Comparison of Vibration Durability Tests with respect to Fatigue Damage & Validation Study

Abstract

In this study, Random and Harmonic vibration durability test specifications for Automotive Lighting systems are compared according to their damage content. Harmonic and Random vibration durability test specifications which have different durations and Acceleration Power Spectrum Densities (PSD G) are plotted and compared according to damage accumulated on single degree of freedom (SDOF) system. Outcome of this study is the fast evaluation of fatigue strength of common or similar parts used on lighting systems which are dedicated to different customers, different car segments; and evaluation of the severity of new customer vibration durability test specifications and evaluation of special design precautions for new design projects. Shorter duration PSD G's and Harmonic sweep tests which have equivalent Fatigue Damage Spectrums (FDS) can be created and instant design improvements can be tested and evaluated. In addition, in this study, random test time reduction formula was validated with physical tests.