Accelerated degradation tests for reliability estimation of a new product: a case study for washing machines.

Articolo in stampa pubblicazione on line 9/9/2013. Accelerated degradation test (ADT) is a valuable technique able to provide information on the duration of highly reliable products. It’s widely used in electronics, where component life often can’t be estimated in an acceptable time with the classic reliability estimation techniques. In the mechanical engineering sector, however, ADTs are not so common. The purpose of this study is to evaluate the applicability of ADT methodology to a new mechanical subassembly of a washing machine. In particular, we tried to identify which was the most appropriate degradation parameter, choosing among three possible alternatives. The methodology was applied to the new oscillating group of a washing machine, with oversized dimensions and innovative materials. The first selection of elements which could be monitored initially provided three parameters: the drum deformation, the bearing temperature and the vibrations of the rotation shaft. The research allowed the identification of the deformation as the most appropriate parameter for the reliability estimation of the oscillating unit. The originality of this study consists in the fact that in the literature ADTs of washing machines are not present. Also you do not find the application of such methodology to three different parameters, in order to select the best one. With this study it was also emphasized another ADT peculiarity: it is possible to quickly enrich the know-how on a new product, allowing an in-depth knowledge of new elements, in far more rapid times than those that would be needed with a traditional approach.