17 results about "Finite element equation" patented technology

The invention relates to the technical field of computer-aided engineering, in particular to a nonlinear efficient iterative solving method for thermal strain load, which is used for solving an obtained finite element equation by using a modified Newton-Raphson method and comprises the following steps of: firstly, establishing a geometric model to be analyzed and performing grid division; the method comprises the following steps: firstly, setting a model to be analyzed, then setting boundary conditions and temperature field change conditions of the model to be analyzed, finally, inputting the conditions into an algorithm solver, solving a nonlinear equation set, iteratively inputting a load continuously according to a modified Newton-Raphson method in the solving process, calculating node displacement until convergence, and solving stress-strain conditions in the welding process according to a material constitutive relation. In the solving process, by judging the size of the two norms of the displacement increment obtained in the adjacent increment step heuristic stage, the convergence of nonlinear solving of the structure is enhanced through the calculation mode, and the solving speed of the nonlinear problem in the thermal elastic-plastic constitutive structure is increased.

The invention provides a wave finite element and boundary element mixed composite board structure sound insulation performance prediction method, and the method belongs to the acoustics field, and comprises the steps: carrying out the post-processing of a wave finite element model based on the wave finite element model of a composite board structure and a corresponding equivalent nodal force, and obtaining the wave finite element equation of the whole composite board structure; based on a sound-structure coupling equation, through a boundary element method, a discrete boundary element equation related to the surface vibration speed of the composite board and the radiation sound wave pressure is constructed; coupling the wave finite element equation and the discrete boundary element equation of the whole composite board structure, and determining the sound pressure of radiation sound waves of the composite board structure and the surface vibration speed of the composite board; and based on the sound pressure of the radiation sound wave of the composite board structure and the surface vibration speed of the composite board, obtaining a sound insulation performance prediction result by calculating the sound power of the incident sound wave and the radiation sound wave, and completing prediction of the sound insulation performance of the composite board structure. The problems that the sound transmission loss of large plates and medium-high frequency plates is difficult to predict and the calculation cost is high are solved.

The invention relates to a physical field coupling simulation analysis method and device of a circuit breaker, computer equipment, a computer readable storage medium and a computer program product. The method comprises the following steps: acquiring distributed conductivity in an arc extinguish chamber of the circuit breaker; according to the distributed conductivity and an electric field finite element equation, an electric field distribution value in the circuit breaker arc extinguish chamber is obtained through calculation; calculating a current density distribution value in the arc extinguish chamber of the circuit breaker based on the electric field distribution value; substituting the current density distribution value into an axisymmetric magnetic field equation, and performing electric field and magnetic field coupling; substituting the port boundary voltage and the port current of the arcing area of the circuit breaker into the circuit matrix equation, and carrying out electric field and circuit bidirectional coupling; the electric field finite element equation, the axial symmetry magnetic field equation and the circuit matrix equation are combined, and the potential distribution value and the magnetic field distribution value of the arcing area of the circuit breaker and the port boundary voltage and the port current of the equivalent resistor are obtained through solving. By adopting the method, the simulation analysis efficiency and precision of the circuit breaker arc extinguish chamber can be improved.

The invention relates to an in-hole transient electromagnetic response characteristic numerical simulation method based on a tunnel three-dimensional geoelectric model and an absorption boundary finite element method, and belongs to the technical field of geophysical exploration. The method comprises the following steps: constructing a tunnel full-space three-dimensional conductivity model; based on a Maxwell equation set, a vector potential and a scalar potential are introduced, a vector control equation of a transient electromagnetic field is derived in combination with Coulomb specifications, first-order absorption boundary conditions are established, and a weak form finite element equation is derived through a Galerkin weighted margin method; generating a global sparse matrix by utilizing spatial discretization and unstructured grid division, and performing iterative solution on the dynamic electromagnetic field by adopting a Newmark time discretization method; and simulating the transient electromagnetic response of geological anomalous bodies with different resistivity and the distance between the geological anomalous bodies and the receiving coil, and analyzing the attenuation characteristic and the geometric gravity center effect to obtain an electromagnetic response rule. The device can accurately simulate the electromagnetic response of abnormal bodies such as aquifers and faults in front of a tunnel face and around drill holes.

The present application belongs to the technical field of numerical simulation of laser directed energy deposition, and relates to a numerical simulation method for the influence of process parameters on the temperature field of laser directed energy deposition of Inconel 718. When calculating the transient temperature field distribution in the process of laser directed energy deposition, the present application needs to complete the definition of material properties, the establishment of a geometric model and mesh division, the establishment of a transient temperature field control equation, the application of a heat source, the application of initial conditions and boundary conditions, the discrete processing of a transient temperature field finite element equation set, latent heat processing, and iterative solving of several parts of work. The numerical simulation method of the present application studies the temperature distribution law in the process of laser directed energy deposition of Inconel 718 material, analyzes the influence of process parameters on the temperature field, establishes and perfects the theoretical basis of laser directed energy deposition of Inconel 718 material, and guides the formulation of process parameters, which has important scientific research significance and engineering application value.

This invention belongs to the field of computer vision and non-rigid point cloud registration technology, and specifically to a scale-adaptive non-rigid point cloud registration method based on gradient decoupling. It includes the following steps: S1: Solving for the stiffness matrix and node multimodal eigenvectors; S2: Solving for the optimal matching point index and robust weights; S3: Solving for the scale gradient and deformation gradient; S4: Solving for the updated scaling coefficients. This invention achieves parameterized separation of scale mismatch and local physical deformation by explicitly introducing a continuously differentiable scale factor into the physical finite element equations and combining it with a spatial orthogonal gradient decoupling strategy. This not only solves the problem of numerical convergence instability caused by misjudging "volume expansion" in traditional methods when scale mismatch occurs, but also ensures that the algorithm maintains stable registration accuracy under scale disturbances.

The application relates to a kind of transient load under the function gradient porous structure of multiphase filling dynamics topology optimization method and system, belong to the topology optimization design field of function gradient porous structure.The technical problems to be solved by the application are: how to fully exploit design space, construct the efficient function gradient porous structure of multiphase filling dynamics topology optimization method, realize the optimal anti-vibration design of porous filling structure with high-quality transient dynamic performance.Technical points: based on characteristic orthogonal decomposition method, the reduced transient dynamic finite element equation of function gradient porous multiphase filling structure is constructed;the material interpolation model and volume constraint model of function gradient porous multiphase filling structure are constructed, and the transient dynamic multiphase filling topology optimization reduced model with the minimum dynamic compliance as the optimization objective is proposed;the reduced sensitivity time-domain accompanying equation is constructed, and the sensitivity of dynamic compliance and volume constraint is efficiently calculated;based on ADMM-MMA hybrid optimization algorithm, the optimal topology design of function gradient porous multiphase filling structure is efficiently solved and obtained.The application can maximize the optimal anti-vibration performance of function gradient porous filling structure, and is especially suitable for the structure lightweight anti-vibration design of large engineering equipment.

The present application belongs to the field of structural deformation reconstruction, and specifically discloses a structural deformation reconstruction method and system based on a four-node inverse plate shell element containing a drilling degree of freedom, comprising: discretizing the structure into a plurality of four-node inverse plate shell elements, and constructing a shear strain matrix by using a discrete shear gap method; kinematically constraining the drilling degree of freedom by using a continuum mechanics rotation field, solving the continuum medium rotation by deriving the global coordinate system from the natural coordinate system shape function, and supplementing the sixth degree of freedom of the element around the normal line; deriving a coordinate transformation matrix based on the assigned sixth degree of freedom, introducing a node coordinate system, transforming the element stiffness matrix to the node coordinate system, and then transforming it to the global coordinate system; and finally, incorporating the above construction method into the least squares functional framework, assembling the global inverse finite element equation by minimizing the error between the theoretical strain and the measured strain, and reconstructing the full-field displacement of the structure. The present application can realize high-precision deformation reconstruction of complex stiffened plate shells and large-curvature structures.

The invention relates to the field of thin film antennas, in particular to a thin film antenna form analysis method and system considering crease factors. Constructing a finite element model of the folded membrane structure based on the folding scheme; the finite element model comprises a fold unit finite element equation, a cable membrane unit and structure finite element equation and boundary relation processing of fold units; designing an optimization model of the folded membrane structure based on the finite element model, including defining design variables and constraint conditions, constructing a multi-objective optimization problem according to the design variables and the constraint conditions, and converting the objective optimization problem into a single-objective function; and performing iterative solution on the single objective function based on a genetic algorithm to obtain the optimal form of the folded membrane structure. According to the method, the shape and stress design of the folded film structure can be effectively realized, the system modeling and analysis of the film antenna crease problem can be realized, the influence of the crease on the stress uniformity of the film structure can be improved in combination with an optimization algorithm, the stress uniformity of the effective area of the film can be ensured, and wrinkles in the film can be effectively avoided.

The application discloses a ground penetrating radar time domain finite element fast simulation method, system and equipment. The method comprises the following steps: setting geometric parameters and electrical parameters of a two-dimensional complex geoelectric model; constructing a weak form of a two-dimensional electromagnetic wave equation; forming a time domain finite element equation; establishing a linear equation group after central difference time discretization; giving a time step, judging whether the time step meets a CFL stability condition, if yes, directly solving the linear equation group, if not, performing LU decomposition on a coefficient matrix of the linear equation group, and disturbing unstable eigenvalues in the coefficient matrix until absolute values of all eigenvalues of the decomposed coefficient matrix are less than or equal to 1, and generating a reconstruction coefficient matrix; and solving the reconstructed linear equation group, so that the time step breaks through the CFL stability condition. The application can improve the simulation precision of the ground penetrating radar.

The invention belongs to the technical field of structural finite element data processing, and particularly relates to an iterative solution method and device for a finite element equation set of a whole machine structure. The method comprises the steps of obtaining a complete machine structure sparse positive definite stiffness matrix and a load vector applied to a complete machine structure, and constructing a complete machine structure finite element equation set used for representing the relation among the complete machine structure sparse positive definite stiffness matrix, the load vector and a displacement vector; performing degree-of-freedom elimination on the sparse positive definite stiffness matrix of the whole machine structure to obtain an independent degree-of-freedom matrix; performing bandwidth optimization sorting on the independent degree-of-freedom matrix to obtain a sorted stiffness matrix; processing the sorted stiffness matrix based on an algebraic multi-grid preprocessor to obtain a preprocessed sub-matrix; and calculating a displacement vector by adopting a conjugate gradient iteration method according to the pre-processing sub-matrix. According to the method, the problem that the sparse matrix of the aviation structure is not converged in iterative solution can be effectively solved, and the solution efficiency is remarkably improved while the calculation precision is ensured.

The present invention discloses a method, system, and medium for compressing and storing a stiffness matrix based on block symmetry. The method comprises the following steps: constructing a geometric model and obtaining material property parameters; dividing a finite element analysis grid according to the geometric model and numbering the units, nodes, and degrees of freedom; setting boundary conditions and applying load conditions; applying storage space based on the block symmetry of the global stiffness matrix; calculating the unit stiffness matrix, assembling the unit stiffness matrix information into the global stiffness matrix, and applying boundary conditions; and solving the corresponding finite element equations after compressing and storing the global stiffness matrix using a numerical solution method. The present invention maintains the reducibility of the stiffness matrix, reduces the redundant information stored in the stiffness matrix, and reduces the time complexity of stiffness matrix-vector multiplication and other matrix operations, thereby effectively improving the performance of solving linear equations.

The application discloses a kind of gear dynamic engagement stiffness calculation methods, comprising: obtaining the geometric parameters of gear pair, material attribute and gear motion state parameter;Calculate overall stiffness matrix, overall mass matrix, overall damping matrix and overall external load matrix;Establish the dynamic analysis finite element equation when gear engagement, solve the dynamic vibration displacement of engagement point at different time by using average acceleration method;According to dynamic vibration displacement, the dynamic stiffness of two gears in gear pair is calculated, and single-tooth engagement stiffness is obtained;According to the coincidence degree of gear pair, single-tooth engagement stiffness is superimposed to obtain dynamic engagement stiffness;Also disclosed is a kind of device, including motion state module, three-dimensional scanning module and processing module.The application is based on finite element method, not only considers the influence of angular position change on engagement stiffness, but also considers the influence of gear speed on gear engagement stiffness, more truly reflects the dynamic characteristics of gear when transmission, so that the calculation result is more accurate.

The present invention belongs to the technical field of finite element analysis methods, and in particular relates to a dimensionality reduction analysis method for finite elements. It includes the following steps: extracting the basic variable sequence of the finite element model to establish a basic model; collecting or designing samples to be analyzed to generate a finite element model; establishing a finite element mathematical model based on the structural finite element equilibrium equation; designing and determining the fuzzy interval of the finite element variables; based on the fuzzy variable set segmentation processing, involving fuzzy variable differential processing, based on Taylor series fuzzy variable stiffness optimization, finite element equilibrium equation global stiffness optimization, determination of displacement response, and solving separately in the subset interval. This application expands and simplifies the fuzzy variables involved in the finite element analysis process, and derives the optimization calculation through the actual physical relationship between the basic structural set parameters of the finite element equation, which can better simplify and optimize the calculation and analysis process when fuzzy parameters are involved, improve the operation efficiency, and reduce the time consumption of finite element analysis.

The application discloses a proportional boundary perfect matched layer method and system for numerical simulation of infinite domain wave motion, and belongs to the field of dynamic analysis, which comprises the following steps: irregular geometric infinite domain in a Cartesian coordinate system is mapped to a regular geometric domain in a proportional boundary local coordinate system based on proportional boundary coordinate transformation; the radial coordinate of the regular geometric domain is analytically extended to a complex space by using a complex coordinate stretching function, and a proportional boundary perfect matched layer is obtained by truncation processing according to a preset thickness; based on the Galerkin weighted residual principle, corresponding equivalent integral expressions are constructed for the balance equation and the physical equation of the wave motion problem in the proportional boundary perfect matched layer; mixed displacement-stress finite element technology is adopted to perform finite element discrete processing on the displacement, stress and auxiliary variables of stress integral in the constructed equivalent integral expressions, so that mixed displacement-stress finite element equations of the proportional boundary perfect matched layer are obtained; the method has the advantages of simple boundary implementation and good adaptability of the boundary to the inner domain.

The invention belongs to the field of electromagnetic method exploration, and provides a controllable source electromagnetic method three-dimensional numerical simulation method and system considering magnetic conductivity influence, electronic equipment and a storage medium, and the method comprises the steps of model discretization, model parameter reading, variation equation construction, interpolation formula definition, finite element equation construction and equation solution; according to the method, the conductivity-magnetic conductivity two-parameter physical model is constructed, so that the precision and the physical authenticity of electromagnetic field numerical simulation are remarkably improved, false abnormity caused by neglecting magnetic conductivity parameters is inhibited, a reliable basis is provided for data interpretation, and the risk of wrong geological inference is greatly reduced; by introducing the non-structural tetrahedral mesh generation technology, the complex geometrical morphology of the rugged topography and the irregular anomalous body can be accurately described, the resolution and accuracy of electromagnetic field calculation in the key areas are ensured, the calculation scale is effectively reduced, and the calculation efficiency is remarkably improved.

The invention discloses a proportion boundary perfect matching layer method and system for infinite domain fluctuation numerical simulation, and belongs to the field of dynamic analysis, and the method comprises the steps: mapping an irregular geometric infinite domain under a Cartesian coordinate system to a regular geometric domain under a proportion boundary local coordinate system based on proportion boundary coordinate transformation; analyzing and extending the radial coordinates of the regular geometric domain to a complex space by using a complex coordinate stretching function, and performing truncation processing according to a preset thickness to obtain a proportional boundary perfect matching layer; based on a Galerkin weighted residual principle, constructing a corresponding equivalent integral formula according to an equilibrium equation and a physical equation of a fluctuation problem in a proportion boundary perfect matching layer; performing finite element discrete processing on auxiliary variables of displacement, stress and stress integration in the constructed equivalent integral formula by adopting a mixed displacement-stress element finite element technology to obtain a mixed displacement-stress finite element equation of a proportional boundary perfect matching layer; the method is simple in boundary implementation and good in boundary and internal domain adaptability.