The inside-outside contact search algorithm for finite element analysis

A new contact search algorithm (Inside-Outside Algorithm) for the sheet forming simulation has been developed and implemented in the dynamic explicit FE code: 'DYNAMIC'. The inside-outside algorithm is derived based on the feature of the inside-outside status of a nodal 'mesh normal vector' in respect to a surface segment for the judgment of the contact of FE nodes with the tool surface. This new algorithm includes local search, local track and penetration calculation processes. Almost no additional CPU time is required for the local search process, because the calculations for both global and local search are combined. Moreover, the problems of conventional contact searching algorithms, such as iterations for local search and the deadzone problem, are resolved. Therefore, the quick, robust contact searching and accurate evaluation of penetration have been achieved. The numerical results show that the new contact searching algorithm is more cost effective and robust than conventional ones. (C) 1997 John Wiley & Sons, Ltd.