26 results about "Force chain" patented technology

The invention discloses a rock nanoindentation numerical simulation method based on PFC discrete elements, and relates to an unconventional natural gas reservoir fracturing technology. Comprising the following steps: dynamically loading an iterative matching load-displacement curve based on XRD-SEM-EDS mineral spatial distribution of a rock sample and single mineral nanoindentation experimental data microscopic parameters; in combination with mineral space distribution data, constructing a multi-mineral heterogeneous model by stages, and dynamically loading simulation; based on crack number development, force chain distribution and particle displacement vector characteristics, a regulation and control mechanism of a mineral interface coupling effect and pore stress concentration on a crack propagation path is quantitatively analyzed. According to the invention, a heterogeneity evolution mechanism of force chain development and crack propagation in each stage of loading, load holding and unloading can be analyzed, and a dynamic mechanism that mineral components and pore structures cooperatively regulate and control a crack propagation path and nonlinear load response is disclosed; and a solution path is provided for rock microscopic damage mechanism prediction and heterogeneous material discrete element numerical simulation modeling.

The invention discloses a cement stabilized macadam mechanical property analysis method based on maximum aggregate nominal particle size, and relates to the technical field of cement stabilized macadam mechanical property analysis, the method comprises the following steps: preparing skeleton dense type cement stabilized macadam test pieces with different nominal maximum particle sizes; carrying out a macroscopic mechanical test to obtain a stress-strain curve and a crushing value; establishing a three-dimensional discrete element numerical model corresponding to the test piece, performing uniaxial compression simulation, and ensuring the reliability through model verification; and based on the verified model, quantitatively analyzing the contact force distribution, the contact quantity characteristic and the microcrack evolution law from the microscopic level. According to the analysis method disclosed by the invention, a mechanism that the nominal maximum particle size improves the macroscopic performance of the material by regulating and controlling an internal force chain network and inhibiting damage accumulation is disclosed through a macro-micro combination means, and a scientific micro-mechanical basis and a quantitative analysis tool are provided for grading optimization and high-performance design of the cement stabilized macadam base.

The invention discloses a coarse and fine particle inclusion photoelastic sample preparation and contact force chain network analysis method, and relates to the field of particle material mechanical tests, and the method comprises the following steps: calculating target void ratios under different coarse particle contents through a discrete element method; generating a corresponding numerical calculation sample according to the target void ratio and the preset coarse grain content, and exporting related parameters to prepare a coarse and fine grain inclusion photoelastic sample with the same initial compactness; in combination with non-polarization and polarized photoelastic images of the photoelastic sample, extracting intergranular contact force and constructing a contact force network; based on the contact force network, a strong contact force network is extracted and microscomic analysis is carried out, and force transmission characteristic comparison results under different coarse grain content conditions are obtained. According to the method, preparation efficiency of samples with different coarse grain contents and controllability of an initial state are realized, an influence rule of the coarse grain contents on a force chain structure and force transmission characteristics thereof is disclosed based on analysis of a contact force chain network, and the method is of great significance in researching a force transmission mechanism of a coarse and fine grain inclusion system and microstructure characteristics thereof.

The invention discloses a numerical control leveler operation state prediction and control method based on a digital twinborn model, and relates to the technical field of leveling prediction control. Comprising the following steps: S1, collecting leveling physical data in real time, and carrying out data preprocessing; s2, establishing a multi-roller stress chain model, forming a force chain structure, driving the model to continuously correct, and outputting a fusion stress sequence at the same time; s3, analyzing multi-roller local mutation features to identify an abnormal source roller, evaluating upstream and downstream transmission strength of the abnormal source roller in the multi-roller force chain, and judging whether the abnormality has an amplification trend or not; and S4, according to the abnormal source roller and evolution characteristics, the reduction correction amount is judged, the reduction correction amount is adaptively updated under the safety constraint, and closed-loop regulation and control feedback is carried out. The problems that in the prior art, the force chain transmission process between roller systems cannot be captured, a source roller with abnormal local stress cannot be recognized, and whether the source roller is amplified at the downstream position or not, so that the plate shape is unstable are solved.

The application discloses a cement stabilized macadam mechanical property analysis method based on maximum aggregate nominal particle size, relates to the technical field of cement stabilized macadam mechanical property analysis, and comprises the following steps: preparing skeleton dense type cement stabilized macadam test pieces with different nominal maximum particle sizes; performing macroscopic mechanical test to obtain stress-strain curves and crushing values; establishing a three-dimensional discrete element numerical model corresponding to the test pieces and performing uniaxial compression simulation, and verifying the model to ensure the reliability of the model; and based on the verified model, quantitatively analyzing contact force distribution, contact quantity characteristics and microcrack evolution law from a microcosmic aspect. According to the analysis method, the macroscopic performance of the material is improved by regulating the internal force chain network and inhibiting damage accumulation through the nominal maximum particle size, and the analysis method discloses the mechanism that the nominal maximum particle size improves the macroscopic performance of the material by regulating the internal force chain network and inhibiting damage accumulation, and provides a scientific microcosmic mechanical basis and a quantitative analysis tool for gradation optimization and high-performance design of the cement stabilized macadam base.

The invention relates to the technical field of oil exploration and development, and discloses a hot dry rock temporary plugging material optimization screening method based on a multi-parameter coupling model. The method comprises the steps of temporary plugging material data set formation, high-temperature aging experiment, compression resistance test, three-dimensional finite element model construction, force chain structure evolution analysis, indoor crack plugging experiment verification, shear stability evaluation and multi-parameter comprehensive evaluation. According to the method, multi-dimensional parameters such as high-temperature aging, dynamic shear stability and particle matching are integrated, numerical simulation and experimental verification are combined, high-precision and high-efficiency screening of the temporary plugging material is achieved, the problems of single index limitation and environment distortion of a traditional method are solved, scientific and reliable technical support is provided for hot dry rock development, and the method has a wide application prospect. And the problems in the background technology can be effectively solved.

This invention discloses a high-load-bearing backing bearing with a multi-layered composite wall thickness outer ring. The bearing's dynamic blocking transition layer is composed of polyhedral rigid microparticles and a viscoplastic matrix, with the microparticle volume fraction limited within a critical blocking threshold range. Under quasi-static radial heavy loads, the microparticles are in a blocked state, forming a rigid force chain that transmits hydrostatic stress. Under high-frequency transverse shear stress wave excitation, the matrix undergoes transient superplastic rheology, and the force chain enters a locally unblocked state, resulting in micro-rheology and a sudden drop in transverse shear stiffness. Based on the orthogonal decoupling of stress states and the dual-state phase transition characteristics, this invention actively disrupts the subsurface standing wave resonance condition, resolving the contradiction between macroscopic compressive strength and microscopic dissipation. This effectively suppresses deep peeling failure under high-speed, heavy-load conditions, and its material selection and process design fully embody the energy-saving and high-efficiency concept of green manufacturing.

The application discloses a kind of photoelastic test force chain information automatic extraction method, the same test state under the particle image is obtained by polarizing mirror and non-polarizing mirror respectively, and image preprocessing is carried out;For the particle image of non-polarizing mirror, based on Hough transform and Euclidean distance, the particle center coordinates, particle radius, interparticle contact point position and interparticle contact angle are extracted;For the particle image of polarizing mirror, based on the mean square value of color gradient, the contact force information of particle is extracted by mask operation and calibration curve;Finally, based on the composition criterion of force chain and its collimation characteristic, angle threshold is converted into distance threshold, and the force chain information of photoelastic test particle image is extracted.The force chain information automatic extraction method established by the application solves the problem of accurate identification of force chain branch point, distinguishes the strong and weak force chain type, identifies the macroscopic distribution state of force chain, force chain length, force chain quantity and force chain orientation and other force chain network structure information.

The application provides a method for determining the "elastic-skeleton-void" structure of pavement mixture, and belongs to the technical field of pavement materials.The application creatively proposes an "elastic-skeleton-void" structure form aiming at the special material composition of the super-elastic porous mixture, and the structure is the fundamental reason for enabling the super-elastic porous pavement to have the composite functions of noise reduction, drainage, self-stress deicing and the like.Meanwhile, in combination with macroscopic physical and mechanical tests, mesoscopic discrete element simulation and digital image processing methods, and based on the uniaxial compression dynamic modulus of the mixture, the void ratio, the contact number of rubber particles and coarse aggregates, the internal force chain structure composition form and the contact force of the mixture, a method for determining the "elastic-skeleton-void" structure is provided, which is used for determining the skeleton composition structure of the mixture.

The invention relates to the technical field of particle mechanics research, in particular to a force chain visualization model device and method based on a mechanoluminescence particle system. The device comprises a full-transparent shear box, a liquid crystal micro-control ring shear instrument, an upper pressure plate, a lower pressure plate, a displacement meter and a camera module, the lower pressure plate is connected to the liquid crystal micro-control ring shear instrument, the bottom of the full-transparent shear box is fixed to the lower pressure plate, the full-transparent shear box is filled with force-induced luminescent particles to form a particle system, the upper surface of the particle system is flattened, and the displacement meter is arranged on the upper surface of the particle system. The upper pressure plate is placed on the upper surface of the particle system, the displacement meter is arranged at the top of the upper pressure plate, and the camera module is erected in the horizontal direction of the full-transparent shear box and aligned to the particle system. According to the invention, real-time dynamic visualization of contact force and force chain distribution among particles is realized; the limitation of the traditional technology on particle materials, sizes and shapes is overcome, and the method is suitable for multiphase and multiscale particle systems; the experimental platform which is low in cost and easy to operate is provided and serves geotechnical engineering and particle mechanics research.

The present application relates to the technical field of powder machines, and in particular to an intelligent control method and system for a powder forming machine. The method comprises: obtaining powder material parameters and mold parameters, wherein the powder material parameters include particle size distribution, yield strength, and friction coefficient, and the mold parameters include mold geometry parameters; performing particle dynamics analysis on the powder material parameters based on the discrete element method to generate particle mechanical motion characteristic data, wherein the particle mechanical motion characteristic data includes particle position data, velocity data, contact force data, and force chain distribution data constructed from the contact force data; performing structural mechanical analysis on the mold parameters based on the finite element method to generate mold macroscopic mechanical response data, wherein the mold macroscopic mechanical response data includes stress distribution data, strain distribution data, and displacement distribution data; and generating powder pressing path control instructions for the mold based on the particle mechanical motion characteristic data and the mold macroscopic mechanical response data.

This application discloses a method for calculating the horizontal bearing capacity of a single offshore wind turbine pile, comprising calibrating the microscopic parameters of soil particles using the discrete element method; generating a foundation using the sand-rain method in a hypergravity environment based on the friction and rolling friction of the soil particles' microscopic parameters; generating a single pile grid using the finite difference method and penetrating the soil; applying a monotonic horizontal load to the top surface of the single pile; and deriving all data and processing and analyzing the data based on the similarity law of centrifugal simulation. The present invention simulates the microscopic foundation soil preparation process based on the foundation preparation process of a real physical experimental test by using the sand-rain method in a hypergravity field to generate a foundation with a porosity that meets specified requirements and a uniform force chain.

The invention discloses an experimental device for dynamic reconstruction visual monitoring of a microscopic contact force chain of a granular material, which comprises a shearing shaft, the bottom of the shearing shaft is a working part, the shaft diameter is gradually reduced from top to bottom, and the bottom of the shearing shaft is matched with a through hole corresponding to a shearing box, is in contact with the granular material to be monitored and is used for generating shearing and extrusion stress. The innovation value of the method is that dynamic reconstruction and visual real-time monitoring of the microscopic contact force chain of the granular material can be realized, the problem of'black box 'which puzzles particulate matter research for a long time is solved, a key experimental means is provided for establishing a multi-scale correlation model of microscopic force chain evolution and macromechanics response and breaking through the bottleneck of the existing process technology, and the method is worthy of popularization and application. Therefore, the scientificity of key parameter setting of a simulation model and the reliability of a prediction result are remarkably improved, and a theoretical basis is provided for process optimization.

The application discloses a kind of coarse and fine particle inclusion photoelastic sample preparation and contact force chain network analysis method, it is related to the field of granular material mechanics test, comprising: the target porosity under different coarse grain content is calculated by discrete element method;According to target porosity and preset coarse grain content, the corresponding numerical calculation sample is generated, and the related parameters are derived to prepare coarse and fine particle inclusion photoelastic sample with the same initial density;Combined with the non-polarization and polarized photoelastic image of photoelastic sample, intergranular contact force is extracted and contact force network is constructed;Based on contact force network, extract strong contact force network and carry out mesoscopic analysis, obtain the force transmission characteristic comparison result under different coarse grain content conditions.The realization of different coarse grain content sample preparation efficiency and controllability of initial state, and based on the analysis of contact force chain network reveals the influence law of coarse grain content on force chain structure and its force transmission characteristics, it has important significance to study the force transmission mechanism and its mesostructure characteristics of coarse and fine particle inclusion system.

The invention provides a silo anti-arching device, and belongs to the technical field of granaries, the silo anti-arching device comprises a silo and an arching breaking mechanism, the arching breaking mechanism is mounted above a discharge port in the silo and is provided with an annular track, and the annular track is mounted on the inner wall of the silo; when the bottom discharging opening is opened, the anti-arching balls are driven to move downwards through flowing energy of the gravity of materials, the anti-arching balls drive the radial swing arms to swing downwards, meanwhile, the rotating platform can be driven to rotate according to the torque difference generated by the different radial swing arms, and therefore the anti-arching balls can rotate in the silo; therefore, continuous and random shearing and disturbance are formed in the materials, formation of stable force chains among the materials is effectively destroyed, generation of material arches is prevented, no external power source is needed, and energy conservation and environmental protection are achieved.

The application discloses an experimental device for monitoring and visualizing dynamic reconstruction of micro-contact force chains of granular materials, comprising a shearing shaft, a working part at the bottom, and a shaft diameter gradually decreasing from top to bottom, the bottom of the shearing shaft being matched with a through hole corresponding to a shearing box, and being in contact with the granular materials to be monitored for generating shearing and extrusion stress.The innovation value of the application lies in that the dynamic reconstruction of micro-contact force chains of granular materials and the real-time monitoring and visualization thereof can be realized, the "black box" problem long plagued by the research on granular materials is solved, a multi-scale correlation model of micro-force chain evolution and macro-mechanical response is established, a key experimental means is provided to break through the existing process technology bottleneck, and therefore the scientificity of setting of key parameters of a simulation model and the reliability of a prediction result are remarkably improved, so as to provide a theoretical basis for process optimization.

The application discloses a real granite GBM modeling method considering mineral layer structure and relates to the technical field of rock mechanics, and comprises the following steps: obtaining the morphological characteristics, structural characteristics and distribution positions of quartz, feldspar and mica minerals through high-precision nanometer CT; introducing the mineral information into PFC2d discrete element software to perform real GBM modeling; introducing various contact models in the real GBM model to reproduce the process of mineral particle deformation and micro-crack evolution; correcting the mesoscopic mechanics parameters of the real GBM model through indoor experiments to reproduce the process of mineral particle deformation and micro-crack evolution; obtaining the influence law of the mineral layer structure on the rock mechanics characteristics and cracking behavior based on the real GBM model, obtaining the change conditions of the mineral scale crack propagation and the force chain network structure; and combining the high-precision nanometer CT and the discrete element modeling to restore the real layer structure and crystal form of the minerals, and improving the precision and reliability of rock rupture simulation.

The application discloses an indirect tensile internal synergic stress analysis method of asphalt mixture. In order to solve the problems of lacking internal stress data of the asphalt mixture under the indirect tensile stress and the reasonable evaluation method of the synergic stress of the asphalt mixture, the application discloses the following analysis method: one, constructing a coarse aggregate template library; two, establishing a discrete element geometric model of a Marshall test piece; three, giving each component and interface contact parameters; four, performing indirect tensile simulation; five, evaluating the simulation accuracy; six, determining two characteristic time points and obtaining internal force chain information of the characteristic time points; seven, quantifying the strength distribution of the interface force chain; eight, quantifying the direction distribution of the interface force chain; nine, evaluating the internal synergic stress capacity and evolution capacity. The application adopts the discrete element modeling method to obtain the internal component force chain data of the asphalt mixture, proposes force chain uniformity probability and force chain angle distribution uniformity indexes, and effectively quantifies and evaluates the synergic stress capacity and evolution rate of the asphalt mixture.

The invention relates to a dynamic evolution method and system for contact force between soil particles based on a DEM (Digital Elevation Model). A DEM-based dynamic evolution method for contact force between soil particles comprises the following steps: outputting key data of interaction force between large-scale discrete element model particles from simulation data based on an EDEM platform; the particle information at least comprises eight particle information including the size of contact normal force between the particles, coordinates of contact points between the particles in the X / Y / Z directions, particle IDs and particle positions in the X / Y / Z directions; by means of MATLAB, information such as contact force, contact position, particle ID and the like of particles in the large-scale discrete element soil model is identified, screened, extracted, statistically analyzed and sequenced and filtered. According to the method, the problem that a large-scale calculation model in the EDEM cannot clearly and quantitatively display the force chain is solved, and classified presentation of a total force chain network structure, a strong force chain network structure, a secondary strong force chain network structure and a weak force chain network structure and dynamic evolution visualization changing along with time are achieved.

The invention provides a jointed rock mass large-span tunnel multi-stage supporting method based on a space coupling mechanism, and relates to the technical field of large-span tunnel engineering. In order to solve the problem of low supporting efficiency in the prior art, according to a surrounding rock damage field caused by stress redistribution after a target large-span tunnel is excavated, the target large-span tunnel is divided into a far-field primary rock stress area, a middle-field bearing arch forming area and a near-field loosening area; in the near-field loose area, a free face is excavated in a closed mode through flexible net spraying concrete, and a stable base body is provided for the middle-field bearing arch forming area; in the midfield bearing arch forming area, a chain type crack resisting mechanism is adopted to construct a force chain network so as to mobilize the rock self-supporting potential in the midfield bearing arch forming area, and the load of the near-field loosening area is dredged to the far-field primary rock stress area; and in the far-field primary rock stress area, a deep anchoring point is established by adopting a deep anchoring mechanism, and the hole periphery load transmitted by the middle-field bearing arch forming area is converted into axial tension to be transferred to a deep stable rock mass. The supporting method disclosed by the invention has relatively high supporting efficiency.

The present application relates to the technical field of granular mechanics research, and particularly relates to a force chain visualization model device and method based on a force-induced luminescent particle system. The device comprises a full-transparent shear box, a liquid crystal micro-control ring shear instrument, an upper compression disc, a lower compression disc, a displacement meter and a camera module. The lower compression disc is connected to the liquid crystal micro-control ring shear instrument, and the bottom of the full-transparent shear box is fixed to the lower compression disc. The full-transparent shear box is filled with force-induced luminescent particles to form a particle system, the upper surface of the particle system is flattened, the upper compression disc is placed on the upper surface of the particle system, the displacement meter is arranged on the top of the upper compression disc, and the camera module is erected in the horizontal direction of the full-transparent shear box and is aligned with the particle system. The present application realizes real-time dynamic visualization of the contact force between particles and the distribution of force chains. The present application overcomes the limitations of traditional technologies on particle materials, sizes and shapes, and is suitable for multiphase and multi-scale particle systems. The present application provides a low-cost and easy-to-operate experimental platform, and serves the researches on geotechnical engineering and granular mechanics.

The invention discloses a high-bearing-capacity backing bearing with a multi-layer composite wall thickness outer ring, and relates to a bearing, a dynamic blocking transition layer of the high-bearing-capacity backing bearing is composed of polyhedral rigid microparticles and a viscoplastic matrix, and the volume fraction of the microparticles is limited in a critical blocking threshold value interval. When the micro-particles bear quasi-static radial heavy load, the micro-particles are in a blocked state to form a rigid force chain to transmit hydrostatic pressure stress; when high-frequency transverse shear stress wave excitation is borne, transient superplastic rheology happens to a base body, a force chain enters a local unblocking state to generate micro rheology, and sudden reduction of transverse shear rigidity is triggered. Based on the stress state orthogonal decoupling double-state phase change characteristic, the subsurface standing wave resonance condition is actively destroyed, the contradiction between macroscopic compression resistance and microcosmic dissipation is solved, deep stripping failure under the high-speed heavy-load working condition is effectively restrained, and the energy-saving and efficient concept of green manufacturing is fully embodied through material selection and process design.

This invention relates to the field of particle mechanics research technology, and particularly to a force chain visualization model device based on a mechanoluminescent particle system. The device includes a fully transparent shearing box, a liquid crystal micro-controlled ring shearing apparatus, an upper pressure plate, a lower pressure plate, a displacement meter, and a camera module. The lower pressure plate is connected to the liquid crystal micro-controlled ring shearing apparatus. The bottom of the fully transparent shearing box is fixed to the lower pressure plate. The fully transparent shearing box is filled with mechanoluminescent particles to form a particle system. The upper surface of the particle system is flattened, and the upper pressure plate is placed on the upper surface of the particle system. The displacement meter is mounted on top of the upper pressure plate. The camera module is mounted horizontally on the fully transparent shearing box and aligned with the particle system. The liquid crystal micro-controlled ring shearing apparatus has a control display. This invention achieves real-time dynamic visualization of the contact forces and force chain distribution between particles; it overcomes the limitations of traditional technologies on particle materials, sizes, and shapes, and is applicable to multiphase and multi-scale particle systems.

This invention discloses a soil cracking simulation method based on two-dimensional particle discrete elements, relating to the field of soil physics. The method includes the following steps: discretizing the region to be solved using particles and assigning control parameters; performing contact searches between particles and between particles and their boundaries to determine the domains of mechanical and water diffusion, establishing force chains and virtual water diffusion channels between them; calculating water diffusion between particles and between particle boundaries and updating the water content of the particles; and performing mechanical calculations between particles and between particle boundaries and updating crack information. This method can simulate soil cracking due to water loss in two dimensions.

The present application relates to geotechnical engineering calculation and simulation technical field, disclose a kind of quantitative prediction method of rock-filled roadbed particle crushing process, the method includes: build a double-diagram structure including activation map and dormancy map, to characterize the actual force chain and potential contact of particle system;Under the driving of external load, the propagation, dissipation and accumulation of energy are simulated on the activation map, and the energy storage of each particle node is updated;By comparing the node energy storage and the critical breaking energy, determine and handle point dissipation event (particle crushing), and distribute the energy shock wave released by crushing to the adjacent nodes;Using the energy shock wave, determine and handle topological plasticity events;Finally, statistical analysis of the dissipation events in the whole process, generate quantitative prediction results about damage evolution and failure path.The present application greatly improves the calculation efficiency through the energy evolution mechanism driven by events, while truly reproducing the core physical processes of particle crushing and force chain reconstruction.

The invention discloses a real granite GBM modeling method considering a mineral layered structure, and relates to the technical field of rock mechanics, and the method comprises the following steps: obtaining morphological characteristics, structural characteristics and distribution positions of quartz, feldspar and mica minerals through high-precision nanometer CT; mineral information is imported into PFC2d discrete element software, and real GBM modeling is carried out; a plurality of contact models are introduced into a real GBM model, and the process of mineral particle deformation and microcrack evolution is reproduced; the microscopic mechanical parameters of the real GBM model are corrected through an indoor experiment, and the process of mineral particle deformation and microcrack evolution is reproduced; on the basis of a real GBM model, obtaining an influence rule of a mineral stratified structure on rock mechanical properties and cracking behaviors, and obtaining change conditions of mineral scale crack propagation and a force chain network structure; high-precision nanometer CT and discrete element modeling are combined to restore the real layered structure and crystal morphology of the mineral, and the precision and reliability of rock fracture simulation are improved.