90 results about "Multiphysics coupling" patented technology

The invention provides a multi-scale multiphysics coupling simulation method of metal additive manufacturing. The method comprises the following steps: S1, establishing a metal additive manufacturing technology data model; S2, carrying out first-principles calculation by calculation software on a microscale through first principles to acquire micro physical properties of additive metal material; S3, establishing an NxNxN super-cell model of the additive metal material, and carrying out molecular dynamics simulation calculation through molecular dynamics simulation software; S4, studying plasma, which is generated in a melting process of metal powder heated by an electron beam or a laser, on a mesoscale; S5, utilizing a flow-heat-solid-magnet multiphysics coupling simulation platform for simulation calculation; and S6, establishing a technology parameter feedback control model for different types and distribution situations of defects, and optimizing metal additive manufacturing technology parameters. The method forms a macro-micro-integration metal additive manufacturing product quality prediction system by means of multi-scale multiphysics coupling simulation.

The invention relates to an in-situ testing machine for the microcosmic performance for a multi-load and multi-physical-field coupling material, belonging to the technical field of material mechanics property testing. The in-situ testing machine comprises a micro/nanometer-precision driving/transmission module, a 'mechanical-electric-thermal-magnetic' loading module and a control module, is integrated with a high-field-depth 3D (three dimensional) micro-imaging lens, a Raman spectrometer and a visual in-situ monitoring module and is capable of dynamically monitoring deformational behaviors, damage mechanisms and performance evolvement rules of the material in a loading process. The in-situ testing machine has the advantages that the whole structure is compact, and the space layout is saved; the loads of four manners including 'stretching/compression-torsion-bending-indentation' can be singly loaded, two or more loads can be combined to be loaded as well, and externally-applied physical fields such as heat, electricity, magnetism and the like can be combined to maximally simulate the real working conditions of components of the material, and effective measures and methods are provided for testing the micromechanical performance of the material under a service-approximating condition.

The invention discloses a device for testing a coupling function of a multi-physics field of core rock and a use method of the device. The device is a sealed barrel body which is composed of a top cover, a barrel body and a base disc; a column chamber and a temperature sensor are arranged in the device; a plunger is installed inside the column chamber; a pressure groove is arranged inside the barrel body; an airbag and a convex rubber piston are arranged inside the pressure groove; the airbag is connected with an external high pressure gas source; a gas pipeline for filling gas to the barrel body is arranged in the plunger; an acoustic emission sensor is installed inside the rubber piston; the acoustic emission sensor is connected with an external acoustic emission acquiring system; a gas discharge port is arranged on the base disc and is connected with a gas pressure difference transmitter, a gas mass flowmeter and a gas data acquirer; and electric heating wires are arranged inside the base disc. With the adoption of the device, not only the transformation and the acoustic emission activity of a coal test piece at different temperatures and stress states are recorded in real time, but also the absorption and desorption processes of coal-gas are carried out; and the visual microstructure characteristics of the coal test piece are quantified by using the CT (computed tomography) technology.

The invention discloses a multi-physical field coupling simulation method and a multi-physical field coupling simulation system for a submarine high-pressure blow-off pipeline system. The method comprises the steps of establishing a three-dimensional geometrical model of a high-pressure blow-off system pipeline; performing finite element mesh division and boundary condition setting on the three-dimensional geometrical model of the high pressure blow-off system pipeline; performing fluid mechanic simulation calculation to obtain flow field characteristics in the high-pressure blow-off system pipeline and flow-induced noise characteristics in the blow-off system; performing simulation analysis on a fluid-solid coupling problem of the high-pressure blow-off system pipeline based on a multi-physical field fluid-solid coupling simulation calculation method; performing transient acoustic boundary element simulation calculation by use of an acoustic simulation calculation method based on a fluid-solid coupling simulation calculation result; and performing qualitative and quantitative analysis on flow field noises, flow-induced noises and vibration noises of the system pipeline and a watertank based on the multi-physical field fluid-solid-sound coupling simulation method. Through the multi-physical field coupling simulation means, the invention provides a noise prediction system for the submarine high-pressure blow-off pipeline system.

Provided is a ceramic/ceramic connection method for regulating and controlling a middle solder layer through multi-physical-field coupling. According to the ceramic/ceramic connection method, a heat source is adopted to fuse solder or solder and a part of base metal, meanwhile physical fields are additionally applied, the solder is a non-crystalline material or a mixed material of the non-crystalline material and a reinforcement phase, an outer heating source is acetylene flame or oxyhydrogen flame, electric arcs, laser, electron beams or a resistance heating method for melting metal through heat conduction and heat radiation is adopted, and the additionally-applied physical fields are one or more than two of ultrasonic waves, magnetic fields and electric fields which are simultaneously applied. The ceramic/ceramic connection method has the advantages of effectively controlling interface reaction, strengthening liquid metal flowing, regulating and controlling weld joint substance distribution, regulating the metallurgical welding process, controlling a weld joint organization structure, eliminating weld joint defects, reducing residual waste heat stress, improving weld joint toughness, promoting interface bonding, improving the mechanical property of welded joints, decreasing the material using amount and reducing environmental pollution through the additionally-applied physical fields and being widely applied to the fields of aviation, aerospace, electronic devices, fuel cells and the like.

The invention relates to a novel design method of an intelligent alternating-current and direct-current electromagnetic apparatus. An open type background database including electromagnetic systems and contact systems of different structures, shapes and materials is set up, counter force systems and the contact systems are designed according to the needs of on-off currents for counter force and the shape of contacts, the electromagnetic systems meeting the needs are designed according to the counter force systems, and multi-physic-field coupling simulation analysis and structural optimization design are carried out; through multi-software united calling, a multi-physic-field coupling relation between an electric electronic circuit and an electromagnetic apparatus body is introduced into dynamic calculation, and unit time step length closed-loop simulation of a nonlinear time domain of an intelligent control module and the apparatus body is carried out; an arc magnetic fluid kinetic model is built, arc motion conditions under different breaking control schemes are analyzed by combining a dynamic grid technology according to the motion track of the contacts, meanwhile, a breaking process arc equivalent model is obtained according to the arc parameter distribution conditions under different contact strokes at different moments, and arc energy is analyzed. An integrated simulation system with process control and a multi-field coupling electromagnetic apparatus virtual prototype is really built.

The invention discloses an intelligent power module multi-physical field coupling simulation analysis method and system, and the method comprises the steps: building an overall geometric model of an intelligent power module according to an intelligent power module circuit design schematic diagram; Performing finite element grid segmentation and discretization processing on the overall geometric model, performing analyzing to obtain parasitic parameters in a conductive path and a current-carrying element, and generating an equivalent circuit model; Establishing an electrical integrity model ofthe main circuit and the control circuit; Respectively solving the thermal field and the magnetic field, and establishing a stress-strain relationship and a failure model in the system level; Constructing a physical field coupling analysis model according to the stress-strain relationship, the failure model and the electrical integrity model; And based on the coupling analysis model, carrying outcurrent, magnetic field and heat dissipation state rule analysis. Parameter extraction, field distribution and coupling calculation of multi-physical field analysis can be carried out across differentfinite element analysis software, and multi-physical field coupling analysis under complex boundary conditions is completed.

The invention relates to a laser focused ultrasound excitation magnetic acoustoelectric imaging method and device. A laser beam subjected to beam expanding irradiates a carbon nanotube photoacoustic enhancement medium; focused ultrasound is generated; the focused ultrasound and a static magnetic field mutually act in a bioimaging body to generate a local electric field source; and a receiving coil or an electrode detection signal is used for rebuilding a biological tissue conductivity image. The laser focused ultrasound excitation magnetic acoustoelectric imaging device comprises a laser focused ultrasound excitation module, a coupling module, a detection and rebuilding module and a control and synchronization module, wherein the laser focused ultrasound excitation module generates controllable focused ultrasound with high pulse, high frequency and small focal spot; and the coupling module realizes the multi-physics coupling of the focused ultrasound, a target imaging body and electromagnetic excitation. The detection and rebuilding module realizes the detection on weak electric signals and the rebuilding on the target imaging body; and the control and synchronization module realizes the control and synchronization of the whole device.

The invention discloses a method for preparing WC-Co hard alloy by rapid sintering under a multi-physics coupling action, which is characterized by comprising the steps of: evenly mixing powder of WC and Co, wherein the weight ratio of WC to Co is 84-94: 16-6; weighing and then filling into a mould; then, under the conditions that the heating speed is 15-100 DEG C/ s and the vacuum degree is less than or equal to 0.01Pa, electrifying the mould containing the WC-Co powder with alternating current for rapid heating, and applying 10-200MPa acting force to the two ends of the mould; under the continuous action of electric field and force field, carrying out instant electric heating impact for different times when temperature rises to 800-1000 DEG C; and finally, cutting off the power, cooling with air and taking out the product. The electric heating impact comprises the following steps: cooling from the sintering temperature to 400 DEG C at the cooling speed of 15-100 DEG C/ s and then heating to the sintering temperature at the heating speed of 15-100 DEG C/ s; wherein the circulation time(s) is/ are 1-10 time(s). The method simplifies the technological process, is rapid, efficient, energy-saving and environment-friendly, improves the quality of the hard alloy and is capable of replacing the existing preparation method of the hard alloy.

The invention discloses a gas-liquid-dust explosion experiment system for use under multiple working conditions. The system comprises a container main body as well as a material temperature control unit, an inner-layer container temperature control unit, a precise electric spark ignition energy generation unit, a gas concentration testing unit, a humidity control unit, a pressure sensor unit, a flame temperature sensor unit and an air inlet and vacuuming unit which are respectively arranged on the container main body. The system can be used for simulating a complex working condition in which multiple multi-physical fields including the temperature, pressure, impurities, humidity, leaking hole shapes, ignition positions and the like are coupled, determining accurate critical ignition energyvalues of explosion of gas, liquid and dust and finishing the measurement of relevant parameters and can be further used for evaluating the explosion suppression property of explosion suppression materials and verifying an explosion suppression method.

The invention relates to a direct current cable space charge distribution simulation method considering temperature and electric field gradient influence, and belongs to the technical field of directcurrent cable electrical performance research, and the method comprises the following steps: S1, building a two-dimensional physical model of a circular section of a direct current cable; s2, carryingout theoretical analysis of direct current cable insulation layer space charge injection; s3, carrying out theoretical analysis of space charge transport and accumulation in the insulating layer; s4,adding a physical field, and performing multi-physical-field coupling; s5, setting parameters and boundary conditions according to actual operation conditions; s6, carrying out mesh generation on themodel based on a finite element method, and obtaining direct-current cable insulation layer space charge and electric field distribution results under the action of different temperature gradients and electric field gradients through simulation. By adopting the method, the distribution characteristics of space charges and electric fields of the cross section of the cable insulation layer under the conditions of different materials, temperature gradients and electric field gradients can be obtained.

The invention discloses a control method for implementing a microstructure by non quenched and tempered steel hot forging formation in the technical field of forging formation. The method comprises the following steps of: predicting evolution rules of the microstructure in the full multi-procedure hot forging process by using deformation-hot-tissue multi-physical field coupling simulation and adopting commercial finite element software and a microstructure evolution calculation and analysis tool of secondary development, wherein the evolution rules comprise dynamic re-crystallization percentage, grain size and distribution rule of ferrite and pearlite in a forged piece; and then by using uniform dynamic re-crystallization distribution, avoidance of local grain roughening and reasonable distribution of the ferrite and the pearlite in the forged piece as goals, adjusting the hot forging process parameters to acquire reasonable microstructure distribution and realize 'shape control' and 'property control' of non quenched and tempered steel hot forging, and finally obtaining a forged piece product with good comprehensive mechanical properties. The method can avoid practical physical trial manufacture, remarkably shorten the development time and reduce the development cost of the hot forging process.

The invention discloses a method for preparing an MnZn ferrite magnetic core by multi-physical field coupling. The method comprises the following steps of filling MnZn ferrite powder having particle sizes of 0.7 to 2.0 micrometers into a mold, directly powering on the mold with the MnZn ferrite powder to fast heat the mold at a heating rate of 5 to 200 DEG C/s under the pressure of 10<-2> Pa, simultaneously, applying an acting force of 50 to 100MPa to two ends of the mold, heating to a temperature of 600 to 1200 DEG C under the action of a continuous electric field, carrying out heat preservation for 2 to 10min so that the MnZn ferrite powder undergoes a solid-phase reaction in the mold and is molded fast, interrupting power supply, and taking out a sintered body. The method has the advantages that a heating rate is greatly improved so that diffusion between atoms is promoted; and through the pressure on the two ends of the mold, a MnZn ferrite magnetic core solid-phase reaction, compaction molding and compact sintering are carried out simultaneously so that performances of a molded magnetic core are guaranteed.

The invention discloses a temperature field calculation method of a reactor based on multi-physical field coupling. Firstly, a three-dimensional simulation model of the reactor is established. Subsequently, based on the electromagnetic theory of field-circuit coupling, the current of each layer of reactor is calculated by the finite element method, and the winding loss of each layer is calculated,then the thermal density per unit volume of reactor is calculated. Finally, based on fluid-temperature coupling, the finite volume method is used to solve the temperature distribution of the reactorwith the unit volume heat density of the reactor as the heat source parameter. The temperature field distribution of the reactor calculated by the invention provides a theoretical basis for structuralperformance optimization of the reactor and online monitoring of the temperature.

The invention provides a multi-objective topology optimization method for the stiffness and frequency of a structure under a multi-physical field coupling working condition. The structure designed by utilizing the method can ensure the mechanical performance of the structure based on minimum material consumption, and improve inherent frequency characteristics. The method comprises the steps of firstly building a to-be-optimized structure model by applying three-dimensional modeling software Pro/E; performing coupled field finite element analysis on the model under the multi-physical field coupling working condition to obtain equivalent strain information of each node; performing modal analysis on the model to obtain inherent frequency information of the structure; on the premise that a vibration frequency of a system is known, importing the built model into a topology optimization module, and applying a constraint condition taking an equivalent strain as a forced displacement under an original boundary condition; establishing an overall objective function including a stiffness component and a frequency component according to a compromise programming theory, and then performing topology optimization to obtain a density cloud chart of the structure; and according to the density cloud chart, obtaining the designed final structure.

The invention belongs to the technical field of multi-physics coupling computing of a converter transformer, in particular to a calculation method of a composite electric field of the converter transformer considering temperature gradient. The calculation method comprises the steps that firstly, loss of transformer core and winding is calculated; next a fluid-temperature field model of the converter transformer is established, the fluid-temperature field model is discretized into a triangular-quadrilateral network, the distribution of a temperature field when heat flux is coupled inside a fueltank is calculated and analyzed by utilizing a magnetic field loss as the heat source. According to the electric field characteristics, an electric field model is established and divided into a triangular network, and temperature results of a fluid-temperature field are mapped into the electric field model through a fast mapping method; finally, a power transmission system model is built, a ground voltage wave is transformed to the frequency domain, and the results are returned to the time domain by utilizing the Fourier inverse transform, and a non-sinusoidal steady-state alternate current/direct current composite electric field of the converter transformer is analyzed and compared under the condition of homogeneous temperature and non-uniform temperature. The method considers the existence of temperature gradient, improves the calculation accuracy, and makes the calculation results more accord with an actual situation.

The invention discloses a method for evaluating flow impact of a reactor core outlet of a sodium-cooled fast reactor, which comprises the following steps of: carrying out geometric modeling by using Solidworks according to an actual structure of the reactor core outlet of the sodium-cooled fast reactor, and carrying out fluid domain and solid domain subdivision; performing grid division on a fluiddomain in a grid division function of computational fluid mechanics software, setting physical properties and boundary conditions of liquid metal sodium in a fluid computational domain, and performing transient flow field calculation by adopting a high-precision large eddy simulation method; performing condition setting and mesh generation on the solid domain in finite element analysis software;using a multi-physical field coupling platform MpCCI for transmitting flow field parameters obtained through computational fluid mechanics software to finite element analysis software, and making solid structure mechanics calculation in the finite element analysis software; and finally, evaluating the flow impact influence of the reactor core outlet of the sodium-cooled fast reactor through mechanical analysis of a flow field and a solid structure.

The invention relates to a high-voltage direct-current submarine cable simulation method and system. By establishing an electric field module control equation, a flow field module control equation, a solid heat transfer module control equation, a fluid heat transfer control equation and an electrothermal coupling control equation, an electric-thermal-flow multi-physical field coupling simulation method is provided for a high-voltage direct-current submarine cable. The method directly couples physical processes of electric-thermal-flow multi-physical fields; a quick determination method for a temperature, an electric field and a flow velocity is provided for the high-voltage direct-current submarine cable; and the method is simple and universal, is easy to popularize and apply, and is of important significance for guaranteeing safe and reliable operation of a power grid and prolonging the service life of the submarine cable.

The invention relates to a tension-torsion composite clamp under a multi-physics coupling condition, and relates to the technical field of material tests. The rear end of a constant speed hydraulic cylinder is connected with a tension-torsion composite sensor, and the end surface of a piston rod on the front end of the constant speed hydraulic cylinder is coated with a high-temperature ceramic insulating material; a heat insulation part comprises a connecting screw and a rubber insulating mat and is composed of mica sheets and copper sheets in an overlaying manner; the clamp is used for connecting a front-end flange, a positioning piece, the heat insulation part and a clamping part of the constant speed hydraulic cylinder together through bolts, and a wedge block is used for clamping a test specimen under the thrust action of the constant speed hydraulic cylinder; a spline pair is arranged between the front end of the piston rod and a clamp body, and is used for preventing relative rotation of the piston rod and the clamp body and transmitting torque. The tension-torsion composite clamp provided by the invention can be applied to a tension-torsion composite material testing machine with loading modules of temperature fields, electric fields, magnetic fields and the like, and the material testing machine can test the mechanical property of a material approaching to a serving condition under a multi-physics coupling condition and under the simultaneous effect of tension and torsion loads. The tension-torsion composite clamp has the characteristics that the operation is reliable, and the operation is simple.

The invention relates to the technical field of explosion-proof devices for high-voltage cable joints, and specifically relates to a simulation method for the opening radius of an energy release holeof a high-voltage cable joint explosion-proof device, which comprises the following steps of: adopting COMSOL Multiphysics multi-physical field coupling simulation software to construct models of different types of energy release hole explosion-proof devices; adopting the mode of heat-flow-solid multi-physical field coupling, calculating the maximum gas velocity and pressure distribution in the explosion-proof chamber corresponding to the design of different radii of the blowout holes; according to the exponential function law, obtaining the function relation between the maximum pressure and the size of the energy dissipation hole in the explosion-proof device by the least square method. Considering the secondary damage caused by the reduction of the maximum pressure inside the explosion-proof device and the reduction of the jet flow through the vent hole, the optimized radius of the vent hole is designed. The invention can optimize the size design of the energy dissipation hole of theexplosion-proof device of the high-voltage cable joint, save the test cost, improve the protection precision, and provide a reliable theoretical calculation method for the explosion-proof device design.

The invention discloses a converter multidisciplinary optimization design method based on multi-physics field coupling. The converter multidisciplinary optimization design method comprises the following steps: S1.1, selecting a target which needs to be optimized in a converter model, carrying out the parametric modeling of the target, and obtaining a three-dimensional parametric model; S1.2, extracting geometric information of a preset area in the three-dimensional parametric model, modifying configuration parameters to enable non-geometric information to be output, and outputting an intermediate file; S1.3, establishing an optimization process according to the intermediate file, establishing a CFD thermal simulation model, extracting parameterized size variables needing to be optimized, and determining an optimization target and constraint conditions; and S1.4, executing optimization to obtain optimized geometric parameters. The converter multidisciplinary optimization design method has the advantages that the multidisciplinary separation problem existing in traditional design is solved; the design requirements of different disciplines can be fully considered; and the design period of the high-power converter is greatly shortened, and the design cost is reduced.

The invention discloses a temperature control type electro-acoustical pulse-method space charge measuring device. The temperature control type electro-acoustical pulse-method space charge measuring device comprises a direct-current voltage source inputting device for exerting direct-current voltage on the first end face of a measured sample, a pulse voltage inputting device for exerting pulse voltage on the first end face of the measured sample, a metal electrode in contact with the second end face of the measured sample, a temperature regulation and control unit for conducting temperature regulation and control on at least one of the first end face and the second end face of the measured sample, a piezoelectric sensor, a piezoelectric sensor temperature protection unit for regulating and controlling the working temperature of the piezoelectric sensor, and a signal outputting unit for outputting data converted by the piezoelectric sensor. The temperature control type electro-acoustical pulse-method space charge measuring device has the following advantages that a wide-temperature-range regulation and control function, a temperature gradient regulation and control function and a quantitative regulation and control function of multi-physical-field coupling conditions can be achieved, further has the advantages of being small in size and adopting high-voltage-resistance electrode structure design, can meet the measurement demands of insulation materials different in thickness and is simple to manufacture and convenient to operate.