NEW CONTACT-DEFINITION ALGORITHM USING INSCRIBED SPHERES FOR 3D DISCONTINUOUS DEFORMATION ANALYSIS

The speed and stability of three-dimensional (3D) discontinuous deformation analysis (DDA) are strongly dependent on the efficiency and correctness of contact detection and the definition algorithm, which affects the simultaneous equilibrium equations solved in every open-close iteration (OCI) retry. In particular, the definition of vertex-to-vertex contacts in a tangled zone may abruptly change the entrance planes, even in the case of very small displacement of the objects. This study proposes a new contact-definition algorithm using an inscribed sphere virtually installed in every contacting vertex. The suggested algorithm generates virtual entrance planes in the case of a vertex-to-vertex contact, and controls the accuracy of the contact definition process by adjusting the sphere size. Verification tests of the proposed algorithm indicate an increase in the efficiency and stability of 3D DDA.