Search Results

The purpose of this paper is to apply the concept of the frequency spectrum as derived from a Single Degree of Freedom (SDOF) system, establish the accelerated vibration specification, and investigate the specification under customer usage with reliability analysis. The main technique is to convert a time domain signal, which is derived from a Proving Ground or customer usage, to the frequency domain. An automotive headlamp was used in our research. The input signal from the Proving Ground was converted into an eight-hour bench test that is equivalent to a five-year/100,000 km field usage through the theory of Fatigue Damage Equivalence. The fatigue parameters of the materials were then estimated from various vibration conditions with the MIL-STD-810F standard. The benefit of this approach is that we could quickly obtain the material parameters of a complex structure made of composite plastics.

Ride quality analysis involves the study of three topics: ride excitation sources, system dynamics of a vehicle, human perception and tolerance of vibration. In this study, we establish an integration analysis procedure including the system dynamics analysis and the ride quality evaluation. The dynamic responseof a passenger car was simulated by a multi-body model with ADAMS software. The calculated acceleration responses of seats coincide with the field measured ones. The effect of damping ratio (C), stiffness coefficient (K), vehicle speed and seating location on the acceleration response are also investigated. The ride quality analysis was conducted following the ISO 2631 standard. A LabVIEW computer code was developed to provide fast and convenient assessment of the comfort. A 3-axis translational accelerometer was installed on the seat.