18 results about "Macroscopic stress" patented technology

The invention discloses a method for predicting mechanical properties of ultra-high performance concrete, particularly relates to the technical field of dynamic property analysis of building materials, and aims to solve the problem that sudden brittle failure of materials cannot be accurately predicted under impact and explosion loads in the conventional method. The method comprises the following steps: calculating a macroscopic stress-strain response based on a continuum mechanical equation by acquiring a material ratio parameter and a dynamic load condition; constructing topological features through the strain energy entropy change rate to locate a damage area; determining an interface debonding energy threshold value and a crack growth rate of the damaged area in combination with interface fracture mechanics; utilizing the law of conservation of energy to establish dynamic correlation between interface debonding energy and strain energy density; when the crack growth rate exceeds an interface debonding energy threshold value, correcting macroscopic response data of a sudden stress drop interval based on the dynamic association relationship; the cross-scale coupling of a microscopic damage mechanism and a macroscopic mechanical behavior is realized, and the prediction precision under a dynamic load is remarkably improved.

The invention relates to the technical field of nuclear reactor fuel element analysis, in particular to an irradiated zirconium alloy plasticity limit prediction method based on a crystal plasticity finite element, which comprises the following steps: establishing a three-dimensional polycrystalline representative body cell model conforming to the actual grain size of zirconium alloy; based on a crystal plasticity theoretical model, zirconium alloy material parameters are obtained through calculation; boundary conditions and load conditions are determined, finite element calculation is executed in combination with material parameters, and an element stiffness matrix of each increment step is output; assembling the unit stiffness matrix, and obtaining a macroscopic stress-strain matrix of the three-dimensional polycrystal cell model through a homogenization method; and substituting the macroscopic stress-strain matrix into the Rice theoretical criterion, traversing the macroscopic stress-strain matrix of each increment step, and determining the plastic strain meeting the judgment critical condition. According to the method, accurate finite element plastic limit analysis can be carried out on the irradiation material, and the plastic limit strain of the zirconium alloy under the irradiation condition can be accurately judged.

The application provides a method and device for correlatively characterizing stress drop and micro cracks of granite joints under multiple working conditions, computer equipment and a readable storage medium, relates to the technical field of deep hard rock engineering mechanics and geological disaster warning, and the method comprises the following steps: constructing a Voronoi-GBM numerical model; constructing a multi-objective optimization function for optimizing multiple micro mechanical parameters; optimizing the micro mechanical parameters of the Voronoi-GBM numerical model based on the multi-objective optimization function; simulating the operation of multiple granite shear working conditions by using the optimized Voronoi-GBM numerical model; and taking the micro crack characteristic parameters as input samples and the macro stress drop characteristic parameters as output samples, and training a target correlation characterization model. The scheme can effectively mine the correlation characterization of stress drop and micro cracks of granite joints, and realize the prediction of macro stress drop behavior from the micro crack characteristics.

The invention relates to the technical field of roof cutting pressure relief gob-side entry retaining, in particular to a working face roof advanced pressure relief dense hole arrangement parameter design method which comprises the steps that S1, based on dense hole rock macroscopic stress analysis, a calculation relation between dense hole rock macroscopic stress and dense hole plastic zone development radius is established; step S2A, selecting a strength criterion, calculating a dense hole plastic zone development radius, and determining dense hole arrangement spacing; step S2B, based on dense inter-hole rock infinitesimal body stress analysis, establishing a dense inter-hole rock infinitesimal body mechanical equilibrium equation, and in combination with a Mohr-Coulomb strength criterion, establishing a calculation relationship between dense inter-hole rock infinitesimal body stress and an advanced working face distance; and S3, selecting according to a strength criterion, correspondingly establishing an equivalent relationship between the macroscopic stress of the rock among the dense holes and the stress of the infinitesimal body of the rock among the dense holes, forming a calculation relationship between the advance working face distance and the development radius of the plastic zone of the dense holes, and quickly determining the arrangement parameters of the dense holes.

The application discloses a spherical tooth tip blade safety evaluation method and system based on data analysis, and relates to the technical field of cutting processing.The application comprises the following steps: collecting blade surface morphology, microscopic lattice structure and cutting dynamic load data through a white light interferometer, EBSD and a dynamometer; establishing a macro finite element model and embedding a microscopic crystal plasticity submodel; matching macro and microscopic stress fields, calculating lattice orientation conversion matrix and Schmid factor, and extracting slip system characteristic parameters; determining crack initiation, calculating an extension path in combination with an anisotropy criterion, and reconstructing three-dimensional crack morphology; calculating a cumulative damage factor, dividing three-level safety threshold values, and outputting a visual report and a life prediction value.The application establishes a coupling equation of macro stress field and microscopic crystal orientation, integrates the mechanical response characteristics of a material at different scales, and improves the physical authenticity of crack initiation and extension prediction.

This invention provides a method and system for analyzing magnesium alloy sheets based on finite element simulation, relating to the field of manufacturing process technology. The method includes: selecting three sampling regions on the magnesium alloy sheet to define characteristic regions based on macroscopic stress field distribution data, macroscopic strain field distribution data, and rolling force variation data; obtaining adjustment values ​​based on the contour characteristic parameters of the characteristic regions; using the adjustment values ​​to correct the macroscopic stress field distribution data and macroscopic strain field distribution data; identifying the uniformity of stress and strain distribution in the thickness and width directions of the magnesium alloy sheet; and optimizing the rolling temperature, reduction rate, and roll rotation angle in the asynchronous angle rolling process based on the uniformity characteristics to obtain an optimal combination of process parameters. This invention predicts the stress and strain distribution and microstructure evolution during the forming process of magnesium alloy sheets through finite element simulation, reducing costs and improving the quality of sheet products.

The invention discloses a welding joint micro-area fatigue performance testing method, and belongs to the technical field of material fatigue performance testing. The method comprises the following steps: firstly, determining a micro-area microstructure of a welding joint through metallographic phase or electron back scattering diffraction, measuring the length and width of the micro-area, then carrying out a micro-area mechanical property auxiliary test, obtaining hardness and residual stress distribution, and determining whether the micro-area is reasonably divided or not; preparing a fatigue sample which is completely positioned in the micro region; performing cyclic loading on the sample, and synchronously recording mechanical response and fatigue life data; establishing a corresponding relation between macroscopic stress and micro-area stress based on test data, and drawing a micro-area S-N curve; and finally, integrating the micro-area fatigue performance and initial performance distribution, and analyzing a multi-scale correlation mechanism among microstructure evolution, micro-area performance and macroscopic failure. According to the method, the fatigue performance of the local weak area of the welding joint is accurately represented, the limitation of traditional macroscopic overall evaluation is broken through, and a new method is provided for service life prediction and process optimization of a welding structure.

This invention discloses a bedding-parallel landslide testing device, comprising a sliding panel, two retaining glass panels, a retaining box, a loading trolley, a loading chamber, a loading baffle, a retaining structure, and a laser rangefinder. In the laboratory simulation phase, various retaining structures can be used to simulate the macroscopic stress performance of different retaining structures during a bedding-parallel landslide, providing a reference for construction design. The retaining box contains a laser rangefinder to detect the displacement of the retaining structure during a simulated bedding-parallel landslide, determining whether the retaining structure is functioning or has failed. The retaining glass panels are rotatably connected to the retaining box, thus the angle of the sliding panel is adjustable, enabling the simulation of bedding-parallel landslides at different slopes and the displacement of the retaining structure under different slope influences. The loading trolley can carry multiple levels of loading weights, which can be used to simulate the destructive effects of bedding-parallel landslides under different loads on the retaining structure.

The present application relates to the technical field of laser manufacturing and intelligent manufacturing, and particularly relates to a residual stress and deformation prediction method for laser directed energy deposition (LDED) of TA15 alloy components, and a thermal-metallurgical-mechanical multi-physical field coupling model is constructed; firstly, a transient temperature field model during the laser directed energy deposition process is established based on the Fourier heat conduction theory, which comprehensively considers the effects of heat conduction, convection and radiation; then a metallurgical model is established based on the phase transition principle; finally, a multi-stage phase transition dynamics model is established, which considers both diffusion-controlled and non-diffusion-controlled transition mechanisms; by introducing the phase transition dynamics model into the sequentially coupled thermal-mechanical framework, the multi-scale integrated prediction from microstructure evolution to macroscopic stress distribution is realized; and the present application provides a theoretical basis for microstructure regulation and residual stress optimization of the TA15 alloy LDED process.

The invention discloses a virtual body envelope-based multi-scale intestinal torsion simulation method and system. The method comprises the following steps of: constructing an intestinal geometric model comprising a mucous membrane layer, a muscular layer and a plasma layer; adding a virtual enveloping body wrapping the intestinal tract geometric model, and applying external acting force to the virtual enveloping body to obtain deformation characteristics of the virtual enveloping body; substituting the deformation characteristics into the intestinal geometric model to obtain a macroscopic stress field, and calculating a reference feedback force of the intestinal geometric model in the macroscopic stress field; uniformly embedding discrete fiber bundle models in a stress concentration area of the intestinal tract geometric model; the damage rate of the fiber bundle model is calculated according to the overall stretching amount of the fiber bundle model; determining a correction coefficient through damage rate calculation, and correcting the reference feedback force by using the correction coefficient to obtain a tactile feedback force; through multi-scale coupling of virtual body envelope and discrete fiber bundles, synchronous and accurate simulation of macroscopic deformation visual authenticity and microcosmic damage tactile feedback in small intestine torsion simulation is realized.

This invention relates to the field of electronic material manufacturing technology, specifically to an annealing method for large-size sapphire single crystals. For large-size sapphire single crystals with a diameter ≥ 6 inches, the steps include: placing the single crystal in a graphite crucible with a high thermal conductivity synthetic diamond buffer layer on its inner wall; performing dynamic pulse cyclic annealing under a mixed protective atmosphere using independent temperature control in both the center and edge zones; during the annealing process, using a non-contact temperature sensing component to acquire the temperature gradient in real time, and calculating the internal thermal stress value of the single crystal in real time using a stress calculation model; when the thermal stress approaches a preset threshold, the system automatically reduces the heating and cooling rate to actively relieve pressure. This invention, through a virtual stress monitoring system and a high thermal conductivity buffer layer, solves the technical problems of localized heat conduction lag and macroscopic stress runaway in large-size crystals, reducing the internal stress of the annealed crystal to below 50 MPa, significantly shortening the annealing cycle and significantly improving the wafer yield.

A residual stress cross-scale analysis method for a laser additive manufacturing large-size component comprises the following steps that based on feature driving model shape simplification and large-size complex geometric component temperature and residual stress field analysis of a macroscopic thermal-mechanical coupling finite element, a three-dimensional component model is established, and a thermal-mechanical coupling finite element model is optimized; a double-ellipsoid laser heat source model is adopted, simulation calculation is conducted through a three-dimensional transient heat conduction equation, and evolution characteristics and distribution data of a temperature field and a residual stress field in the LP-DED process are obtained; and carrying out microscopic residual stress analysis based on the CP model of the coupled phase field damage PF model and the actual microstructure morphology representative volume element model RVE, and transplanting the obtained spatio-temporal evolution characteristics and distribution data of the macroscopic residual stress field to the mesoscopic CP model as predefined field variables through deep embedding coupling of the PF model and a CP constitutive framework. And establishing a cross-scale transmission analysis channel from the macroscopic stress field to the mesoscopic structure response so as to predict the multi-scale collaborative residual stress.

The application discloses a kind of multi-scale intestinal torsion simulation method and system based on virtual body envelope, method includes: constructing the intestinal geometric model including mucous membrane layer, muscle layer and plasma layer;Add virtual envelope body that wraps intestinal geometric model, obtain the deformation characteristics of virtual envelope body by exerting external force on the virtual envelope body;The deformation characteristics are substituted into intestinal geometric model to obtain macro stress field, and the reference feedback force of intestinal geometric model in macro stress field is calculated;Uniformly embedded discrete fiber bundle model in the stress concentration area of intestinal geometric model;According to the overall tensile amount of fiber bundle model, the damage rate of fiber bundle model is calculated;Determine the correction coefficient by damage rate calculation, and the reference feedback force is corrected to obtain tactile feedback force;The present application realizes the synchronous accurate simulation of macroscopic deformation visual reality and microscopic damage tactile feedback in small intestine torsion simulation by virtual body envelope and discrete fiber bundle multiscale coupling.

The application discloses a numerical calculation method of multi-scale residual stress and application, and belongs to the technical field of residual stress analysis. The calculation method comprises the following steps: (1) according to the structure and manufacturing process of a component sample, a temperature field calculation model is established, and corresponding moving heat source models are respectively set, and the macro temperature field distribution of the overall component is calculated through finite element simulation; (2) a multi-physical mechanism macro residual stress calculation model based on temperature-stress-microstructure coupling is established, and the macro stress field is calculated by using an indirect thermal force coupling method; and (3) by using a submodel technology, a multi-mechanism mesoscopic and microscopic residual stress calculation model based on temperature-stress-microstructure coupling is established, and the mesoscopic and microscopic stress fields are calculated. The application couples the microstructure evolution characteristics in the manufacturing process of the component with macro thermal force boundary conditions, establishes a multi-scale residual stress calculation method based on multi-physical mechanisms, and studies the distribution law of the residual stress from the multi-scale.

The invention provides a crustal stress prediction method and device, equipment and a medium. The method comprises the following steps: acquiring a target rock mechanical parameter of a target well position on a target block; according to the vertical ground stress, the formation pressure and the effective stress coefficient in the target rock mechanical parameters and the macroscopic stress coefficient of the target block, the macroscopic tectonic stress of the target well position is determined; according to the elastic modulus and the Poisson's ratio in the target rock mechanical parameters and the curvature coefficient and the microcosmic stress coefficient of the target well position, the microcosmic structure stress of the target well position is determined; and according to the vertical ground stress, the macroscopic tectonic stress and the microscopic tectonic stress, predicting the target principal stress of the target well position. The influence of the microstructure stress on the main stress of the target is considered, and the prediction accuracy of the crustal stress is improved.

The invention provides a method and system for predicting the ballistic performance of a composite material and a storage medium, and relates to the technical field of material performance evaluation, and the method comprises the steps: obtaining a macroscopic stress wave time sequence signal of the composite material in a ballistic impact process; mapping the macroscopic stress wave time sequence signal into a mesoscale damage state hidden variable through an online multi-scale damage feature mapper, and synchronously generating a preliminary ballistic performance result; based on the mesoscale damage state hidden variable, dynamically correcting the preliminary trajectory performance result through a physically constrained data adaptive calibration ring to obtain a corresponding trajectory performance prediction result; the ballistic performance prediction result comprises a penetration threshold, a back plate recess depth and a damage evolution time sequence.

This invention discloses a digital twin control method for ultra-thin strip rolling shape based on a multi-scale surrogate model, belonging to the field of metal rolling shape control technology. The method includes: firstly, real-time acquisition of the operating parameters of the physical rolling mill, inputting them into a pre-trained macroscopic surrogate model to predict post-rolling macroscopic stress and node positions; then, extraction of boundary conditions corresponding to mesoscopic representative volume elements, inputting them into a mesoscopic surrogate model to predict internal grain stress; subsequently, fusion of macroscopic and mesoscopic stress data to calculate a comprehensive stress uniformity index S; when S is below a preset threshold, optimizing the operating parameters in virtual space with the goal of minimizing index deviation, generating an optimal control strategy, and issuing it to the rolling mill for execution. This invention effectively suppresses shape defects caused by microstructural inhomogeneities and achieves feedforward precise intelligent control of the ultra-thin strip rolling process.

The invention relates to the field of metal fatigue life prediction, in particular to a stress concentration area roughness-based additive fatigue life dispersity prediction method, which comprises the following specific steps of: S1, giving measurement information of roughness Ra and roughness Rz; s2, constructing a submillimeter-level chamfer surface infinitesimal finite element model according to detail information, obtained through laser measurement, of the roughness of the chamfer surface; s3, simulating the most real stress condition of the hole edge chamfering infinitesimal element; s4, through finite element calculation, stress distribution of the hole edge chamfering infinitesimal elements is obtained; s5, the function relation between the chamfer surface roughness Rz and the stress concentration coefficient KT is obtained; and S6, calculating the fatigue life under different stress amplitude loads under different chamfer surface roughness conditions to obtain a life dispersion zone, and adopting a submillimeter infinitesimal finite element model with the minimum mesh of 1 [mu] m to simulate the actually measured surface topography and quantify the influence of microscopic roughness on macroscopic stress concentration.