48 results about "Thermomechanical coupling" patented technology

The invention belongs to the field of deep high-temperature and high-pressure oil and gas exploitation rock mechanical testing, and particularly relates to a gas permeation testing method in low-permeability rock time-dependent deformation under the action of thermal-gas-mecha-nical coupling. The method includes the following steps that a rock core test piece is installed into a clamp holder, and the leakproofness of gas permeation testing is checked; the confining pressure, the temperature, the air pressure and the axial pressure are sequentially applied to a triaxial cell to predetermined values; the pressure of a high air pressure tank is increased instantaneously, the gas permeation parameters in the time state are calculated, and accordingly the rock gas permeation rate existing when the numerical value of a low air pressure tank is equal to the numerical value of the high air pressure tank is calculated; the gas pressure is adjusted to an initial value, the gas permeation rates at other moments are determined, and the gas permeation rates are given to a computer for drawing output. By the adoption of the method, the gas permeability of low-permeability rock under different time-dependent scales can be determined, the relation among the permeability parameter, the temperature parameter, the time parameter, the stress parameter and the strain parameter can be drawn automatically through a computer program, data result errors caused by not taking multi-field coupling and time-dependent factors into account in an existing device are avoided, and measurement accuracy is improved.

The invention relates to a method for building a lubricating oil film model, in particular to a method for building a lubricating oil film model after thermal coupling deformation of a static pressure center frame. The method aims to solve the problem that an existing method for building an oil film model has errors in workpiece efficiency and precision. The method comprises the steps that 1, a workbench, a base, supporting tiles on the two sides, a flat bottom deep oil chamber middle supporting tile and the model of an initial oil film are built, and the workbench, the base and the supporting tiles are assembled; 2, the model of the initial oil film is pretreated; 3, a flow diagram is built in the workbench, and thermal coupling computational analysis is carried out on the static pressure center frame; 4, the clearance between the workbench and an oil chamber is sealed; 5, the model of a clearance lubricating oil film is acquired. In actual application, the method is used for verifying the reasonable control over the flow of the lubricating oil of a large-size machine tool by the large-size machine tool so that it can be guaranteed that the large-size machine tool operates normally and safely, and the situations of dry friction, boundary lubrication and other lubrication failures are avoided.

A cutting device is characterized in that the cutting device comprises a particulate knife, a cutting worktable, a micro-jet spray head and a hydraulic device, relative linear movement is achieved between the cutting worktable and the micro-jet spray head, the particulate knife comprises a cutter body and a cutter bit, the cutter bit is arranged on the outer surface of the cutter body in an outward-protruding mode, the geometric dimension of the cutter bit is 10nm-1mm, a balancing weight is arranged in the cutter body, a spray cavity is formed in the micro-jet spray head, a spray mouth is formed in the bottom of the spray cavity, the spray mouth can generate an annular flow, the particulate knife is captured by the annular flow, and the outer diameter of the particulate knife is matched with the inner diameter of the annular flow. The cutting device has the advantages that the particulate knife is driven by water-caused rotation (namely the rotation of micro-jets) or is fixedly clamped to achieve micro-cutting, the micro-flow takes away heat generated during cutting in time, the inhomogeneous deformation field caused by thermomechanical coupling is greatly reduced, quality and working efficiency of micro-cutting are guaranteed, and a novel micro-cutting method is obtained.

The invention relates to a robust thermal-mechanical coupled topology optimization method considering random-interval mixing. First, based on the mean and variance intervals of structural compliance, the worst-case robust objective function is defined and a robust thermal-mechanical coupled topology optimization model is constructed; then, the univariate dimensionality reduction method and the chaos-Chebyshev polynomial expansion method are combined , developed an efficient mixed uncertainty analysis method to calculate the uncertain performance response of thermally coupled structures; finally, based on the proposed mixed uncertainty analysis method, the sensitivity of structural topology design variables was derived, and a gradient-based The optimization algorithm is used to solve the problem, and finally the robust topological configuration of the thermal-mechanical coupling structure is obtained. By constructing a polynomial expansion model based on a dimension reduction integral strategy, the present invention effectively improves the efficiency of solving the uncertain performance response of the thermal-mechanical coupling structure, and realizes the efficient and robust topology optimization design of the structure under the thermal-mechanical coupling working condition.

The invention relates to a method for measuring austenitization in the heat treatment process of metal materials, which belongs to the technical field of multi-field coupling numerical simulation, and is used to solve the problem that the existing numerical simulation cannot obtain the experimental data of the thermal physical properties of the material at the high temperature stage and does not consider changing the material composition The technical problem of the influence of phase change and thermal physical parameter difference on the calculation results of multi-field coupling. The method comprises the following steps: S1. Establishing a method for obtaining the phase transition and thermophysical parameters of the material for the composition and temperature of the metal material; S2. Establishing a finite element model for thermomechanical coupling calculation or heat transfer calculation of the temperature field-stress field; S3 . Calculating the temperature field or thermal stress of the metal material; S4. Obtaining the distribution of the temperature field and thermal stress of the metal material over time; S5. Obtaining the austenitization measurement results during the heat treatment of the metal material. This method takes into account the influence of composition on thermophysical parameters and phase transformation stress, and can accurately calculate the influence of phase transformation on temperature field and residual stress, which can be used to optimize the heat treatment process of different materials.

The invention relates to a layered stress calculation method of a steel-cored aluminum stranded wire under a thermo-mechanical coupling effect. The method comprises the following steps of: calculating to obtain the average running tension of a conductor at a solved temperature; substituting the average operation tension of the conductor at the temperature into an axial total strain calculation expression to obtain the axial total strain of the conductor and the strand direction strain of stranded wires; removing the temperature strain from the strand direction strain of the stranded wires to obtain the strand direction strain of the stranded wires under the action of tension; solving the axial strain of the stranded wires under the action of tension; acquiring the axial stratification stress of the stranded wires by multiplying the axial strain of the stranded wires under the action of tension by the elastic modulus of each layer of stranded wires; and calculating the layered stress of the wire steel core and the aluminum stranded wires under the extreme weather condition, and judging whether the conductor meets the safety design and the anti-fatigue performance under the extreme weather condition. According to the layered stress calculation method, layered stress calculation expressions of stranded wires of different materials are obtained through theoretical derivation, layered stress values of all layers can be obtained through programming calculation, and important reference is provided for safety design and selection of overhead lines and anti-fatigue performance research.

The invention provides a particle flow based irregular particle numerical simulation research method for microwave induced damage. According to a basic algorithm, a thermodynamic coupling numerical model with a specified size is established and endowed with the parallel bonding performance; round particles are generated by utilizing a written FISH language algorithm, and then aggregate shape based irregular clump blocks are formed; a corresponding relationship between macroscopic thermodynamic parameters and microscopic thermodynamic parameters is established by adopting a ''cut-and-try'' method; different aggregates are endowed with different microscopic thermodynamic parameters; and the microwave induced damage in different discontinuous scales is subjected to numerical simulation research. According to the research method provided by the invention, a novel research approach is provided for performing irregular particle numerical simulation of the microwave induced damage by adopting a discrete element method.

The invention discloses a finite element solution optimization method for structural thermal response caused by re-entry aerodynamic environment, which includes: discretizing the coupled control equation based on heat conduction and material thermoelastic dynamics through the finite element method and providing a corresponding algorithm flow; wherein, In the algorithm process, for time-dependent partial differential equations, the finite element method discretizes the spatial region first, and obtains the grid division of the solution region, and then differentially discretizes the time item. According to the iterative coupling relaxation calculation principle, step by step Advance to capture the vibration of structural materials in space and the nonlinear behavior of thermal response deformation of large spacecraft after de-orbiting and re-entry into a strong aerodynamic thermal environment. The present invention provides an optimization method based on the finite element method for solving thermal-mechanical coupling response, which is beneficial for analyzing and researching the thermal-mechanical coupling response of material structures under strong aerodynamic / thermal environments, and is conducive to carrying out the performance prediction of aircraft and spacecraft structures with simulation.

The invention discloses a method for constructing the thermal-mechanical coupling constitutive relationship of zirconium alloys under neutron irradiation conditions. The method of the invention combines the elasto-viscoplastic self-consistent theory to establish a cross-scale theoretical system from single crystal to polycrystal. The Matlab calculation program can easily, quickly and accurately calibrate the model parameters, and the numerical results of the model can be in good agreement with the experimental data under different external load conditions. The theoretical model framework has wide applicability and scalability, and can provide a reliable theoretical basis for the study of the macroscopic mechanical behavior of nuclear materials.

A three-dimensional finite element simulation method based on a multi-step metal cutting process, comprising the following steps: (1) establishing a three-dimensional model of a workpiece and a tool and assembling it; (2) setting dynamic thermal-mechanical coupling analysis steps and restart parameters; (3) Mesh the model; (4) Set the contact properties and boundary conditions of the cutting in the first step; (5) Submit the model for the first calculation to extract the cutting force and cutting temperature; (6) Set the first The results of this operation are imported into the model as the initial conditions of the unloading process in the first step; (7) Set the analysis step, restart parameters, contact properties and boundary conditions when the tool and workpiece are unloaded, and perform restart calculations; (8) Extract the residual stress of the first working step; (9) Import the calculation results of the previous step into the model as the initial conditions of the second working step; (10) Extract the cutting force, cutting temperature and residual stress of the second working step. This method has high simulation accuracy, fast calculation speed, and greatly reduces the cost of cutting experiments.

The invention discloses an optimization design method for structural parameters of a solid rocket engine jet pipe. The optimization design method comprises the following steps: 1, constructing a material thermophysical parameter model of each component of the jet pipe through a segmented cubic Hermite interpolation method; 2, constructing a thermal boundary condition model of the inner wall of the spray pipe through a Lagrange interpolation method; 3, analyzing and considering the temperature distribution and the thermal failure stress of the nozzle in the complex environment of interface debonding through a complete thermal coupling finite element method or a sequential thermal coupling finite element method; and 4, calculating peak values of thermal stress curves of the nozzle in working time under different axial lengths of the expansion section and different inclination angles of the contact surface of the expansion section and the throat liner, and obtaining the relationship between the maximum thermal stress value of the nozzle and the axial height of the expansion section and the inclination angles of the contact surface of the expansion section and the throat liner for structural optimization of the solid rocket engine nozzle. According to the method, the parameter selection and design of the nozzle structure can be optimized while the thermal stress extreme value of the nozzle is effectively reduced.

The invention discloses a micro-truss structure carrying and thermal protection structure multi-objective optimization method, and belongs to the field of spacecraft instrumentation overall design andmultifunctional structure material design. A flow channel is introduced into a micro-truss sandwich structure, multi-objective optimization of temperature and stress is realized by thermal transfer and force transfer coupling calculation, and final design meets a design process and the lightest front edge structure of a design boundary. The problem of thermal mechanical coupling under practical working conditions is taken into full consideration, the influence of the temperature on strength is introduced, processing technology boundary conditions are considered, and optimum structural designis realized by an optimization algorithm. The method is simple and effective, optimum design can be realized by small calculated amount, and time and cost consumed by trial and errors are greatly reduced.

The invention discloses a rough set theory-based uncertainty analysis method for a thermal coupling system, relates to the field of mechanical engineering, and is used for solving the problems that the uncertainty analysis of the thermal coupling system depends on priori knowledge and is low in efficiency. The method comprises the following steps: determining a discourse domain of uncertain parameters of the coupling system, and constructing a knowledge base of the discourse domain according to experimental measuring points; for any uncertain region in the discourse domain, constructing an upper and lower approximation set and calculating approximation precision; an initial Kriging model is established through Latin hypercube sampling and system finite element calculation, and Kriging model parameter correction is realized by using a maximum likelihood estimation and pattern search method; and based on a maximum mean square error point adding criterion, establishing an adaptive Kriging model, and further calculating response upper and lower bounds of the upper and lower approximation sets to obtain response approximation precision. By applying the rough set theory, when uncertainty analysis is carried out on the thermal coupling system, dependence on priori knowledge is not needed, and efficiency is high.

The invention provides a calculation method for a bloom rolling temperature field considering uneven deformation heat, which belongs to the technical field of iron and steel metallurgy. The method first uses the three-dimensional structure finite element method to establish a single-pass rolling calculation model of the bloom; then outputs the stress and strain field during the rolling process; finally uses the two-dimensional temperature finite difference method to establish the single-pass rolling temperature field of the bloom Computational model. The rolling temperature prediction model for rods and wires generally assumes that the heat of deformation is evenly distributed on the entire cross-section, and does not consider the influence of uneven heat of deformation on the rolling temperature field. It is more in line with the actual situation of uneven distribution of deformation during bloom rolling, and can improve the accuracy of the model. Compared with establishing a complete three-dimensional thermal-mechanical coupling model, the indirect coupling method can reduce the modeling scale, shorten the calculation time, and save time and efficiency.

A finite element modeling method of macroscopic thermal stress field based on the self-healing effect of laser stereoforming in the present invention comprises the following steps: step 1, establishing a thermomechanical coupling model for unilateral clamping of a laser stereoforming substrate; step 2, establishing a laser stereoforming Thermal-mechanical coupling model of the i-th cladding layer of the formed component; Step 3, calculate the temperature field of the i-th cladding layer of the laser three-dimensional forming component; Step 4, calculate the stress field and deformation of the i-th cladding layer of the laser three-dimensional forming component ; Step 5, judging whether the bulge on the deposition surface of the i-th cladding layer of the component can be eliminated; Step 6, judging whether the i-th cladding layer is the last layer; In the case that the process is eliminated, if the i-th cladding layer is the last layer, the simulation processing ends, otherwise, enter step 2, and repeat this cycle until the macroscopic thermal stress field simulation calculation of the entire laser stereoforming is completed.

The invention discloses a hydro-thermo-mechanical coupled subgrade dynamic response testing device and a method thereof. The device comprises a subgrade body, a water supply system, a loading system,a temperature control system and a data acquisition and processing system. The method comprises the following steps: connection of a data acquisition unit; consolidation and stabilization of the subgrade body; the vacuum insulation process; setting of water supply conditions and operating temperature of a bottom thermostat; the freezing process of the subgrade body; the melting process of the subgrade body; and hydro-thermo-mechanical coupled subgrade dynamic response testing and data acquisition and processing. According to the testing device and the method provided by the invention, by the utilization of a loading frame, a pressure chamber, a constant temperature system, the water supply system and the data processing system and by combining the dynamic loading technology with differentaxial frequencies, the large-scale subgrade loading technology of applying dynamic loads with different frequencies in the axial direction of the subgrade and adding confining pressure transversely isrealized, the experimental results provide accurate physical parameters for the establishment of a realistic hydro-thermo-mechanical coupled subgrade dynamic response model, and the subgrade materialcan be optimized.