On field durability tests of mechanical systems. The use of the Fatigue Damage Spectrum

In the present paper the authors, starting from a previously proposed method for the combination and the synthesis of equivalent load conditions (by only managing PSD representations of the load conditions), developed a new approach based on the concept of Fatigue Damage Spectrum and on the system dynamics. The proposed approach was then validated by a durability test case, in which two different acceleration motion based load conditions, a norm load condition (by using laboratory test) and an operative one (by using acceleration measurements acquired during an experimental activity conducted on a transport vehicle) were compared.