Techniques and Pitfalls in Random Vibration Testing

Noise Control ◽  
1959 ◽  
Vol 5 (5) ◽  
pp. 7-12
Author(s):  
Robert C. Lewis
Keyword(s):  
Random Vibration ◽  
Vibration Testing

scholarly journals Analysing Random Vibration of KLT Box during Transporting by Finite Element Method

10.29007/b1th ◽  
2022 ◽  
Author(s):  
Cong Hoa Vu ◽  
Ngoc Thien Ban Dang
Keyword(s):  
Finite Element ◽  
Spectral Density ◽  
Power Spectral Density ◽  
Automotive Industry ◽  
Random Vibration ◽  
Element Model ◽  
Vibration Testing ◽  
Time Data ◽  
Power Spectral ◽  
The Impact

Today, freight is an extremely important industry for the world we are living. Fast transportation, large volume...will optimize the cost, time and effort. Besides, ensuring the products safety is a matter of concern. During transporting, it is inevitable that the vibration caused by the engine, rough road surface...the cargo inside can be damaged. Automobile industries have prime importance to vibration testing. Sine vibration testing is performed when we have been given with only one frequency at given time instant. Trend to perform random vibration testing has been increased in recent times. As random vibration considers all excited frequencies in defined spectrum at known interval of time, it gives real-time data of vibration severities. The vibration severity is expressed in terms of Power Spectral Density (PSD). KLT box is an industrial stacking container conforming to the VDA 4500 standard that was defined by German Association of the Automotive Industry (VDA) for the automotive industry. The aim of this paper is study about random vibration and power spectral density analysis, how it can be used to predict the impact of hash road to the KLT box on container / truck during transportation. Finite element model is developed in ANSYS, modal analysis and random vibration analysis were done.

Vibration Testing Using Spectra with 20 to 50 Breakpoints

1987 ◽  
Vol 30 (5) ◽  
pp. 37-41
Author(s):  
Arthur Edelstein ◽  
Ray DeWinter
Keyword(s):  
Test Data ◽  
Random Vibration ◽  
Space Shuttle ◽  
Vibration Testing ◽  
Test Program ◽  
Sample Test ◽  
Break Points ◽  
Technical Systems ◽  
Technical Solutions ◽  
Three Space

This paper discusses the approach used by engineers at National Technical Systems to perform vibration testing on three Space Shuttle components in 1982 and 1983. All three programs involved sinusoidal, random, and combined sinusoidal/random vibration, with the random vibration in some cases involving high numbers of break-points and some programs requiring applied temperature and/or pressure in addition to the applied vibration. Each test program is briefly summarized in terms of specific requirements, after which the technical difficulties and technical solutions are discussed. Equipment schematics and sample test data in the form of x-y plots are also presented.

On accelerated random vibration testing of product based on component acceleration RMS–life curve

2017 ◽  
Vol 24 (15) ◽  
pp. 3384-3399 ◽  
Author(s):  
Zhi-Wei Wang ◽  
Li-Jun Wang
Keyword(s):  
Root Mean Square ◽  
Time Scale ◽  
Random Vibration ◽  
Response Spectrum ◽  
Equivalent Stress ◽  
Practical Method ◽  
Mean Square ◽  
Vibration Testing ◽  
Validation Experiment ◽  
Von Mises

Accelerated random vibration testing is usually used to certify a product in random vibration environments. The current certification method is based on the inverse power law and is strictly valid only for Basquin’s type of damage and fatigue of materials. Based on the response spectrum analysis of the product in “the simply scaled accelerated vibrations” and taking the size of acceleration power spectral densities (PSD) the component is undergoing as an index to characterize and compare the damage of the component in different experiments, this paper develops a more practical method in engineering for accelerated random vibration testing of the product in the framework of linear random vibration theory and the rule of acceleration root mean square (RMS)–life curve of the component. The suggested method shows that the time scale is determined by the zero-th and second-order response acceleration spectral moments of the component in real vibration and that simulated in the laboratory, which demonstrates its potential value and advantage in practical application when compared with that based on the von Mises equivalent stress. Simplifications of the method are discussed in detail. In “the simply scaled accelerated vibrations”, the time scale is determined by the acceleration root mean square of the component in real or simulated vibration. It is coincident with the form reported by Allegri but having different physical significance in the case of Basquin’s type of damage and fatigue of the component. The validation experiment with a desk computer was carried out, leading to the verification of the present method.

Sign in / Sign up

Export Citation Format

Share Document