9 results about "Spectral element method" patented technology

The invention provides a frequency dispersion curve calculation method based on a decoupling type Legendre-Gauss-Labatto spectral element method, and belongs to the technical field of discrete solution of guided wave propagation in a thin plate, and the method comprises the following steps: S1, constructing a wave equation which comprises a Cartesian space coordinate system based on an orthotropic plate, and combining a constitutive equation, a geometrical relationship under the coordinate system and guided wave displacement to obtain a wave dispersion curve; substituting into a control equation when the volume force is zero to obtain an improved three-dimensional elastic wave equation; s2, a differential matrix is constructed, wherein discretization and decoupling are carried out on a wave equation on the basis of a Lagrange interpolation basis function of a Legendre-Gauss-Labatto node; s3, explicitly embedding the stress free boundary condition into the solving process through matrix line transformation, and solving to obtain a frequency dispersion curve, the derivation process is simplified, the boundary and the interior of the material are decoupled, and the physical significance is clearer. And meanwhile, the high-precision advantage of the spectrum method is maintained, and the calculation rate is remarkably improved.

The invention discloses a broadband seismic oscillation simulation method and system based on probabilistic seismic risk analysis, and relates to the technical field of field seismic oscillation, and the method comprises the steps: carrying out the seismic risk decoupling through employing a Chinese probabilistic seismic risk analysis method, determining a target potential source area corresponding to the maximum contribution degree with probability significance and a potential source magnitude and an epicentral distance of the target potential source area; calculating a fault size parameter of the target potential source area based on the potential source magnitude and a preset scaling rate; calculating fault distribution parameters of the target potential source area based on the fault size parameters and the mixed seismic source model; combining the three-dimensional longitudinal wave velocity model and the shallow structure model to construct a three-dimensional calculation model; and performing deterministic low-frequency simulation and deterministic high-frequency simulation on the three-dimensional calculation model based on a spectral element method and a three-way stochastic finite fault method respectively, and then performing broadband time program sequence synthesis to obtain a broadband seismic oscillation simulation result. The technical problem of low simulation result accuracy in the prior art is relieved.

This invention relates to a tunnel full-waveform inversion method based on spectral element forward modeling and physical information neural network, comprising: collecting engineering geological data and obtaining physical property parameters; establishing a two-dimensional finite element model and obtaining spatial information; constructing a wavefield model and performing wavefield forward modeling simulation to obtain synthetic full-waveform data; collecting measured waveform data and preprocessing it, performing time registration and normalization processing on the preprocessed measured waveform data and synthetic full-waveform data, and extracting multiple features; constructing a parameter training set; constructing and training a physical information neural network model, constructing a comprehensive loss function during the training process; and using the physical information neural network model to perform full-waveform inversion. This invention deeply integrates finite element forward modeling, full-waveform inversion, and physical information neural network, taking into account both data fitting and physical consistency, significantly improving the quantitative accuracy and reliability of tunnel advanced geological prediction.

This invention discloses an implicit large eddy wall simulation method based on the high-precision spectral element method. This method constructs an implicit large eddy simulation (SVV-iLES) based on the hp-type spectral element method combined with the spectral viscosity elimination method (SVV), and implements wall simulation within this framework. The method includes the following steps: adjusting the boundary layer according to the actual situation of the turbulent boundary layer to ensure that the corresponding points fall within the logarithmic region; interpolating the element velocity and velocity u within the spectral element method code framework to obtain velocity components parallel to the wall velocity, which are then substituted into the algebraic model; analytically obtaining the wall stress through the algebraic model; and finally, modifying the boundary conditions in real time using the logarithmic rate model to complete the simulation. This significantly reduces the enormous computational burden caused by fine boundary layer meshes in flow problems. This invention also proposes an application of this simulation method to high Reynolds number wall flow scenarios, providing an efficient foundation for accurate flow calculations.

This invention relates to the field of geophysical exploration technology, specifically to a high-precision three-dimensional forward modeling method for airborne electromagnetic spectral elements considering induced polarization effects. Based on the Cole-Cole model, a complex conductivity expression considering induced polarization effects is established, and the frequency domain Helmholtz equation is introduced to construct the corresponding governing equations. A regular hexahedral mesh is generated, and reference domain vector basis functions are constructed using the Gauss-Lobatto-Legendre orthogonal polynomial method according to the spectral element method. The mapping relationship between these functions and physical mesh elements is established. The Galerkin weighted residual method is applied to discretize the governing equations into element system matrices, which are then assembled to form the overall system matrix and the corresponding linear equation set. A direct solver is used to obtain the frequency domain three-dimensional electromagnetic response, and the time domain three-dimensional forward modeling result of the computational region is obtained through Hankel transformation. This invention achieves rapid and high-precision three-dimensional forward modeling simulation of complex geological models containing induced polarization effects.

The invention relates to the technical field of electromagnetic full-wave inversion, in particular to a two-dimensional cross-layered efficient electromagnetic full-wave inversion method based on a spectral element boundary integral method.During forward modeling calculation, a scatterer crossing multiple horizontal layers is surrounded by a one-dimensional smooth boundary, and two-dimensional electromagnetic field distribution is solved by adopting a spectral element method in a region; accurately truncating an SEM solving domain on the boundary by using a boundary integral equation; for a transverse electric mode and a transverse magnetic mode, equivalent current / magnetic current is solved by using BIE, and a receiver scattering field is calculated in combination with a layered two-dimensional vector Green function; in the full-wave inversion, in order to reconstruct TE mode isotropic scatterer model parameters and TM mode anisotropic scatterer model parameters respectively, first-order derivatives of a mass matrix and a stiffness matrix relative to the corresponding parameters are calculated respectively, a sensitivity matrix is constructed, and an LM optimization algorithm is adopted to iteratively call an SEBI forward solver to complete inversion; multiple groups of numerical experiments verify the accuracy and high efficiency of the SEBI-LM algorithm in forward modeling and FWI.

The application discloses a kind of ocean sound field parallel simulation methods based on DR-SETD, belong to the technical field of simulation calculation.This application includes: three-dimensional fluid-structure interaction model is simplified to axisymmetric model to reduce the scale of calculation;Adopt high-order spectral element method based on orthogonal polynomial to carry out spatial dispersion, and numerical singularity is handled for axisymmetric property;The weak form of time-domain wave equation of fluid domain and solid domain is respectively constructed, and is solved by interface coupling condition;Efficient parallelization of solving process is realized using explicit time integration format and shared memory parallel computing architecture.This application realizes the high-precision, high-efficiency full-wave simulation of fluid-structure interaction sound field containing complex terrain.

This invention discloses a parallel computation method for time-domain spectral element simulation of ultrasonic guided wave propagation in CFRP structures, relating to the field of nondestructive testing technology. The purpose of this invention is to address the low computational efficiency of current methods for ultrasonic guided wave propagation in large-area composite plate structures. It employs multi-node spectral elements to mesh the large-area composite plate, designs a mesh numbering algorithm to divide the mesh into sub-blocks (domain decomposition), creates subsets of disjoint nodes, and combines the high-order time-domain spectral element method with a Computational Unified Device Architecture (CUDA) to achieve parallel computation. A stepwise time integration algorithm based on a central difference scheme is used to implement unit-level parallel computation to solve the wave equation on a GPU. This method combines the high-order time-domain spectral element method (SEM) with CUDA, improving computational efficiency and accelerating the computation of ultrasonic guided wave propagation in large-area composite plate structures. It has broad application prospects in health monitoring methods for composite plate structures.

The invention discloses a basin-hill coupling site broadband seismic oscillation simulation method and system based on a mixing method, and relates to the technical field of site seismic oscillation simulation, and the method comprises the steps: building a kinematics mixed seismic source model of a to-be-simulated near-fault basin-hill coupling site based on a concave-convex body seismic source model and a random seismic source model; performing low-frequency seismic oscillation simulation on the kinematic mixed seismic source model based on a spectral element method to obtain a low-frequency simulation result; performing high-frequency seismic oscillation simulation on the kinematics mixed seismic source model based on a three-dimensional random finite fault method to obtain a high-frequency simulation result; and combining the low-frequency simulation result and the high-frequency simulation result to obtain a broadband seismic oscillation simulation result of the near-fault basin-hill coupling site to be simulated. According to the invention, the technical problems of high calculation cost and unreliable high-frequency part result in the broadband seismic oscillation simulation process for the near-fault basin-hill coupling site in the prior art are solved.