Multisine load cycle design for fatigue testing

To experimentally quantify the fatigue life of critical airplane components (such as, for instance, the slat tracks), extensive tests must be performed on a test rig. In this paper, a method is proposed to design the load signal which has to be applied in order to exactly obtain a certain damage content. The method presented uses a (band-limited) perturbed multisine (MS) excitation signal. Therefore, the load can be easily controlled. In addition, because the designed multisine is periodic, the health of the structure can easily be monitored on-line. The proposed method will be validated both on simulations and on (low cycle) fatigue measurements of a steel beam.