Time filter

Source Type

Jenison, MI, United States

Van Baren J.,Vibration Research Corporation
Sound and Vibration

The Fatigue Damage Spectrum (FDS) function has been added to a vibration test controller in order to regulate the rate at which fatigue is induced into a unit under test without distorting the real-world Power Spectral Density (PSD) profile. Source

Van Baren P.,Vibration Research Corporation
Sound and Vibration

Control and conduct of a random vibration test is all about probabilities. What is the chance of any single PSD spectral line being less than X? More than Y? What percentage of the test time will the amplitude at any frequency be between X and Y? Well established statistical calculations answer these important questions. In this article we present various procedures for determining the statistical properties of random waveforms. Probability and confidence interval tables are introduced for common degrees of freedom. Source

Van Baren J.,Vibration Research Corporation
Sound and Vibration

John Van Baren, Vibration Research Corporation, Jenison, Michigan, US, shares his views on some of the features and advantages of the random vibration testing method. One of the main goals or uses of random vibration testing in the vibration testing industry is to bring a device under test (DUT) to failure. A company will desire to find out how a particular product can fail due to various environmental vibrations encountered by it. The company will simulate these vibrations on a shaker and operate their product under those conditions. Testing the product to failure will teach the company many important things about its product's weaknesses and ways to improve it. Random vibration is also more realistic than sinusoidal vibration testing, as it simultaneously includes all the forcing frequencies and simultaneously excites all the resonances of the product. Source

Jung S.G.,Calvin College | Van Baren J.,Vibration Research Corporation
SAE Technical Papers

Methods for conducting accelerated vibration fatigue testing of structures, such as MIL-STD-810G, allow for the non-linear scaling of the test time with the inverse of the rms vibration amplitude based on the slope of the material S-N curve obtained from cyclic fatigue tests. The Fatigue Damage Spectrum (FDS) is used as a method to allow for different level scalings at different frequencies in a broadband vibration environment using the relative responses of resonances in the structure. A recent development in industry has been to mix impulses with random excitations to increase the vibration peak levels (as measured by the kurtosis), thereby accelerating the fatigue even more than would occur with a Gaussian excitation. This paper presents results from a study to determine the conditions under which high kurtosis, impulsive excitations actually produce high kurtosis responses in structural resonances thus increasing the level of the FDS. © 2016 SAE International. Source

Minderhoud J.,Vibration Research Corporation
Sound and Vibration

The use of automatic phase/frequency control for sine resonance track-and-dwell (SRTD) tests is proposed. the technique makes fatigue tests consistent with real-life excitations. Source

Discover hidden collaborations