Reliability-based Test Track Schedule Development for a Vehicle Suspension System 2007-01-1653

A process for establishing an accelerated proving ground durability schedule for a vehicle suspension system, based on real customer roads, was developed in this work. The available road load data for a specific chassis design was acquired by using a test vehicle that was equipped to measure the front and rear spindle loads, wheel-to-body displacements, and body mount loads. The test target representing the customer usage consists of a combination of 5 tracks of public roads located in Michigan, adding up to 100 miles, and is based upon a previous work by Ferris, J.B. and Larsen, J.L. [2]. It was then extrapolated to a target customer equivalent mileage of 150, 000 miles with an assigned extrapolation factor for each public road. A repeat value for each of seven test tracks at the Chelsea Proving Grounds was generated using state-of-the-art optimization techniques to match the weighted, rainflow cycle histograms from the road load data channels, . These repeat values represent how many total passes of each event would need to be combined to duplicate spindle loads and wheel-to-body displacements during 150, 000 miles of public road usage for the 95^th percentile customer.