Constrained dynamics of geometrically exact beams

Geometrically exact beams are regarded from the outset as constrained mechanical systems. This viewpoint facilitates the discretization in space and time of the underlying continuous beam formulation without using rotational variables. The present semi-discrete beam equations assume the form of differential-algebraic equations which are discretized in time. The resulting energy-momentum scheme satisfies the algebraic constraint equations on both configuration and momentum level.