Vibration testing of vehicle components by fatigue damage spectrum control

Abstract

Random vibration testing with increased kurtosis introduces high peaks into shaker drive signals to simulate land vehicle vibration more accurately or to shorten duration of fatigue damage testing. For the latter, the kurtosis control method must be able to pass high kurtosis values from the generated shaker vibration into the stress response of the tested component. It was verified and confirmed in the paper that the method of phase manipulation based on the analytical relationship between the IFFT phases and kurtosis was capable of doing so if the resonance frequency of the component is known. However, the fatigue damage spectrum model used for evaluation of time-to-failure considers not just one but a number of resonance frequencies constituting a certain test profile which cannot be simulated by the kurtosis control alone. For this purpose, the phase manipulation method was developed further and verified for operational vibrations of a railway vehicle.