This article presents a methodology — for Multiple Degree of Freedom (MDOF) systems — to identify the modal parameters of a steel catenary riser (SCR) by employing both the Hilbert and the wavelet transforms. To validate the proposed approach, a set of experiments were performed in a small scale model of a real SCR that is installed in the P18 platform operating in Campos Basin, Brazil. During the experiments, the damping factor along the SCR was modified by adding viscoelastic sandwich layers on its structure. Each change was recorded with two accelerometers mounted at the bottom of the riser; one of them was set to get measurements in the catenary plane and the other one to get measurements out of the plane. Then, in order to obtain the impulse response of the structure — from which is possible to obtain the modal parameters — some hammer impacts were applied at locations close to these accelerometers.

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