THE INSIDE-OUTSIDE CONTACT SEARCH ALGORITHM FOR FINITE-ELEMENT ANALYSIS

A new contact search algorithm (Inside-Outside Algorithm) for the shee t 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 nor mal vector' in respect to a surface segment for the judgment of the co ntact of FE nodes with the tool surface. This new algorithm includes l ocal search, local track and penetration calculation processes. Almost no additional CPU time is required for the local search process, beca use the calculations for both global and local search are combined. Mo reover, the problems of conventional contact searching algorithms, suc h as iterations for local search and the deadzone problem, are resolve d. Therefore, the quick, robust contact searching and accurate evaluat ion 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.