597 results about "Natural frequency" patented technology

The invention discloses a curtain wall structural adhesive damage detection method and device based on modal difference and digital twinning, and belongs to the technical field of digital twinning structural adhesive damage detection and evaluation. The problem that in the prior art, a traditional glass curtain wall structural adhesive damage detection and evaluation method based on the first-order inherent frequency is not sensitive to local boundary adhesive failure, and consequently the specific damage position cannot be positioned is solved. The method comprises the following steps: acquiring vibration data of a group of hidden framing glass curtain walls to be detected and a group of hidden framing glass curtain walls in a lossless state to obtain normal acceleration time history data; primarily screening second-order and third-order inherent frequencies, and judging whether the structural adhesive is damaged or not according to a difference constraint condition; further positioning the damage by using the boundary relative curvature modal difference, and judging whether the current measuring point is a damage point or not; and constructing a digital twinborn model and damage early warning, and outputting a parameter report and a visual damage evaluation result. The method effectively improves the boundary damage positioning precision, and can be applied to glass curtain wall structural adhesive damage detection.

The invention provides an acoustic coalescence elimination method for hydrogen bubbles in molten aluminum, and belongs to the technical field of molten aluminum bubble elimination. According to the method, sound field collaborative focusing is achieved by arranging a phase control array transducer set in a molten aluminum smelting furnace, primary gathered sound waves and efficient coalescence sound waves are applied in stages according to bubble size evolution in a double-frequency scanning mode, and the hydrogen bubbles in the molten aluminum are eliminated. A target frequency is dynamically adjusted in combination with a bubble resonance frequency optimization model to match the inherent frequency of a bubble, a sound-bubble coupling dynamic tracking system is used for monitoring bubble evolution triggering stage switching in real time, and a sound field focus point dynamically scans and covers a three-dimensional space area through phase delay control. A delay detection method is adopted to eliminate cavitation bubble interference and accurately measure the hydrogen content, sound intensity and frequency parameters are optimized according to a sound field parameter self-adaptive regulation and control model, and the technical problem that hydrogen bubbles in a molten aluminum deep area are difficult to be effectively driven by sound waves and cannot be fully coalesced and eliminated is solved.

The invention discloses a method for correcting a predicted value of inherent frequency of a bridge under an operation condition, and belongs to the technical field of bridge monitoring, and the method comprises the following steps: S1, collecting bridge data; s2, data preprocessing; s3, environment and load interference decoupling is carried out; s4, constructing a model; s5, correcting the AI driving model; s6, verifying and iterating the mechanism; according to the method, breakthrough is made in three aspects of environmental interference stripping, parameter dynamic optimization and intelligent algorithm iteration, so that the prediction precision is improved, the engineering efficiency is optimized, the safety is ensured, the environmental interference stripping technology can effectively eliminate external environmental noise, and the accuracy of prediction data is ensured; a parameter dynamic optimization technology can dynamically adjust model parameters according to real-time data, so that a prediction result is closer to reality; the intelligent algorithm iteration continuously optimizes the model through machine learning and improves the intelligent level of prediction, and the method of updating posteriori distribution through Bayesian is adopted, so that the prediction model can be continuously corrected according to newly acquired data, and the prediction accuracy is ensured.

The application discloses a curtain wall structure adhesive damage detection method and device based on modal difference and digital twinning, and belongs to the technical field of digital twinning structure adhesive damage detection and evaluation. The application solves the problem that the traditional glass curtain wall structure adhesive damage detection and evaluation method based on the first-order natural frequency cannot locate the specific position of damage due to the insensitivity to local boundary delamination. The application collects vibration data of the test group of hidden frame glass curtain walls and the non-damage state group of hidden frame glass curtain walls to obtain normal acceleration time history data. The second-order and third-order natural frequencies are preliminarily screened, and whether the structure adhesive is damaged is judged through the difference constraint condition. The boundary relative curvature modal difference is used to further locate the damage, and whether the current test point is a damage point is judged. A digital twinning model and damage early warning are constructed, and a parameter report and a visual damage evaluation result are output. The application effectively improves the boundary damage positioning accuracy and can be applied to glass curtain wall structure adhesive damage detection.

The invention relates to a composite vibration feeding device and method suitable for a seed color sorter, and the composite vibration feeding device comprises a stock bin, a feeding device arranged below the stock bin, and a vibration device for promoting the feeding device to vibrate; the feeding device comprises a receiving disc and a feeding disc; the driving end of the vibration device is connected with the material receiving disc; one end of the feeding disc is connected to the receiving disc through an elastic structure, and the other end of the feeding disc is a free end. The feeding disc is provided with a plurality of sets of conveying channels arranged in the direction perpendicular to the conveying direction of materials. The difference value between the vibration frequency output by the vibration device and the inherent frequency of the feeding device is controlled to be within the preset range so as to excite modal resonance of the feeding device, and the modal resonance and the vibration effect of the vibration device are coupled to form composite vibration. The materials are promoted to be converted into a single-layer and single-row arrangement state from a stacked state through the compound vibration, and meanwhile the materials continue to move towards a discharging port of the feeding device.

The invention provides an inhaul cable self-vibration fundamental frequency automatic identification method and system based on a harmonic product spectrum, and relates to the technical field of structure monitoring, and the method comprises the steps: receiving vibration acceleration data of an inhaul cable, carrying out the windowing processing of the vibration acceleration data through employing a Hanning window, and generating a windowed signal; carrying out fast Fourier transform on the windowed signal, and improving the frequency resolution by implementing zero filling to obtain an initial frequency spectrum; smoothing the initial frequency spectrum to form a smooth frequency spectrum; performing passband clipping on the smooth frequency spectrum to zero the passband outer amplitude to form a clipped frequency spectrum; calculating the signal-to-noise ratio of the frequency spectrum after cutting, and comparing the signal-to-noise ratio with a preset threshold value; if the signal-to-noise ratio is lower than a preset threshold value, judging that the signal quality is unqualified and terminating the processing flow; and if the signal-to-noise ratio is equal to or higher than the preset threshold value, continuing the normal processing flow. According to the invention, automatic and high-precision identification of the self-vibration fundamental frequency of the inhaul cable can be realized.

The invention discloses an intelligent regulation and control method and system for the environmental comfort degree of a central air conditioner terminal, and relates to the technical field of air conditioner regulation and control. The intelligent regulation and control method comprises the following steps that a pressure fluctuation track generated by aerodynamic disturbance is collected in the operation process of a draught fan, and the pressure fluctuation track is converted into energy spectrum distribution in a time sequence; establishing dynamic energy representation of the fan frequency; based on dynamic energy representation of fan frequency, a sound vibration field is projected in a spatial range, excitation response of inherent frequency is synchronously recorded through a room structure sensing array, and instantaneous energy coupling fingerprints of a room structure are formed. Through dynamic energy characterization and structural response coupling analysis, real-time identification and quantitative control of the standing wave noise risk are realized, a phase drift mechanism is introduced at a risk critical point, a fan disturbance phase is actively adjusted, standing wave superposition is effectively blocked, and acoustic safety and operation stability of a tail end environment are improved.

The invention relates to the technical field of hydraulic control, and discloses a hydraulic motor constant torque self-adaptive PID (Proportion Integration Differentiation) control system which comprises a controller and a hydraulic driving unit, the controller performs frequency domain separation on the pressure signal by using a signal preprocessing module, and extracts an average pressure difference representing the driving force and a ripple amplitude representing the fluid rigidity; the state observation module estimates an instantaneous volume elastic modulus based on the ripple amplitude, corrects a compression item in a flow continuity model by using the elastic modulus, and calculates an instantaneous leakage coefficient of the motor in real time; the self-adaptive control module establishes dynamic mapping of PID gain and physical parameters, the proportional gain is adjusted by using a leakage coefficient to match system damping, the integral gain is adjusted by using a volume elastic modulus to adapt to inherent frequency, and a control instruction is synthesized by combining feedforward compensation. According to the method, the problem of model mismatch caused by oil characteristic change and motor abrasion is effectively solved, and the whole-life-cycle control precision of the system is improved.

To set specifications while suppressing antiresonance in a vibration control device having a plurality of tuned mass dampers.SOLUTION: A method for setting specifications of a vibration control device 10 having a plurality of tuned mass dampers 14 includes a step of assuming that the plurality of tuned mass dampers 14 are sequentially installed on a structural material 52, setting a natural frequency of the tuned mass damper 14 assumed to be first installed to a primary natural frequency of the structural material 52, and then obtaining a frequency of antiresonance generated by one or a plurality of tuned mass dampers 14 assumed to be previously installed; Is repeated.SELECTED DRAWING: Figure 6

The invention relates to the field of gates, and provides a gate vibration online analysis early warning method and system, and the method comprises the steps: training the historical monitoring data of a gate through a machine learning algorithm, and constructing a mapping relation between an independent variable and a dependent variable; upstream and downstream related independent variable information of the gate is obtained, and the gate vibration state is calculated online according to the mapping relation; analyzing and calculating the natural vibration frequency of the gate based on the modal analysis model of the gate; and evaluating the safety state of the gate according to the gate vibration state and the natural vibration frequency of the gate. When the system is used, the problems of data islanding, prediction lag, model distortion and low decision efficiency in the traditional technology are solved, high-precision and full-period intelligent guarantee is provided for hydraulic engineering safety, the resonance accident risk is remarkably reduced, and gate operation and maintenance management is promoted to be upgraded to the standard and unmanned direction.

The invention relates to the technical field of intelligent logistics and operation planning optimization, and discloses an import and export multimodal transport intelligent stowage service method based on a hybrid planning algorithm, which comprises the following steps: establishing an intermodal transport node operation impact database and an intermodal transport network diagram, and defining a node stacking operation state set; according to the force transmission attribute of the corner column of the container, the discrete stacking hierarchy is mapped into vertical pre-pressure, and the node working condition inherent frequency of the container-cargo combination is calculated through a pre-pressure and rigidity correlation model; in combination with node pulse dominant frequency data, constructing a response gain index including resonance interval intensity and parameter fluctuation sensitivity; and establishing a multimodal transport stowage optimization model, bringing the index into a target function, and carrying out collaborative solution on a cargo loading layout, a transport link and a node stacking level. Resonance risks caused by discrete stacking and lateral impact coupling can be effectively recognized and avoided, and a stowage scheme with high structural safety is output.

A method for determining a vortex-induced resonance region of a wind turbine blade and an anti-vortex device are provided, and relates to the technical field of wind power equipment. The method includes: obtaining the natural frequency of the wind turbine blade; segmenting the wind turbine blade to obtain a plurality of blade sections; calculating a vortex shedding frequency of a cross section of each of the plurality of blade sections at different wind speeds or under different operating conditions; and determining at least one vortex-induced resonance region of the wind turbine blade by comparing the vortex shedding frequency of the cross section of each of the plurality of blade sections at different wind speeds or under different operating conditions with the natural frequency.

The invention discloses a control method, system and device of a stacking machine and a medium, and relates to the field of motion control. According to the scheme, through establishment of the modal parameter library, the corresponding inherent frequency and damping ratio can be quickly inquired and obtained under different shelf layer numbers and load working conditions, the input shaping pulse sequence is generated based on the adaptive modal parameters, the original speed curve is shaped, and the target speed curve more conforming to the actual working condition is obtained. The motion trail of the stacking machine does not depend on complex high-order motion curve design or a high-performance controller any more, swing of the cargo carrying table in the acceleration and deceleration stages is restrained through input shaping, and cargo stability improvement, positioning precision improvement and operation efficiency guarantee are achieved.

The invention discloses a beam structure fault intelligent diagnosis method based on a DIC and a CNN. The method comprises the steps that a beam structure model is established in finite element analysis software, a plurality of node positions corresponding to DIC measuring points are arranged on the surface of a structure, loads are applied, time domain vibration response signals of the multiple measuring points are extracted, and Gaussian white noise is superposed; performing wavelet packet analysis and multi-band adaptive noise reduction on the acquired multi-channel vibration signals, judging the energy distribution characteristics of the signals by using the change rate of wavelet energy entropy, and adaptively adjusting the length of a segmented window to decompose original non-stationary signals into a plurality of stationary time periods; the inherent frequency, the damping ratio and the vibration mode modal parameters of the structure are obtained through working modal analysis; and constructing a feature sample set by taking the extracted modal parameters and time domain features as inputs, inputting the feature sample set into a convolutional neural network model for training and prediction, and realizing classification and identification of various states such as structure health, early cracks, middle cracks and late cracks.

An offshore wind turbine jacket foundation capable with adjustable natural frequency and motion damping and a control method, comprising: a jacket; a tuned liquid damper system, comprising a central liquid tank communicated with seawater and distributed liquid tanks, wherein the central liquid tank and the distributed liquid tanks carry out liquid delivery through pipelines; a flow monitoring and control system configured to obtain storage information of each liquid tank by data acquisition; an acceleration data acquisition and analysis system configured to acquire acceleration data at key nodes of the jacket foundation; the pump on each pipeline is controlled based on the obtained data to realize the redistribution adjustment of the liquid storage and liquid level of each liquid tank in the damper system in a short time, and the mass distribution of the jacket structure as a whole is adjusted, so as to adjust the natural frequency and motion damping.

The invention relates to a pipeline acoustic vibration analysis method and system and a computer readable medium, and the analysis method comprises the steps: obtaining a three-dimensional pipeline model, and constructing the three-dimensional pipeline model into a pipeline geometric model; performing grid division on the pipeline geometric model to obtain one-dimensional sound units; generating a one-dimensional sound vibration calculation file according to the one-dimensional sound unit; calculating the inherent frequency of the pipeline acoustic vibration according to the one-dimensional acoustic vibration calculation file; and according to the inherent frequency of the acoustic vibration of the pipeline, the flow-acoustic coupling risk and / or the acoustic-solid coupling risk of the pipeline are / is judged. According to the method, dimension reduction processing can be automatically carried out on the three-dimensional pipeline model, the flow-sound coupling risk and the sound-structure coupling risk can be analyzed, and the efficiency and accuracy of analyzing the corresponding coupling phenomenon of the pipeline are improved.

The application discloses an adjustable nonlinear dynamic vibration absorber and system, and has the technical scheme that a tuning mass block is slidably connected to the surface of a support plate, and first scissor structures are rotatably connected between the tuning mass block and the two ends of the support plate; the first scissor structures are provided with second scissor structures and dampers, the second scissor structures and the dampers can drive the first scissor structures to stretch and contract through elastic belts, the second scissor structures are provided with elastic elements for driving the second scissor structures to stretch and contract; the stretching direction of the elastic elements is parallel to the sliding direction of the tuning mass block, and is perpendicular to the damping direction of the dampers, so that the first scissor structures and the second scissor structures can realize vibration absorption through geometric nonlinearity when moving. The stiffness and damping characteristics of the application can be adjusted, and the linear elements can be used to realize nonlinear stiffness, damping and super-low natural frequency, and the problem of Duffing system instability that cannot be eliminated by traditional nonlinear vibration absorbers is solved.

The invention discloses an inclined shaft freezing long-distance full-closed-loop hydraulic formwork trolley lining method, and relates to the technical field of mine and tunnel engineering construction, and the method comprises the following steps: forming a fixed boundary through formwork back shore, applying continuous and controllable micro-amplitude sweep frequency excitation in a freezing layer stable stage, collecting a displacement phase difference between a formwork and a freezing layer, and calculating the displacement phase difference between the formwork and the freezing layer; the local inherent frequency and the damping factor are obtained through calculation, a freezing layer rigidity spectrogram is generated, and an initial base line is established. According to the method, the displacement phase difference between the template and the frozen layer is collected in real time, the inherent frequency and the damping factor are calculated, the stiffness spectrogram is generated and dynamically corrected, self-adaptive adjustment of the vibration frequency, amplitude and residence time is ensured, the dynamic state of the frozen layer is accurately matched, and vibration energy accumulation is avoided. The anti-phase vibration suppression operation and the feedback check closed loop ensure the stability of the freezing layer, so that cracks and structural instability are avoided, the operation safety and stability are improved, and the engineering quality and the personnel safety are ensured.

An accessory (200) for an oscillating power tool (12) is provided. The accessory (200) includes an attachment portion (215) configured to be coupled to an oscillating power tool (12); an elongated working portion (202) extending generally along a longitudinal axis (X), the working portion (202) having a rear end (210) coupled to the attachment portion (215), a front cutting edge (222) opposite the rear end (210), a first side edge (224) extending from the front cutting edge (222) to the rear end (210), and a second side edge (226) opposite the first side edge (224) and extending from the front cutting edge (222) to the rear end (210), the working portion (202) having a length of at least 89 mm (3.5 inches) from the rear end (210) to the front cutting edge (222); and one or more openings (290, 291, 292) defined in the working portion (202) and extending along the longitudinal axis (X). The one or more openings (290, 291, 292) collectively reduce a mass of the working portion (202) by between approximately 4% and approximately 25%. None of the natural frequencies of the accessory (200) are within an operating frequency range of the oscillating power tool (12).

The invention discloses a cutting force prediction modeling method related to workpiece rigidity characteristics. The method includes: designing a thin-wall test piece considering workpiece thickness; a cutting experiment scheme is formulated by considering the weak rigidity characteristic of the workpiece and the influence of milling cutter parameters and cutting parameters; carrying out a thin-wall test piece cutting machining experiment and data preprocessing; carrying out cutting force influence factor range analysis, and carrying out necessity dimensionality reduction on parameters based on an influence degree analysis result; solving the first-order inherent frequency of the workpieces with different thicknesses based on modal simulation; and a cutting force index regression model related to the machining parameters and the inherent frequency is constructed. According to the method, the rigidity is represented by the workpiece thickness, an experimental scheme is designed in combination with a response surface method and an orthogonal method, and parameter dimension reduction is realized by using range analysis; the cutting force index regression model is constructed by adopting the first-order inherent frequency representation rigidity of the workpiece, the precision and reliability of cutting force prediction are remarkably improved, and the technical problem that the rigidity characteristic of the workpiece is not considered in a traditional model is solved.

The application provides a three-dimensional braided composite coupling design method and system based on cross-scale analysis, and belongs to the technical field of electric digital data processing. The application establishes a representative volume element model with a specific braiding angle and fiber volume fraction for different spatial positions of the coupling; through finite element analysis and volume averaging method, the macroscopic equivalent elastic modulus and strength of each position are obtained; then a macroscopic finite element model of the coupling is established, and the equivalent performance parameters are given to analyze the failure index and natural frequency of the coupling under the design load; taking the minimization of the mass as the target, and taking the failure index and natural frequency as the constraints, an optimization model is constructed, and the braiding angle, volume fraction and structure size are iteratively adjusted through a heuristic algorithm to realize the lightweight and performance collaborative optimization of the coupling. The application solves the design problems caused by the multiple parameters and strong multi-scale coupling of the three-dimensional braided coupling, and can efficiently and automatically obtain an optimized design scheme meeting the requirements of complex working conditions.

The invention relates to a conduit assembly (70.1, 70.2, 70.3) for a system (1, 101) for semiconductor technology, comprising at least one elastic fluid conduit section (76) for guiding a fluid (40, 79) and a shell (78) surrounding the elastic fluid conduit section (76), wherein the shell (78) and the elastic fluid conduit section (76) are connected to each other via at least one connecting adapter (74.1, 74.2) and / or at least one conduit connection (73.1, 73.2) of the conduit assembly (70.1, 70.2, 70.3) such that the shell (78), the elastic fluid conduit section (76) and the at least one connecting adapter (74.1, 74.2) and / or the at least one conduit connection (73.1, 73.2) enclose a gas space (77). The line assembly is characterized by the fact that at least one interference contour (SK) is formed in the gas space (77).Furthermore, the invention relates to a method for adjusting the natural frequencies of a gas volume defined by a gas space (77) of a conductor assembly (70.1, 70.2, 70.3) for semiconductor technology, comprising the following process steps: . - Determination of the expected natural frequencies of the gas volume. - Adjustment of the design parameters.

The application provides a tunnel surrounding rock inherent frequency determination method and system based on numerical sample, relates to the technical field of tunnel engineering, and comprises the following steps: obtaining geological survey data of a target deep buried joint rock mass tunnel engineering; according to the geological survey data, combining a three-dimensional numerical inversion method to establish a parameter model and set parameters, obtaining a parameterized model configuration; according to the parameterized model configuration, carrying out numerical model construction processing to generate an inherent frequency numerical sample data set; according to the inherent frequency numerical sample data set, carrying out sensitivity analysis to obtain a main control factor screening result; according to the main control factor screening result, establishing a prediction model to obtain an inherent frequency prediction model; inputting real-time main control factor data obtained through field monitoring into the inherent frequency prediction model for prediction processing to obtain inherent frequency time-frequency characteristics and main frequency information of the target deep buried joint rock mass tunnel. The application significantly improves construction safety and engineering decision efficiency.

The invention relates to an air conditioner control method, device, equipment, medium and program and an air conditioner, and relates to the technical field of air conditioners. The method comprises the steps that the air column audio frequency of the air conditioner in the running process is determined; and according to the preset pipeline inherent frequency and the air column audio frequency, the operation parameters of the air conditioner are adjusted, and the operation parameters comprise one or more of the valve opening degree, the outdoor unit rotating speed and the compressor frequency. According to the embodiment, the operation parameters of the air conditioner are adjusted through the preset pipeline inherent frequency and the preset air column audio frequency, abnormal sound generated by sound cavity resonance of the refrigerant pipeline of the air conditioner can be reduced in real time, the method is suitable for air conditioners with different types of pipeline assembly states, and on the premise that the temperature control of the air conditioner on the indoor environment is not affected, the indoor environment can be effectively protected. And the operation noise of the air conditioner is dynamically reduced in real time.

The invention relates to the technical field of blade machining equipment, in particular to a multi-shaft rotary polishing machine tool for turbine blade machining, which comprises a rack, a grinding tool seat, a mounting shaft and a clamping seat, the mounting shaft is rotationally connected to the rack; the clamping seat is rotationally connected to the mounting shaft; the grinding tool seat is connected to the rack; the supporting mechanism can clamp the blade and conduct flutter treatment on the flutter portion of the blade, so that the rigidity of the clamped portion of the blade is improved, the frequency of the blade is improved, and flutter is eliminated. When the blade is polished and ground, the clamping shafts clamp the front side and the rear side of the thin part of the edge of the blade, so that the rigidity of the ground and polished part of the edge of the blade is improved, and then the inherent frequency of the part of the blade is improved; and the inherent frequency of the blade at the ground part is staggered from the high-frequency vibration frequency generated by rapid rotation during grinding of the grinding tool seat, so that the chatter phenomenon during grinding and polishing is reduced.

The application relates to the field of vibration reduction technology and discloses an active anti-vibration base and a mounting method thereof. Through cooperation of an electromagnetic coil and a magnet rod, the epoxy cover plate is pushed upward by the pushing force of the electromagnetic coil, so that a magnetic suspension support is formed to reduce vibration, the influence of external vibration on equipment can be reduced, and meanwhile, through cooperation of a piston pipe and a lifting piston, when the base vibrates, the external air is pumped into the air spring through the up-and-down vibration of the lifting piston, so that the pressure of the air spring is increased, the natural frequency of the system can be changed, the resonance frequency is avoided, and the influence of resonance is reduced.

This invention provides a structural monitoring device that can estimate the natural frequency of a structure even when using data obtained from low-precision sensors. [Solution] The present invention includes: a first control means that extracts acceleration in two directions from orthogonal acceleration data of two or more dimensions obtained by measuring a vibration waveform and determines a correlation function for each frequency component; a second control means that detects peaks from the correlation of the correlation function and determines the peak frequency and peak height for each peak; a third control means that detects peaks appearing in the frequency spectrum obtained based on the acceleration data and determines information about the peak, including the peak frequency and peak height, for each peak; and a fourth control means that finds the peak on the frequency spectrum closest to the peak frequency of the correlation function and estimates and outputs a candidate natural frequency as a natural frequency.

This application discloses a method for calculating the vibration isolation of ship vibration isolation devices based on isolator type spectrum data, relating to the field of ship vibration isolation design. The method includes: acquiring the type spectrum data and impedance test data of the target isolator; determining the stiffness and damping parameters of the target isolator based on the type spectrum data and impedance test data; constructing a finite element model of the ship vibration isolation device; inputting the stiffness and damping parameters of the target isolator into the finite element model for calculation, and obtaining the vibration isolation calculation results of the target isolator. This method can efficiently utilize isolator type spectrum data to conduct vibration isolation calculation and evaluation of ship vibration isolation devices during the ship design phase, avoiding resonance between the natural frequency of the vibration isolation device and the excitation frequency of the equipment, and improving the vibration isolation effect.

The application provides an oil fume machine vibration testing device and a design method thereof, and relates to the technical field of oil fume machine vibration testing equipment. The design method mainly comprises the following steps: constructing a finite element model of the target oil fume machine vibration testing device; determining whether all the natural frequencies of the finite element model are located outside a preset motor excitation frequency range; if not, modifying the current finite element model to pass the modal checking stage; for the finite element model that passes the modal checking stage, applying a preset virtual load at the motor installation position to perform vibration simulation, and determining whether the maximum displacement is greater than or equal to a predetermined threshold; if not, modifying the current finite element model to pass the stiffness checking stage, and repeating the modal checking stage; iteratively performing the modal checking stage and the stiffness checking stage. Through the embodiments provided in the application, the oil fume machine vibration testing device designed can simulate the vibration of the oil fume machine during operation, and reduce the influence of resonance and forced vibration.

The application discloses a vehicle modal identification measuring point setting method and device based on a particle swarm algorithm, and the method comprises the following steps: constructing a vehicle finite element model based on the size parameters of the vehicle, the material parameters of each vehicle body element and the setting positions of each vehicle equipment; performing eigenvalue solving on the vehicle finite element model to obtain first modal parameters; performing a modal test based on the vehicle entity and preset sensor setting position information to obtain second modal parameters; when the difference between the first natural frequency and the second natural frequency is greater than a preset frequency difference, performing particle swarm optimization iteration solving based on the first modal parameters to determine optimal sensor setting position information; the application can globally optimize and select the sensor measuring points under the condition that the number of sensors is limited, reduces the correlation between different modes, improves the independence, accuracy of vehicle modal identification and the scientificity of measuring point arrangement.