Accelerated Sine-on-Random Vibration Test Method of Ground Vehicle Components over Conventional Single Mode Excitation

Abstract

Automotive manufacturers typically assess the mechanical durability performance of ground vehicle components for vibration excitation using either random or harmonic spectral loading patterns, such as the loading patterns suggested in international standards (e.g., ISO-16750-3). Selection of the correct excitation profile is dependent on the service condition of the component of interest. However, in the instance where the vehicle component is exposed to both harmonic excitations and background noise, the severity of impact of the in-service environment cannot be satisfied via a single random or harmonic test alone. In this case, the optimal test strategy is to evaluate the vehicle component under a sine-on-random excitation. Within this study, a uniaxial excitation test was conducted for a notched simple specimen under three spectral loading cases (harmonic, random, and sine-on-random), and the test severity was determined based on two kinds of fatigue damage: the physical damage from measured strain and the calculated pseudo-damage from acceleration measurements, as indicated in ISO-16750-3. Based on this comparison of accumulated fatigue damage, the efficiency of the proposed sine-on random vibration was proved against conventional single spectral pattern test methods.

Keywords

• sine-on-random
• spectral loading pattern
• ground vehicle component
• uniaxial vibration test
• notched simple specimen