El-Sabaa, F.MAmer, T.S.Gad, H.MBek, M.A2020-09-112020-09-118/31/202022113797https://doi.org/10.1016/j.rinp.2020.103352http://repository.msa.edu.eg/xmlui/handle/123456789/3768ScopusThis paper presents the motion of a harmonically excited dynamical system with three degrees of freedom (3-DOF) in which it consists of a connected rigid body with a damped spring pendulum whose suspension point moves in a Lissajous curve path. Multiple scales method is utilized to obtain the asymptotic solutions of the equations of motion up to third approximation. Some types of resonances and the conditions of solvability for the steady state solutions have been clarified in light of the achieved modulation equations. The temporal representation of the achieved solutions and resonance curves are presented in some plots to show the good effect of the distinct parameters on the dynamical motion of the investigated system. The numerical solutions of the governing system of motion are gained utilizing the Runge–Kutta method from fourth order. The comparison between these solutions and the analytical ones reflects the good accuracy of the analytical solutions and the used perturbation techniquesen-USHarmonic excitationResonanceSpring pendulumLissajous curveArticlehttps://doi.org/10.1016/j.rinp.2020.103352