Dynamic elastic analysis of 3-D flexible pavements under moving vehicles: A unified FEM treatment

• Elastic flexible pavements under moving loads.
• Unified 3-D FEM treatment.
• Acceptable error with respect to deflections and stresses.
• Practical modeling guidelines (geometry, load, time step).

The dynamic response of flexible road pavements to moving vehicles is numerically obtained by the time domain finite element method under three-dimensional conditions with the aid of the commercial program ANSYS. Both the uniform elastic half-space and the layered elastic half-space with or without damping are considered. The moving with constant speed loads (wheels) of the vehicle are simulated by assigning time dependent load values at all the surface nodes along the vehicle path, which are activated at the time it takes for every load to travel the distance from the origin to every node׳s location. Both concentrated (one or a series of them) and distributed moving loads are considered. Simple supports on rollers and viscous absorbing boundaries of the pavement domain are both considered. Comparisons with analytical exact solutions for the half-space model under moving loads and analytical approximate solutions for the layered half-space model under static loads are made for validation and comparison reasons, respectively. The cases of static versus dynamic loads, of a single load versus a series of loads and low versus high vehicle׳s velocity are also compared and discussed from the viewpoint of how they affect the response of the pavement.