Algorithmic robustness for contact analysis of polyhedral blocks in discontinuous deformation analysis framework

Algorithmic robustness is important in the contact interaction analysis of polyhedral blocks using discontinuous computation methods. Several robustness issues of contact analysis associated with the identification of four contact types are discussed here, including rounding errors of floating-point operations, criteria and tolerances in contact type identification, and restrictions of input parameters. This paper also proposes revised criteria to identify contact types and general rules to specify tolerances regarding contact searches, quasi-parallel edges, overlapping angle and maximum displacement in a time step. These rules facilitate robust contact analysis of polyhedral blocks in the discontinuous deformation analysis framework.