parameters are adjusted and controlled, and then the wheel disc mortise broaching force is optimized to meet the actual processing requirements, which provides support for reducing the tool optimization design cost and improving the wheel disc processing quality.
Owner:ZHEJIANG SCI-TECH UNIV +1

A shallow foundation bearing capacity calculation method fusing machine learning and non-local algorithm

This invention discloses a method for calculating the bearing capacity of shallow foundations by integrating machine learning and nonlocal algorithms, belonging to geotechnical engineering. 1. The type of foundation soil is determined through indoor triaxial tests; strain-hardening foundation soils are analyzed; 2. Strain-softening foundation soils are analyzed; 3. A finite element model is established for refined simulation, followed by 7. 3. A constitutive model combined with a nonlocal algorithm is used for refined simulation, then proceeds to 4. 4. The influence range (DL) of the shallow foundation analysis is calibrated. f DL is determined by the softening rate control parameter β. f If suitable, proceed to step 7; otherwise, proceed to step 6. Step 6 involves building and training a machine learning agent model to ultimately obtain a suitable deep learning (DL) algorithm. f Shallow foundation analysis was performed with β1 and 7 to obtain the predicted value of the foundation bearing capacity. The present invention uses the above method to achieve efficient inversion of nonlocal parameters, thereby obtaining a reasonable predicted value of the shallow foundation bearing capacity.
Owner:BEIHANG UNIV

A method and system for dividing underground engineering into deep and shallow burying based on tunnel excavation effect

The application provides a deep and shallow buried division method and system of underground engineering based on tunnel excavation effect, and belongs to the technical field of computer-aided design. The scheme comprises the following steps: obtaining an initial ground stress field of a tunnel area; sampling the tunnel area, carrying out a conventional triaxial test, and obtaining a full stress-strain curve of surrounding rock; obtaining ground stress information of a given engineering section according to the initial ground stress field of the tunnel area, establishing a three-dimensional numerical model of the tunnel, carrying out numerical simulation by using a constitutive model considering strain softening, and obtaining a stress field after tunnel excavation; and based on the full stress-strain curve and the stress field after tunnel excavation, deep and shallow buried division is carried out. The scheme fully considers that the occurrence of tunnel disasters under strong tectonic stress is significantly affected by true three-dimensional stress, considers the tunnel excavation effect, carries out deep and shallow buried division based on the true three-dimensional stress field, provides clear suggestions for the selection of the constitutive model of surrounding rock in the design process, and provides clear guidance for support design.
Owner:CENT SOUTH UNIV

Method for determining blasting loosening range of rock burst coal seam

The invention relates to the crossing field of coal mine safety and blasting engineering, and particularly discloses a method for determining the blasting loosening range of a rock burst coal seam, which comprises the following steps: S1, based on rock burst coal seam parameters actually measured on site, substituting the parameters into a dynamic correction formula to calculate an initial blasting loosening radius; s2, a strain softening-dynamic instability coupling constitutive model matched with the rock burst coal seam is adopted, blasting parameters consistent with theoretical calculation are simulated through LS-DYNA software, and an irregular loosening range boundary and a simulated loosening radius and a fracture extension form under a non-uniform medium are output; s3, testing is carried out in stages after blasting, and data are obtained by combining multi-directional test hole arrangement; and S4, correcting theoretical calculation and numerical simulation results based on field test data to obtain a final blasting loosening range. According to the method, the defects of poor adaptability, simulation distortion, inaccurate test and no closed loop of the existing method are overcome, the accurate quantification of the loosening range is realized, and the method adapts to multiple working conditions and impact grades.
Owner:SHANDONG HUAKUN GEOLOGICAL ENG +1

Soft rock rheological mechanical property testing method based on vibration-seepage pressure coupling

The invention discloses a soft rock rheological mechanical property test method based on vibration-seepage pressure coupling, which comprises the following steps: selecting and processing a soft rock sample, and constructing a test system comprising a vibration loading module, a seepage pressure applying module and a data acquisition module; seepage pressure is applied to the soft rock sample, pore water pressure data are collected, periodic vibration loads are applied after stabilization, and strain and stress data are synchronously collected; importing the data into a ZSoil three-dimensional finite element analysis platform, calling a strain softening aging viscoelastic-plastic algorithm to establish a mechanical response analysis model, and then introducing a fluid-solid thermal coupling fractional order rheological model and a vibration-seepage pressure dynamic full-coupling model to simulate long-term rheological characteristics. According to the method, through a multi-model cooperation and integrated test process, the problems of insufficient model coupling, rough characteristic description and low efficiency are solved, the soft rock rheological parameters are accurately obtained, and reliable support is provided for design optimization and safety guarantee of projects such as water conservancy and hydropower, mineral exploitation and the like.
Owner:HOHAI UNIV

A method for evaluating and regulating stability of a tunnel-type artificial gas storage cavern of a pumped storage power station

This invention discloses a method for stability evaluation and control of tunnel-type artificial gas storage caverns in pressurized gas storage power plants, relating to the field of underground engineering technology. Addressing the shortcomings of existing technologies that fail to consider differences in operating conditions across all stages and neglect intermediate principal stresses and strain softening effects, this method first collects rock mass, geological, and design parameters. Then, based on elastoplastic theory and a unified strength criterion, it constructs stability evaluation criteria suitable for both q≥p and q≤p operating conditions in stages (site selection and design, construction, and operation and maintenance), dividing the process into stable and unstable segments. Furthermore, it controls the unstable segments through active avoidance, pressure adjustment, and reinforcement measures, clarifying the quantitative formula for the radial influence radius. This method takes into account differences in intermediate principal stresses and stress paths, achieving accurate evaluation and quantitative control. The process is simple, highly applicable, and can ensure the safe and stable operation of artificial gas storage caverns throughout their entire life cycle.
Owner:CHINA POWER CONSRTUCTION GRP GUIYANG SURVEY & DESIGN INST CO LTD +1

A soil body deformation analysis method and system based on energy change rate

The application discloses a kind of soil deformation analysis method and system based on energy change rate, comprising: obtaining the stress-strain data of soil by triaxial shear test;Based on the principle of energy conservation, the energy change rate under unit shear strain is calculated;Draw and identify the morphological characteristics of energy change rate-shear strain relationship curve, especially the platform-slow descent characteristics presented in shear failure stage;Based on the state-dependent dilatancy theory, an analytical relationship between energy change rate and soil dilatancy parameters is established;Combined with the curve characteristics and analytical relationship, an explicit constitutive relationship model between stress ratio and dilatancy parameters is constructed.The model can be used to directly judge the stability of soil deformation or calibrate the constitutive model parameters.The application reveals the coupling mechanism of soil strain softening and dilatancy behavior from a new perspective of energy compensation, dynamically correlates macroscopic mechanical response with microscopic parameters, and provides a theoretical basis and practical tool for soil constitutive model development and engineering stability analysis.
Owner:GUANGXI TRANSPORTATION SCI & TECH GRP CO LTD

Nonlinear finite element method and system for determining critical stability section of underground cavern

This invention provides a nonlinear finite element method for determining the critical stability section of an underground cavern. Based on rock mechanics tests in actual engineering, the rock mass strain softening parameters are determined. A secondary development of the rock mass constitutive model is performed based on these parameters. An initial nonlinear finite element model for solving the critical stability section of the underground cavern is constructed based on the secondary developed rock mass constitutive model. The nonlinear finite element model is solved to obtain the overall tangential stiffness of the model at the calculation step. Based on the overall tangential stiffness, the minimum eigenvalue of the overall tangential stiffness matrix is ​​calculated. Based on the minimum eigenvalue, the critical stability section of the underground cavern is determined. This invention directly and quantitatively reflects the essential characteristics of stiffness loss and bearing capacity reduction in the entire cavern structure system after considering complex nonlinear deformation paths, including strain softening, thereby accurately capturing the critical instability moment and potential instability sections.
Owner:CHINA RAILWAY SIYUAN SURVEY & DESIGN GRP CO LTD +1

Method and system for constructing constitutive model of magnesium oxide reinforced coastal soft soil

The invention relates to a constitutive model construction method and system for magnesium oxide reinforced coastal soft soil, and the method comprises the steps: constructing a hyperbolic stress-strain relational expression based on a Duncan-Tensile model; constructing a strain softening component expression; collecting deviatoric stress of the magnesium oxide reinforced soft soil during damage to obtain damage deviatoric stress; constructing a final stress-strain relational expression according to the hyperbolic stress-strain relational expression, the strain softening stress-strain relational expression and the failure deflection stress; constructing a Lorentz component and a Gaussian component; constructing an initial tangent modulus expression according to the Lorentz component and the Gaussian component; by fusing parameters such as curing time and confining pressure, a unified constitutive model strictly fusing the curing time effect, the confining pressure and strain softening is formed, and the defect that the time-pressure effect cannot be considered at the same time in the prior art is overcome.
Owner:WUHAN INST OF TECH +1

Slope displacement prediction method and device based on earthquake induction

PendingCN121838420Areduce dependenceEffectively capture non-linear mapping relationshipsDesign optimisation/simulationAlarmsPredictive methodsClassical mechanics
The embodiment of the invention provides a side slope displacement prediction method and device based on earthquake induction, and belongs to the technical field of early warning of side slope disasters induced by earthquakes. The corresponding method comprises the following steps: acquiring a plurality of seismic records of a side slope and a plurality of first displacements of the side slope corresponding to the plurality of seismic records; performing background grid strain on the initial material point of the slope according to a predetermined strain softening constitutive model of the slope so as to determine a final material point of the slope; determining a plurality of second displacements of the slope under different characterization parameters according to the final substance point; generating a displacement prediction model according to the plurality of seismic records, the plurality of first displacements and the plurality of second displacements so as to predict the displacement of the slope corresponding to the seismic oscillation acceleration time history; wherein the displacement prediction model is generated by training a plurality of seismic records, a plurality of first displacements and a plurality of second displacements based on a deep learning algorithm. According to the method, the uncertainty of earthquake-induced soil slope displacement prediction can be reduced, and the displacement prediction precision is improved.
Owner:雅江清洁能源科学技术研究(北京)有限公司 +1

Evaluation method of ductility of grouted rock mass for advanced renovation of water-sand mixture inrush area

Provided is an evaluation method of ductility of a grouted rock mass for advanced renovation of a water-sand mixture inrush prevention area including following steps: first, acquiring a spatial distribution law of cracks in overlying strata, and establishing a three-dimensional geological model and a grouted rock mass unit geological model; calculating rock mass quality standard of the target rock strata; performing compression tests on multiple groups of grouted consolidated bodies, and calculating an average value of strain softening indexes of the multiple groups of grouted consolidated bodies; selecting multiple groups of grouted target rock strata, and calculating an average value of unstable fracture ductility of the multiple groups of grouted target rock strata; finally, acquiring a permeability strength of the grouted rock mass, and calculating and grading an evaluation index of ductility of the grouted rock mass.
Owner:CHINA UNIV OF MINING & TECH +1

Rock mass equivalent GSI parameter valuing method based on three-dimensional strength and strain softening

The invention belongs to the technical field of geotechnical engineering, and discloses a rock mass equivalent GSI parameter valuing method based on three-dimensional strength and strain softening, and the method comprises the steps: determining rock mass mechanical parameters and tunnel excavation parameters; calculating the plastic zone radiuses Rp and epp of the model by adopting the peak value GSIp and the ideal elastic-plastic model; calculating an attenuation factor k according to the determined parameters; determining a proportionality coefficient beta through an exponential decay relation based on the decay factor k and the model plastic zone radii Rp and epp, and further obtaining an equivalent parameter GSIeq; and finally, calculating the mechanical response of the surrounding rock by adopting the equivalent parameter GSIeq and the ideal elastic-plastic model. According to the method, the equivalent GSI parameters are introduced, the complex strain softening problem is converted into the ideal elastoplasticity problem of efficient calculation, the calculation efficiency is remarkably improved while the calculation precision is guaranteed, the influence of the three-dimensional stress state is fully considered, and a practical and reliable technical means is provided for stability analysis of tunnel engineering.
Owner:TONGJI UNIV +2

Method for testing rheological mechanical properties of soft rock based on vibration-seepage pressure coupling

This invention discloses a method for testing the rheological mechanical properties of soft rock based on vibration-seepage pressure coupling. The method includes: selecting and processing soft rock samples; constructing a testing system containing modules for vibration loading, seepage pressure application, and data acquisition; applying seepage pressure to the soft rock samples and acquiring pore water pressure data; after stabilization, applying periodic vibration loads and simultaneously acquiring strain and stress data; importing the data into the ZSoil three-dimensional finite element analysis platform; using the strain softening-aging viscoelastic-plastic algorithm to establish a mechanical response analysis model; and then introducing a fluid-structure-thermal coupling fractional-order rheological model and a vibration-seepage pressure dynamic fully coupled model to simulate long-term rheological properties. This method, through multi-model collaboration and an integrated testing process, solves the problems of insufficient model coupling, coarse characteristic characterization, and low efficiency, accurately obtaining soft rock rheological parameters, and providing reliable support for the design optimization and safety assurance of water conservancy, hydropower, and mining projects.
Owner:HOHAI UNIV

Slope instability full-scale test device and test method

The invention relates to the technical field of slope instability testing, in particular to a slope instability full-scale testing device and method. The water collecting channel is arranged at the lower end of the to-be-tested side slope and used for collecting water flowing down from the to-be-tested side slope; the isolation structures are arranged on the two sides of the slope to be tested and used for blocking lateral seepage of water; the spraying device is used for spraying water to the side slope to be tested; the water supply device is used for supplying water to the spraying device and comprises a water supply pipe as well as a variable frequency water pump, a water meter, a pressure stabilizing valve and a water pressure gauge which are connected in series on the water supply pipe; the full-scale test device for slope instability can be used for carrying out a full-scale rainfall instability test on a slope, a slope instability mechanism is reflected more truly, a test basis is provided for slope protection, and test data is also provided for a strain softening and seepage-stress coupling model of a to-be-tested slope.
Owner:FIFTH ENGINEERING BRANCH OF CCCC SECOND NAVIGATION ENGINEERING BUREAU CO LTD +3

Method for determining equivalent GSI parameters of rock mass based on three-dimensional strength and strain softening

The application belongs to the technical field of geotechnical engineering, and discloses a rock mass equivalent GSI parameter value determination method based on three-dimensional strength and strain softening, which comprises the following steps: determining rock mass mechanical parameters and tunnel excavation parameters; calculating model plastic zone radius by using peak GSI p and ideal elastic-plastic model R p,epp ; calculating an attenuation factor according to the determined parameters k ; determining a proportional coefficient based on the attenuation factor k and the model plastic zone radius R p,epp ; determining a proportional coefficient by an exponential attenuation relationship β , and obtaining equivalent parameter GSI eq ; finally, calculating the mechanical response of surrounding rock by using equivalent parameter GSI eq and ideal elastic-plastic model. The application converts the complex strain softening problem into an efficient ideal elastic-plastic problem by introducing the equivalent GSI parameter, significantly improves the calculation efficiency while ensuring the calculation accuracy, and fully considers the influence of the three-dimensional stress state, thereby providing a practical and reliable technical means for tunnel engineering stability analysis.
Owner:TONGJI UNIV +2

Three-dimensional crustal stress prediction method based on structure size deformation and numerical simulation

PendingCN121995531AOvercoming the problem of oversimplificationOvercoming difficult establishment issuesMeasurement of force componentsClassical mechanicsGeological exploration
The invention discloses a three-dimensional crustal stress prediction method based on structure size deformation and numerical simulation. The method specifically comprises the following steps: S100, a first stage: constructing large deformation simulation; comprising the following steps: S110, establishing a three-dimensional frame model by using depth domain horizon data according to a seismic interpretation result; s120, setting a constitutive model and a strain softening mode; s130, stratum mechanical parameters are set; s140, setting a boundary condition; s150, setting speed boundary loading; s160, carrying out numerical calculation, comparing strain distribution in a simulation result with fault distribution obtained through geological exploration, and checking the correctness of a large-deformation simulation result of the structure; s200, in the second stage, small strain simulation is constructed, the simulation result in the first stage serves as an initial model, and speed boundary loading is modified into stress boundary loading; carrying out numerical calculation, and comparing stress distribution of a simulation result with an actual measurement result; according to the method, the model constraint degree is increased, and the reliability of a three-dimensional crustal stress prediction result can be improved.
Owner:CHINA PETROLEUM & CHEMICAL CORP +1