Vortex-induced vibration experiments with a long semi-immersed flexible cylinder under tension modulation: Fourier transform and Hilbert–Huang spectral analyses - Franzini, Guilherme Rosa; Gonçalves, Rodolfo Trentin; Pesce, Celso Pupo; Fujarra, André Luis Condino; Mazzilli, Carlos Eduardo Nigro; Meneghini, Julio Romano; Mendes, Pedro (Journal of the Brazilian Society of Mechanical Sciences and Engineering, 2015)