“…Parametric resonance PR is the state of oscillating instability which can arise under periodic disturbance of a parameter of the structure, for example, under periodic variation of the pendulum length or the tensile force in a beam, plate or a flexible screen (Parszewski, 1992; Virgin, 2007). The problem of the parametric resonance in mechanical systems is studied by numerous researches and development centres (Başar et al, 1987;Bąk et al, 2013;de Silva, 2005;Hagedorn and Koval, 1971;Michalczyk, 1995;Nguyen, 2013;Osiński, 1985;Parszewski, 1982;Slepyan, 2013, 2014). The parametric resonance phenomenon has been known since 19th century.…”