Numerical Investigation of the Dynamic Response of Symmetric Laminated Composite Beams to Harmonic Excitations

Abstract

The aim of this study is to investigate the dynamic response of a laminated composite beam subjected to a harmonic excitation by a numerical time integration method known as Newmark method. The finite element method based on the classical laminated plate theory is used in order to obtain structural stiffness. The structural damping is modelled as proportional damping which is referred to as Rayleigh damping and two different damping ratios are used. The effect of damping on the frequency response of the beam is investigated for a broad range of excitation frequency. The effect of excitation point on the harmonic response is also considered. Four different lay-up configurations namely [0]2s, [0/90]s, [45/-45]s and [90]2s are considered in order to show the effect of the stacking sequence on the frequency response of the beam. The numerical results presented in this study show that, the magnitude of the harmonic response of the beam reduces considerably as the damping ratio increases and [90]2s lay-up produces largest dynamic response due to the reducing flexural rigidity. Numerical results also show that the location and frequency of the harmonic excitation has important role on the dynamic response of the beam.