Contact in multibody systems

Multi Body Systems (MBS) consist of a finite number of interconnected elast ic and/or rigid bodies. If its number of d.o.f varies due to contact it is advantageous to calculate dynamics in terms of subsystems. Partitioning int o subystems is fluent but at least reasonable at points of possible contact . Corresponding equations are then suitably structurized in terms of elemen t matrices yielding a (state dependent) Finite Element structure. When cont act(s) take place one ist left either with a (often unsolvable) combinatori cal problem or with the question of how to solve the contact case uniquely and in an optimal way. The access to the latter is obtained with HELMHOLTZ' s auxiliary equation leading to GAUSS' principle of least constraints.