Contact Simulation in Finite Deformation — Algorithm and Modelling Issues

Many problems, involving finite deformation, necessitate an accurate treatment of sliding interface boundaries and impact conditions. Examples of this are the accidental impact of radioactive waste transportation packages, crashworthiness, fluid-structure interaction and various manufacturing processes including metal forming and cutting. In terms of general use and applicability, large scale nonlinear simulations involving arbitrary contact continues to pose a number of challenging issues. Faster computing processors and parallel processing strategies have helped to mitigate the impact of some of these issues on modelling. However, there is room for overall improvement in accuracy, efficiency and user-friendliness of contact algorithms used in the modelling of multiple body impact/contact, eroding surfaces where new free contact surfaces are created, large interface motions of initially unconnected surfaces and post-buckling behaviour of structures where surfaces fold onto themselves. For example, the benefits of using a faster processor with an iterative solver on an elliptic class of problem could be quickly neutralized if the number of iterations rise due to inaccuracies in the contact algorithm. In this paper, salient features of state-of-the-art general three-dimensional contact algorithms for use in finite element software based on explicit and/or iterative solution techniques are reviewed and some of the more complex modelling issues faced by users of such algorithms are addressed.