16 results about "Finite element method" patented technology

This invention discloses a simulation method, apparatus, equipment, and medium for an electromagnetic railgun. Compared to constant load parameter values, it employs a finite element method combined with equivalent circuit analysis. The rail is divided into N segments, and the armature is positioned at the end of the i-th segment. The current equivalent load parameters of the rail are updated based on the circuit parameters at each discrete time point, thereby approximating the true value of the equivalent load parameters segment by segment. The current equivalent load parameters are then substituted into the circuit and mechanical equations to calculate the discrete data when the armature is positioned at the end of the i-th segment. If i < N, let i = i + 1, and iterate the above simulation steps; if i = N, then fit all the calculated discrete data between the armature velocity and discrete time points to obtain continuous data between the armature velocity and time. It is evident that this invention corrects the equivalent load parameters whenever the armature moves a certain distance, thus simulating an electromagnetic railgun firing process that more closely approximates the real situation.

The application provides a heavy-load multi-rotor propeller design optimization method, and relates to the technical field of multi-rotor propeller design.The application realizes fine design of the blade shape through parameterized modeling, can flexibly adjust key parameters for different radius positions, and effectively matches the complex working condition requirements.Combining segmented aerodynamic force analysis and blade element momentum theory, the overall thrust and torque of the propeller can be accurately obtained to provide data basis for structure and performance evaluation.Through finite element method, structural static force and vibration modal analysis are carried out to identify stress concentration areas and potential resonance risks, so that system evaluation of multi-target performance is realized.Combining the multi-target optimization model of aerodynamic efficiency and structural safety, the optimal geometric parameters of the blade are automatically iteratively searched, the structural stress and vibration risk are effectively reduced while meeting the heavy-load thrust requirement, and the stability and reliability of the aircraft are improved.

The application belongs to the technical field of aviation structure impact dynamics, and is a kind of crash dynamics modeling method for simplifying fuselage frame section structure of an airplane. A fuselage frame section model is established by corresponding structural characteristics of the fuselage frame section, the position and deformation mode of a large deformation region in the fuselage frame section model are determined, the large deformation region is simulated into a plastic hinge, and torque and axial force performance parameters corresponding to the plastic hinge are determined. Different gravity fields and initial velocities are given to the fuselage frame section, and the response of the plastic hinge of the fuselage frame section structure at different deformation degrees is calculated. Based on the plastic large deformation principle, the advantages of simple connection relationship model, fast calculation efficiency and high calculation accuracy of the finite element method are fully combined, the calculation efficiency of the crash finite element analysis of the fuselage frame section of the airplane is improved, and potential calculation non-convergence problems in the calculation of the plastic large deformation region of the fuselage frame section structure of the airplane can be avoided, the design cycle of the airplane structure adaptability is shortened, and the application prospect is great.

This invention discloses a method for structured conversion of geometric data in CATIA part files, relating to the field of CAD data processing technology. The method includes: establishing a Beltrami partial differential equation in the complex domain based on the directional attribute of directed common edges; substituting the complex coordinates of the two-dimensional parameter domain curve as Dirichlet boundary conditions into the Beltrami partial differential equation; and numerically solving the equation using the finite element method to obtain the three-dimensional boundary curve of the two-dimensional parameter domain curve in three-dimensional space; determining whether the three-dimensional boundary curve and the three-dimensional space curve satisfy the geometric consistency condition based on the curve consistency deviation; and when the geometric consistency condition is met, converting the B-Rep geometric data and directed common edges into structured geometric data using JSON format. This invention improves the data fidelity and geometric robustness of computer-aided design part files during the structured conversion process.

The application discloses a robot joint reducer dynamics modeling method, device, equipment and medium, and relates to the technical field of transmission systems. The method comprises the following steps: acquiring double circular arc tooth profile parameters; obtaining multi-tooth meshing force distribution under different load conditions based on the double circular arc tooth profile parameters and a finite element method; calculating multi-tooth comprehensive meshing stiffness according to the multi-tooth meshing force distribution; establishing a multi-coordinate system framework during joint movement of an industrial robot; deducing an absolute acceleration expression of a harmonic reducer in a rotating non-inertial coordinate system based on the multi-coordinate system framework; constructing a generalized force excitation model according to the absolute acceleration expression; and establishing a harmonic reducer dynamics equation considering pose changes according to the multi-tooth comprehensive meshing stiffness and the generalized force excitation model. The method can more accurately predict transmission errors and dynamic responses of the harmonic reducer under high dynamic conditions.

The disclosure provides a construction method including steps of: constructing a detailed model and a simplified model of the rail vehicle using finite element method based on the three-dimensional structure of the rail vehicle; initially setting the simplified model in accordance with the detailed model, including specifying materials, mechanical properties parameters, and mass point; setting different simplification thickness ratio to obtain a plurality of sets of the simplified models, designing longitudinal and lateral collision conditions, and in each type of the collision conditions, performing collision simulations on the detailed model and each set of the simplified models under each thickness ratio to obtain respective collision response curves; calculating a total CORA value corresponding to the plurality of sets of the simplified models; selecting an optimal simplified model from n sets of the simplified models with the highest total CORA values.

The application provides a deep hole blasting parameter optimization method, device, equipment and storage medium, and relates to the technical field of blasting engineering. The method comprises the following steps: acquiring a simulation working condition set; wherein the simulation working condition set comprises multiple working conditions, and each working condition is a group of candidate blasting parameters; adopting a nonlinear dynamic finite element method and a discrete particle cohesive model, a whole process simulation of blasting is carried out for each working condition to obtain physical evolution data of each working condition; based on the physical evolution data of each working condition, multi-dimensional blasting quality indexes of each working condition are calculated; multi-objective comprehensive evaluation is carried out on the multi-dimensional blasting quality indexes of each working condition, and an optimal working condition is selected from the simulation working condition set as an optimal blasting parameter combination output. The application can significantly improve the comprehensiveness and reliability of blasting design, effectively reduce the cost of field test, and realize fine design of deep hole blasting.

The application discloses a fire dynamic simulation method and system for an open-space steel structure canopy, and the method comprises the following steps: establishing a fire scene of the steel structure canopy, extracting state information of the fire scene, constructing a time-space distribution heat input function of each structure node of the steel structure canopy, and calculating total surface heat input flux of the structure node at each position; taking the total surface heat input flux as a boundary condition, constructing a heat conduction control equation, solving the equation by using a finite element method, and calculating a thermal failure probability of the structure node at each position according to a solving result; taking the thermal failure probability as an integral kernel, combining with a structure importance weight, calculating a risk index of each structure node, and monitoring risks of each structure node of the steel structure canopy in real time according to the risk index.

This technology provides a preprocessing method that differs from the conventional approach of employing a single preprocessing technique. [Solution] The disclosed method is a computer implementation method performed by a computer. The computer implementation method includes numerically analyzing eddy currents by solving the discretized governing equations using a preprocessing algorithm with the finite element method. The preprocessing in the preprocessing algorithm is a composite preprocessing that performs different types of preprocessing on multiple parts of the governing equations.

The application provides a kind of extrusion stress prediction method based on point-field double path fusion physical AI model, by combining global point-to-point prediction (MLP path) and local overall field prediction (GCN path), realize the high-precision prediction of stress-strain relationship of multi-layer structure of mobile phone screen in the process of extrusion loading.The application effectively solves the problems of low calculation efficiency, modeling difficulty, poor adaptability of nonlinear materials and other problems existing in the traditional finite element method in processing ultra-thin screen multilayer composite material, the accuracy of stress propagation modeling is significantly improved by double path fusion strategy, the standardization input of different grid structures is realized by using geometry template mapping, combined with small sample learning enhancement and physical constraint embedding, the calculation efficiency and the generalization ability of the model are greatly improved while ensuring the physical consistency of the prediction results, providing an efficient and reliable simulation solution for screen extrusion failure analysis.

This invention discloses a finite element method for finding the shape of a multi-span transmission line based on the BFGS optimization algorithm. The method includes the following steps: discretizing the transmission line with insulator strings using finite element methods to obtain multiple two-node rod elements; defining the endpoints of the two-node rod elements as discrete nodes, and forming a node set based on the multiple discrete nodes; constructing a total potential energy function of the system based on the node set, and using the total potential energy function as the objective function to transform the transmission line shape finding problem into an unconstrained optimization problem; iteratively solving the objective function to output the set of node coordinates that minimizes the total potential energy; calculating the axial stress of each two-node rod element by combining the material parameters and cross-sectional parameters of the transmission line and insulator strings; and using the axial stress and the final set of node coordinates as the finite element shape finding result of the transmission line.

The application discloses a kind of fluid distribution dynamic regulation method and device based on shale reservoir microstructure, it is related to oil and gas exploitation technical field, the method includes: the microstructure parameter of target shale reservoir is obtained by core experiment, and multiple scale model is constructed based on it;Determine the control equation of different physical fields of multiple scale model;The control equation of different physical fields is coupled, and is solved by finite element method;Numerical simulation experiment is carried out based on multiple scale model and the solution result to determine the regulation parameter;Regulation parameter is input into multiple scale optimization model to optimize regulation parameter, and regulation strategy is obtained.The existing displacement experiment is relatively single, the complex interaction process under actual exploitation environment is not considered comprehensively, which leads to the problem that the guiding effect of exploitation work is limited.It can guide business personnel to develop development scheme more scientifically and accurately, improve exploitation efficiency and success rate, also can reduce development cost, improve economic benefit at the same time.

Provided is technology for executing preconditioning using an approach different from the conventional approach of adopting a single method for the preconditioning. The disclosed method is a computer-implemented method executed by a computer. The computer-implemented method includes numerically analyzing an eddy current by solving discretized governing equations with a preconditioned algorithm using the finite element method. The preconditioning in the preconditioned algorithm is composite preconditioning for performing different types of preconditioning on a plurality of parts of the governing equations.

The application provides a design method of a V-shaped notch ultrasonic fatigue variable cross-section cylindrical sample, and relates to the technical field of ultrahigh cycle fatigue performance analysis, and comprises the following steps: obtaining one-dimensional longitudinal vibration equation of the V-shaped notch ultrasonic fatigue variable cross-section cylindrical sample based on elastic wave theory; obtaining displacement amplitude differential equation by separation of variables method; giving vibration displacement amplitude function and harmonic length analytical formula of the V-shaped notch sample; obtaining required harmonic length and basic size of the sample according to test material and given conditions. The reliability of the analytical design method is verified by analyzing the inherent frequency of the sample under the axial tension and compression state by the finite element method. The method is suitable for analytical design and verification of the notch variable cross-section cylindrical sample under the ultrasonic fatigue loading working condition, enriches the sample type and design method of the ultrasonic fatigue test, and when the notch angle, test design frequency and metal material change, the sample only needs to be adjusted in the harmonic length, the principle is simple, and the method is convenient to apply.

Examples of topological acoustic (TA) sensing techniques for localizing defects in plate structures utilize Lamb waves. TA sensing exploits changes in geometric phase of acoustic waves to detect perturbations in the supporting medium. This approach uses a geometric phase change – index (GPC-I), a measure of the geometry of the acoustic field averaged over a spectral domain, as detection metric in lieu of VD or AR. Calculations based on the finite element method (FEM) in Abaqus / CAE software verifies the effectiveness of the proposed GPC-I-based method. Randomly located defects on the surface of a plate are localized with higher sensitivity and accuracy, by the GPC-I method in comparison to VD or AR-based methods.