37 results about "Non linear wave" patented technology

The invention discloses a significant wave height two-stage space-time prediction method and system based on diffusion residual correction, and relates to the technical field of sea wave prediction, historical significant wave height data and corresponding historical wind field data are input into a significant wave height space-time prediction model for processing, and a preliminary significant wave height prediction result is obtained; and inputting the initial prediction error, historical significant wave height data and synchronous forecast wind field data into a residual error correction module based on a diffusion model, and compensating the initial prediction error to obtain a final significant wave height prediction result. A diffusion model based on an EDM framework is innovatively introduced to carry out refined reconstruction on a prediction residual error, and a basic prediction field, a synchronous wind field dynamic factor and a prediction aging code are used as multi-dimensional physical strong conditions to be injected into a diffusion generation process. According to the method, high-frequency texture details and non-linear fluctuation components missed by the first-stage model can be certainly recovered, long-term deviation accumulation is relieved to a certain extent, the high-wave region prediction quality is improved, and the prediction stability is improved.

The invention discloses a laser radar multi-target ranging method and system based on adaptive waveform matching, and relates to the technical field of laser ranging, and the technical scheme is characterized in that the adaptive waveform matching mechanism proposed by the invention dynamically adjusts convolution kernel sampling points through a deformable convolutional network (DCN), and the adaptive waveform matching is realized; various nonlinear waveform distortions caused by electric field interference and complex target reflection characteristics can be actively adapted, and a customized matching template is generated for each input waveform. Equivalently, the system is endowed with the capability of eliminating counterfeit and keeping true in a strong electromagnetic interference environment, so that the robustness to special working conditions of ultra-high voltage hot-line work is fundamentally improved.

The invention relates to the technical field of ocean engineering, in particular to a wave force estimation method which can accurately predict a circular rod piece and the like in an ocean structure located in an area near a free surface, and is particularly suitable for wave force estimation of a cylindrical structure horizontally arranged in an extreme wave environment under the action of transient strong nonlinear waves. The wave load calculation method for the near-free-surface cylindrical structure in the marine environment specifically comprises the steps that a wave force calculation model is established based on a classical Morrison equation, a focused wave field is constructed, focused waves are constructed by superposing a plurality of regular wave components, and the focused wave field is constructed by superposing a plurality of regular wave components; compared with the prior art, the method has the advantages that the applicability is wider, broadband multi-component focused wave field modeling can be effectively processed, and the method is particularly suitable for being applied to engineering early-stage design and parameter sensitivity analysis.

The application relates to the technical field of ocean engineering, in particular to a wave load calculation method for a near-free-surface cylindrical structure in a marine environment, which can accurately predict a circular rod and the like in a marine structure located in a region near a free surface, is especially suitable for wave force estimation of a horizontally arranged cylindrical structure under the action of transient strong nonlinear waves in an extreme wave environment, and improves the precision of structure stress prediction and the safety of engineering design, and specifically comprises the following steps: a wave force calculation model is established based on a classic Morison equation, a focused wave field is constructed, wherein the focused wave is constructed by superimposing multiple regular wave components, so that an idealized free liquid surface profile is formed, and then horizontal wave force and vertical wave force are respectively calculated in the focused wave field, compared with the prior art, the method has wider applicability, can effectively process wide-frequency multi-component focused wave field modeling, and is especially suitable for application of engineering early design and parameter sensitivity analysis.

The invention belongs to the technical field of nondestructive testing, and relates to a phase group velocity matching frequency dispersion removal method. The method comprises the following steps: S1, exciting a signal in a propagation medium, collecting a propagation signal, removing a frequency spectrum of an excitation signal in the propagation signal, and carrying out normalization processing; s2, solving a nonlinear frequency-wave number spectrum; s3, performing linear mapping according to the propagation medium frequency dispersion curve to obtain a linear frequency-wave number corresponding relation; s4, setting equal-interval wave number vectors, and performing linear mapping from the nonlinear wave number spectrum to obtain a linear wave number spectrum; s5, converting the linear wave number spectrum into a new normalized frequency spectrum according to a wave number-frequency corresponding relation, and adding an excitation signal frequency spectrum component to obtain a frequency spectrum of a non-dispersion propagation signal; and S6, performing calculation to obtain a frequency-dispersion-free reconstructed time domain signal. According to the method, the wave packet of the target mode can be extracted and separated, the frequency dispersion signal is recovered to the non-frequency dispersion signal, the signal quality and accuracy are improved, and the method is suitable for scenes such as structure health of ultrasonic detection.

The application discloses a nonlinear Lamb wave excitation deviation evaluation method and system under dispersion constraint, belongs to the technical field of ultrasonic nondestructive testing and structural health monitoring, and is based on a Rayleigh-Lamb frequency equation and a second-order perturbation theory to construct a second harmonic displacement field model, divides a phase velocity matching mode pair into an intersection type, a longitudinal wave type and a cutoff type; the contraction law of a propagation distance and a mode order on an excitation window is quantitatively analyzed, an excitation tolerance coefficient and a relative gain coefficient are introduced, a two-dimensional quantitative evaluation system of mode pairs is established, three typical mode pairs are divided and are adapted to different detection working conditions, and an aluminum alloy sheet experiment is completed to verify the application. The application adopts the above-mentioned nonlinear Lamb wave excitation deviation evaluation method under dispersion constraint, establishes a standardized mode evaluation system, and significantly improves detection sensitivity and engineering reliability.

The application discloses an effective wave height double-stage space-time prediction method and system based on diffusion residual correction, relates to the technical field of sea wave prediction, and inputs historical effective wave height data and corresponding historical wind field data into an effective wave height space-time prediction model for processing to obtain a preliminary effective wave height prediction result, and then inputs the preliminary effective wave height prediction result, the historical effective wave height data and synchronous forecast wind field data into a residual correction module based on a diffusion model to compensate for the preliminary prediction error and obtain a final effective wave height prediction result. The diffusion model based on the EDM architecture is innovatively introduced to finely reconstruct the prediction residual, the basic prediction field, the synchronous wind field dynamic factor and the prediction time limit are taken as multi-dimensional physical strong conditions to inject the diffusion generation process, the application can deterministically restore the high-frequency texture details and nonlinear wave components missed by the first-stage model, to a certain extent, the application can relieve the long-term deviation accumulation, improve the prediction quality in high wave areas and improve the prediction stability.

This invention discloses a nonlinear Lamb wave detection method for micro-damage in plate structures based on a flexible sensor array, belonging to the field of nondestructive testing technology. The method includes: generating a sinusoidal modulated excitation signal using a Hanning window; extracting nonlinear characteristic parameters reflecting micro-damage in the plate structure from the preprocessed signal using time-frequency analysis and empirical mode decomposition algorithms; generating a fused damage probability map based on compressed sensing theory and the extracted nonlinear characteristic parameters; constructing a damage distribution profile in the thickness direction by analyzing the penetration depth differences of Lamb waves at different frequencies; and automatically quantifying and analyzing the identified damage areas to obtain the damage detection results. This invention aims to achieve early identification and precise localization of micro-damage in plate structures, effectively overcoming the shortcomings of low sensitivity and inaccurate localization in traditional detection methods, and significantly improving detection accuracy, efficiency, and automation.

The present invention discloses a nonlinear component for wavefront control based on a graphene nonlinear metasurface. The nonlinear component comprises a plurality of periodically distributed metagratings, each comprising a metal substrate provided with a plurality of periodically distributed grooves filled with a dielectric layer, and the dielectric layer covered with periodically distributed graphene ribbons. Independent voltages are applied to the graphene ribbons to control their chemical potential, thereby achieving a nonlinear phase gradient. In the terahertz domain, the present invention provides an improved diffraction law for nonlinear wavefront control based on a graphene nonlinear phase gradient metasurface. This law can overcome the limitations of NGSL for nonlinear wavefront control. By rationally adjusting the chemical potential of graphene through applied voltage, multifunctional control of nonlinear waves, including reflection and beam steering, is achieved, thereby enabling the design of nonlinear components.

Systems and methods for generating a phase-resolved ocean wave forecast with ensemble based data assimilation are disclosed. An example method includes receiving radar data corresponding to an ocean surface, and determining a surface elevation and a surface potential of a portion of the ocean surface. The example method also includes generating an ensemble of perturbed ocean surface data, and applying a phase-resolved nonlinear wave model to the ensemble of perturbed ocean surface data to generate a set of forecast ocean surface data. The example method also includes receiving a subsequent set of radar data corresponding to the ocean surface, and determining a subsequent surface elevation and surface potential of the portion of the ocean surface. The example method also includes combining, by applying an ensemble Kalman filter, the set of forecast ocean surface data with the subsequent surface elevation and surface potential to generate a phase-resolved ocean wave forecast.

The application provides a vertical multi-plate wave making system with linkage of a rod system and high-precision control and a control method thereof. A computer control system generates a nonlinear wave control signal, and a controller and a driving device are used to independently drive the hinged points on each wave making plate, so that fine adjustment of local movement of the wave making plate is realized, and the vertical velocity and displacement profile of a target wave are highly accurately reproduced by precisely controlling the displacement of each hinged point. Specifically, a transfer function of the swing amplitude of each plate of the vertical multi-plate wave making machine and the wave height is derived by using the ideal fluid potential flow theory of hydrodynamics, the consistent relationship between the swing amplitude of each plate and the ratio of the displacement or velocity of the nonlinear wave vertical distribution, and the geometric invariable characteristics of each wave making plate are combined, and the specific displacement of each hinged point is solved, and then the motion law of the servo motor is obtained according to the geometric nonlinear relationship between the hinged points of the wave making plate and the linkage motion of the servo sliding block, so that the high-precision reproduction of the target wave by the vertical multi-plate wave making system is realized.

The invention relates to an RKHS projection adaptive beamforming algorithm for suppressing interference, which comprises the following steps of: 1, modeling a receiving signal of a receiving array, and constructing a nonlinear beamformer; step 2, mapping the received signal to a regeneration kernel Hilbert space through a kernel function, constructing a convex constraint about a target direction and an interference direction in the regeneration kernel Hilbert space, and constructing a non-differentiable convex loss function; step 3, setting initialization parameters; and 4, carrying out projection iteration on the plurality of hyperplanes to solve the weight of the beam former. According to the invention, target orientation estimation under multiple interferences can be realized.

The application discloses a low-voltage power supply pile management method and system, relates to the technical field of intelligent power supply pile management, and samples through a signal sampling and processing module at a high frequency greater than 50 kHz, and constructs an original current set and a preprocessing set, so that subtle disturbances and nonlinear fluctuation characteristics in a power supply process can be accurately captured, the technical limitation that only 'exceeding the limit can be identified' is broken from the root, and the capacity of discovering abnormal signal rudiment in advance is possessed. The ripple feature extraction module constructed by the system not only identifies the ripple density change in the current, but also fuses information in multiple dimensions such as frequency spectrum energy discreteness and phase jitter intensity, and forms a micro-disturbance feature set. Different from the traditional method of only paying attention to the mean value or the peak value, the system identifies the structural change and the continuity change of the disturbance through multiple angles, greatly enhances the identification capacity of the system to the implicit problem in the complex disturbance scene, and improves the resolution and sensitivity of the electrical behavior identification.

The invention relates to the technical field of seismic data processing, and particularly discloses a full-waveform inversion wave field reconstruction method and device based on wavelet extension, and the method comprises the steps: carrying out the wave field simulation through seismic wavelets, and obtaining a simulated seismic record; calculating a wave field residual error based on the simulated seismic record; performing deconvolution operation on the wave field residual error to obtain a deconvolution operation result; performing wave field back propagation on a deconvolution operation result and summing each channel to generate an extended wavelet corresponding to a residual wave field; and performing wave field propagation by using the extended wavelets to form a reconstructed wave field, thereby obtaining a final wave field. According to the method, the extended seismic wavelets are obtained through deconvolution, back propagation and summation of the wave field residuals, the extended seismic wavelets are used for reconstructing the nonlinear wave field, the problem that full-waveform inversion is prone to falling into a local extremum due to linearization of seismic wave numerical simulation in conventional full-waveform inversion is solved, and inversion reliability is improved.

The invention provides a non-reference damage imaging method based on nonlinear Lamb waves and Bayesian inference, and relates to the field of damage imaging, and the method specifically comprises the following steps: collecting nonlinear Lamb wave signals of a plurality of propagation paths; an enhanced second harmonic signal is obtained through a pulse inversion technology; extracting a flight time feature of the envelope signal; the frequency spectrum of the nonlinear Lamb wave signal is obtained through fast Fourier transform, and nonlinear coefficient damage index features are obtained through calculation; feature level fusion is carried out based on Bayesian estimation; and solving a posterior probability density function of the damage position parameter by using Hamiltonian Monte Carlo sampling, and carrying out damage probability imaging positioning according to posterior probability distribution. According to the technical scheme, the problems that in the prior art, a large number of sensors usually need to be deployed, and the dual requirements for high-precision damage detection and sensor number minimization in engineering practice are difficult to meet are solved.

This invention relates to an experimental apparatus and method for simulating ship motion under severe sea conditions, belonging to the field of ship wave load testing technology. It addresses the problem that existing severe sea condition wave load testing technologies are insufficient in simulating realistic waves under actual sea conditions, such as high wave heights, distorted waves, and breaking waves. The wave-generating system includes a wave-generating plate located at one end of a water tank and swinging along the length of the tank, and a driving component for driving the wave-generating plate's swing. The nonlinear wave generation system includes a wave-generating rod and several jet pipes. The wave-generating rod is arranged along the width of the water tank and slidably set along the height of the water tank via a height adjustment component. The jet pipes are all located at the bottom of the water tank. This invention enables the simulation of the water-air mixture flow field and accurate measurement of loads in distorted and nonlinear waves under severe sea conditions. It allows for a wide variety of experimental types and diverse functions, and can replace the expensive and costly towing tanks used for general ship models.

The invention provides a non-linear Lamb wave frequency dispersion effect-based fingerprint iterative imaging method. The method comprises the following steps of: acquiring a time domain sound field signal and a fingerprint grayscale image when a fingertip presses a glass plate; frequency dispersion curve changes of Lamb wave fundamental waves and second harmonics are calculated, and second harmonic excitation parameters are determined; constructing a fingerprint ridge-valley image, and establishing a speed model; determining a second harmonic propagation velocity by using a group velocity frequency dispersion curve, extracting signal features, and establishing a frequency domain sound field matrix; fingerprint primary positioning is completed through secondary harmonic ray tomography, and an initial model and a sound field matrix are updated; establishing an offline training data set, and training by adopting a supervised descent method; and completing fingerprint iterative imaging by using the descending gradient matrix output by training. According to the method, the high sensitivity of the nonlinear Lamb waves to fingerprints is utilized, the method has the characteristics of zero occupation of space under a transducer screen, small data set and low imaging error, and wide-area, accurate and rapid representation of submillimeter fingerprint details can be realized.

The present application relates to the technical field of wireless communication, and particularly relates to a power amplifier digital predistortion method based on a TCN-GRU hybrid network, which captures long-range timing dependence of signals through a timing convolution network, and models short-time correlation in detail through a gated recurrent unit, so as to realize joint suppression of harmonic distortion and intermodulation distortion of a short-wave power amplifier in a digital domain. Based on deep analysis of distortion characteristics of the short-wave power amplifier, the present application studies and finds that the distortion contains both long-range memory caused timing dependence and short-time characteristic change caused by nonlinear fluctuation in a saturation region, which exactly matches the natural complementarity of TCN and GRU. Under the premise of accurately capturing long-range timing dependence, the present application further makes fine short-time characteristic fitting on the features output by the TCN through the GRU module, finally realizes joint suppression of harmonic distortion and intermodulation distortion, and completes adaptation and innovative application of cross-domain technologies.

The application provides a gas concentration detection method and device, terminal equipment and medium, comprising controlling a laser to output a laser signal covering a characteristic absorption spectral line of a to-be-detected gas, and converting the laser signal into an original electric signal after passing through the to-be-detected gas via a standard-free light path; demodulating the original electric signal to extract first-order and second-order harmonic signals, and calculating a multi-dimensional harmonic characteristic ratio; obtaining temperature and pressure, introducing a spectral line broadening correction coefficient to construct a physical temperature and pressure model, and correcting the multi-dimensional harmonic characteristic ratio; extracting a waveform feature of a non-absorption reference region, performing nonlinear waveform distortion self-calibration on the corrected harmonic characteristic ratio, and obtaining a final harmonic characteristic ratio; establishing a theoretical mapping relationship between the final harmonic characteristic ratio and a to-be-detected gas concentration based on the Lambert-Beer law, and substituting the final harmonic characteristic into the to-be-detected gas to obtain a gas concentration detection result of the to-be-detected gas. The application can improve the accuracy and robustness of gas concentration detection.

The invention belongs to the technical field of ship and ocean engineering, and discloses a short-peak wave nonlinear characteristic enhancement forecasting method, which comprises the following steps of: firstly, constructing a weak nonlinear fluctuation characteristic propagation parameter matrix extraction and forecasting method based on an ICWM wave theory to provide a weak nonlinear wave component forecasting result meeting a wave propagation physical rule; then designing and constructing a nonlinear feature mapping operator by adopting a KAN neural network, and performing feature fitting on a nonlinear residual term between a weak nonlinear wave forecasting result and an actual wave by utilizing the operator to realize effective extraction of a strong nonlinear wave component; and finally, high-precision forecasting of complete wave information is realized through superposition of forecasting results of the two wave components. According to the method, the defects that the precision of a current hydrodynamic forecasting method is insufficient when the current hydrodynamic forecasting method faces strong nonlinear feature forecasting and an abnormal forecasting result is generated due to the lack of physical constraints of a neural network method are effectively overcome, and the stability and the accuracy of strong nonlinear short peak wave forecasting are effectively improved.

This invention provides a method and apparatus for nonlinear wave field reconstruction and prediction based on lidar. The method involves scanning the wave field with lidar to obtain the coordinates of sampling points, setting a cost function, and solving the cost function with the sampling point coordinates to obtain the wave surface expression. This improves the efficiency of wave surface reconstruction while ensuring reconstruction accuracy. Based on the wave surface expression, a predictable region is obtained. An objective equation is set to iteratively solve the wave surface expression to obtain the corresponding discrete values ​​of velocity potential, avoiding the Jacobian matrix generated during Newton iteration, thus improving the efficiency of velocity potential solution. Finally, based on the wave surface expression and the corresponding discrete values ​​of velocity potential, the wave surface condition at subsequent time points is predicted, and the prediction results within the predictable region are taken as the valid prediction results.

A method of detection of electromagnetic fields is provided. The method includes the steps of: providing a first beam in a first direction through a vapor cell, the first beam having a frequency ωp; providing a second beam in a second direction through the vapor cell, the second beam having a frequency ωd; providing a third beam in the second direction through the vapor cell, the third beam having a frequency Ωc; frequency stabilizing the first beam, the second beam, and the third beam to successive stepwise resonant transitions resulting in the excitation of a Rydberg state; applying symmetrical radio frequency sidebands to the third beam, the symmetrical RF sidebands with frequency spacing ωRF from Φc;coherently transferring the symmetrical RF sidebands to the first beam via a nonlinear wave mixing in the vapor cell; and determining an electromagnetic field inside the vapor cell.

The invention discloses a frequency modulation instruction prediction method based on a nonlinear domain and a related product, and belongs to the technical field of power system energy storage equipment. According to the frequency modulation instruction prediction method based on the non-linear domain, the original frequency modulation sequence is constructed, multi-round iterative decomposition is performed, the optimal prediction sequence is screened in the non-linear domain and input into the neural network for prediction, and finally the prediction results are superposed and merged, so that the non-linear characteristics of the fused salt energy storage frequency modulation instruction can be effectively captured, and the prediction precision is improved; the method has the technical effect of solving the problem that a traditional method is insufficient in nonlinear fluctuation processing.

The invention discloses a non-linear hydrodynamic calculation method for a shallow water floating body based on a finite water depth Green function, which realizes double breakthrough in precision and efficiency. A finite water depth Green function strictly meets a water bottom boundary condition, instantaneous wet surface dynamic iteration is combined, and shallow water nonlinear wave body interaction is accurately captured; a far-field Green function and a recursive convolution dimension reduction technology are analyzed by adopting a stable-phase method, so that the calculation efficiency is greatly improved; the influence of shallow water on diffracting force, radiation force and motion attitude of the floating body is researched, a floating body motion differential equation is solved according to nonlinear hydrodynamic force borne by the floating body to obtain the position, motion speed and motion attitude of the floating body, balance of precision and efficiency is achieved, the shallow water nonlinear calculation bottleneck is overcome, and high-precision calculation is achieved.

The application provides an iterative quantitative imaging method based on a nonlinear Lamb wave mixing sound field, and steps are as follows: a finite element model of a metal plate containing a complex mode early damage is established; a mixing fundamental wave mode pair and a working frequency are determined; mixing sound field signals in a non-damage state and a damage state are obtained through finite element simulation, and a frequency domain sound field matrix of a difference frequency, a sum frequency and a fundamental frequency is extracted; ray tomography positioning representation is carried out by using the frequency domain sound field matrix of the difference frequency, first imaging is realized, the first imaging is fused with the fundamental frequency sound field feature to strengthen positioning representation, and an initial velocity model of iterative quantitative imaging is established; an offline training data set is constructed, a nonlinear mapping model of sound field changes and model changes is learned based on a conjugate gradient method, online inversion based on the optimal nonlinear mapping model is carried out, and second imaging is realized; and the application extracts the sum frequency and the difference frequency component, keeps high sensitivity of the nonlinear ultrasonic to microscopic and mesoscopic damage, and significantly improves detection reliability.

The application provides a non-reference damage imaging method based on nonlinear Lamb waves and Bayesian inference, relates to the field of damage imaging, and specifically comprises the following steps: collecting nonlinear Lamb wave signals of multiple propagation paths; obtaining enhanced second harmonic signals through a pulse inversion technique; extracting time-of-flight characteristics of envelope signals; obtaining frequency spectra of the nonlinear Lamb wave signals by using fast Fourier transform, and calculating nonlinear coefficient damage index characteristics; performing feature-level fusion based on Bayesian estimation; solving a posterior probability density function of a damage position parameter by using Hamilton Monte Carlo sampling, and performing damage probability imaging positioning according to the posterior probability distribution. The technical scheme of the application overcomes the problem in the prior art that a large number of sensors usually need to be deployed, and it is difficult to meet the dual requirements of high-precision damage detection and minimization of the number of sensors in engineering practice.

The application discloses a kind of electric vehicle charging load prediction method and system based on space-time frequency multi-domain state space model.The method first uses discrete wavelet transform to decompose non-stationary load data into orthogonal low-frequency trend component and high-frequency characteristic component, the frequency domain component is fused with time embedding feature and space embedding feature, realize the multi-dimensional feature extraction of original charging load sequence;Subsequently, the extracted features are input into the hierarchical coding structure, and the core uses parallel bidirectional Mamba processing flow to synchronously capture the forward and backward long-term time dependence of the sequence.Thirdly, the encoded latent variable is input into the symmetric multi-layer decoder, the multi-scale information from the encoder is integrated using the skip connection, and the recursive feature recovery and refinement are performed through the bidirectional Mamba flow.Finally, the high-precision prediction result is output through the linear mapping layer.The application uses a linear computational complexity state space model to solve the problem of excessive computational overhead when the traditional Transformer model processes long sequences, as well as the non-linear, volatility and long-distance dependence problems that traditional models cannot handle.Experiments show that the method improves the prediction accuracy while greatly reducing the inference power consumption, and the system is suitable for deployment on the power grid scheduling terminal with lightweight requirements, helping to balance and schedule the load in the power network.

The application provides a ship hydroelastic one-way coupling numerical algorithm based on a viscous flow theory, comprising the following steps: determining external force and external torque of a ship under the action of a wave flow, and determining the speed and acceleration of six-degree-of-freedom motion of the ship; inputting ship segmented hydrodynamic load into a one-dimensional beam model of a ship beam elastic deformation module, and calculating the bending deformation of the ship beam through the one-dimensional beam model; determining the rigid body displacement of the time step according to the speed of the six-degree-of-freedom motion of the ship, updating the node coordinates of the flow field body grid according to the rigid body displacement of the time step, and then updating the flow field calculation domain grid by solving Laplace equation; and iteratively calculating the updated flow field calculation domain grid; the application has the beneficial effects that the application can realize the hydroelastic one-way coupling numerical calculation considering the elastic effect of the ship, can better capture the hydroelastic response influence brought by strong nonlinear wave slamming, and can further provide data support for the strength analysis of the ship structure.

The application discloses a simulation generation method and device for near-shore strong nonlinear waves and a terminal, and relates to the technical field of ocean engineering, in particular to a simulation generation method for near-shore strong nonlinear waves. The method comprises the following steps: acquiring sea surface height data of a tsunami wave at a certain position; inputting the sea surface height data into a wave speed variation and water depth variation relationship model, wherein the wave speed variation and water depth variation relationship model outputs wave flow speed; and obtaining a tsunami wave based on the sea surface height data and the wave flow speed. Compared with the prior art, the application can accurately generate strong nonlinear waves in a computational fluid dynamics model, fills the gap of the model method in this aspect, lays a foundation for the research on strong nonlinear waves, such as extreme storm surges and tsunami waves, and engineering effects thereof, and thus can more accurately understand, simulate and quantify the engineering effects of extreme wave disasters.

The application discloses a method for evaluating micro crack damage by using nonlinear Lamb waves and belongs to the technical field of ultrasonic nondestructive testing. x The method comprises the following steps: obtaining signals based on a sensor array to form a signal library, obtaining signals in the signal library and performing band-pass filtering on the obtained signals to form a signal matrix, solving a correlation matrix R x based on the signal matrix, obtaining a corresponding eigenvector E N based on the correlation matrix and the eigenvector, obtaining a spatial intensity spectrum, positioning and imaging micro cracks through the spatial intensity spectrum to construct an image library, obtaining a spatial intensity angle, and constraining a maximum angle as a beamforming pointing angle θ0, performing spatial filtering by using a beamforming algorithm, and completing positioning of imaging in the image library. The application can quickly image and position and evaluate micro cracks.