326 results about "Finite element computation" patented technology

The invention relates to a modeling method of a motor in electromagnetic field-flow field-temperature field coupling calculation. The method comprises the following steps that (1) a finite element calculation model of the motor is established, and an electromagnetic field value is calculated; a rotor calculation domain is set into a multi-component fluid calculation domain, and a model calculation domain of air, a rotor conductor and a rotor iron core is established; (3) the value is calculated in the corresponding model calculation domain, and the velocity of movement is worked out; (4) a result which is worked out from the calculation of the electromagnetic field value and the calculation domain of each part of the multi-component fluid serves as load and is loaded into a temperature field to solve and calculate, and a temperature result is worked out. The method is adopted to set the rotor calculation domain into multi-component fluid; in such a manner, after a rotor part which is originally slid is equivalent into liquid, the rotor part can be processed and solved quickly and conveniently through a fluid control equation, so that not only is the heat loss of all parts in the motor calculated comprehensively and precisely, but also the calculation time and calculation complexity can be greatly reduced.

The invention belongs to the field of aircraft flight load actual measurement and relates to a method for actually measuring wing torque loads of a high-manoeuvrability aircraft. The method comprises the following steps: 1, determining a structure or a part sensitive to influences of wing aerodynamic loads on wing torque loads by virtue of wing finite element computation and analysis; 2, realizing a torque load test system for each section of wings by virtue of adopting a sensitive torque bridge piece distribution scheme and a torque bridge combination technology; 3, performing a ground calibration test on the torque loads according to the structure or part sensitive to the influences of the aerodynamic loads on the wing torque loads, thereby obtaining conversion relation between external loads and bridge strain gauge signals by virtue of the ground calibration test; 4, performing a flight load actual measurement flight test, thereby obtaining the torque loads of each section of the wings according to the bridge strain gauge signals during flight. The method has the advantages that by virtue of aiming at the implementation difficulty in aircraft wing torque load actual measurement, the implementation problem of a torque load flight actual measurement test is solved, and the accuracy and high precision of the wing torque load test are ensured.

The invention relates to a pipeline valve safety assessment method based on limit external load calculation. The method comprises steps as follows: S1, establishing a three-dimensional geometrical model of a valve, a pipeline and a connecting piece; S2, performing finite element mesh generation on the three-dimensional geometrical model to establish a finite element mesh model; S3, establishing a limit external load finite element calculation model on the finite element mesh model; S4, performing calculation according to the limit external load finite element calculation model to obtain a limit external load; S5, establishing multiple combined external load finite element calculation models under the combined action of the limit external load and the maximum working pressure on the finite element mesh model; S6, calculating the stress distribution of the pipeline valve through the combined external load finite element calculation models and determining the safety performance of the pipeline valve according to the stress distribution. With the adoption of the method, the effect caused by the external load on the pipeline valve can be considered before prototype production, whether the strength property of the valve meets the design requirement or not can be judged, potential risks can be predicted, and the product development cycle is shortened.

The invention provides a metamaterial light curing 3D printing method based on holographic optical tweezers. The method comprises the following steps: choosing liquid photosensitive resin as a raw material of a metamaterial base material and choosing solid particles as artificial micro-structures; designing a geometrical structure and a topological structure of a targeted metamaterial according to a result of finite element computation of a computer; generating a print document and a holographic image document by using source data; respectively transmitting the print document and the holographic image document to 3D printing equipment based on three-dimensional light curing forming and the holographic optical tweezers based on a diffractive optical element; simultaneously generating a plurality of optical potential wells which are distributed in a fixed manner in the liquid photosensitive resin by using the holographic optical tweezers according to the holographic image document; capturing the artificial micro-structures in the various potential wells so that the artificial micro-structures are orderly arranged according to the designed topological structure; setting a print focal distance in the depth of the arranged artificial micro-structures by using the 3D printing equipment based on three-dimensional light curing forming; curing a liquid original base material; and continuously manufacturing in a lamination manner according to the print document so that the three-dimensional complex-curved-surface metamaterial comprising different material base bodies and micro-structures can be produced conveniently.

The invention discloses a vortex flow transducer evaluation method based on fractal information dimensions and relates to an optimization algorithm of a stimulation curve in planar vortex flow transducer design. Information dimensions in a fractal geometry theory are adopted, finite element calculation is performed on vortex flow distribution produced on the perfect conductor surface by an exciting coil, information entropy, distributed in different directions, of virtual cracks at different scales in the strongest vortex flow position is obtained, and information dimensionality of the information entropy changing with virtual crack scale variation is obtained. The fractal information dimension is taken as an optimization method of a vortex flow transducer stimulation curve, and the changing speed of the intensity of the mutual action between vortex flow and cracks induced by the stimulation curve with reduction of crack lengths is evaluated.

The invention provides an integral computation method of welding residual stress and deformation of a super-large structure. Components are sorted according to the manufacturing sequence of the super-large structure, and welding joints of each component are sorted according to the welding technological regulation, sequence and manner of each component; sorting is conducted according to the thicknesses, types and groove forms of different welding joints; welding joint equivalent samples with the same sizes as the welding joints of the actual super-large equivalent samples are produced, an equivalent thermal source method is adopted to simulate the residual stress distribution of each type of welding joint equivalent samples to obtain welding seams of the welding joints of each component andthe magnitude of residual stress of a thermal influencing area, and therefore the integral residual stress distribution of the super-large structure is deduced; obtained joint internal original stress is taken as an initial stress according to the positions where the welding joint equivalent samples of each component are located to be imported to a housing unit integral model of the super-large structure to perform elastic finite element computation, and therefore the deformation distribution of the whole super-large structure is finally obtained.

The invention discloses a soil landslide monitoring, early warning and evaluating method which comprises the following steps: S1, acquiring landslide topography and geological data to be monitored, and acquiring a rock-soil parameter test value through an indoor test; S2, establishing a landslide geologic model, carrying out limit analysis, determining a landslide damage mode and carrying out landslide monitoring; S3, uniformly designing parameter combinations for the rock-soil parameter test values, performing finite element calculation on all the parameter combinations to obtain a displacement field calculated by each parameter combination, and recording the displacement of each monitoring point to obtain a 'parameter combination-displacement' neural network model; S4, according to the landslide real-time cumulative displacement monitoring data and the parameter combination-displacement neural network model, performing rock-soil parameter inversion correction, obtaining rock-soil real-time strength parameters, and performing precision inspection; and S5, performing limit analysis by adopting real-time strength parameters, establishing a 'real-time cumulative displacement-safety coefficient' relation curve, establishing a landslide monitoring three-level early warning grade evaluation system, and evaluating the monitored landslide.

The invention discloses a design method of a permanent magnet motor capable of reducing cogging effect and a permanent magnet motor. Each magnetic pole in the permanent magnet motor at least comprises two permanent magnets with the same magnetic pole directions, and corresponding parameters of permanent magnets subjected to circular arc top surface or chamfering treatment when the cogging effect of the permanent magnet motor is the minimum are acquired by a finite element computation method, wherein the parameters of the permanent magnets mainly comprise the number n (n>=2) of the permanent magnets the magnetic pole directions of which are the same in each magnetic pole, the width of each permanent magnet, and the distance between two adjacent permanent magnets. The permanent magnet motor disclosed by the invention can reduce cogging torque/cogging force peak value borne by a single tooth and reduce complicated harmonic components, thereby effectively reducing the cogging torque/cogging force of a surface type permanent magnet motor.

The invention provides a design method and a system for a cast-in-place reinforced concrete pipe ditch, wherein size parameters of the reinforced concrete pipe ditch are acquired; a three-dimensional model of the reinforced concrete pipe ditch is established; according to finite element theories, the model is converted into a two-dimensional model of the reinforced concrete pipe ditch for finite element computation; any cross section in the two-dimensional model of the reinforced concrete pipe ditch is extracted; according to finite element computation results, positive stress and shear stress of each node on the extracted cross section are obtained; the bending moment, axial force and shear force values of an equivalent column cross section of the extracted cross section are computed; reinforcement computation is conducted to the extracted cross section; reinforcement computation results of the different cross sections are computed; and design results of the cast-in-place reinforced concrete pipe ditch are obtained. During the whole course, the three-dimensional model is converted into the two-dimensional model for processing based on the finite element theories; finite element computation is conducted to the two-dimensional model; the bending moment, axial force and shear values of the equivalent column cross section of the extracted cross section are obtained; and then the reinforcement computation is conducted to the extracted cross section. In this way, the cast-in-place reinforced concrete pipe ditch can be designed accurately.

The invention provides a process parameter optimization method based on a BP neural network. The specific thought of the method is as follows: based on a finite element calculation method, establishing a laser welding model and loading a heat source, correcting the heat source model through experimental temperature measurement, and then analyzing a temperature field and a change rule obtained through calculation to obtain training sample data of the neural network. The BP algorithm is a multi-layer feedforward network trained according to an error back propagation algorithm, the learning ruleis a steepest descent method, the weight and threshold of the network are continuously adjusted through back propagation, and the network error is reduced. The welding process parameter adjusting process is simplified, and high-quality process parameters can be quickly adapted according to welding workpiece parameters; and technological parameters are optimized, and the mechanical property of a weld joint is improved.

The invention discloses a parameterized computational analysis system for a lubricating oil film of an oil film bearing and an operating method of the parameterized computational analysis system. The invention belongs to the technical field of designing of the oil film bearing. A foreground human-computer interface comprises a welcoming interface module, an account management module, a parameter input module, a parameter guide module, a working condition selection module, an analysis flow module and a clock and state prompt module. A background computation program comprises a parameter initialization module, an Ansys parametric design language (APDL) command module, a common command language (CCL) command module, a compound file explorer (CFX) finite element computation module, a different-working-condition program module and an analysis file input/output module. The operating method comprises the following steps of: (1) installing an Ansys in a D disk; (2) starting the parameterized computational analysis system and logging in the system; (3) inputting corresponding parameters; (4) generating an APDL file; (5) starting the Ansys in the background, and generating a model; (6) generating a CCL file; (7) activating a CFX, and carrying out CFX pre-processing; (8) importing an analysis file, and directly solving; (9) carrying out CFX post-processing, checking an analysis result, and outputting an analysis report; and (10) logging out of the system.

The invention discloses an intensity finite element computing method for a wind generating set lifting tool. The method comprises the steps that firstly, an actual lifting three-dimensional model is built in Solidworks software, then, model simplification is performed in a Workbench, and a finite element computing model is built in a Hypermesh; finally, assembling, parameter setting, loading computing and post-processing are performed in ANSYS, stress of a bolt and a lifting base is analyzed, and the security is checked. Finite element computing is adopted, the influence of the rigidity of thelifting tool on stress distribution and the stress state of the local structure of the lifting tool are considered, and the welding seam with the most risky stress is subjected to intensity analysis;in addition, the influence caused by slippage on bolt stress and hole forming in the binding face portion caused by unbalance loading can be sufficiently considered. Accordingly, the method can moreaccurately and visually reflect the actual stress state in the lifting base and bolt lifting process, and therefore the reliability and safety of the lifting operation are improved.

The present invention discloses a CT gray-material property assignment finite element modeling method used for osteotomy. The method comprises: (1) skeleton three-dimensional model reconstruction; (2) hook surface construction and substantialization of a skeleton surface model; (3) skeleton segmentation of a bone entity model; (4) meshing and output of a skeleton member entity model that the position of which is not changed; (5) position adjustment of a skeleton member entity model that the position of which is changed and establishment of a reference model; (6) CT image gray-material property experience formula based mesh model assignment; and (7) position adjustment of a skeleton member mesh model and processing before finite element modeling, and obtaining a final skeleton finite element model. The method disclosed by the present invention can realize random adjustment of the position of the skeleton member model, has gray assignment based non-uniform element material properties, and has characteristics of high reducibility of a model material, simple operations, an accurate finite element calculation result, and the like.

The invention discloses a computing method for an equivalent elastic modulus of two-dimensional porous materials. The computing method comprises the following steps of: firstly building a finite element computation model of the two-dimensional porous materials, then dividing a grid, exerting a displacement load, obtaining a resultant force of all nodes at fixed ends of loads along a direction of the equivalent elastic modulus, and finally obtaining the equivalent elastic modulus of the finite element computation model of the two-dimensional porous materials according to formula computing. Themethod disclosed by the invention is applicable to solving of the equivalent modulus of the two-dimensional porous materials with regular and irregular conformation in a covariance direction, moreover, size limit of a product is avoided, and the computing method has the advantages of simplicity and rapidness.

The invention discloses a prediction method for the residual bearing capacity and the crack propagation path of a crack-containing structure based on LSTM-cGAN. The method comprises the following steps: at a training stage, firstly, obtaining the strength of a structure containing cracks of different degrees and a crack propagation path of the structure under a loading condition through finite element calculation or field actual measurement; and based on a conditional generative adversarial network model and a long-short-term memory method, simultaneously training four deep neural networks including a generation network G and a judgment network D, an LSTM network for processing a time sequence and a convolutional neural network CNN for judging crack structure strength; after the training is completed, inputting the structure crack propagation history measured on site into the generation network G and the LSTM network to obtain the prediction of the corresponding structure strength andcrack propagation path. According to the method, the strength and the crack propagation path of the crack-containing structure can be efficiently predicted, and the in-situ nondestructive monitoring of the crack-containing structure can be effectively realized.

The invention discloses a noise prediction method for an automobile exhaust system. The method comprises: establishing a sound-vibration coupling finite element calculation model between an in-vehiclesound cavity and a vehicle body in advance; pre-calculating an exhaust system lifting hook vibration transmission force-in-vehicle target point noise sound pressure transmission function in a frequency domain under different operation conditions, and storing the function into a database; pre-calculating an exhaust system lifting hook suspension point vibration displacement-lifting hook vibrationtransmission force transfer function in a frequency domain under different operation conditions, and storing the function into a database; establishing a kinetic finite element calculation model of the exhaust system, and calculating the vibration displacement at the suspension point of the lifting hook; and multiplying the vibration displacement by a vibration transmission force-in-vehicle targetpoint noise sound pressure transmission function and a vibration displacement-lifting hook vibration transmission force transmission function in a database to predict the noise sound pressure of thein-vehicle target point. Because the two transfer functions do not need to be calculated during noise prediction, the calculated amount is greatly reduced, and the prediction speed of the noise in thevehicle is improved.

The invention relates to an all-parameter customized type dropper three-dimensional pre-configuration method and system. The method comprises the steps: adding an all-line three-dimensional world coordinate system for modeling in a dropper pre-configuration process; adding weight reduction models of all types of additional loads; defining the position of each dropper, the position and tension of an elastic sling and the position and weight of an additional load; adding a midspan dropper point height correction algorithm, adopting a finite element calculation method, calculating three-dimensional coordinates of a full-line contact network to calculate an accurate solution of the dropper length is solved. A full-line and full-parameter customization mode is adopted, the problems that an existing method cannot be applied to differential design and existing railway transformation customization calculation are solved, a three-dimensional space modeling mode is adopted, and the calculation precision is improved compared with the existing method. According to the method, a good engineering application effect is obtained, and through inspection, on the premise that all links are accurate,dropper calculation under all working conditions can be achieved, and the dropper can be installed in place at a time.

The invention discloses a large-scale vibration engineering control device optimization arrangement method. A control device refers to a steel spring vibration isolator. The method includes the steps of (1), determining a steel spring initial arrangement scheme according to the actual engineering; (2), building an integral finite element calculation model of a vibration isolation system; (3), determining a loading condition; (4), calculating actual bearing capacity F of each steel spring by software through finite element calculation; (5), calculating vibration isolation efficiency Etan of each steel spring according to the formula Etan=actual bearing capacity F/ultimate bearing capacity[F]; (6), uniformizing the vibration isolation efficiency and calculating the uniform vibration isolation efficiency[Eta] according to the formula [Eta]=(Eta<1>+Eta<2>+Eta<3>+...+Eta<n>)/n; (7), if the vibration isolation efficiency Etan meets the formula (Eta<n>-[Eta])/[Eta]</=10%, then determining the effective scheme; (8), carrying out model calculation and analysis to the whole vibration isolation model; (9), determining the final scheme if requirement for model is met, in other words, the modal calculation fundamental frequency error is lower than 10%; and (10), arranging the steel springs according to the determined final scheme.

The invention discloses a blade root structure optimization method of a dimensionality reduction simulated annealing algorithm. The method includes the steps that firstly, a design variable in the optimization process is determined, and two-dimensional parameterization modeling and three-dimensional parameterization modeling of a target blade are completed; secondly, an N0 set of design variables is randomly generated, an initial average value mu0 and an initial standard deviation delta0 of maximum stress value relative errors of a two-dimensional model and a three-dimensional model under the N0 set of design variables are calculated through a finite element method; thirdly, according to a computation result of the three-dimensional finite element model, the blade root is optimized through the simulated annealing algorithm, a dimensionality reduction rule is introduced according to the initial average value mu0 and the initial standard deviation delta0 of the relative errors in the Metropolis sampling process, the finite element computation amount is reduced, and the average value and the standard deviation of the relative errors is updated after three-dimensional model computation is conducted; when the annealing temperature is lower than a set value or a target function value is stable, the computation process is converged if the result is verified to be within a permissible error range, and optimization is completed. The method has the advantages of being high in convergence speed, capable of saving computation resources and time and the like.

The invention discloses a three-dimensional random seepage field simulation method and device based on finite elements, and belongs to the field of geotechnical engineering random seepage field simulation. Based on finite element grid integral point coordinates, a relationship between a permeability coefficient of a material and a temperature field is established through a UTEMP subprogram, and anon-uniform three-dimensional random seepage field in a three-dimensional space can be simulated and realized. In order to meet the requirement of the permeability grade of the material, the permeability coefficient is regarded as a random variable obeying uniform statistical distribution, and meanwhile, the correlation length in an autocorrelation function can be adjusted to reflect the correlation of the permeability property of the material in each direction of space. Generation of the three-dimensional random seepage field and finite element calculation are efficiently combined, the methodcan be applied to three-dimensional random seepage field models of any complex shape, and the calculation capacity and efficiency are effectively improved. The finite element calculation result can truly reflect the change rule of the seepage state under the condition that the permeability coefficient of the material is not uniform, and the uncertainty source of the total seepage flow of the model can be further clarified.

The invention discloses a material constitutive model based on deep learning and a finite element method, which belongs to the technical field of artificial intelligence and material constitutive models, and comprises the following steps: establishing a finite element model according to the size of an earth and rockfill dam material test piece, and inputting a stress-strain curve obtained by a compression test to perform finite element calculation; extracting real stress, strain and incremental data of the model to form a data set; learning the data set by adopting deep learning, and outputting deep learning model parameters; ccording to the deep learning model parameters, compiling a material constitutive subprogram, and constructing an earth and rockfill dam material constitutive model based on deep learning and finite element unit method. According to the construction method of the earth and rockfill dam material constitutive model, the used deep neural network can infinitely approach any continuous function, Therefore, the method can be used for constructing a complex nonlinear earth and rockfill dam material constitutive model, the deep neural network constitutive model is only based on test data, no hypothesis is made, the model is not affected by the shape of a stress-strain curve, and the model is more objective.

The invention belongs to a simulation design method for a skid landing gear structure of a helicopter, and discloses a simulation design method for a skid landing gear. The simulation design method comprises the following steps: S1, carrying out finite element model simulation on a skid landing gear, and calculating a model of a finite element of the skid landing gear; S2, performing drop performance simulation on the skid landing gear to obtain an energy absorption curve and a landing load of the skid landing gear; S3, calculating the strength and rigidity of the skid landing gear; and S4, according to the energy absorption curve and the landing load of the landing gear and the strength and rigidity of the skid landing gear, obtaining parameters needed by structural design of the skid landing gear, designing the skid landing gears of various configurations, and designing the landing gear made of composite materials.

The invention discloses a method for determining the position of a bridge closure section of a cooperative system, which belongs to the technical field of bridge design and comprises the following steps that a full-bridge finite element calculation model is established, and a reasonable bridge forming state is determined; the closure section is preliminarily set to be located on the outer side ofthe side sling, and based on the unstressed state quantity construction control theory, the beam end vertical displacement delta s of the suspension end of the closure section is obtained through finite element calculation; if delta s is within the set interval range, it is determined that the preliminarily set closure segment position is basically reasonable; and if delta s is not in the set interval range, the overlapped section of the cable-stayed section and the suspension section serves as an interval, the position of the closure section is reset through a dichotomy, the full-bridge finite element calculation model is updated, and the vertical displacement delta s of the beam ends at the two ends of the closure section is recalculated till delta s is within the set interval range. Theoptimal closure position can be calculated, the position of the closure section and the closure scheme can be quickly calculated and determined, the operability is high, the calculation period is shortened, and the design efficiency is improved.

The invention discloses a high-pier large-span T-structure bridge temperature field distribution analysis and temperature effect control method. The method comprises the following steps: establishinga finite element calculation temperature field distribution model, dividing sections of a main beam, a longitudinal beam, a span beam and a pier into thermodynamic plane units of a nonlinear temperature field, and setting boundary constraints; setting material parameters of concrete; setting a temperature gradient model and a loading load according to the material parameters of the concrete; according to a temperature gradient model and a loading load, applying a corresponding heat flux density boundary condition to the cross section for thermodynamic simulation analysis to obtain temperatureinformation of each thermodynamic plane unit; and performing temperature deformation coupling analysis on the high-pier large-span T-structure bridge according to the temperature information of the thermodynamic plane unit so as to calculate stress and displacement. The method can effectively guarantee high bridge construction precision and good construction quality.