Elaborate Analysis Method for Vibration Deformation in Strongly-Coupled Vehicle-Track-Subgrade-Foundation Broad System Due to Vehicle Operation

The two types of popular dynamic models currently simulating vehicle running on subgrade are multiple rigid body model in linear elasticity and multiple rigid-solid body hybrid model.The integrated model for fully flexible, strongly nonlinear and strongly-coupled vehicle-track-subgrade-foundation was developed using elaborate modelling method to overcome the disadvantages of the two type models mentioned above, and then the dynamic analysis method was proposed.The layer-by-layer construction of subgrade was modeled after the generation of initial stress state in foundation, and then the track system was placed, which served as the starting condition for vehicle operation.The elastoplastic wheel-rail rolling contact algorithm was introduced to describe the dynamic wheel-rail interaction in time domain considering the presence of random irregularity distributed across the whole rail top surface.The verified three dimensional viscoelastic static-dynamic unified artificial boundary with high precision and robustness was adopted to reflect the radiative damping and elastic recovery of infinite domain.The validated acceleration strategy was used to ensure that the vehicle can accelerate to the expected speed from rest and then keep running at the desired constant speed on the rail all the time.The tough issue with original stress-strain condition and wave propagation boundary was then solved in three dimension by this elaborate method.The subgrade was chosen as an example and the vibration deformation characteristics of the vehicle-track-subgrade-foundation coupled broad system is carefully investigated.The simulated results verified the method.Furthermore, the method presented in this paper can also be used in high-speed railway engineering, metro engineering and heavy haul railway engineering to conduct the dynamic analysis for coupled vehicle-track-infrastructure (tunnel, bridge, transition zone, et al).