In the first part of this paper, a viscoelastic model is used to numerically study the cellular foam core fatigue behaviour. Material’s temperature evolution is quantified with a numerical/experimental confrontation. In the second part, the slamming phenomenon is discussed by measuring the panel flexural strain on a racing sailboat during navigation. Making use of these results, a new slamming test rig was developed to evaluate the fatigue of sandwich structure under realistic loading. Four-point bending and slamming tests were performed on sandwich beams in order to compare their fatigue life and to discuss the physical parameters.