Image-Based Lagrangian Analysis of Granular Kinematics

In this paper, algorithms to describe mesoscale and microscale kinematics of granular flow using image analysis are described. At the mesoscale, digital image correlation (DIC) is employed to derive displacement fields, from which rigid body rotation and strains are calculated using continuum mechanics descriptions of kinematics. Moreover, Lagrangian and Eulerian trajectories are obtained from DIC analysis. At the microscale, individual particle kinematics is resolved using particle identification and tracking algorithms. Microscale analysis of kinematics is then performed using definitions of affine and nonaffine local motion. In order to demonstrate the application of the algorithms an experimental setup of pile penetration in a plane strain calibration chamber is presented. Mesoscale and microscale analysis is performed on high-resolution images acquired from incremental jacking of the pile. It is shown through analysis of captured images that the developed tools can be effectively employed in the study of granular flow, particularly in the presence of soil-structure interaction.