8 results about "Flow stress" patented technology

The embodiment of the invention discloses a metal flow stress prediction method and system based on multi-physics field attention, and the method comprises the steps: carrying out the material characteristic coding of the material components and microstructure parameters of a metal material through employing a material characteristic embedding layer of an improved Kolmogov-Arnod network KAN, and obtaining the material characteristics of the metal material; obtaining a characteristic vector of the metal material; carrying out weighted fusion on a plurality of physical field parameters corresponding to isothermal strain measurement by adopting a multi-physical field attention layer of an improved KAN to obtain a high-order feature vector; and performing flow stress prediction on the high-order feature vector and the feature vector based on the temperature value of the isothermal strain measurement by adopting the improved KAN mixed sensing layer to obtain the flow stress of the metal material under the isothermal strain measurement. The accuracy of flow stress prediction can be improved.

The invention belongs to the technical field of protection, and particularly relates to a method and device for evaluating the damage degree of a functional gradient multilayer metal plate under a near-field explosion load. The method specifically comprises the following steps: determining the pulse pressure generated by explosion according to the spatial distribution characteristic of the peak value of the pulse pressure on a loaded surface and the attenuation change rule of the pulse pressure along with time; calculating the plastic work of the first layer of metal according to the plastic strain component expression of the first layer of metal and the incompressibility principle; according to the plastic work of the first layer of metal, the total kinetic energy of the multiple layers of metal plates and virtual work of pulse pressure generated by explosion on virtual displacement, a control differential equation of transverse displacement of the multiple layers of metal plates is obtained; solving the differential equation to obtain the maximum lateral displacement of the multilayer board, calculating the average strain rate according to the maximum lateral displacement, and updating the flow stress; the differential equation is solved again through the flow stress obtained through updating till the set condition is met, and the currently obtained maximum transverse displacement of the multi-layer board serves as the damage degree.

The invention belongs to the technical field of metal material hot working, and provides a method and system for constructing a thermal deformation constitutive model of a spray-formed 2195 aluminum-lithium alloy, and the method comprises the following steps: obtaining flow stress data according to a hot compression test; correcting the flow stress data to obtain calibrated flow stress data; identifying a peak stress and a material constant according to the calibrated flow stress data, and summarizing a Z parameter expression; introducing a strain influence function according to the material constant, and fitting a strain function; and substituting the strain function into the Z parameter expression to obtain a constitutive model. According to the method, the high-precision constitutive model considering the strain influence is established for the extrusion state spray forming 2195 aluminum lithium alloy for the first time, material parameters under different strains are identified through a system, the applicability of the model in a large deformation forming process is remarkably improved, and the prediction error is lower than 5%; a reliable theoretical tool is provided for formulating a hot working process, the trial and error cost is reduced, and the product quality and the structure uniformity are improved.

The present application relates to the turbine disc and compressor disc processing and manufacturing technical field of aero-engine, gas turbine, etc., and discloses a wheel disc mortise broaching force regulation and control method and system, the method comprises the following steps: obtaining broach geometric parameters, broaching process parameters and workpiece material physical properties; based on the broach geometric parameters, the broaching process parameters and the workpiece material physical properties, the shear flow stress on the main shear surface in the cutting process is calculated, and the cutting force considering the strain softening and temperature-strain rate coupling effect is further calculated; based on the broach geometric parameters and the shear flow stress, the edge extrusion force caused by the broach edge roundness radius is calculated; the broaching force and the edge extrusion force are superimposed to obtain the wheel disc mortise broaching force; according to the wheel disc mortise broaching force, the broach geometric parameters and the broaching process parameters are adjusted and controlled, and then the wheel disc mortise broaching force is optimized to meet the actual processing requirements, which provides support for reducing the tool optimization design cost and improving the wheel disc processing quality.

The invention discloses a dynamic strain measurement method, a test block and a testing machine for an ultrahigh-strength material greater than 2GPa. The dynamic strain measurement method comprises the following steps: measuring and acquiring workpiece measurement parameters of each rate test under various rate tests and the highest temperature T of a test section of the test piece; based on the workpiece measurement parameters, actual workpiece parameters are obtained through calculation; and fitting to obtain a dynamic stress-strain curve for simulation analysis based on a plurality of groups of workpiece actual parameters obtained by various rate tests and the highest temperature T of the test section of the test piece. Measurement of the temperature of a test section of a test piece is introduced, temperature measurement parameters are added into the model to construct a new Johnson-Cook constitutive model, a calculation method for correcting strain rate and temperature coupling based on the new Johnson-Cook model is adopted, test data are converted into constitutive parameters capable of being directly used for simulation, and data practicability is improved; and the correction precision of the influence of the introduction of the temperature data on the flow stress is greatly improved. The test piece is prevented from slipping in the clamp by adopting two measures of positioning pins, positioning holes and crossed lines.

The application discloses a damage simulation method based on deform, which comprises the following steps: a macro flow stress constitutive model is established according to stress-strain curves and experimental data of fracture strain under different temperatures and stretching speeds; a material library based on Deform is established by combining basic properties of elastic parameters and thermal performance parameters of the material; a damage prediction module for predicting a forging hot forming process is established, a ductile fracture criterion model is established according to obtained data of influences of the temperature and the strain rate on the strain at the time of fracture, and the temperature, the strain rate in the forging process and fracture in the forming process are predicted.

The invention discloses a multi-core copper-tin-titanium / niobium composite blank extrusion process design method based on machine learning, which comprises the following specific steps: carrying out an isothermal thermal compression experiment on a copper-tin-titanium alloy bar to obtain true stress and true strain data; constructing a flow stress-strain constitutive equation and a dynamic recrystallization kinetic model of the copper-tin-titanium alloy according to the true stress and the true strain data; establishing a thermal-mechanical coupling finite element model; constructing a data set according to an output result of the thermal-mechanical coupling finite element model; inputting the data set into a prediction model for training to obtain a trained prediction model; and optimizing hot extrusion process parameters by using the trained prediction model. The method is high in prediction precision, and the design period of the hot extrusion process is greatly shortened.

The application discloses a kind of metal material's flow stress prediction method, device and related equipment.It includes: obtaining the model parameter of the modified Johnson-Cook constitutive model of the metal material to be measured;The modified Johnson-Cook constitutive model is added in Johnson-Cook constitutive model Electric plasticity effect factor, model parameter includes yield stress, strain hardening coefficient, strain hardening index, strain rate hardening coefficient, high temperature softening index and electric plasticity effect coefficient;Determine the plastic strain of the metal material to be measured, plastic strain rate, current deformation temperature and current current density using a predetermined algorithm;It is input into the modified Johnson-Cook constitutive model, and the flow stress of the metal material to be measured is obtained.Thereby, the stress, strain and temperature change of metal material in self-resistance heating process can be more accurately predicted and controlled.