453 results about "Random vibration" patented technology

The invention provides a vibration fatigue life predication method and system for a micro-packaging assembly. The method comprises the following steps: creating a vibration simulating finite element model according to the structures of the micro-packaging assembly and a fixing part; extracting the verification characteristics parameters; modifying the vibration simulating finite element model according to the verification characteristics parameters and the experimental characteristics parameters of the micro-packaging assembly to obtain a vibration simulating model; performing random vibration stress response simulation analysis for the micro-packaging assembly according to the vibration simulation model to obtain a dangerous vibration fatigue point; extracting equivalent stress power spectrum density of the dangerous vibration fatigue point under the random vibration load; converting the equivalent stress power spectrum density to obtain cyclic stress time domain data; calculating the vibration fatigue life of the dangerous vibration fatigue point under the random vibration load according to an S-N curve and the cyclic stress time domain data of the dangerous vibration fatigue point; predicating the vibration fatigue life of the micro-packaging assembly by the method of synchronously extracting the response data of the fixing part and the micro-packaging assembly. With the adoption of the method and system, the testing accuracy is improved.

The invention relates to a finite element analysis based pipeline random vibration fatigue life analyzing method, which mainly includes: by finite element analysis, after acquiring response of structural dynamic stress power spectrum density (PSD) on the condition of random vibration of pipelines, combining a damage model and a material S-N curve (stress-number of cycles curve) to compute fatigue life of a pipeline structure, and accordingly, judging whether the pipeline structure stays at the safety working state or not, if not, optimizing the pipeline structure until the pipeline structure is qualified. The finite element analysis based pipeline random-vibration fatigue life analyzing method solves the problem about vibration fatigue life analysis prediction of existing launcher model pipelines and provides guidance and verification for design and test of pipeline vibration fatigue life, can effectively analyze and predict the fatigue lives of the liquid launcher pipelines under the action of random-vibration load, provides guidance and verification for fatigue design of the pipeline structures, is sufficiently applied in the computing analysis of conveying pipes of manned space launchers and achieves excellent effect.

Embodiments of the invention couple a non-linear force to a vibration element such as a piezoelectric cantilever to introduce chaotic, i.e., non-resonant vibration in the vibration element and thereby improve the non-resonant response of the vibration element. By doing so, the vibration element is responsive to a wider frequency range of vibrations and thus may be more efficient in scavenging energy in environments where the vibration frequency is not constant, e.g., in environment subject to multi-mode or random vibration sources.

The invention discloses an analysis method for testing the fatigue life of components based on vibration signals. The analysis method comprises the following steps that (1) a power spectral density function Ga (f) of working field random vibration acceleration load of the components is calculated according to the acquired random vibration acceleration load time domain signals xa(t) of the components; (2) a stress frequency response function HS(f) under the unit acceleration (1g) load of the components is solved by utilizing finite element harmonic response analysis; and a stress power spectral density function of the structure is acquired through combination of (1) based on the working field random vibration acceleration load of the components; and (3) a stress load distribution probability density function of the components is solved according to a Dirlik method by utilizing the working field random vibration acceleration load power spectral density of the components, and a random vibration fatigue analysis load spectrum is established to perform random vibration fatigue analysis on the components. The problem that stress amplitude information of the components working in the complex working conditions is difficult to obtain directly and fatigue life pre-estimation cannot be performed can be solved.

The invention discloses a method for predicting influence of vibration deformation on electric performance of an array antenna. The method comprises the following steps of: 1) determining a geometric model file of the array antenna; 2) establishing a finite element model of the array antenna in ANSYS; 3) presetting an acceleration power spectrum, calculating random vibration deformation, and extracting position offset of each radiation unit; 4) calculating a pattern function of the array antenna; and 5) judging whether the pattern function satisfies design requirements. According to the conventional method, whether the structure strength of the antenna satisfies the requirement is analyzed according to the acceleration power spectrum, and the electrical performance cannot be determined according to array plane deformation errors. The method provided by the invention can realize the prediction on the electrical performance of the antenna according to the offset caused by random vibration; the method provided by the invention is more succinct, can introduce the offset into an electromechanical coupling model to calculate the electrical performance, and does not need to repeat electromagnetic modeling according to the change of the offset; and the method provided by the invention is used for analyzing the influence of vibration on the antenna and finding main structural factors, thereby ensuring that the antenna is protected from being damaged, and the electrical performance of the antenna in a working state is improved.

The invention discloses a real-time random vibration fault diagnosis method for a turbo generator set, relates to the automatic on-line vibration state monitoring of the turbo generator set, and belongs to the fields of vibration state monitoring and fault diagnosis of large rotating machinery. The method comprises the following steps: acquiring bearing pedestal bush vibration signals and shaft vibration signals of a shaft system of the turbo generator set; performing necessary data preprocessing on the vibration data such as calibration conversion, abnormal point elimination and the like; adopting the Fast Fourier Transform (FFT) spectrum analysis method to perform relevance analysis between the bush vibration low frequency vibration and the shaft vibration on the vibration data, and further performing real-time quantitative computation and analysis on the bearing pedestal bush vibration data such as condition verification of low frequency vibration amplitude, the condition verification of the main frequency for the low frequency vibration, the dispersibility verification of low frequency vibration frequency components and the like, and automatically diagnosing in real time whether the random vibration fault occurs in the set by combining various verification results based on the real-time quantitative computation and analysis.

The invention provides a method and a system for predicting random vibration life of a PCB solder point. Based on a sinusoidal vibration test and harmonic response simulation analysis, a stress-life curve of the PCB solder point is determined; According to a stress-time curve of a random vibration fatigue dangerous part of the PCB solder point or a strain-life curve of a PCB, the cycle number, stress amplitude and mean distribution of the random vibration fatigue dangerous part of the PCB solder point are determined with a rain-flow counting method; the random vibration fatigue loss of the PCB solder point is determined; and finally based on a Miner rule, according to the random vibration fatigue loss of the PCB solder point, the random vibration life of the PCB solder point is predicted. The whole process is based on precise data processing, the operability is strong, and a stress and time response signal is subjected to cycle number statistics and sorting with the rain-flow counting method, so that the data acquisition accuracy in the process for predicting the random vibration life of the PCB solder point is ensured.

The invention relates to a method for testing random vibration structure damage based on cross-correlation function peak value vector. It uses the relation between the frequency respond function of the cross-correlation function of the two points respond signal of the vibration structure and the structure out-exiting frequency spectrum to collect the respond signal of a period times of a plurality of measuring points, it dose cross-correlation function computing to one point respond signal with other points respond signals, it uses the largest peak of each cross-correlation function to construct the cross-correlation function peak value vector, it compares the relative factor of the intact structure and the current structure cross-correlation function peak value vector to quote weather the structure is damaged, it analyzes the content change of the corresponding elements to ascertain the damaged location.

The invention discloses system for testing the rotation and vibration performance of an inertia device, which consists of a rotation driving system, a vibration test system, a rotation and vibration tool and a data testing system. In the rotation driving system, a motor drives the inertia device to be tested to rotate through a flexible shaft; in the vibration test system, a vibration table drives the inertia device to be tested to vibrate through a gapless bearing; and in the data test system, the output data of the inertia device to be tested are tested by a conducting slip ring. In the system for testing the rotation and vibration performance of the inertia device, the motor operates in a non-vibration environment, the bearing has excellent vibration performance, and the data test system is free from data wire torsion. The system testing the rotation and vibration performance of the inertia device can be used to test the performance of various inertia devices when the inertia devices rotate on any shaft and vibrate along a direction parallel or perpendicular to the shaft, and has a rotation speed of 0 to 10,000 degrees per second, a rotation angle free from limitation, a random vibration of 1 g<2>/Hz within a range from 10 to 2,000 HZ, and the sine sweep vibration of 30 g within a range from 10 to 2,000. At present, no other system can achieve the same goal.

The invention discloses an electric automobile battery pack random vibration fatigue acceleration method based on a real road spectrum. The method comprises the steps of (1) acquisition and analysis of the road load spectrum; (2) calculation of full life circle fatigue damage spectrum of the battery pack; and (3) formation of battery pack vibration fatigue acceleration (laboratory standard). Electric automobile battery pack laboratory stand vibration fatigue acceleration is performed for different installing positions of different automobile battery packs according to the actually measured road spectrum of the electric automobile driving so that the problem of single evaluation standard can be solved, and the China's electric automobile operation condition can be further met on the basis of the domestic road condition and the battery manufacturing level of the domestic enterprise.

A multi-beam-hole splicing and synthesizing system based on the stable control of light beam directing comprises a multi-channel laser, a light-beam-expanding collimator, a plurality of titling mirrors, a plurality of reflecting mirrors, a base, a light beam synthesizing sensor, a light beam splitter, a control computer and a multi-channel tilting mirror amplifying power supply. According to the multi-beam-hole splicing and synthesizing system, the multi-channel light beam with high duty ratio is realized by utilizing the step-shaped base and the special-shaped design of the plurality of reflecting mirrors; and the light beam synthesizing sensor is used for detecting the vibration and the drifting of each light beam, and the plurality of titling mirrors are utilized for realizing the stable control of an optical axis of each light beam, so that the high-precision light beam synthesizing of the multi-channel light beam can be realized. The system can be used for the synthesizing emission of multiple paths of light beams and also can be sued for occasions such as the communication of multiple paths of laser. The system also can be used for moving platforms such as vehicles, ships, airplanes and the like as the dynamic random vibration and the drifting of each light beam can be controlled.

The invention discloses a method for controlling the random vibration of an electrohydraulic servo system based on RLS filters, which comprises the following steps: converting an acceleration power spectral density reference signal into an acceleration time domain driving signal; taking an acceleration input signal of the electrohydraulic servo system as that of an RLS filter I; online regulating weights of the RLS filter I and an RLS filter II in real time by using an RLS adaptive filter algorithm and performing identification on a frequency response function of the electrohydraulic servo system and an impedance function of the RLS filter I respectively; and constructing a filter III based on the identification result of the impedance function of the RLS filter II, filtering the acceleration time domain driving signal and taking an output signal of the filtration as the acceleration input signal of the electrohydraulic system. The convergence property of the RLS adaptive filter algorithm adopted by the method guarantees the convergence property of the real-time online iteration of acceleration power spectral density when the characteristics of the electrohydraulic servo system and a test piece are changed.

The invention discloses a collimating and beam expanding device for semiconductor laser sources of a laser radar. The collimating and beam expanding device is mainly composed of an aspherical lens, a quartz positive lens, a tunable flange and the like. The collimating and beam expanding device is simple in structure, low in cost and good in beam collimation performance, a divergence angle of a semiconductor laser is compressed from 0.2X0.4rad to below 0.2mrad, and the requirement of the laser radar for probing light sources is met; the device is stable in optical and mechanical properties, can be used under level-18 random vibration at the environment temperature from minus 30 DEG C to minus 50 DEG C, and meets the requirement of the laser radar on stability in bad conditions; the device is provided with the flange, semiconductor laser sources different in divergence angle can be obtained by fine tuning of the flange of the beam expanding device; by tuning of the flange, the device can also be applied to beam collimation of other different-wavelength light sources.

The present invention discloses a vehicle suspension leaf spring frequency domain fatigue analysis method. The method is characterized by comprising: targeted at a pre-stress and a large transformation effect of a leaf spring, establishing a leaf spring geometric model in a free state and importing the leaf spring geometric model into finite element software for analysis; by applying a displacement constraint on a plate spring seat and applying a theoretical axle load on front and rear lugs, obtaining stress distribution in an operating state of the leaf spring, so as to obtain a leaf spring modality result file; by acquiring experimental data of a vehicle on a durability test road, obtaining a power spectrum density of a relative acceleration; and targeted at the obtained leaf spring modality result file, by using the obtained power spectrum density as a load input, executing a random vibration analysis in the finite element software, extracting a dynamic response result of a virtual prototype under a random excitation and estimating fatigue performance of the leaf spring on the durability test road according to a Gaussian three interval method. The method disclosed by the present invention is accurate in result and high in operation efficiency.

A data storage device adapted to compensate for physical disturbances has a storage medium, a read-write mechanism positionable relative to the storage medium, and a disturbance observer. The read-write mechanism is adapted to read and write data. The disturbance observer compensates a position of the read-write mechanism according to low-frequency components of physical disturbances.

The invention provides an avionic device operating modal measuring method for vibration finite element model correction. The method includes the following steps that firstly, response test points are arranged, and piezoelectric acceleration transducers are pasted, wherein the n response test points are arranged on a circuit board, and the piezoelectric acceleration transducers are pasted on the response test points respectively; secondly, an avionic device and a test device are installed, and an operating modal test platform is built; thirdly, time domain response data of the avionic device under the random vibration condition are acquired; fourthly, data processing is conducted through modal recognition software, and operating modal parameters of the avionic device are acquired. Through the steps, an avionic device operating modal measuring system for vibration finite element model correction is established, and the overall process from generation of random vibration signals to acquisition of the time domain response data and from generation of a time domain response data sample and a cross-spectrum function to recognition of the operating modal parameters of the avionic device is finished. According to the method, online modal recognition is achieved, and test time is saved and test cost is reduced.

The invention discloses a combined environment test method for an integrated circuit, which comprises the following steps of: S1) acquiring the highest test temperature, the lowest test temperature, the highest test temperature change rate delta TE, a test power density spectrum, a test humidity and a test electric stress according to the basic product information of the integrated circuit and the used environment information, S2) according to the test data, performing a temperature cycling test, a random vibration test and a humid test while respectively exerting a rated operational voltage, the maximum operating voltage and the minimum operating voltage on the integrated circuit, and S3) after finishing the tests, performing a functional test on the integrated circuit, confirming the integrated circuit invalid if the integrated circuit loses the function or any property parameter value exceeds a designed scope, otherwise, confirming the integrated circuit being in good condition. The invention can really simulate the actual using environment of the integrated circuit, quickly and completely arouse the faults of the products and provide a reference to improve the design and the manufacturing shortcomings of the integrated circuit.

The invention discloses a control device and a control method used for a multi-dimensional random vibration test. The device comprises a Personal Computer (PC) or an industry control computer and a VXI measurement and control system. The PC or the industry control computer comprises a display interactive module and a calculation control module. The method comprises the following steps of: setting the condition of the multi-dimensional random vibration test, and the reference spectrum matrix of a controlling point; calculating a frequency domain driving signal by the calculation control module; generating continuous time domain random driving signals, and driving the vibration of the controlled objective; forming a control spectrum matrix; calculating an error matrix between the control spectrum and the reference spectrum on each control frequency point; judging the threshold value of the error matrix; modifying the spectrum modified matrix in an iterative manner; and calculating a new random driving signal of the modified matrix. The control device and the control method have high performance in the functions of collecting and processing the dynamic signal and generating the arbitrary waveform with high stability, reliability and openness, and can ensure the precision and the real-time performance of collecting the vibration response signal and transmitting the driving signal.

A power transmission line wind vibration control method based on power transmission line iron tower and lead or ground wire integrated system model calculation and multi-dimensional random gust field simulation includes the steps: firstly, generating a wind load time history sample by the aid of harmonic synthesis to simulate a wind field based on a multi-dimensional random vibration theory; secondly, establishing a dynamic model of an integrated system of a tower, lead or ground wire and wind vibration control device, analyzing the initial state of a lead or a ground wire and setting boundary conditions of the model; thirdly, converting wind load into wind pressure, loading a power transmission tower and line system and calculating time history of axial stress and displacement of an iron tower rod by the aid of simulation software; and fourthly, analyzing and judging wind vibration strength and wind vibration suppression effects and improving control effects by the aid of an optimization scheme. On the basis of rigid-flexible dynamic coupling among a power transmission line tower, the lead and the ground wire and fluid-solid coupling between a random gust wind field and a tower and lead or ground wire system structure, the determined wind vibration control method has better implementation effects.

The invention belongs to the field of automatic machinery and provides an automatic feeding device. The automatic feeding device comprises a vibrating feeding device, a material conveying device, an automatic material taking device and a circulating feeding device. The vibrating feeding device is used for conducting vibration feeding on materials so that the materials can be fed in a random vibration mode. The material conveying device is used for receiving the materials from the vibrating feeding device. The automatic material taking device is used for taking the materials with the postures capable of meeting the requirement from the material conveying device. The material conveying device is further used for conveying the materials with the posture incapable of meeting the requirement to the circulating feeding device. The circulating feeding device conveys the materials with the postures incapable of meeting the requirement to the vibrating feeding device again. By the adoption of the automatic feeding device, random feeding is conducted on the materials in a mechanical vibration mode, vibration feeding is conducted on the materials with the postures incapable of meeting the requirement again, and therefore the automatic feeding device is high in universality and suitable for various materials with different shapes.

The invention discloses a random vibration analysis and calculation method of free body multi-point correlated pulsating pressures. The method comprises the steps that firstly, a finite element discrete model of free body structure dynamics is established; secondly, modal analysis of a free body is conducted; thirdly, a dynamic equation of rigid body motion and elastic motion of a free body structure is established; fourthly, corresponding modal of the pulsating pressures participates in the calculation of coefficients; fifthly, the random vibration power spectral density response calculation is conducted on the rigid body response, the elastic response and the coupling response under the pulsing pressure effect; sixthly, root mean square equivalent response of the whole structure is calculated. The random vibration analysis and calculation method has the advantages that the proposed method is fast in calculation speed, easy to expand and large in computation scale and the like, meanwhile considering the influence of the rigid body modal and the elastic modal, the response characteristic of an aircraft reentering a flying process is more accurately simulated, and the fast vibration response can be solved for the fine finite element model of an aircraft structure.