Experimental Determination of the Damping Loss Factor of Highly Damped Ribbed-Stiffened Panels

Vibration levels of structures can be significantly reduced by adding some damping materials to the vibrating surfaces. The viscoelastic behavior of these materials induces losses of kinetic energy when they undergo cyclic deformation. A good estimate of the damping loss factor is an important design parameter allowing the creation of efficient damping treatments. For Statistical Energy Analysis (SEA) purposes, the damping loss factor is usually estimated through the Power Injection Method (PIM). This paper presents the application of PIM to obtain the damping loss factor of a typical fuselage panel. In this case, the structure under study is a curved ribbed-stiffened panel. Tests are carried out for undamped and damped conditions. The added damping is provided by layers of viscoelastic material attached to the fuselage skin. The results show the applicability of the method for this kind of structure. It is shown that the high damping imposed by the viscoelastic material leads to some difficulties concerning the measurement technique.