24 results about "Strain softening" patented technology

The invention provides a nonlinear finite element discrimination method for a critical stable section of an underground cavern, and the method comprises the steps: determining a rock mass strain softening parameter according to a rock mass mechanical test in actual engineering; performing secondary development on a rock mass constitutive model based on the rock mass strain softening parameters; based on the rock mass constitutive model after secondary development, a nonlinear finite element initial model for solving the critical stable section of the underground cavern is constructed; the nonlinear finite element model is solved, and the overall tangent rigidity of the model in the calculation time step is obtained; based on the overall tangent stiffness, calculating to obtain a minimum characteristic value of an overall tangent stiffness matrix; and based on the minimum characteristic value, distinguishing the critical stable section of the underground cavern. The method directly and quantitatively reflects the essential characteristics of rigidity loss and bearing capacity reduction of the whole cavern structure system after a complex nonlinear deformation path including strain softening is considered, so that the critical instability moment and the potential instability section are accurately captured.

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 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.

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.

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.

The present invention proposes a method and system for predicting the loading deformation of overburden foundation sand and gravel materials. The method includes conducting triaxial shear tests on graded, formed sand and gravel samples to obtain axial strain, volumetric strain, and deviatoric stress; establishing a tangent elastic modulus relationship for material strain softening based on the deviatoric stress and axial strain; calculating lateral strain based on the axial strain and volumetric strain, and establishing a Poisson's ratio relationship for the material's dilatancy properties based on the lateral strain and axial strain; constructing a constitutive model based on the tangent elastic modulus relationship and the Poisson's ratio relationship; and using the constitutive model to predict simulated data of the overburden foundation sand and gravel material, predicting how the deviatoric stress and volumetric strain change with the axial strain during loading, to obtain prediction results. This method effectively predicts the loading deformation characteristics of overburden foundation sand and gravel materials, minimizing the deviation between the predicted and actual results.

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.

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.

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.

The invention relates to the field of UHPC material constitutive model calculation, in particular to a UHPC uniaxial tensile strain softening type constitutive model calculation method based on the fiber mixing amount and orientation, and the method comprises the following steps: S1, constructing a three-dimensional mesoscopic numerical model of UHPC; s2, performing uniaxial tensile simulation on the sample by using the three-dimensional mesoscopic numerical model to obtain a stress-strain curve data set of the sample; s3, dividing the application range of the constitutive model according to the stress-strain curve data set; and S4, based on the volume fraction of the steel fibers in the UHPC and the orientation angle of the steel fibers, a constitutive model is constructed, and the constructed constitutive model is a strain softening type constitutive model. According to the method, the UHPC uniaxial tensile constitutive model considering the steel fiber mixing amount and orientation is constructed, the calculation precision of the UHPC tensile strength is effectively improved, and the problem that an existing UHPC tensile constitutive model is insufficient in precision in macroscopic finite element analysis calculation is solved.

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.

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.

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.

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.

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.

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.

The application discloses a kind of calculation method of slope stability analysis associated with displacement, comprising the following steps: for any one strip block, establish horizontal and vertical static equilibrium equation and the moment equilibrium equation in the plane of the strip block;From the motion compatibility between each strip block, start from the first strip block, establish the displacement coordination relationship between each strip block in turn, determine the displacement expression of any one strip block;For the bottom surface of any one strip block, the relationship between its tangential stress and shear displacement is characterized by strain softening model;According to the condition that the inter-block force transmitted by the first strip block is zero, form the calculation control equation set;For the displacement of each strip block, start from zero, and form a series of displacement values with certain displacement increment;Under each displacement value of each strip block, the average value of the local stability coefficient of all strip blocks is used as the overall stability coefficient of the slope body, i.e. the relationship between the overall stability coefficient of the slope body and the potential sliding body displacement is obtained.

The application discloses a kind of for analyzing the calculation method of anchor rod tensile load bearing characteristics, belong to roadway support numerical calculation field.The application includes seven steps of generating anchor unit, defining large deformation calculation mode, defining attribute parameter, defining fish function "initialise", executing fish function "initialise", defining fish function "modifying", executing fish function "modifying".The application divides anchor unit into elastic stage, yield stage, strain hardening stage, strain softening stage and breakage stage after being pulled.The application proposes yield stage formula, strain hardening stage formula and strain softening stage formula and embeds formula in fish function "modifying".Based on fish function "modifying", the simulation of yield characteristics, strain hardening characteristics and strain softening characteristics of anchor unit can be realized.The application designs breakage stage for anchor unit.When anchor unit is pulled and enters breakage stage, the load bearing capacity of anchor unit drops to zero instantaneously.Compared with original anchor unit calculation, the application can better simulate the tensile load bearing characteristics of anchor rod.

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.

The application discloses an anti-instability titanium alloy and a preparation method thereof, and belongs to the technical field of titanium alloy processing. The titanium alloy takes a beta titanium alloy as a matrix, adds 0.05% to 0.2% of boron (B) elements to form intermetallic compound TiB, and makes the intermetallic compound TiB directionally distribute along a rolling direction through thermal mechanical processing. The titanium alloy contains Cr: 5.4 to 6.2 wt.%, Mo: 4.8 to 5.2 wt.%, Al: 4.4 to 4.7 wt.%, V: 4.9 to 5.1 wt.% and the balance of Ti according to mass percentage. The preparation method comprises the following steps: adding B elements in the titanium alloy matrix, smelting to obtain an ingot, carrying out homogenizing annealing, forging, hot rolling, solid solution treatment in a beta single-phase region and finally obtaining the anti-instability titanium alloy. The introduction of TiB significantly improves the work hardening capacity of the alloy, effectively avoids the strain softening behavior of the traditional beta titanium alloy in the initial stage of plastic deformation, and solves the problem of weak anti-instability capacity of the solid solution titanium alloy. The application is suitable for high-performance structural materials in the fields of aviation and spaceflight.

The invention discloses a research method for a horizontal clipper test of carbonaceous mudstone in natural and water-saturated states. According to the method disclosed by the invention, a large-scale horizontal shearing field test is carried out on the carbonaceous mudstone body soaked in the natural state and the saturated water, the shearing strength of the carbonaceous mudstone under the natural condition and the saturated water state is measured, and a result shows that the carbonaceous mudstone can show a good structural property under the natural condition and shows a typical strain softening characteristic; the fracture surface, the shear strength and the shearing deformation process of the carbonaceous mudstone sample are greatly changed after being soaked in saturated water, and particularly, the shear strength is greatly reduced.

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.

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.

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.