Third medium contact in the finite cell method

Modelling of contact in the finite cell method (FCM) has been challenging due to immersed boundaries. Traditional approaches known from finite element methods (FEM) are not straight forward to use in immersed finite element methods, since explicit boundary descriptions are usually needed. A simple approach to introduce contact is the third medium contact (TMC) formulation, where the void domain is filled with a soft material which acts as a barrier between possible contact pairs. In the present work, we apply the TMC to the FCM by using a local enrichment strategy. By doing so, the weak discontinuity induced by the material interface to the third medium can be resolved. Various numerical examples show, that the combination of TMC and FCM and local enrichment opens the field for further research into contact formulations using TMC and the FCM.