Methodology to Derive Reliable Laboratory Tests Using Limited Service Load Data

Often complete vehicle, aggregate and component fatigue testing in the laboratory is conducted using one specific field or track recording of pre-selected vehicle component response data. These data become the targets which are reproduced in the laboratory with various test methods. These data are usually edited using various accelerated test methods to achieve shorter test time. The final drive signals at the minimum error condition are used to conduct the durability test on the vehicle. The fatigue failures that are obtained in the laboratory test could be biased due to the limited data set.

A study was carried out where data were collected using multiple drivers and multiple repeats from the same test tracks. Multiple sets of component and aggregate response data were analyzed in terms of damage and other fatigue related properties. In practical engineering situations it is not possible to collect such large volumes of data. The paper discusses how the statistical properties of the fatigue parameters obtained from this study can be applied to the situation where only one data set is available to estimate the durability performance of the component or aggregate.