Vibrational Behaviour of a Double Rayleigh Beam System coupled by Damped Pasternak Layer under a Moving Load

Abstract

This study analysed the dynamic response of a Pasternak damped double Rayleigh beam system subjected to a concentrated moving load. The two parallel beams are interconnected by a viscoelastic Pasternak layer, with the moving load applied to the upper beam. The study incorporate rotary inertia, interlayer stiffness, shear interaction, damping, and moving load velocity. A finite Fourier sine integral transform is deployed initially to reduce the governing partial differential equations while differential transform methods (DTM) are subsequently employed to obtain approximate analytical dynamic responses. Parametric analyses are conducted to examine the effects of moving load velocity, viscoelasticity, rotary inertia, interlayer stiffness, and Pasternak shear parameter on the transverse responses of the beams. The results show that the velocity of the moving load causes deflection in the entire system, while the rotary inertia tends to reduce these deflections. Viscoelasticity reduces the vibration of the lower beam, causing the upper beam to behave like a rigid body due to better energy absorption. However, stiffening the interlayer and Pasternak shear increases the deflection of the upper beam but increases the vibration of the lower beam due to increased load transfer. The findings clearly demonstrated the importance of rotatory inertia and combined effect of viscoelastic and shear coupling in dynamic load distribution of a double Rayleigh beam system.