Abstract
In design of large scale circuits and multibody systems, it is indispensable to model the systems as interconnected systems by focusing upon structural relations via energy flow. The idea of Dirac structures has been known as an useful tool in relations with nonlinear control theory, which is a generalized idea of symplectic and Poisson structures.In the paper, we demonstrate how interconnected mechanical systems can be formulated in the framework of the implicit Hamiltonian system based on the Dirac structure. We also illustrate the case of interconnected mechanical systems having kinematical constraints together with an illustrative example of a vertical disk rolling on the plane.