274 results about "Vibration velocity" patented technology

The invention relates to an underground cavern surrounding rock three-dimensional vibration measurement method and device, and the method comprises the steps: generating a light spot meeting a preset clear condition through beam splitting laser; acquiring the vibration condition of the laser source and the vibration condition of the photographic lens; cutting the tracking record image of the light spot, and respectively calculating the relative displacement time history of the feature points and the boundary of the light spot; based on curvature, length and area changes of the circular light spot in different directions, a vertical relative displacement time travel curve of the light spot perpendicular to the surface of the surrounding rock of the target underground cavern is calculated; and differentiating the obtained plane and vertical displacement time histories to obtain corresponding vibration velocity time histories, and combining to construct the actual three-dimensional vibration velocity of each light spot. According to the embodiment of the invention, the monitoring cost is reduced, the field monitoring efficiency and the monitoring data volume are improved, the applicability in the construction environment with poor light of the underground cavern is higher, the defects of a high-speed photographing single lens in three-dimensional data representation are overcome, and effective monitoring and evaluation of three-dimensional vibration of the underground cavern are realized.

The invention discloses a double-row medium-length hole blasting method for a filling stope. According to the method, a theoretical value range of each blasting parameter is deduced according to field engineering practice, an ore rock blasting crushing mechanism and a blasting parameter theoretical formula. The method comprises the following steps of: constructing a stope blasting model with different hole bottom distances, explosive unit consumption and resistance line combinations by using ANSYS numerical simulation software in combination with physical and mechanical properties of ore rocks and field explosive performance parameters, and preferably selecting double-row medium-length hole blasting parameters according to a chamber effective stress distribution rule and a roof area vibration velocity peak value of the ANSYS blasting model. According to the method, by selecting the double-row optimal medium-length hole blasting parameters, it is guaranteed that ore rocks in the chamber are fully crushed, the effective stress invading the roof and the blasting vibration velocity peak value are reduced, and the roof is prevented from being damaged. And meanwhile, the explosive loading amount is reduced, the economic cost is reduced, and the production efficiency of a mine is improved.

The invention provides a method for measuring acoustic impedance of a material surface in situ by using an embedded microphone array. The method comprises the following steps: arranging a rectangular microphone array on the surface of a material to be measured; the microphones are divided into two groups; setting a sound wave incidence angle, arranging a sound source in a half space on one side of the surface of the material based on the sound wave incidence angle, and collecting sound pressure through two groups of microphones; respectively describing a sound source radiation sound field and a boundary reflection sound field by using two groups of spherical wave primary functions; on the basis of the two groups of spherical wave primary functions, a mass point vibration velocity component in a unit normal vector direction is obtained, and the mass point normal vibration velocity at the first group of microphones is reconstructed by using sound pressure distribution collected by the two groups of microphones; and based on the material surface sound pressure and the mass point normal vibration velocity collected by the first group of microphones, calculating the acoustic impedance rate at the first group of microphones, and averaging to obtain the surface acoustic impedance rate of the to-be-measured material. Influence of sound scattering of components on a sound field is avoided, and sound pressure measurement precision is improved.

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

The invention belongs to the technical field of acoustics, and particularly relates to an index type open-pore rigid plate internal vector sound field calculation method, program and equipment and a storage medium. According to a Webster equation satisfied by a simple harmonic plane sound source excitation sound pressure field, circular piston radiation acoustic impedance on an infinite baffle plate is adopted to represent radiation impedance at an opening of an exponential open pore, a sound field analytical solution of any depth in the open pore of the exponential open pore rigid plate is constructed, system calculation is carried out in combination with sound source conditions, and a sound field of any depth in the open pore of the exponential open pore rigid plate is obtained. Therefore, sound field quantities such as internal accurate sound pressure and vibration velocity of the exponential type open-pore rigid plate under the vertical incidence condition can be quickly solved, and sound field distribution conditions under different section change rules and different open-pore rigid plate sizes can be calculated. According to the method, the calculation complexity is low, the influence problem caused by sound field changes under the non-free field condition can be solved, and the calculation stability and reliability under the complex boundary condition are ensured.

The invention provides a big data-based material detection method and system, relates to the field of material quality detection, and solves the technical problems of insufficient detection precision and poor supply chain quality control linkage in an existing material detection method. The method comprises the following steps: transmitting sweep-frequency sound waves to warehouse-in materials of a peripheral warehouse by using a sound wave transmitting device; collecting vibration velocity spectrum data and sound pressure gradient data of the warehouse-in material after the warehouse-in material receives the frequency sweep sound wave; according to the vibration velocity spectrum data and the sound pressure gradient data, calculating a defect index of the warehouse-in material; and when the defect index is greater than a preset threshold value, marking the warehousing material as a defective material, sending a traceability detection instruction to a previous node warehouse, and starting a grading detection process of the previous node warehouse. The method and the device are used for warehousing detection, quality traceability and full-chain management and control processes of the materials in the supply chain.

The invention relates to the technical field of tunnel engineering, in particular to a method and a system for optimizing design parameters based on unsymmetrical pressure tunnel blasting excavation dynamic response. The method comprises the following steps of obtaining geological parameters and construction parameters of surrounding rock of the bias tunnel, constructing a discontinuous structure equivalent damage model, and obtaining initial stress field distribution of a rock mass in combination with the discontinuous structure equivalent damage model, the geological parameters and the construction parameters; analyzing the time-varying modified dynamic mechanical parameters, and calculating through a stress wave propagation path and an energy dissipation rule to obtain a time travel curve of dynamic stress and vibration speed of each point of the surrounding rock in the blasting process; correcting a dynamic response index by using a self-adaptive artificial boundary condition to obtain a dynamic response state characteristic; and on the basis of the initial stress field distribution of the rock mass, the time history curve and the dynamic response state characteristics, optimal design parameters are obtained according to optimal design indexes. According to the method, the balance between the blasting vibration strength and the construction efficiency is realized by optimizing and adjusting the design parameters.

The invention discloses a tunnel blasting vibration prediction method suitable for a sand shale interbed area, and mainly relates to the technical field of tunnel blasting. Comprising the following steps: S1, determining key factors influencing the vibration velocity; s2, building a blasting vibration prediction model in the sand shale interbed area; s3, carrying out data normalization processing; s4, introducing a BP neural network to train the prediction model; s5, introducing a particle swarm optimization algorithm and initializing related parameters of a particle swarm; s6, improving a particle swarm optimization algorithm; s7, a sand shale interbed tunnel blasting vibration prediction model of the improved particle swarm optimization BP neural network is obtained, the model is combined with blasting characteristic parameters of specific sand shale interbed area tunnel engineering for prediction, and a blasting effect prediction result is obtained; according to the method, important theoretical guidance can be provided for blasting vibration prediction of the stratified structure with changeable rock strata, and a practical safety evaluation tool is provided for ground surface vibration velocity control of similar projects.

The invention discloses a method for judging the safety state and interference construction of a buried gas pipeline based on vibration waveforms. The method specifically comprises the following steps: S1, establishing a vibration waveform database of the buried gas pipeline at the cross construction section through a large amount of monitoring data; s2, vibration monitoring is carried out on the buried gas transmission pipeline in the cross construction section, and a vibration speed measured value and a vibration speed threshold value of the buried gas transmission pipeline in the cross construction section are compared to judge the safety state and the interference construction type of the buried gas transmission pipeline in the cross construction section; and S3, the judgment result is transmitted to an early warning platform for early warning. According to the method, the effectiveness, accuracy and reliability of safety state judgment of the buried gas pipeline can be improved, early warning can be performed in time, main factors possibly influencing safety operation of the pipeline can be clearly determined, a reliable basis is provided for later control, and the situation of one-step construction beside the pipeline is avoided.

The invention discloses a non-linear static analysis method for influence of blasting vibration on surrounding buildings based on field measurement vibration velocity, and belongs to the technical field of engineering blasting. The safety evaluation method comprises the following steps: step 1, field detection and data acquisition; the vibration velocity condition of the target structure and a blasting seismic wave velocity vibration curve of the blasting at the target structure are obtained; 2, calculating a structure inelastic quasi-absolute acceleration-relative displacement SA, e-SD, e curve, namely a demand curve of a target structure; 3, establishing a multi-degree-of-freedom structure model, performing static pushing analysis on the multi-degree-of-freedom structure model to obtain a load and displacement response relation V-D curve of the structure, and performing deformation to obtain a capacity curve of the equivalent SDOF structure; and 4, moving the demand curve and the capability curve of the target structure into the same coordinate system, wherein the intersection point of the demand curve and the capability curve reflects the local damage condition of the structure. By adopting the method, whether the structure is integrally damaged or not can be judged, and the local damage condition and position can be analyzed.

The invention discloses a laser piston sounder normal vector microphone low-frequency calibration device and method, and solves the technical problems that the calibration frequency range is limited, the model dependence is strong and the environmental noise interference is obvious in a low-frequency band in the existing vector microphone calibration method. The device comprises a piston sounder, a laser interferometer, a vector microphone and a data acquisition system, the piston sounder comprises a piston, an excitation source and a piston cavity, an end cover of the piston cavity is provided with an optical window, and the laser interferometer measures the movement speed and displacement of the piston through the optical window; the vector microphone is hermetically coupled to the piston sounder from the side wall of the piston cavity through the adapter; and electric signal outputs of the laser interferometer and the vector microphone are connected to an input channel of the data acquisition system. The calculation model of the sound pressure and the particle vibration velocity in the piston sounder is clear, does not depend on the type of a piston excitation source, and is high in universality.

The invention discloses a flow-induced vibration velocity effect similarity method based on an equivalent mode, and belongs to the field of aircraft structure dynamic strength optimization. According to the method, the scaling model is established, the flow velocity difference caused by different sound velocities of the scaling model and the full-size model is considered at the same time, a new thickness scaling factor is established in combination with the velocity ratio on the basis of a length scaling factor, and the structural vibration parameters of the full-size model are predicted through the scaling model. The influence caused by flow velocity difference can be made up, the characteristic frequency and the structural response of the full-size model can be accurately predicted through the scaling model, and the flow-induced vibration velocity effect similarity prediction precision based on the equivalent mode is improved. According to the method, a complex structure characteristic frequency is changed into a similar form only containing the combination of a thickness scaling factor and a length scaling factor through an equivalent modal method, and a curved plate flow-induced vibration structure response similar expression is deduced, so that the defects of a current flow-induced vibration similarity theory are overcome; and the prediction reliability of the aircraft structure dynamic response similarity method is improved.

The invention discloses a woodworking machine tool noise sound power level measurement method based on a sound intensity method, and belongs to the technical field of machine tool noise measurement, and the method specifically comprises the steps: determining a housing surface covered by a tool rotation plane projection as a main sound radiation region, and determining a main bearing pedestal installation surface as an infrasound radiation region; sound pressure, vibration acceleration signals and dynamic air pressure signals of a main sound radiation area are collected; resampling a dynamic air pressure signal rotation angle domain, extracting a reference pneumatic pulsating waveform synchronous with tool tooth sweeping, and establishing an airflow induced sound pressure model according to the reference pneumatic pulsating waveform and a phase relation; calculating a surface normal vibration speed according to the vibration acceleration, and establishing a structure radiation sound pressure model in combination with a sound wave equation; decomposing the sound pressure signal to obtain two types of component estimation values, and performing parameter optimization to obtain net sound intensity of a main sound radiation area; extracting vibration frequency band energy of an infrasound radiation area, calculating equivalent sound intensity by combining a sound radiation efficiency model, and outputting a total sound power level by space integration; the invention provides an effective method for accurately measuring and controlling the noise of the woodworking machine tool.

The invention discloses a method for identifying blade surge characteristics based on blade tip vibration velocity, and relates to the technical field of non-contact measurement of rotating machinery rotor blades. According to the method, the vibration speed and the vibration displacement of the blade tip are monitored according to the two blade tip timing sensors installed in a small angle difference mode, the theoretical arrival time of the blade does not need to be considered when the vibration speed and the vibration displacement of the blade tip are calculated, and the calculation efficiency and the calculation accuracy are greatly improved; in combination with the time-frequency enhancement characteristic of a synchronous compression wavelet transform method, the dominant subsynchronous frequency of the blade is tracked and identified through the blade tip vibration speed, and meanwhile, a frequency ridge line is extracted for surge frequency identification and a surge interval is positioned; and finally, the vibration intensity during blade surge is judged according to a proposed intensity quantized value calculation method based on the blade tip vibration speed. The method for efficiently calculating the blade tip vibration parameters is provided, the surge frequency can be quickly recognized, the surge interval can be positioned, and the surge intensity can be quantitatively evaluated.

The invention discloses a method for rapidly and accurately judging a blasting vibration safety allowable distance, and belongs to the technical field of geotechnical engineering blasting. The method specifically comprises the steps of establishing a simplified mathematical model of explosive wave propagation and an explosive wave propagation control equation; basic mechanical parameters of rocks of the blasting engineering are obtained; obtaining a blast hole wall stress wave action time history curve; solving the explosion wave propagation control equation to obtain a radial stress complex variable function and a mass point displacement complex variable function at any moment around an explosion source; obtaining a radial stress time domain variable function and a mass point vibration velocity function; constructing a characteristic function relationship between a radial stress peak value and a mass point vibration velocity peak value, introducing a peak value stress wave propagation attenuation function, finally obtaining a mass point peak value vibration velocity, and drawing a mass point peak value vibration velocity distribution curve; and the blasting vibration safety allowable distance is obtained. According to the method, the blasting vibration safety allowable distance conforming to the specification can be rapidly and accurately calculated, the calculation efficiency is high, and the prediction result is accurate.

The invention discloses a high-precision identification method and system for a noise source of an asynchronous motor, and relates to the technical field of asynchronous motor detection, and the method comprises the following steps: constructing a finite element model of a to-be-analyzed asynchronous motor, dividing the surface into a plurality of detection sub-regions, and carrying out the operation simulation of the finite element motor, analyzing vibration speed and sound pressure signal data of each sub-region, synchronously acquiring actual signals, calculating relative differences with simulation data, evaluating detection priorities by combining historical fault times, forming a detection sequence according to the priorities, and sequentially performing sound-vibration coherence analysis and coherence function calculation to obtain a sound-vibration coherence detection result; according to the method, noise frequency bands are classified into structural noise and air noise, order tracking analysis is performed on the structural noise obtained through classification, an amplitude stability index and an amplitude change gradient are calculated, automatic classification and identification of electromagnetic noise and mechanical noise are realized based on a preset threshold value, and the efficiency and accuracy of fault processing are remarkably improved.

The invention discloses an airspace guiding covariance matrix self-adaptive beam forming method based on sound pressure and vibration velocity combined processing, belongs to the field of underwater acoustic detection, and particularly relates to the airspace guiding covariance matrix self-adaptive beam forming method. The objective of the invention is to solve the problem that when sound pressure and vibration velocity three-channel data are used, the SSTCM algorithm cannot carry out azimuth estimation in a specific angle range. The method comprises the following steps: 1, constructing a vector double-row array receiving data model; 2, obtaining a combined vibration velocity Vc (t); 3, based on the combined vibration velocity Vc (t) and the sound pressure channel data P (t), constructing a sound pressure and vibration velocity covariance matrix in a (P + Vc) (P + Vc) combined form; 4, calculating an airspace guiding covariance matrix based on the sound pressure vibration velocity covariance matrix and the observation orientation; and 5, estimating a direct current component in the airspace guiding covariance matrix as an orientation estimation result.

The invention discloses an underwater sound absorber with low-frequency broadband sound absorption and high pressure bearing performance and a design method of the underwater sound absorber. The sound absorber comprises a plurality of hexagonal honeycomb units which are spliced in sequence. Each honeycomb unit is composed of a hexagonal metal honeycomb framework, a rubber coating, a special-shaped embedded neck part and a cavity. The hexagonal honeycomb framework forms a hexagonal cylindrical cavity, the side wall and the bottom plate of the honeycomb framework are coated with the rubber coating, the acoustic impedance of the rubber coating is matched with the underwater acoustic impedance, and sound wave energy can be effectively absorbed. The special-shaped embedded neck part is embedded into the cavity of the honeycomb framework, and the neck part structure protrudes inwards, so that the vibration velocity and the hot sticking loss of sound waves are remarkably improved. The cavity is formed by a honeycomb framework and a rubber coating and used for storing sound energy and providing a resonance space. Multi-path dissipation and broadband sound absorption of sound energy are achieved through viscoelastic dissipation of the rubber coating and hot viscous loss of the special-shaped embedded neck part, and the composite material has remarkable potential application value in the field of underwater low-frequency noise control.

The invention provides a method and system for determining time delay between auxiliary hole subsection detonating network sections, and belongs to the technical field of tunnel blasting design. A single-hole blasting experiment and blasting experiments with different explosive loads are carried out to obtain the change relation of the single-hole vibration speed along with time and the relation between the explosive loads and the waveform vibration speed peak value, and the time delay of the auxiliary hole subsection detonating network sections is determined according to the change relation of the single-hole vibration speed along with the time. And determining a peak value of the explosive load based on a safe vibration velocity threshold value, meanwhile, setting inter-section delay and inter-row delay of the same row based on an auxiliary hole same-row segmentation mode, an inter-row segmentation mode of auxiliary holes and a blasting sequence, constructing a single-section blasting vibration waveform function, and carrying out superposition and calculation on multi-section vibration waveforms of the same row, so as to obtain a multi-section blasting vibration waveform. According to the method, the optimal delay time between the same-row segmental blasting segments is determined, then the optimal delay time between the rows is determined by constructing a single-row blasting vibration waveform function and carrying out multi-row vibration waveform superposition and calculation, finally, a blasting delay scheme is generated, and accurate control over blasting vibration is achieved.

The invention discloses a graded blasting construction method for a shallow-buried soft rock tunnel sensitive section. The method comprises the steps that measuring points are arranged in a tunnel chamber, a ground surface non-cavity section and a cavity section, and blasting vibration data are obtained; peak vibration velocity prediction models are established in a partitioned mode, an attenuation model is adopted in a chamber, a correction term is introduced into a non-cavity section of the earth surface to correct the attenuation model, and a multivariable model is established for the cavity section through dimensional analysis by integrating the horizontal distance, the elevation difference, the explosive quantity, the rock mass density and the tensile strength; determining a ground surface vibration velocity safety threshold, and quantifying a cavity vibration velocity amplification coefficient and an influence range thereof; based on the peak vibration velocity probability distribution and a preset safety level, establishing a safe dose prediction model and a safe range model; and dividing control areas according to the model, and implementing graded construction. According to the method, the vibration propagation law can be accurately described, the cavity amplification effect can be quantified, dynamic prediction of the blasting safety explosive quantity and range is achieved, and disturbance of blasting vibration to surrounding rock is effectively controlled through hierarchical management and control.

The invention belongs to the technical field of blasting protection, and relates to a human body comfort level zoning method under the influence of blasting vibration, which comprises the following steps: 1) acquiring first information which at least comprises blasting point position parameter information; 2) constructing a vibration speed prediction model based on the first information obtained in the step 1); 3) according to the vibration velocity prediction model obtained in the step 2), obtaining the vibration velocity of each position in the blasting influence range area when blasting is about to be carried out; 4, the human body comfort level of the earth surface is partitioned on the basis of the vibration velocities and the vibration frequencies, obtained in the step 3, of all the positions in the blasting influence range area when blasting is about to be carried out. According to the human body comfort level partitioning method under the blasting vibration influence, the blasting vibration harm can be effectively reduced, and the blasting safety can be improved.

The invention provides an internal vibration monitoring system and method for surrounding rock in a time-delay type rockburst risk area of a tunnel, and belongs to the field of tunnel engineering.The method comprises the steps that the surrounding rock and a potential time-delay type rockburst risk area are exposed behind a cutterhead, and holes with different radial depths are drilled; installing a vibration sensor in each hole, and plugging each hole by using a plugging material; connecting a signal cable of each vibration sensor in series to an acquisition port of an intelligent sensing gateway server; the axial, radial and vertical vibration speeds and accelerations acquired by each vibration sensor are acquired by adopting an intelligent sensing gateway service; the vibration sensor is fixed in the hole, the coupling degree of the sensor and the surrounding rock is enhanced, it is ensured that the vibration speed and acceleration between the sensor and the surrounding rock are kept consistent, and therefore the monitoring accuracy is improved.

The invention belongs to the technical field of underwater acoustic array signal processing, and particularly relates to an acoustic vector circular array orientation estimation method based on cross covariance matrix construction, a program, equipment and a storage medium. The method comprises the following steps: introducing a preprocessing matrix to transform the output of an acoustic vector circular array, and constructing a cross covariance matrix of sound pressure and different vibration velocity components according to the transformed vector; combining and arranging the cross covariance matrixes of the sound pressure and the different vibration velocity components to obtain a combined arrangement matrix; performing singular value decomposition on the combined permutation matrix, and reconstructing a cross covariance matrix by using a unitary matrix formed by left singular vectors of the combined permutation matrix and a diagonal matrix formed by singular values; and implementing a spatial spectrum estimation method by using the cross covariance matrix, and taking the scanning angle corresponding to the maximum value in the spatial spectrum as an orientation estimation result of the detection target. The method is suitable for a column barrier condition, and can effectively improve the dual-target resolution and orientation estimation performance of the acoustic vector circular array under a low signal-to-noise ratio condition.

The invention relates to a mobile dipole sound source positioning device and method of a minimum aperture array, the device comprises a vector sound transmission array and a processor, the vector sound transmission array comprises at least three array elements, the distance between the array elements is 1 / 6 lambda, lambda is the wavelength, the vector sound transmission array is used for measuring sound pressure signals, the processor is used for processing the sound pressure signals, and the processor is used for processing the sound pressure signals. And a positioning result of the dipole source is solved through a nonlinear optimization algorithm. The method comprises the following steps: measuring a sound pressure signal within a preset time by using a vector sound transmission array, and converting a measured time domain sound pressure signal into a frequency domain sound pressure signal; calculating a vibration velocity signal according to the frequency domain sound pressure signal, and establishing a dipole sound source propagation model; and performing nonlinear optimization solution on the dipole sound source propagation model to obtain a positioning result of the dipole source. Compared with the prior art, high-precision and real-time positioning of the moving dipole source can be realized.

The application discloses a kind of millisecond blasting initiation interval determination method, device and system.Compared with prior art, according to actual working condition, single-hole blasting test is carried out, and the measured vibration data of multiple monitoring points are obtained, then the frequency domain distribution is obtained by Fourier transform, the most dangerous monitoring point is determined according to the frequency domain distribution of each monitoring point and its measured vibration velocity and control vibration velocity, and the initiation interval is determined according to the measured vibration data of the most dangerous monitoring point, so that the vibration velocity is effectively controlled, and the construction is safer.Secondly, by adjusting the initiation interval in real time, the vibration velocity is less than the control vibration velocity, which further ensures the safety of blasting construction.

The invention relates to the technical field of fan quality evaluation, in particular to a vehicle-mounted fan state evaluation method based on multi-information fusion, and the evaluation method comprises a quality detection step which comprises the following steps: collecting thermotechnical data, image information, three-phase current, vibration speed, sound and vibration acceleration of a vehicle-mounted fan; calculating the fan power according to the thermotechnical data; extracting blade turning information according to the image information; current unbalance is extracted according to the three-phase current; calculating an RMS value according to the vibration speed; calculating sensitive characteristics according to the sound and vibration acceleration; and judging whether the vehicle-mounted fan is qualified or not based on the fan power, the blade steering information, the current unbalance amount, the RMS value and the sensitive characteristics, comprehensively realizing the quality evaluation of the factory product by combining the industry standard and the machine learning method aiming at the obtained multiple physical quantity signals of the factory vehicle-mounted fan, and further performing grade evaluation. And finally, fault identification is realized based on an evaluation result, and the accuracy and the practicability are high.

The present invention discloses a method for measuring the acoustic nonlinear coefficient of a material by using the phase relationship. It uses finite-amplitude ultrasound to perform non-destructive testing on a material with mechanical nonlinearity, performs Hilbert transform processing on the detected and / or calculated displacement signal or particle vibration velocity signal to obtain the phase of the nonlinear signal, and then obtains the normalized angular frequency through numerical calculation, so as to measure the acoustic nonlinear coefficient according to the maximum value of the normalized angular frequency. The method of the present invention is simpler, and can expand the experimental conditions. The nonlinear coefficient can still be measured under conditions of longer distance, stronger excitation, and larger nonlinear coefficient, and the test results are more accurate; the applicable conditions of the present invention can approach the generation position of the shock wave.

The invention relates to the technical field of industrial automation control, and discloses a control method for reducing dehydration vibration of a centrifugal dehydrator. Comprising the following steps: acquiring sampling period information, and respectively acquiring angle information, acceleration information and angular velocity information on x, y and z axes of a roller rotating mechanism of the centrifugal dehydrator according to time set by a sampling period; filtering the collected angle information, acceleration information and angular velocity information; respectively calculating the vibration speed, the vibration displacement and the vibration frequency of the three axes; inputting the vibration speed into a PID algorithm to generate a control instruction; the control instruction is sent to an execution mechanism; the device has the advantages of actively inhibiting vibration and improving the stability of equipment.

This invention provides a caster quality detection device and its operating method. The caster quality detection device includes a support base, a caster fixing assembly, a pressure mechanism, a rotating mechanism, a vibration velocity sensor, and a controller. The support base is provided with a guide post extending in the vertical direction. The pressure mechanism is mounted on the support base, and the caster fixing assembly is mounted on the drive shaft of the pressure mechanism. The pressure mechanism drives the caster fixing assembly to move vertically along the guide post. The rotating mechanism includes a drive component and a turntable. The drive component drives the turntable to rotate. The turntable is located below the caster fixing assembly. The pressure mechanism can apply a force toward the turntable to the caster fixing assembly. The vibration velocity sensor is disposed close to the caster fixing assembly. The vibration velocity sensor, the pressure mechanism, and the rotating mechanism are all electrically connected to the controller. The caster quality detection device can detect the caster quality in real time.

The invention relates to a wave node tube and method for measuring a vibration velocity vector sensor, the wave node tube is composed of a cylindrical tube body, four standard pressure-resistant hydrophones and four high-pressure-resistant transmitting transducers, the four high-pressure-resistant transmitting transducers are of the same batch and the same model and are arranged oppositely in pairs, and the sound axes are perpendicular to each other; the standard pressure-resistant hydrophones are positioned on a sound axis and are arranged in a central symmetry manner; when in use, a measured sensor is in the center of the corrugated tube. The node tube can be used for measuring a vibration velocity vector sensor, and during measurement, the push-pull effect is generated by controlling the vibration phase of the transducer, so that the radiation impedance during vibration of the transducer is greatly reduced; and finally, by controlling the vibration amplitude of the transducer, the direction of a vibration velocity field in the tube can be controlled, and a pressure-resistant rotating device does not need to be developed.