2907results about "Vibration testing" patented technology

The invention relates bridge structure safety evaluation technology by means of combining vibration measuring and structural model analysis techniques for bridge erosion evaluation and pre-warning monitoring applications. This technology can also be applied for long-term bridge structure monitoring and safety evaluation as well as judgment and evaluation of rail structure abnormality.

The invention discloses a method for testing the assembly performance of a rotor of an aircraft engine, which comprises the following steps of: firstly exciting and vibrating a rotor of an aircraft engine with a vibration exciter; obtaining a multiple carrier-coupled impulse response signal of the rotor of the aircraft engine with a vibrating sensor and signal-acquiring system software; analyzing the obtained multiple carrier-coupled impulse response signal of the rotor of the aircraft engine by means of dual-tree complex wavelet transform to obtain eight signal carrier-coupled impulse response signals of the rotor of the aircraft engine; and distilling the average assembly performance index of the obtained eight signal carrier-coupled impulse response signals of the rotor of the aircraft engine, wherein the assembly performance of the rotor of the aircraft engine is judged to be qualified if the obtained average assembly performance index is larger than or equal to 10, and the assembly performance of the rotor of the aircraft engine is judged not to be qualified if the obtained average assembly performance index is less than 10, so that the rotor needs to be repaired.

An acoustic monitoring device has at least two acoustic sensors with a triggering mechanism and a multiplexing circuit. After the occurrence of a triggering event at a sensor, the multiplexing circuit allows a recording component to record acoustic emissions at adjacent sensors. The acoustic monitoring device is attached to a solid medium to detect the occurrence of damage.

An apparatus (10) for applying at least one load to a specimen (12) according to one embodiment of the invention may comprise a mass (18). An actuator (20) mounted to the specimen (12) and operatively associated with the mass (18) moves the mass (18) along a linear displacement path (22) that is perpendicular to a longitudinal axis of the specimen (12). A control system (26) operatively associated with the actuator (20) operates the actuator (20) to reciprocate the mass (18) along the linear displacement path (22) at a reciprocating frequency, the reciprocating frequency being about equal to a resonance frequency of the specimen (12) in a test configuration.

The invention relates to an eccentric pump vibration accidence fusion diagnose method and relative vibration signal collector, wherein said invention is characterized in that: it uses the eccentric pump vibration signal collector to collect the normal state, the quantity imbalance, asymmetry rotate and loose base of eccentric pump; uses wavelet decomposition and reconstruction to extract the character of vibration signal; and inputs the character vectors into sub fuzzy neural networks I and II; to be treated and replace the relation factor matched with sensor signal function; the whole fuzzy neural network comprises data fuzzy layer, input layer, hidden layer and output layer; uses D-S theory to obtain the fused signal function distribution, realize the fusion diagnose on normal state, quantity imbalance, asymmetry rotate and loose base. The invention has simple structure and high effect.

Disclosed herein is an apparatus for evaluating the safety of a building. The apparatus includes first and second measurement instruments which measure earthquake accelerations of the top and bottom stories, a fast Fourier transform unit which performs fast Fourier transform on the earthquake accelerations, an integration unit which double-integrates the measured earthquake accelerations and creates drift data of the top story and the bottom story, a maximum inter-story drift ratio calculation unit which calculates a maximum inter-story drift ratio, a natural frequency change rate calculation unit which determines a natural frequency of the building, and compares the natural frequency with an ambient natural frequency of the building so as to calculate a natural frequency change rate, and a building safety evaluation unit which compares the maximum inter-story drift ratio and the frequency change rate with preset evaluation criteria and outputs a result of evaluation in the safety of the building.

The invention discloses a ground testing system for on-track micro vibration of a spacecraft, which comprises a vibration isolating foundation, a supporting truss with a framework structure, a suspended positioning platform, a gravity suspended compensation unit, an integrated control subsystem, a micro vibration measurement subsystem and a test data processing and analyzing subsystem, wherein the vibration isolating foundation is connected with the ground, the supporting truss with the framework structure is fixedly supported on the vibration isolating foundation, the suspended positioning platform is supported on the supporting truss, the gravity suspended compensation unit is hung on the suspended positioning platform, and the integrated control subsystem is used for controlling the positioning and the fixation of the suspended positioning platform via coordination of sensors in various positions and performing the overall integrated control on the state of the system. By adopting the system, the ground simulation of the on-track micro vibration environment, the measurement of micro vibration and the data processing can be realized for the spacecraft at the system level and the component level, the technical level of testing the micro vibration of the spacecraft can be improved, and the demands for testing and verification of the on-track micro vibration environment in research on the spacecraft, particularly the high-precision satellite, can be satisfied.

The invention provides a method and system used for monitoring the vibration states of impellers of wind generating sets. The method includes the steps that the vibration acceleration of a predetermined measuring point on a vane of each wind generating set in at least one direction is detected according to a preset detection period, data of operating parameters of at least one of the wind generating sets are synchronously acquired, and the acquired data of the operating parameters of the set and the detected vibration acceleration data are recorded; data sets of recorded operating parameter data and recorded vibration acceleration data exceeding the preset amount are selected; according to the operating parameters of the wind generating sets, vibration acceleration data detected when the wind generating sets are in abnormal working conditions are removed from the data sets; operating mode analysis is carried out on the vibration acceleration data detected at the measuring points of the vanes, at least one of the inherent frequency, the damping ratio and the vibration mode of each vane in the operating state is extracted, and whether the impellers of the wind generating sets break down or not are determined according to the extracted inherent frequency, damping ratio and vibration mode.

In the invention, a high g value impact acceleration simulation test system, a method thereof and the application of the test method, belonging to the technical fields of impact testing and tests. The test system comprises three parts: the high g value impact acceleration simulation test system, the test method and the application of the test method. In the high g value impact acceleration simulation test system and the test method, an impact acceleration signal with the amplitude of (0.1-1.5)*10<5>g and impulse width of 150-600mus is generated by the collision of a projectile shot by a gas cannon and a collided object, thus providing the test system and the test method for various performance researches on a projectile-borne electronic instrument under high impact environment. The test system and the test method have advanced designs and leading technical performances, can be applied to the aspects of projectile-borne testing instrument, inertial measurement unit, black box, intelligent fuze, gyro, MEMS device and the like for the calibration of an acceleration storage testing device under application environment, high impact resisting performance research of the projectile-borne electronic instrument, cushion performance research of a cushion part of a projectile-borne testing device and return-to-zero characteristic research of a high impact accelerometer.

Output-only modal testing of an object. Vibrations are excited in said object and measured by a number of vibration sensitive detectors. From the data of the measurements, a spectral density matrix function is determined. From this density matrix, auto spectral densities for the individual modes are identified performing a decomposition based on the Singular Value Decomposition technique. From the auto spectral densities of the individual modes, natural frequencies and damping ratios for the modes can be estimated, and from the singular vectors of the Singular Value Decomposition, the modes shapes can be estimated.

The invention belongs to the technical field of vibration test, in particular to a thin-walled structure part vibration test device and a method based on a piezoelectric ceramic vibration exciter. The device comprises a signal generator, a piezoelectric ceramic drive power supply, a piezoelectric ceramic vibration exciter, a feedback attenuator, a laser vibration meter, a data acquisition analyzer and an upper computer. The method comprises the steps of performing modality test on a thin-walled structure part, determining a linear relationship between excitation voltage and critical excitation frequency of the signal generator and calibrating an excitation force of the piezoelectric ceramic vibration exciter based on a cantilever theory. According to the device and the method, an excitation signal can be effectively acquired; the magnitude of the excitation force when the piezoelectric ceramic vibration exciter excites the structure part is defined; the stable designated excitation force and the linear excitation signal of the excitation frequency can be generated; influencing factors of non-linear piezoelectric ceramic excitation are effectively eliminated; the piezoelectric ceramic vibration exciter is adopted to realize high-frequency vibration excitation; additional mass is low; and the device is convenient to use.

A testing apparatus for use with a data storage component that includes a base platform and a retaining element coupled to the base platform. The retaining element is sized and configured to retain the data storage component. The retaining element is linearly movable relative to the base platform during a linear acceleration mode without substantial rotational movement. The retaining element is rotationally movable relative to the base platform without substantial linear movement during a rotational acceleration mode. The testing apparatus further includes an actuator disposable in mechanical communication with the retaining element for moving the retaining element relative to the base platform.

A health and usage monitoring system (HUMS) and method for monitoring the health and/or usage of one or more components of a vehicle. In various embodiments, the present invention uses a plurality of wireless sensors configured, when activated by a vibration of the vehicle, to monitor one or more components of the vehicle and to communicate health and/or usage data of the one or more components of the vehicle to a data access point. The data access point may relay real-time health and/or usage data to an operator of the vehicle, or the health and/or usage data may accessed later. Such a system allows critical components of the vehicle to be monitored so as to reduce failures, and so that repairs to, or replacements of, the critical components of the vehicle may be planned, thus reducing unscheduled downtime.

The invention discloses a method and a system for analyzing vibration and diagnosing failure for a wind generating set. The method comprises the following steps: firstly, acquiring vibration data of the wind generating set; finishing the analysis of the vibration data of the wind generating set according to structure parameters, history records and knowledge base of the wind generating set to generate a human-editable analysis report; diagnosing according to a vibration monitoring analytical standard and the operating state of the wind generating set; leading the diagnosis result to form a vibration monitoring report, and submitting the vibration monitoring report to a user; and finishing maintenance to the wind generating set according to the vibration monitoring report by the user. The technical scheme of the invention can greatly reduce workload of the vibration analysis of the wind generating set, and improve efficiency and accuracy of vibration analysis and failure diagnosis of the wind generating set.

A vortex-exciting vibration test device of flexible pipe fittings model set vertically in pull water pool is prepared as passing pipe fittings model through flow-speed increasing unit; setting said model and said unit vertically in pull water pool; supporting two ends of said model by support mechanism; using vertical test support to connect said unit and support mechanism with trailer and distributing various instruments of measurement-analysis system in said model, said units, said mechanism, said support and said trailer.

The present invention provides methods of assessing damage on a joint that includes energizing the joint, detecting the vibration of the joint using one or more signal generating sensors, processing the signal(s), and applying a damage index to the processed signal(s), wherein the damage index incorporates a processed control signal generated by a sensor(s) at or near the joint when the joint was healthy, i.e., in a substantially undamaged state. Another aspect of the present invention provides a pipeline that includes at least two pipe segments, at least one joint connecting the two pipe segments, and at least one signal generating sensor affixed to the pipeline that is capable of detecting vibration at or near the joint, at least one signal processor that is capable of EMD processing the signal, and an output device (e.g., computer monitor, LED display, a light bulb, an electronic alarm, or other sound or light generating device).

The invention discloses a marine riser vibration characteristic simulation test device under a deepwater well drilling working condition. The marine riser vibration characteristic simulation test device comprises a pool (1) and a trailer (2), wherein a lifting device A (3) is arranged on a horizontal sliding rail (8) of the trailer (2), a marine riser model (5) is connected with a connector A (9) at the bottom of the lifting device A (3) and a connector B (10) at the bottom of a lifting device B (4), the connector A (9) is communicated with a container (6), the connector B (10) is communicated with a liquid pump (7), and a tension adjusting device (33) is further arranged on the marine riser model (5). The invention further discloses a test method of the device. The marine riser vibration characteristic simulation test device has the advantages of being capable of simulating vibration performance of a marine riser of deepwater well drilling under different working conditions, suitable for marine riser models with different lengths, capable of simulating influence of different types of tensile force, different well drilling fluid density, different drilling fluid viscosity, different well drilling discharge capacity and different well drilling rotating speeds on vibration characteristics of the marine riser models, and capable of accurately obtaining real-time data in the test process.

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 provides a device for testing anti-loosening property of a threaded fastener. The device comprises a base, a power system, an amplitude regulating system, a transverse vibrating system and a sensing system, wherein the power system, the amplitude regulating system and the transverse vibrating system are fixedly arranged on the base; the power system is a variable frequency motor which is connected to the amplitude regulating system by virtue of a coupling; the amplitude regulating system is mainly used for regulating a vibrating amplitude by virtue of an eccentric wheel; the eccentric wheel can drive the transverse vibrating system to do horizontal motion by virtue of a connecting rod; and the vibrating amplitude of the testing device is monitored by virtue of the sensing system in real time. The testing device disclosed by the invention is simple in structure, convenient in amplitude regulation and precise in testing data, and is capable of truthfully reflecting the change situation of the pre-tightening force of the threaded fastener under the action of a transverse load.

The invention discloses a test bench of the comprehensive performance of an air spring, and belongs to the technical field of vehicle engineering. The test bench can effectively achieve the aims of carrying out the vertical, transverse and twisting tests of the air spring at the same time and simulating the actual working states of the air spring. A rack of the test bench is in a four stand column type, a bearing platform is arranged in the middle of the rack, a device for bearing balance weight is arranged above the rack, a sensor is arranged below the rack, each stand column of the rack is provided with a cone-shaped fixing nut, a vertical hydraulic actuator which is arranged in a plane triangle mode is arranged below a workbench, and the volume of an additional air chamber is adjustable. The influence to the dynamics performance of the air spring by regional environment with different temperatures can be simulated by an external air conditioner system, multi-dimensional simulation is applied to the air spring through a shock excitation source, changes of loads and deflection of the air spring under the conditions with different environment temperatures and physical parameters are measured, and parameters such as dynamic stiffness, static stiffness, damping ratio and transfer ratio of the air spring are calculated through parameters of vibration characteristics. The test bench is mainly used for testing the comprehensive performance of the air spring.

The invention discloses a method and a device for testing dynamic stiffness of a vibration isolator. The method comprises the steps of establishing an equivalent test model of a single-degree-of-freedom vibration system in a vibration isolation direction by using a static loading device, a combined vibration mass block and an elastic simply supported beam, measuring a frequency response function of the equivalent test model by an exciting method, and then indirectly obtaining the dynamic stiffness of the vibration isolator by virtue of a vibration equation, the similarity of the vibration system and the characteristics of the single-degree-of-freedom system. The method avoids the problem that the existing methods all need to simulate a rated load or a working load with an equivalent mass block in an ingenious way, and solves the problem that the test system is clumsy, high in test cost and test difficulty and even unachievable if the mass block is used for simulating high rated load or working load; the testing device is light and simple in structure, convenient to operate, and economical and practical; the method and the device are applicable to the dynamic stiffness tests of all single-axis vibration isolators, high in applicability, and especially capable of realizing testing of the dynamic stiffness of a large-rated load vibration isolator and ensuring high precision.

The invention provides a rolling bearing performance degradation evaluation device and method. The device comprises an acceleration sensor, a data acquisition module, a feature extraction module, an SVDD evaluation module and a verification module. According to the method, the acceleration sensor is made to be used for acquiring vibration signals of a bearing to be measured and converting the vibration signals to simulation signals; the data acquisition module is made to be used for conducting amplifying, smoothing and other processing on the simulation signals, converting the simulation signals into digital signals and then transmitting the digital signals to a computer; the feature extraction module is used for extracting wavelet packet singular spectrum entropies of the vibration signals to serve as input feature vectors so as to be used for the SVDD evaluation module; The SVDD evaluation module is used for establishing a self-adaption SVDD model and evaluates the performance degradation process of the rolling bearing through the self-adaption SVDD module to obtain a performance degradation index DI; the verification module verifies the correctness of the evaluation result through an Hilbert envelope demodulation method based on EMD. The rolling bearing performance degradation evaluation device and method are applied to performance degradation evaluation of the rolling bearing in the whole life cycle.

The invention relates to a rolling bearing error auto diagnose system. It takes testing analysis and kurtosis analysis to the bearing vibration, and calculates the kurtosis by virtual device and DSP, analyzes and compares the spectral configuration to accurately measure the acceleration and speed of bearing vibration, and achieve accurate analysis to automatically judge the place of the error.

The invention provides a method and device for measuring low-frequency and small-range vibration signals. The method mainly comprises the steps that an acceleration sensor is arranged on a measured object; after the low-frequency and small-range vibration signals sent by the measured object are detected by the acceleration sensor, the low-frequency and small-range vibration signals are converted to vibration acceleration signals; the integration-amplification vibration acceleration signals are output, and the resonant frequency of an integration-amplification acceleration sensor is larger that the largest effective vibration frequency of the vibration signals sent by the measured object; primary integration amplification is conducted on the vibration acceleration signals output by the integration-amplification acceleration sensor so that vibration speed signals can be obtained, and secondary integration amplification is conducted on the integration-amplification vibration speed signals so that vibration displacement signals can be obtained. According to the method and device for measuring the low-frequency and small-range vibration signals, the problem of the failure of the measured signals due to the phenomena of mechanical fatigue and blocking of mechanical components and the like is effectively solved, the resonant frequency of the acceleration sensor is far higher than the largest effective vibration frequency of the measured objects such as the structure of a water-turbine generator set, resonance signals of the acceleration sensor are completely filtered, and the function that a rear-end circuit is not influenced by the resonance signals of the acceleration sensor is guaranteed.

The invention discloses a test bed for simulating longitudinal vibration of a marine propulsion shafting. The test bed comprises a movable loading module (1), a base (12), a fixed loading module (3), a transmission shaft (4), a split coupling (6), a thrust bearing (7), an elastic coupling (8), a gearbox (10) and a frequency conversion motor (11). The fixed loading module (3), the transmission shaft (4), the split coupling (6), the thrust bearing (7), the elastic coupling (8), the gearbox (10) and the frequency conversion motor (11) are arranged on the base (12) in turn. The movable loading module (1) is connected with the fixed loading module (3) through an ejector rod (2) and used for supplying longitudinal alternating exciting force for simulating a propeller. The fixed loading module (3) is connected with one end of the transmission shaft (4). The other end of the transmission shaft (4) is connected with a thrust shaft of the thrust bearing (7) through the split coupling (6). The other end of the thrust shaft is connected with the output shaft of the gearbox (10) through the elastic coupling (8). The gearbox (10) is connected to the frequency conversion motor (11). The test beddisclosed by the invention has the advantages of compact structure, convenient operation, safety and reliability and can satisfy practical application requirements for teaching and researching.

The invention discloses a reliability test platform for a frame and a traction transmission system of a bogie of a bullet train. The platform comprises a mechanical assembly part, a test platform base and a hydraulic pump station, wherein the test platform base consists of a concrete base of a rectangular pit, and a No.1 counterforce seat base platform, a No.2 counterforce seat base platform, a large-range adjustable platform, a base pit platform, a driving device base platform and a No.3 counterforce seat base platform which are poured in the concrete base and are positioned in the same horizontal plane; the mechanism assembly part comprises loading devices, an excitation system assembly and a semi-vehicle quality simulation device; the loading devices are fixed on the driving device base platform and the large-range adjustable platform; the excitation system assembly is provided with four vertical actuators and two horizontal excitation assemblies; the bottom ends of the four vertical actuators are fixedly connected with the base pit platform; one end of one horizontal excitation assembly and one end of the other horizontal excitation assembly are fixedly connected with the large-range adjustable platform and the No.3 counterforce seat base platform; and the bottom end of the semi-vehicle quality simulation device is fixed on the test platform base.

The invention discloses a rigid-body mode integration test method for an automobile power assembly and a suspension system. By adopting a constant-velocity amplitude sinusoidal scanning excitation signal as an excitation source of a four-channel vibration table, the method not only can test the translation rigid body modes along X, Y and Z directions and the rotation rigid body modes around the X, Y and Z directions of the power assembly relatively well, but also can test the homonymous jump mode and incongruous jump mode of the suspension system relatively well.

Systems and methods for identifying the presence of a defect in vibrating machinery. An exemplary method comprises analysis of frequency spectrum vibration data of the machine. The method comprises deriving a harmonic activity index based on estimates of the energy associated with the frequency spectrum and the energy associated with the defect's harmonic series. The method may comprise deriving a value K by estimating a value M indicative of the energy of the defect's harmonic series and dividing M by the number of spectral lines corresponding to the defect's harmonic series. The method may further comprise deriving a value R by estimating a value Q indicative of the energy in the frequency spectrum data and dividing Q by the number of spectral lines of the frequency spectrum data. The method further comprises deriving the harmonic activity index based on the estimated K and R. Related systems for executing the methods are also disclosed.

The invention relates to an accelerated life test method of an aircraft brake system. The environment conditions of applying temperature stress, vibration stress and the like in a combined way are adopted, the operating conditions are added and the operating frequency of the whole system are increased during the test process, so that the hidden fault dangers of the brake system are stimulated, and the test time is shortened. The method is circularly carried out according to the test profile during the test process until the required reliability index is reached. The power-on operating conditions, the brake applying pressure operating conditions and the rotating speed change conditions in use are converted into the test time according to the applied operating frequency, and the operating frequency adopted in the test is greater than the actual operating frequency in use. The reached reliability index is assessed according to the method in GJB1407 and recommended degree of confidence after the test is finished, and the degree of confidence for assessing the reliability index is 90%; and the empirical coefficient of life assessment is 1.5. The purpose of performing the accelerated life test on the brake system is realized by verifying whether the brake system has hidden fault dangers under various operating states.

The invention discloses a system and a method for testing analyzing automobile vibration, comprising a three-direction acceleration sensor, a single-direction acceleration sensor, a signal regulating module, a radio data collecting card and a monitoring computer. The three-direction acceleration sensor and the single-direction acceleration sensor are arranged on a key part during the running of the automobile and are used for respectively obtaining and outputting the vibrating signals of each key part during the running of the automobile; the signal regulating module is connected with the output ends of the three-direction acceleration sensor and the single-direction acceleration sensor and used for regulating and outputting the signals output by the three-direction acceleration sensor and the single-direction acceleration sensor; the radio data collecting card is connected with the signal regulating module and used for collecting and wirelessly outputting the regulated signals of the signal regulating module; the monitoring computer is provided with a radio data receiving end and is used for receiving the radio signals output by the radio data collecting card as well as testing and analyzing the vibration signals during the running of the automobile. The device has simple hardware structure, realizes the diagnosing and analyzing function by software, facilitates the upgrading and maintenance, and is conveniently carried.