LAUSR

With the postulation of the principle of virtual action, we propose in this paper a variational framework for describing the dynamics of finite dimensional mechanical systems which contain frictional contact interactions. Together with the contact and impact laws formulated as normal cone inclusions, the principle of virtual action directly leads to the measure differential inclusions commonly used in the dynamics of nonsmooth mechanical systems. The discretization of the principle of virtual action in its strong and weak variational form by local finite elements in time provides a structured way to derive various time-stepping schemes. The constitutive laws for the impulsive and non-impulsive contact forces, i.e. the contact and impact laws, are treated on velocity-level by using a discrete contact law for the percussion increments in the sense of Moreau. Using linear shape functions and different quadrature rules, we obtain three different stepping schemes. Besides the well established Moreau time-stepping scheme, we can present two alternative integrators referred to as symmetric and variational Moreau-type stepping schemes. A suitable benchmark example shows the superiority of the newly proposed integrators in terms of energy conservation properties, accuracy and convergence.