| This thesis presents a numerical approach for large-scale discrete element simulations. The problem involves contact/impact of a large number of three-dimensional deformable bodies which are modeled as separate points, each having three directors attached to it to account for deformation. This model is based on the theory of a Cosserat point. An alternative formulation of the model, which is known as a theory of a pseudo-rigid body, is also utilized for computational purposes.;A robust and efficient contact-detection algorithm for the simulation is developed. This algorithm detects possible contacts and determines unique contact points between any two colliding pseudo-rigid spheres which deform into ellipsoids in the current configuration due to the kinematic assumption of spatially homogeneous deformation. In order to reduce the complexity of the program, an object-oriented programming paradigm (OOPP) has been adopted as the programming framework. This offers a transparent and reliable way to develop, maintain and extend the program.;The thesis concludes with a number of computer simulations, which present an accuracy test of contact-detection in a wave problem and an application to a process engineering problem, hopper flow, to validate the methodology and the capability of the program. |
