Stability and patch test performance of contact discretizations and a new solution algorithm

Stability and patch test performance are two important issues influencing the selection of discretization algorithms for flexible body contact problems. The patch test performance is dictated by the accuracy of evaluation of the contact integrals, not by the specific form of the gap, contact pressure, or contact surface definitions. Stability on the other hand, is related to the form of the assumed contact pressure distribution. In this paper, several commonly used contact algorithms are briefly summarized, and their stability in an inf–sup test and performance in a contact patch test are assessed. The existing algorithms do not satisfy both requirements. This fact has motivated the development of a new algorithm for flexible body contact problems that results in a symmetric coefficient matrix and satisfies both the stability and the contact patch conditions.