scholarly journals Rancang Bangun Vibration Test Bench untuk Mensimulasikan Kondisi Unbalance dengan Pengaturan Putaran dan Beban Unbalance

2017 ◽  
Vol 3 (1) ◽  
Author(s):  
Imam Maolana
Keyword(s):  
Electric Motor ◽  
Test Bench ◽  
Load Condition ◽  
Axial Direction ◽  
High Amplitude ◽  
Vibration Measurement ◽  
Wave Form ◽  
Vibration Test ◽  
Vibration Testing ◽  
Rotating Machine

The goal of this work is to design and build a vibration test bench to simulate unbalance in rotating machine. The vibration test bench made of a 25 mm diameter steel shaft and length of 410 mm supported by two ball bearings. Two steel discs to variate unbalance load installed in the shaft powered by 0.5 Hp electric motor with maximum rotation of 1400 RPM. Inverter used to control rotation from electric motor. Vibration testing conducted at two condition; (1) without load and rotation variation, (2) unbalance load with variation of unbalance mass. Pick up point of vibration measurement at bearing house in radial and axial direction. The vibration parameter measured are amplitude and spectrum (wave form). Amplitude measurement using hand held vibrometer, while spectrum using accelerometer conected to a Data Acquisition. After testing the condition using unbalance load, we conclude that the vibration test bench match unbalance condition as described in theory which is high amplitude at machine frequency, and it’s value proportional to unbalance mass. We find that the highest amplitude is at horizontal direction where machine stiffnes is smallest. Vibration testing with no load condition show that there is harmonic in vibration spectrum indicating rotating looseness, probably caused by bearing wear. 

scholarly journals Research on Modal Parameter Identification Method of Railway Carbody Based on 6-DOF Vibration Test Bench

2021 ◽  
pp. 1-15
Author(s):  
Jia Zhang ◽  
◽  
Jinghan Wen ◽  
Ye Song ◽  
Pingbo Wu
Keyword(s):  
Test Bench ◽  
Load Capacity ◽  
Excitation Frequency ◽  
Test System ◽  
Modal Parameters ◽  
Vibration Test ◽  
Vibration Exciter ◽  
Modal Parameter ◽  
Additional Influence ◽  
Elastically Supported

In order to avoid the additional influence on the test results caused by the inconsistency between the boundary conditions of the carbody and the reality when using the vibration exciter or hammer to test the free mode of the carbody, a 6-DOF vibration test bench is tried to simulate the actual motion posture of the carbody to test its modal parameters. For in-depth discussion, a full-scale virtual prototype of the 6-DOF vibration test bench was built, and on this basis, the test bench-carbody rigidflexible coupling virtual test system was established. According to the modal frequency range of the carbody to be tested and the actual load capacity of the test bench, the excitation frequency and amplitude of the test bench are determined. Through the virtual modal test, it is determined that the carbody should be elastically supported when testing the modal parameters of the carbody by using the vibration test bench, so as to accurately obtain the modal parameters of the carbody.

Reaction Wheel Disturbance Characterization by Analysis of Micro-Vibration Measurements

2012 ◽  
Vol 232 ◽  
pp. 445-449 ◽  
Author(s):  
Florian Liebold ◽  
Stephan Wiegand ◽  
Ronny Käso
Keyword(s):  
Test Bench ◽  
Vibration Test ◽  
Frequency Range ◽  
Reliable Measurement ◽  
Mechanical Oscillations ◽  
High Information Content ◽  
Micro Vibration ◽  
Production Errors ◽  
High Information

Structural stability of satellites is of vital significance for the operation of sophisticated payload systems. Therefore manufacturers of satellite components, such as reaction wheels, make huge efforts to assure the convenient vibration behavior of their products. To meet that demand a device for the detection of mechanical oscillations with very small amplitudes was developed. The described micro-vibration test-bench allows the detection of vibrations with amplitudes > 10 5 Newton in a frequency range of < 20 kHz generated by a test item with a mass up to 30 kg. The quality of the thereby obtained data makes it possible to identify the sources of the observed vibration. The high information content of the measurements originates from a set of high resolution force sensors, variably arranged on a mechanically isolated platform. The sensitivity of the used equipment (charge cables, charge amplifiers and signal analyzers) and its resistance to ambient disturbances allow the high accuracy of the measurement as mentioned above. The described micro-vibration test-bench additionally provides opportunity to detect production errors non-destructively and helps to reduce the inherent noise of the item under test. It therefore represents a reliable measurement device to quantify and assess detrimental vibrations.

scholarly journals Perceived discomfort for typical helicopter vertical sine vibrations for seated participants

2021 ◽  
pp. 146134842097975
Author(s):  
Laurianne Delcor ◽  
Etienne Parizet ◽  
Julie Ganivet-Ouzeneau ◽  
Julien Caillet
Keyword(s):  
Frequency Dependence ◽  
Power Law ◽  
Test Bench ◽  
Ride Comfort ◽  
Estimation Procedure ◽  
Vibration Velocity ◽  
Vibration Test ◽  
Main Rotor ◽  
The Relationship ◽  
Vertical Excitations

Vibrations contribute to helicopter’s ride comfort. This study aimed to determine the relationship between main rotor vertical excitations and discomfort. Fifty-three participants, seated on a helicopter seat fixed to a vibration test bench, evaluated the discomfort of vertical sinusoidal vibrations using a magnitude estimation procedure. Stimuli had a frequency between 15 and 30 Hz and a level between 0.32 and 3.16 m/s2. The average discomfort was shown related to vibration velocity using Steven’s power law, without any frequency dependence. The exponent depended on velocity and was 1.18 for higher velocities (approx. above 0.008 m/s) and 0.65 for velocities below that limit.

scholarly journals MTG-SCA micro-vibration test bench development using linear interferometry

2017 ◽  
Author(s):  
Luis Pascual ◽  
Santiago Pasalodos ◽  
Jose Ignacio Bueno ◽  
Marcos Ubierna ◽  
Antonio Gonzalez-Elias
Keyword(s):  
Test Bench ◽  
Vibration Test ◽  
Micro Vibration
Sign in / Sign up

Export Citation Format

Share Document