Nonlinear Vibration Of Vehicle-pavement Coupled System Based On High-order Galerkin Truncation

In recent years, the highway which plays an important role in socialdevelopment and construction is of rapid development. Because of the high costof the highway construction, how to reduce the maintenance and repairs of thevehicle and pavement relates to lots of the key technical issues during theeffective lifetime of the pavement. The resonance occurs if the excitationfrequency from the roughness of the road surface approaches the naturalfrequency of the elastic oscillator, then the vehicle vibration increases, whichmay reduce the vehicle’s driving safety and riding comfort. As a result, thedynamical tire force increases greatly. Therefore, the vehicle and pavement areinteracted and coupled.In this dissertation, the vehicle model, pavement model and foundationmodel are linked by the road surface roughness. Based this coupled system, thenonlinear partial differential governing equations of the vehicle-pavementcoupled vibration are developed. The pavement structure is modeled as an Eulerbeam on a nonlinear viscoelastic Winkler foundation or a Timoshenko beam ona nonlinear viscoelastic Pasternak foundation. The moving vehicle is modeled asa two DOF spring-mass-damper system or a moving load. The dynamicresponse of coupled system is solved using the high-order Galerkin truncationmethod in conjunction with Runge-Kutta method. The effects of differenttruncation terms on the dynamical responses of the vehicle-pavement nonlinearvibration are discussed in detail, and the convergence of the Galerkin truncationto investigate the vehicle-pavement coupled vibration are determined for thefirst time. Meanwhile, the physical parameters of the vehicle–pavement systemsuch as the shear modulus are compared for determining their influences on thecoupled vibratory response, and the coupling effects between the pavement andthe vehicle are numerically examined by using the convergent modal truncation. The study shows that the numerical investigation into dynamical responseof the asphalt pavement on soft soil foundation needs high-order modes. Bycomparing the excitation frequency of the surface roughness and the naturalfrequency of the vehicle, when they are close, the vehicle is near to resonance,and the amplitude of the vibration of the vehicle becomes much bigger, however,the amplitude of the vibratory responses of the pavement becomes much smaller.Therefore, a vehicle-pavement coupled system is established. Moreover, thenumerical results also show that the vibration of the vehicle becomes strongerwith greater amplitude of road roughness, but becomes weaker with greatersuspension damping. Furthermore, as the nonlinear elasticity parameter, theshear deformation coefficient, the rocking stiffness and the damping coefficientof the subgrade, and the shear modulus of the pavement increase, the responseof the pavement decreases.