Vibration Testing Machine Research Articles

On developing structural and technical solutions to ensure the vibratory displacement of the working medium

A research study into using vibration technologies for the transport of granular working medium was carried out. A vibration testing machine, whose calculation model includes a mechanical vibration system having two degrees of freedom with a rigid body on elastic supports, was selected as an object of research. The study involved analysing the variation in the system vibrations by using the structural theory for vibration isolation systems, where a dynamic equivalent represented by a structural diagram of an automatic control system is compared to the initial calculation model. The structural diagram of the system is based on the motion equations in operator form obtained using Lagrange differential equations of the second kind. The Laplace transform was used to transform the initial data for the system of differential motion equations. The paper addresses the characteristics of a new structural and technical solution in the field of vibratory displacement of a granular working medium using the working body of a vibration technological machine, which involves introducing a number of additional weights, levers, springs, and hinges. Here, springs comprise generalised structures containing both elastic elements and vibration dampers. To connect the coordinates of the endpoints in the working body of the vibration technological machine, analytical relations were obtained. It was established that varying the parameters of the elements within the elastic-lever blocks allows the dynamic state of the vibration technological machine to be controlled. In addition, it was shown that the obtained structural diagram helps to derive mathematical expressions for transfer functions, comprising the ratio between the motion coordinates of a technical object and an external force disturbance. On the basis of these expressions, the transfer function for the ratio of the motion coordinates of the vibration technological machine was formulated. A mathematical model of a vibration technological machine was obtained in the form of a transfer function, including a large number of additional elastic and massinertial elements, where the parameters of vibration displacement can be adjusted automatically. The research results will allow the existing technical solutions in the field of technological engineering to be modernised.

Prototyping of vibration testing machine that is generated non-gaussian random vibration which is determined by probability density function and power spectrum

Prototyping of vibration testing machine that is generated non-gaussian random vibration which is determined by probability density function and power spectrum

Prototyping of vibration testing machine that is generated non-gaussian random vibration which is determined by probability density function and power spectrum

Prototyping of vibration testing machine that is generated non-gaussian random vibration which is determined by probability density function and power spectrum

Experimental study on effects of sound on vibratory sensation of horizontal vibration

Humans are exposed to both vibration and noise when riding in vehicles such as cars and trains. Therefore, an evaluation of the vibratory sensation based on the combined effect of vibration and noise is needed. This study aims to determine the effects of sound on whole-body vibratory sensations of horizontal vibration. In this study, we conducted two experiments to research the influence of sound on vibratory sensation using an electrodynamic vibration test machine. The first experiment measured the point of subjective equality of the magnitudes of vibration and sound, and the second experiment measured the psychological effects of sound on vibratory sensations using the magnitude estimation method and the seven-grade rating scale method. This paper describes the results of investigating vibration dominance in a combined environment of vibration and sound and the effects of sound on the subjective magnitude of vibration and vibration discomfort.

Effect of Gear Transmission System to Vibration Test Machine

This research aims to investigate the vibration analysis for equipment test of chassis. The frame model of the gear transmission vibration test is developed. The prototype of the vibration and noise testing tool was constructed for the gear transmission system. The vibration equipment test consists of three gears that function as a gear transmission. The chassis is considered to be one of the vital elements of equipment. The rotation of gears and shafts can occur the vibration. The simulation with the 3D model using ANSYS was resulted in structure analysis. The simulation was resulted in total deformation, equivalent strain, and equivalent stress where the structure of the equipment was definitely safe and had good stability.

Free Vibration Analysis of Composite Cylindrical Shell Reinforced with Silicon Nano-Particles: Analytical and FEM Approach

Previous research presented the effect of nanomaterials on the mechanical properties of composite materials with various volume fraction effects; in addition, their research presented the effect of nanomaterials on the same mechanical characteristics for a composite plate structure, such as vibration and thermal buckling behavior. Therefore, since the use of shell structures is for large applications, it is necessary to investigate the modification of the vibration characteristics of its design with the effect of nanomaterials and study the influence of other reinforced nanoparticle types on its features. Therefore, in this work, silicon nanoparticles were selected to investigate their effect on the vibration behavior of a shell structure. As a result, this work included studying the vibration behavior by testing the shell structure with a vibration test machine. In addition, after manufacturing the composite material shell with various silicon volume fractions, the mechanical properties were evaluated. In addition, the finite element technique with the Ansys program was used to assess and compare the vibration behavior of the shell structure using the numerical technique. The comparison of the results gave an acceptable percentage error not exceeding 10.93%. Finally, the results evaluated showed that the modification with silicon nanomaterials gave very good results since the nanomaterials improved about 65% of the shell's mechanical properties and vibration characteristics.

Study on Evaluation of Loosening Threaded Fasteners Using a Vibration Testing Machine

NAS vibration testing is one of the typical methods to evaluate loosening threaded fasteners. Using a jig based on NAS3350 and a commonly used vibration exciter, loosening tests can be performed without a specialized tester for the evaluation. Basically, the only result obtained from the NAS test is the time from the test start until the fastener is disassembled. It has been difficult to understand how fasteners would loosen during the test. The purpose of this study was to investigate its behavior on the test. The tests were conducted for M8 bolt (strain gauge is embedded axially) and nut fasteners using existing vibration testing machine. Time history of the strain that is related to bolt axial force was obtained during testing. The sound pressure induced during the vibration testing was also measured at the same time. Time-frequency analysis of these measured data was performed using the short-time Fourier transform to obtain the distribution of the sound spectrogram. From these results, it has been achieved to determine when the fastener is completely loosened by measuring sound pressure.

High-strength mechanical joints under combined mechanical and medial loads

This paper introduces a test method for joined hot-dip galvanized steelwork test specimens. The specimens joined by means of a lock bolt system were subjected to a simultaneously combined mechanical and medial loading. This was achieved by combining a vibration testing machine and a condensation chamber that was expanded by an electrolyte dosing unit. The electrolyte was dosed on one side of the specimen in the area around the lock bolt head. The zinc dissolution is locally accelerated in the area around the joining element possibly due to superimposed bimetal and crevice corrosion. In addition, the electrolyte enters the space between the joined steel sheets and initiates corrosion processes there, too. Besides the expected zinc ions, potassium ions were also detected in the collected electrolyte by means of elemental analysis. These are originally part of the friction-increasing coating.

An Arrangement and Performance Analytics of Elements of Vibration Testing Machine for Taper Roller Bearing

The paper addresses the need for automation in production line. A detailed evaluation of various components required for converting a manual bearing vibration testing machine to an automatic one is carried out. Function and Description of each component is studied. The components include conveyor belts, laser Doppler vibro meter, pneumatic system, mechanical probe, timing and control sensors, speed control system, data analysis and storage unit. A method of selecting each component for automatic vibration testing machine is offered. Based on the structure of automated machine the initial set of alternate variants is defined and a formal model of automatic vibration testing machine is developed. Design of conveyor belt, linear drives, pneumatic system, isolation pad, PLC and HMI system is discussed below. Analysis of supporting structure of Vibration Testing Machine is done using ANSYS 18.1 and results are shown.

An Efficient Synthesis of a-Aminophosphonates through Kabachnik-Fields Reaction Protocol by using Cobalt Chloride Doped Polyaniline as the Nano Catalyst

The paper addresses the need for automation in production line. A detailed evaluation of various components required for converting a manual bearing vibration testing machine to an automatic one is carried out. Function and Description of each component is studied. The components include conveyor belts, laser Doppler vibro meter, pneumatic system, mechanical probe, timing and control sensors, speed control system, data analysis and storage unit. A method of selecting each component for automatic vibration testing machine is offered. Based on the structure of automated machine the initial set of alternate variants is defined and a formal model of automatic vibration testing machine is developed. Design of conveyor belt, linear drives, pneumatic system, isolation pad, PLC and HMI system is discussed below. Analysis of supporting structure of Vibration Testing Machine is done using ANSYS 18.1 andresults are shown.

Design of Modular Vibration Testing Equipment

Vibration testing is used by introduction of a force function into system, usually with the use of a shaker or vibration testing machine. These induced vibrations, aid in the laboratory or production floor for a variety of things, proof of concept, standard assessment, fatigue testing, and evaluating performance. Electrodynamic shakers are well suited for most vibration tests and offer several advantages over alternative approaches. Resonance searches involve sine sweep to obtain a transfer function for evaluation of resonance characteristics, usually by a crank mechanism. Fatigue testing is an expensive and long term test, not being the most accurate one, due to the fact that the functioning of any machine is not repetitive nor reproducible regarding vibrations.Random vibration testing better represent real world data by providing statistical confidence with random time data that has an average targeted frequency content and amplitude over the duration of the test. By controlling amplitude and frequency, test data can be correlated to real world data sets.Throughout this paper we present the outlines for the design of a modular fatigue testing machine with pseudorandom vibrations. Due to the nature of the modular approach for our equipment, the rig can be appropriately configured to perform multiple laboratory tests.

The Study on the Wear Characteristics of Flank Lock Type Precision Locknut in the Dynamic Conditions

This study investigated the wear characteristics and anti-loosening characteristics of flank lock type precision locknut in the dynamic percussion vibration test. The experiment was conducted by using horizontal realistic dynamic percussion vibration test machine. The objective is to simulate the loosening condition of the locknut which was assembled in ball screw and machine tool spindle. Through this study, the wear resistance and anti-loosening characteristics of the precision locknut under the dynamic test were investigated by closely observing the roughness, flatness and tooth angle, seat surface and surface morphology before and after the test. The test results were used to calculate axial force ratio and anti-loosening ratio to understand the wear properties and anti-loosening properties of precision locknut under the dynamic conditions.

The Study on Dynamic Mechanical Response under Staged Loading

Based on MTS-810 type vibration testing machine, morphological characteristics of hysteretic curves of frozen clay are quantitatively studied, and dynamic mechanical response are analyzed consisting of stiffness, viscosity, degree of microscopic damage, residual strain and energy dissipation. The studies have shown that the higher vibration frequencies are, the greater the stiffness is, while the smaller viscosity, the degree of microscopic damage, residual strain and energy dissipation are. Stiffness, viscosity, degree of microscopic damage, residual strain and energy dissipation are less affected by confining pressure. With increasing dynamic stress amplitude, stiffness decreases gradually, while viscosity, degree of microscopic damage, residual strain and energy dissipation increase gradually.

Correlation Between Pressure and the Amplitudes of Potential and Current in Electrochemical Oscillations Under the Conditions of Cavitation

The methods of adaptive medial filtration are used to select components of the initial electrochemical signal that can be identified as pressure pulses under the conditions of cavitation in the tests carried out in a vibration-testing machine. We determine the time dependences of the pressure pulses and selected electrochemical signals under the conditions of cavitation for a given potential.

Based on Mechanical Vibration Test Machine V-Belt Transmission Design

The essay has solved the optimization problem turning multi-objective problem into a single target by using weighting factor to the use of V-belt driving gear. According to engineering requirements, mechanical vibration test machine has determined the coordination of the various coefficients as a single objective optimization function after considering multiple conflicting incommensurability of the objective function, and combining practical experience and computing experience. Conditions on system requirements and relative constraints have been given in the form of constraint functions. Finally, the overall optimal solution has been calculated with the direct method, and an integrated optimal solution can have different numerical values by calculating it for different project objectives and specific requirements.

Improvement of Acceleration Tracking accuracy of Electrohydraulic Vibration Testing Machine

A new control technique is proposed to realize accurate acceleration tracking for repetitive desired acceleration waveforms in an electrohydraulic vibration testing machine. In the proposed algorithm for iterative waveform reformation, the control signal sequence for next operation is determined by utilizing the information of the frequency-response function of the servo mechanism as well as the tracking error obtained from the past operations. It is theoretically clarified first that the stability limit of the iterative reforming process and the convergence speed of the tracking error are predominantly decided by the estimation accuracy of the frequency-response function. Experiments show that nearly perfect tracking can be achieved by using the proposed technique for iterative waveform reformation utilizing the adaptively estimated information of the frequency-response function regardless of kinds of desired waveforms even under operating conditions subjected to inherent highly nonlinearities.

高速巡視船の衝撃緩衡用椅子の効果

In order to protect crew against a large accerelation caused by sailing in the rough waves, high-speed patrol ships have been equipped with shock-absorbing seats (seat damper), now. Although the seat damper is popular among the crew, there are some reports of doubtful whether the seat damper is effective to reduce the shock or not.The author investigated the shock-absorbing effect of the seat damper with a vibration testing machine and the accerelation measurement onboard ship.The present investigations are as follows. The natural frequency of the seat damper is about 1.8 Hz when a person is seatted on it, and it is considered theoretically that the damper has no shock-absorbing effect unless the frequencies of the impact accerelation are higher than 4 Hz. Both the present results with the vibration testing machine and the data onboard ship endorses also the vibration isolation theory.When the patrol ship runs in full speed, the main spectrum of the accerelation caused by the sea waves is about 0.3Hz, and no shock-absorbing effect of the seat damper is obserbed in these frequency region. However, in the higher frequencies up to several decade Hertz, considerable vibration reduction is recogniged by using the seat damper.

練習船におけるロックウール式浮き床の振動疲労耐久性に関する調査研究

The vibration isolation effect of rockwool type floating floor set up in a training ship was measured for ten years to know the vibration durability of rockwool.The floating floor could maintain the vibration isolation ability not less than the value at the construction time after ten years.The life time of rockwool used in a floating floor in a ship might be estimated more than 100 years, considering the on board experiments and a fatigue acceleration test of rockwool by a vibration testing machine.

Vibration testing system

ABSTRACT OF THE DISCLOSURE Rapid exchange vacuum fixture vibration system adapted for use with a vibration testing machine designed to move a surface to induce vibration in a fixture attached to a unit under test. The invention includes an adapter plate attached, at a first surface, to the surface of the vibration testing machine. A vacuum panel assembly, housing a vacuum pump, is included for creating a vacuum between the upper surface of the adapter plate and the lower surface on the fixture whereby the fixture and the unit under test attached thereto is secured to the adapter plate and thereby secured to the vibration testing machine without using bolts or other hardware for clamping. Thus, the method of the invention includes the steps of attaching an adapter plate to the vibration machine; easily placing a fixture, with a unit under test attached, on the adapter plate; and evacuating the volume between the adapter plate and the fixture to create a holding force therebetween sufficient to hold the fixture to the adapter plate during vibration testing.

Simulation of Vibration Damage in Produce Transportation

ABSTRACT MODUS operandi of measuring, recording and synthesizing transportation vibration environments for produce damage simulation in the laboratory is described. Based on measurements of typical produce transport routes, realistic simulation of damage in containers and unit loads of fresh produce may be achieved in a fraction of the real journey's time, by reproducing maxi-max envelope peak acceleration spectra. A semi open loop control strategy, for an electrohydraulic vibration testing machine was developed, utilizing commonly available and relatively inexpensive analog instrumentation and components, while digital hardware and software is implemented on a microcomputer. Once a control signal, simulating a given transport environment is developed, for a particular brand and type of vibration machine, it can be stored on FM analog magnetic cassette tape. Copies of this tape may be played back, as command signals on similar machines, for simulating that environment, hence further reducing cost and complexity. Simulation experiments are reported, wherein columns of containers filled with dummy fruit and oranges, were subjected to a typical maxi-max acceleration envelope spectrum. These show, that the highest acceleration levels are encountered in the bottom tier containers, whether the load is strapped down or not. The low frequency end of the spectrum is significantly amplified in the top tier containers, when the column is strapped down. The high frequency end of the spectrum is generally attenuated from the bottom to the top tier containers.