33 results about "Modal superposition" patented technology

The invention relates to the field of mechanical engineering, in particular to a hydraulic-structure collaborative optimization design method for a shield pump, and aims to solve the problems of load distortion and structure matching imbalance caused by traditional staged optimization. The method comprises the following steps: constructing a fluid-solid bidirectional coupling simulation model, and extracting transient hydraulic loads under multiple working conditions; establishing a structure dynamic response agent model based on modal superposition and Gaussian process regression; key coupling parameters such as the impeller outlet width and the volute base circle diameter are recognized through a Sobol method; and the efficiency, the lift fluctuation rate, the stress and the vibration are taken as multiple targets, and a Pareto optimal solution is searched through an improved genetic algorithm. Manufacturing constraints are embedded in the optimization process, the single period is shorter than 48 hours, and fatigue life evaluation and knowledge base intelligent recommendation are supported. According to the method, closed-loop cooperation of hydraulic excitation and structural response is achieved, the vibration prediction error is lower than 10%, the optimization dimension is compressed to be within 5 dimensions, the efficiency is improved by 20 times or above, and the performance reliability and the design intelligence level of the shield pump are remarkably improved.

The invention provides a temperature field reconstruction method and system based on digital twinning and application thereof, and the method comprises the steps: obtaining multi-moment temperature field data of target equipment, and carrying out the spatial dimension reduction processing, and obtaining K dominant modes; based on the multi-moment temperature field data and the K dominant modes, calculating modal coefficients of the temperature field at each moment in each dominant mode, and forming modal coefficient time sequences in one-to-one correspondence with the dominant modes; training a time sequence prediction model based on the modal coefficient time sequence and the operation condition physical parameters of the target equipment in time alignment with the modal coefficient time sequence, and predicting an initial modal coefficient at a future moment by using the time sequence prediction model; performing feedback correction on the initial modal coefficient based on a correction mechanism to obtain a corrected modal coefficient; and reconstructing the temperature field of the target equipment by using the corrected modal coefficient and the K dominant modals. According to the method, through a technical chain of space dimension reduction, working condition fusion, feedback correction and modal superposition, high calculation efficiency and high full-field reconstruction precision are both considered.

A rocket system level structure vibration simulation and verification method, comprising: constructing a rocket system level structure finite element model based on modal superposition method, carrying out harmonic response analysis, constructing excitation-response transfer function in frequency domain, and determining dynamic load transfer path and amplification effect; combining the power spectral density of the rocket vibration environment, implementing random vibration analysis, quantifying the system level structure strength safety margin by calculating the fatigue life; selecting weak components or typical components to carry out targeted vibration test, and verifying the reliability of the system level vibration simulation method in the above steps through test data. The method can effectively improve the vibration environment prediction accuracy and structure design reliability.

This invention relates to a data processing method and storage medium for ice-elastic plate compression tests in the field of ship structural mechanics. The method includes the following steps: performing a compression test by compressing an ice sample with an elastic plate; after the compression test, obtaining the test pressure value and strain gauge test values ​​of the ice sample under compression; selecting a preset order mode shape using the modal superposition method to obtain a fitted deflection function; determining the fitted strain value corresponding to each test point of the elastic plate based on the fitted deflection function; calculating the time coefficient by combining the strain gauge test values ​​and the fitted strain values ​​using the least squares method to obtain the fitted deflection distribution function of the elastic plate; and calculating the compression energy of the elastic plate and the ice sample based on the fitted deflection distribution function and the test pressure value. This method focuses on the deformation of the elastic plate to explore the interaction between ice and the structure from an energy perspective, considering the feedback influence of structural deformation on the action process, thus forming a universal method for predicting ice loads.

The invention discloses a structure nonlinear dynamic response incremental modal overlay analysis method and system, and belongs to the field of aerospace structure dynamics calculation. The method comprises the steps of constructing a finite element model and obtaining an initial matrix; dispersing the time-varying temperature field into a plurality of time increment intervals, updating material parameters in each interval, and calculating an instantaneous matrix; carrying out eigenvalue analysis and converting the kinetic equation into a modal coordinate system; solving a modal response increment by adopting a numerical integration method and converting the modal response increment to a physical coordinate system for superposition; and circularly executing until a full-time-history response is output. According to the method, the problem of rigidity nonlinearity caused by the temperature is solved through incremental linearization and modal order reduction, high calculation precision and high efficiency are achieved, and the method is suitable for dynamic design and analysis of aerospace structures in the high-temperature variable-temperature environment.

The present application relates to a kind of wave environment under suspended tunnel dynamic response frequency domain calculation method, belong to the field of tunnel structure.Based on classical dynamics theory, the elastic foundation beam simplification of pipe body with discrete anchor is carried out, the motion control equation of suspended tunnel is established using Hamilton principle, the wave force on suspended tunnel pipe body is calculated by potential flow theory and combined with boundary element numerical calculation method, finally the dynamic response of suspended tunnel is obtained by solving wave-solid coupling equation using modal superposition method.Based on potential flow theory, the accuracy and efficiency of the solution can be focused on simultaneously, it is suitable for large-scale structure, and the combination of elastic foundation beam model makes the calculation of wave-solid coupling not consume too much computing resources, comprehensive multi-parameter multi-condition analysis is carried out on the structure, the coupling effect of pipe body horizontal displacement and torsional displacement is considered, compared with the previous method, the calculation of the situation that pipe body appears larger horizontal displacement or torsional displacement will be more accurate.

The invention provides a reduced-order galloping analysis method based on intelligent mode selection, and belongs to the technical field of electric power operation and maintenance, and the method comprises the steps: building a digital model of a power transmission conductor, and representing the geometric configuration of the conductor; performing finite element modal analysis on the digital model to obtain a multi-order vibration modal vector of the conductor; implementing intelligent modal screening; quantifying key point displacement characteristics for each order of modal; constructing a modal feature vector, inputting the modal feature vector into the trained convolutional neural network for modal classification and dominant evaluation, and screening out a dominant modal set; performing mode superposition by using modes in the dominant mode set, and describing vertical vibration displacement and out-of-plane vibration displacement of the wire; and constructing a reduced-order kinetic energy and potential energy expression based on the dominant mode set, and obtaining a dimensionality-reduced kinetic model for solving. The method has the advantages that only key modals are reserved through the intelligent screening technology, the dimensionality of a kinetic equation is reduced, simulation analysis is converted into rapid completion from traditional long-time calculation, and the analysis period is shortened.

The invention discloses a multi-batch three-dimensional sensor optimization layout method in a modal test, which is used for extracting candidate sensor positions from a finite element model and solving the optimization problem by simultaneously considering a reference sensor and a mobile sensor. Firstly, a modal addition method is carried out on candidate sensor positions extracted from a finite element model, a reference sensor candidate set is selected, then an improved three-dimensional independence criterion and a minimum variance criterion of structural response estimation errors are combined, and three-dimensional sensor optimization layout is achieved by optimizing a batch with the worst objective function result. According to the method, the modal test precision of a large-scale structure or a complex structure can be effectively improved.

This invention relates to a time-domain calculation method for the dynamic response of suspended tunnels under multi-load coupling, belonging to the field of dynamic response analysis of suspended tunnels. Addressing the problems of poor versatility and difficulty in handling multi-load coupling and structural variations caused by inconsistent governing equations in traditional methods, this invention proposes establishing a unified equation of motion for the tunnel body. This equation is decomposed into a system of generalized coordinate ordinary differential equations using the modal superposition method. An implicit Newmark-β method is employed for solving the equations, and a sub-loop iteration mechanism is embedded to achieve dynamic coupling between loads and tunnel motion. By independently modeling anchor cable constraint reactions and using a modular environmental load interface, the method is compatible with complex terrain and various load coupling effects. This invention improves the versatility and computational efficiency of dynamic response analysis of suspended tunnels, solves the accuracy and stability challenges under multi-load interaction, and provides a reliable basis for engineering design.

The invention discloses a simple harmonic vibration analysis method based on a modal superposition method, and the method comprises the steps: carrying out the modal analysis of a three-dimensional model of equipment, and obtaining a solution of the modal space of the equipment; a periodic load is obtained, the previous solution of the modal space is selected as the solution of the displacement response of the system in the physical space, the system motion equation under the simple harmonic vibration after coordinate transformation is solved, and a frequency response curve of the equipment structure is obtained; whether the maximum deformation value of the equipment structure under the action of the corresponding periodic load is smaller than an allowable value or not is analyzed by combining the frequency response curve of the equipment structure, and if yes, it is verified that the equipment design meets the requirement; otherwise, verifying that the equipment design does not meet the design requirement, performing reinforcement design on the part with weak structural strength, and repeating the steps until the equipment design meets the requirement. The method ensures that the use of the equipment is not influenced when the equipment is subjected to specified periodic load, and is used for improving the product design efficiency and shortening the equipment design period.

This disclosure relates to a method and system for predicting the surface roughness of side milling based on multi-mode superposition, including: acquiring multi-mode parameters of the cutting tool and machining parameters; determining an ideal tool tip trajectory based on the machining parameters; establishing a tool vibration response model under periodic cutting force excitation based on the principle of modal superposition and the multi-mode parameters, and calculating the vibration amplitude distribution at different heights along the tool axis; extracting the time-domain vibration response at the tool tip height as a vibration disturbance term, superimposing it onto the ideal tool tip trajectory to construct the tool tip motion trajectory; constructing a surface morphology model based on the tool tip motion trajectory to obtain the theoretical distribution law of surface roughness with the tool axial height; constructing a neural network prediction model based on the multi-mode parameters, machining parameters, and theoretical distribution law, training the model using a loss function based on the tool vibration response model, and obtaining the surface roughness prediction result of the tool. This disclosure can improve the accuracy and reliability of roughness prediction.

The application discloses an immersion interactive method and device for appreciating artifacts, and relates to the technical field of human-computer interaction. The method comprises the following steps: in an immersive digital experience cabin, the three-dimensional coordinates of the user's double pupils and the hand skeleton node coordinates are collected, the gesture instruction is analyzed, and the three-dimensional space viewpoint parameter set of the next moment is predicted; in a virtual engine scene, the UV texture coordinates are obtained by ray intersection, the three-dimensional region of interest is demarcated, the candidate tile set and the tile topology feature matrix are retrieved and generated; based on the pre-constructed fitness function, the improved tornado optimization algorithm is used for solving, and the global optimal tile loading sequence is output; the naked-eye light field rendering and the three-dimensional space multi-modal superposition are performed on the global optimal tile loading sequence, and the fusion picture of the artifacts and the suspended interpretation is presented on the naked-eye 3D cabin screen. The application solves the problems of viewpoint prediction lag, texture tile loading leading to video memory overflow or picture damage, and lack of spatial multi-modal fusion in the prior art.

The invention relates to a modal method and geometric precision beam mixed three-dimensional large deformation monitoring method for a beam structure, belongs to the technical field of structure health monitoring, solves the problems of high generalized strain calculation complexity of the structure and too high requirement on the mounting position of a sensor in the prior art, and comprises the following steps: S1, initializing calculation; mathematical representation is carried out on the geometric configuration of the to-be-monitored beam structure, and a global coordinate system and a local coordinate system are established; s2, obtaining generalized strain of a beam center reference line of the to-be-monitored beam type structure based on a modal superposition method; s3, calculating a spatial position vector of a beam center reference line; s4, calculating a spatial position vector of any point on the to-be-monitored beam structure after deformation; and S5, outputting the obtained spatial position vector of the to-be-monitored beam structure after deformation as a monitoring result, and providing the monitoring result to a structure instability risk early warning program.

The invention relates to the technical field of engineering machinery, and provides a pipeline management method based on modal displacement and electronic equipment, a multi-body dynamics-fluid pressure coupling simulation model is constructed based on a hydraulic excavator working device pipeline system, and target position parameters of a lug are obtained through a free modal method and a modal displacement algorithm. The multi-mode superposition effect principle is applied to layout optimization of the engineering machinery pipeline lug, accurate optimization of the position of the pipeline lug is achieved by modeling and analyzing the coupling vibration problem of a multi-order mode, and the problem of stress concentration caused by resonance is effectively avoided. Furthermore, actually-measured acquisition data are acquired through load spectrum acquisition, dynamic response analysis is performed to execute dynamic monitoring and early warning, and a dynamically-optimized and continuously-monitored closed-loop system is established through comparative analysis of simulation and actually-measured data, so that the simulation precision is improved, dynamic adjustment and early warning of actual working conditions are realized, and the working efficiency is improved. And the applicability and the reliability of the system are obviously improved.

This invention discloses a dynamic analysis method for beam structures with arbitrary curvature and varying thickness in a plane, belonging to the field of aerospace structure and structural dynamics modeling technology. The method first inputs the upper and lower surface functions of the curved beam to solve for its neutral surface function; secondly, it constructs a family of orthogonal displacement functions specific to this beam structure with arbitrary curvature and varying thickness, and establishes an integral mapping relationship between the global coordinate system and the dynamic sub-coordinate system; subsequently, based on the displacement function family and the integral mapping relationship, it derives and solves the energy equation of the beam structure; finally, it obtains the mode shapes and natural frequencies based on the Rayleigh-Ritz method, and calculates the dynamic response and dynamic stress of the structure using the modal superposition method. This invention overcomes the shortcomings of existing semi-analytical modeling methods for the dynamics of complex curved beam structures with varying thickness, and can efficiently and accurately predict and analyze the dynamic characteristics of beams with arbitrary curvature and varying thickness in a plane.

The embodiment of the application provides a kind of hydrogen fuel flow simulation CFD's post-processing method, device, equipment and medium, it is related to numerical simulation technical field, wherein, the method is realized by the following steps: the hydrogen fuel flow CFD simulation based on aero-engine is executed, and unstructured grid data is generated;Unstructured grid data is converted into a plurality of simulation result files, and the grid geometry information and numerical distribution data in simulation result file are sorted, time snapshot matrix is generated, and the mode corresponding to each eigenvector of hydrogen fuel flow field is obtained by calculating time snapshot matrix accompanying matrix S;The magnification g i And modal coefficient amplitude b a Of each eigenvector of hydrogen fuel flow field is calculated by the mode corresponding to the mode superposition method, dynamic reconstruction and prediction are carried out on hydrogen fuel flow field.The scheme can reconstruct and predict the flow field state at any time by the method of modal superposition, improve the efficiency of post-processing.

This invention provides a ticketing tailgating control method and apparatus based on multimodal data, relating to the field of access control technology. The method includes: acquiring target image information, target point cloud data, and target occlusion time-series signal of the target area after a target person enters a detection area through a first verification; fusing the target image information, target point cloud data, and target occlusion time-series signal to obtain a multimodal fusion feature vector; inputting the multimodal fusion feature vector into a pre-trained classifier to obtain the ticketing tailgating analysis result output by the classifier; the classifier is trained based on the sample feature vector; and controlling access to the target gate based on the ticketing tailgating analysis result. This invention, by fusing image information, point cloud data, and time-series signal, and using a pre-trained classifier, can improve the accuracy and reliability of tailgating recognition, achieving a recognition rate far higher than existing single-modal or simple dual-modal superposition schemes.

The invention discloses a quantitative analysis method for a vibration stress state of a turbine blade under a working condition. The quantitative analysis method comprises the following steps: establishing a finite element simulation model and applying a boundary condition; three-dimensional non-uniform temperature field data and non-uniform pneumatic pressure field data of the blade surface are obtained through CFD calculation; coupling and applying a temperature field, pneumatic static pressure and a centrifugal force load in static structure analysis to obtain a basic stress state; pre-stress modal analysis is carried out, blade dynamic frequency containing centrifugal stiffening and thermal softening effects is calculated, and a Campbell diagram is drawn to identify resonance points under the working rotating speed; in harmonic response analysis, pneumatic pressure pulsation components extracted according to CFD results are applied to resonance points to serve as excitation, and vibration stress distribution of the blade under thermal-centrifugal-pneumatic three-field coupling loads is obtained through a mode superposition method. According to the method, high-precision quantification of the resonance stress state of the blade under the multi-field coupling load is realized, and a precise basis is provided for high-cycle fatigue life prediction and reliability design of the turbine blade.

The application discloses a kind of multi-split conductor icing characteristic test device and its torsional rigidity design method, the device includes two support frames and is arranged between two support frames multiple multi-split conductor sections;Through the transmission direction of thin rope change horizontal spring tension, the torsional rigidity of the multi-split conductor icing characteristic test device remains constant when large angle torsion, can be used for multi-split conductor large angle torsion icing characteristic test;The torsional rigidity design method of the application, based on modal superposition method and dynamic similarity criterion, obtains each physical parameter of the multi-split conductor icing characteristic test device, by using different horizontal spring stiffness and torque loading disc radius combination, realize the accurate design of the torsional rigidity of the multi-split conductor icing characteristic test device, accurately simulate the icing characteristic of any real multi-split conductor at any position.

The invention discloses a machine tool cutting stability-oriented weak pose and sensitive structure identification method and device. The machine tool cutting stability-oriented weak pose and sensitive structure identification method comprises the following steps of: dividing a machine tool into a plurality of substructures, and sampling different positions of each substructure in a working space to obtain a pose parameter sample set; a machine tool whole machine pose related reduction dynamic model is constructed; calculating a frequency response function matrix of the tail end of the main shaft in the AC swing head by adopting a mode superposition method; a response coupling substructure method RCSA is adopted to obtain a pose-related tool nose frequency response function; the maximum dynamic flexibility peak value in the tool nose frequency-response function is used as a stability weakness judgment index, and a three-layer progressive search strategy is adopted to identify weak poses in the working space; and at the weak pose, taking the mass of each substructure, the stiffness matrix and the stiffness of the joint part as influence factors, generating a matrix sample according to a quasi Monte Carlo sequence, and calculating the first-order sensitivity and the total effect index of each influence factor to the maximum dynamic flexibility peak value by adopting a Sobol sensitivity analysis method so as to identify the sensitive structural member.

The invention discloses a complex scene multi-modal imaging sensing system, and belongs to the field of multi-modal imaging detection. Through deep fusion of multi-modal data of visible light, infrared and laser radar information, unique advantages of each sensor in the aspects of high spectral resolution, long wave penetration characteristics and three-dimensional modeling are fully played, and the problem of performance degradation of a traditional technology in complex scenes such as low illumination and severe weather is effectively solved. Meanwhile, high-precision sensing of the target space pose is realized; deep fusion of three types of multi-modal information is realized through modular process design of'feature fusion, region enhancement, channel simplification, multi-modal superposition 'and the like, the accuracy of a multi-modal fusion result is improved, and reliable data support is provided for subsequent decision making; through the lightweight design of screening redundant channels through BN layer scale factor gamma regularization, the model parameter quantity and the calculation quantity are reduced, and it is ensured that real-time reasoning of the fusion model is achieved on embedded equipment.

The application discloses an optimization modal superposition stress reconstruction method based on time domain coupling solution, which comprises the following steps: 1) establishing a finite element model based on design data of a target structure, and constructing a basic modal database; 2) forming a stress monitoring numerical matrix and a modal information matrix; 3) dividing the stress monitoring numerical matrix by a sliding time window; 4) forming a standard quadratic convex optimization equation form by jointly solving a modal coefficient in the time window, and jointly solving a multi-time step modal coefficient matrix in each time window; 5) calculating a stress time history result in each time window; and 6) splicing the stress time history results in all time windows, and outputting a result. Compared with the MS method, the application avoids peak and valley weakening or loss, is more optimal in phase consistency, and improves a determination coefficient to above 0.98. The application converts an underdetermined and ill-conditioned problem into a convex quadratic optimization problem through three types of regularization constraints, and the number of modes is not limited by the number of measuring points, and the solution result is unique and stable.

The invention provides a method for vibration characteristic analysis and structure optimization of a gear system. The method comprises the following steps: S1, carrying out accurate modeling on a tooth surface of a bevel gear; s2, establishing a three-dimensional entity simulation analysis model, and setting connections among components; s3, the unbalance amount is set on the structure of the bevel gear; s4, setting a load working condition to carry out advanced gear tooth bearing contact analysis, and calculating a transmission error and a deformation amount of a gear system; s5, taking the transmission error and the initial deformation as input, and analyzing the change condition of the vibration characteristics of each key position of the system along with the rotating speed under the excitation of the rotating frequency and the meshing frequency by adopting a modal superposition method; and S6, in combination with a vibration characteristic analysis result and a modal analysis result, judging a vibration generation reason, and optimizing the structure. According to the method, the spiral bevel gear tooth surface is accurately modeled, the influence of different machining tooth surfaces on the transmission error of the gear system is considered, the calculated transmission error is used as excitation for vibration characteristic analysis, and the accuracy of analysis model input is improved.

The application discloses a curve track-bridge coupling system support stiffness identification method based on a vehicle scanning method, belongs to the field of engineering structure monitoring, and establishes a curve double-beam system mechanical model with a mobile elastic mass, deduces a control equation, and solves the control equation by using a modal superposition method and Laplace transformation, extracts a coupling system frequency from a contact point or a vehicle response, and especially efficiently identifies track modulus by using a fourth frequency component of a first-order modal. The application has the advantages of strong operation maneuverability, high cost benefit ratio and outstanding implementation efficiency, and is suitable for health monitoring of a curve track-bridge coupling system.

The invention provides an FBG acceleration sensor research and development method based on an infinite degree-of-freedom system vibration theory (a distributed parameter model), and belongs to the technical field of structural intelligent health monitoring and vibration measurement. The core of the method is that an acceleration sensing structure is regarded as a continuous medium elastomer, based on an infinite freedom degree system vibration theory, mass distribution and fluctuation characteristics of the elastomer are considered, a distribution parameter model is established, a fluctuation equation of the distribution parameter model is solved, and the inherent frequency, the modal shape and the dynamic response of the system are accurately analyzed through a modal superposition method. Further, the sensitivity characteristic of the sensor is deduced, the coupling rule of the sensitivity and the frequency response under the multi-order modal coupling effect is disclosed, and the method is used for guiding accurate design and performance optimization of the sensor. According to the acceleration sensor research and development method provided by the invention, the influence of the design parameters of each module of the sensor on the resonant frequency and sensitivity can be accurately quantified, the directional optimization (such as high and low frequency high-sensitivity design) of the sensor performance is guided, and the durability is improved.

Disclosed in the present invention is a method for performing stability analysis and transient calculation on a fluid-filled rotor on the basis of multi-frequency whirl decomposition. The implementation steps of the method comprise: 1) establishing a "dual-rotor" finite element model, acquiring an uncoupled fluid cross-stiffness state space, and calculating feature values corresponding to modes in various orders of a system; 2) on the basis of a multi-frequency whirl hypothesis, calculating, order by order, a fluid cross stiffness under the feature value corresponding to the mode in each order of the system, coupling the fluid cross stiffnesses into a state space equation of the system, and performing iterative calculation to obtain a converged feature value of each order of the system under the influence of fluid-structure interaction; 3) on the basis of the converged feature values of the system, calculating a liquid excitation force of the mode in each order, and decomposing, on the basis of a modal superposition principle, the total displacement response of the system into the modes in the various orders of the system; and 4) in view of an explicit-implicit-segregated solution framework, performing, with respect to the mode in each order, transient dynamic calculation and analysis on a dynamic rotor model obtained after fluid-structure interaction. The method solves the problem of a traditional lumped-mass model in a traditional fluid-structure-interaction rotor stability analysis method only being capable of processing a single whirl frequency.

The invention relates to the technical field of steel cold roll forming, and discloses a digital twinning-based steel cold roll forming resilience value accurate prediction and mold cavity self-adaptive correction method, which comprises the following steps of: constructing a cross-scale twinning body fusing a macroscopic FEM and a microscopic CPFEM, and introducing an online microscopic vision system to collect a grain-level structure signal to realize holographic data perception; a physical mechanism and data are fused by adopting a physical information neural network, and prediction results of PINN, FEM and CPFEM are dynamically weighted in combination with an attention mechanism, so that high-precision springback amount prediction is realized; a mold cavity correction main mode is extracted through principal component analysis, correction is decomposed into mode coefficients, and a piezoelectric ceramic fiber composite (MFC) actuator array is driven to achieve profile self-adaptive correction; and realizing multi-factory collaborative model evolution based on a federated learning framework. According to the method, through cross-scale modeling, PINN and attention fusion, modal superposition correction and federated learning, the problems of low prediction precision, response lag, data island and poor generalization of an existing method are solved.

This invention discloses a decoupling analysis method for flutter characteristics based on energy flow direction of aeroelastic coupling modes, comprising: setting a training signal, obtaining high-confidence aerodynamic data using CFD, and constructing a reduced-order aerodynamic model; based on the reduced-order aerodynamic model, simultaneously establishing structural dynamic equations based on modal superposition to construct aeroelastic state-space equations and determining the aeroelastic state matrix; thereby transforming the local stability analysis problem of the aeroelastic system of the analyzed object into a characteristic analysis problem of the aeroelastic state matrix; extracting aeroelastic modes based on the aeroelastic state matrix, setting a forced motion excitation signal, defining an energy flow direction calculation formula to characterize the energy dissipated by the structure through the fluid-structure interaction interface into the flow, and the energy flow direction at a certain point on the fluid-structure interaction interface; examining the aerodynamic work done by the analyzed object in the next cycle of forced motion using CFD to obtain the energy flow direction distribution.

The application discloses a power equipment health state evaluation method and system based on multi-modal sensor data fusion, relates to the technical field of multi-modal sensor detection, and comprises the following steps: reconstructing a graph structure of a target power distribution network, determining a power graph structure, and determining that the ground state of each power equipment is a superposition state of a normal ground state and a multi-element fault ground state; acquiring multi-modal sensor data of the target power equipment by adopting multi-source joint detection, and collecting the data by constraining a sparse dot matrix structure; establishing a power evaluation module by taking multi-modal superposition and VR complex reconstruction as double-mode evaluation, jointly analyzing data, combining the superposition state collapse of the power graph structure, determining the health state of the equipment, and performing operation and maintenance management according to the health state. The application solves the technical problems that the traditional power equipment health evaluation has single data dimension, lacks hierarchical correlation in analysis, and has poor connection between evaluation results and operation and maintenance management, achieves accurate evaluation of the health state of the power equipment, efficiently connects operation and maintenance management, and guarantees the technical effect of the safe operation of the power distribution network.

This invention belongs to the field of harmonic analysis technology, and provides a method and system for harmonic resonance analysis considering the location of harmonic sources. It obtains the network topology and component parameters of a power system, constructs the node admittance matrix of the system at a specific frequency, and performs eigenvalue decomposition on the node admittance matrix. Based on modal analysis theory, each element of the node impedance matrix is ​​represented as a superposition of all modal impedances, establishing a mapping relationship between each node impedance and modal impedance, left eigenvector, and right eigenvector. According to the modal superposition expression, an improved modal participation factor considering the location of harmonic sources is constructed and screened to quantify the resonance degree and modal composition of each node in the system, identifying the key resonant nodes and dominant modes of the system. This invention solves the problem of large evaluation deviations of traditional participation factors under complex operating conditions with complex network structures and multiple resonant points, improving the accuracy and applicability of harmonic resonance analysis.