Resonances Excited in an Elastically Connected Double-Beam System by a Cyclic Moving Load

Abstract

Resonance conditions are derived for an elastically connected double-beam system in which one of the members is subjected to a moving point load that oscillates longitudinally along the beam about a fixed point. The magnitude of the load is also considered to vary sinusoidally. The analysis indicates that, in addition to the usual case of resonance—which occurs when the frequency of load magnitude variation corresponds to a principal frequency of the system for the rth mode of vibration—resonances of the system may occur due to the load-movement frequency. It is found that there are an infinite number of load-movement frequencies that will excite a given principal frequency of the system for the rth mode of vibration.