Dynamic response of vehicle–road coupling with initial defects in asphalt pavements by discrete element method

Abstract

Simulating the macroscopic physical and mechanical properties of asphalt concrete pavement with finite element theory and related software will lead to inaccurate results of vehicle–road coupling responses in the constructed model. To accurately study the influence of initial defects on the mechanical response of vehicle–road coupling in asphalt pavement, a mesoscopic multi-layer subgrade and pavement model was established using the discrete element method. This model explores the response of asphalt concrete pavements with initial defects under vehicle–road coupling. Following a comparison of the data from the uniaxial compression simulation experiments of each structural layer with the actual experimental data, multiple iterative operations were performed. The mesoscopic parameters of each pavement structural layer will be obtained and used as the model parameters. The model uses a discrete fracture network (DFN) to characterize the initial fractures inside the pavement. Research shows that the number of micro-fractures in the upper layer significantly influences the vertical and horizontal shear stresses. Similarly, the number of micro-fractures in the lower layer significantly impacts the vertical and horizontal stresses, as well as the horizontal shear stress between the upper and lower layers. When the number of micro-fractures in the lower surface layer increases, the horizontal shear stress between the upper and lower layers rises. Therefore, changes in the number of micro-fractures significantly impact the stress magnitude of each structural layer.