Civil Engineering CE 5990 Graduate Seminar
Thursday, Jan. 12
Time: 4-5 p.m.
Location: Dow 642
Public is welcome
Presenter: Dr. Qingli Dai, Assistant professor, Department of Civil and Environmental Engineering.
Abstract: This study developed two-dimensional (2D) and three-dimensional (3D) micromechanical finite element (FE) models to study the viscoelastic properties of heterogeneous infrastructure materials. For example, asphalt mixtures are consisted of very irregular aggregates, asphalt matrix and a small amount of air voids. The internal microstructure of asphalt mixtures was captured with X-ray Computed Tomography (CT) imaging techniques. The 2D and 3D digital samples were created with the reconfiguration of the scanned slice images. The FE mesh of digital samples was generated with the locations of image pixels within each aggregate and asphalt matrix. Along the boundary of these two phases, the aggregate and matrix FEs share the nodes to connect the deformation. The micromechanical FE modeling was conducted by incorporating the captured microstructure and ingredient properties (viscoelastic asphalt matrix and elastic aggregates). The generalized Maxwell model was applied for viscoelastic asphalt matrix with calibrated parameters from the nonlinear regression analysis of the lab test data. The 3D simulation with digital samples generated better prediction than the 2D models. These favorable comparison results indicate that the developed micromechanical FE models have the ability to accurately predict the global viscoelastic properties of the heterogeneous infrastructure materials.