A decoupling solution method for implicit numerical integration of constrained mechanical systems

A decoupling solution method is presented for implicit numerical integratio n of constrained multibody systems. compared to implicit numerical integrat ion methods, explicit numerical integration methods usually spend less comp utation time per iteration, since the equations of motion and an explicit i ntegration formula coupled with the constraint manifolds are solved separat ely. However, the integration step size can be excessively small for highly nonlinear or stiff problems, due to the small stability region of the expl icit method. In contrast, implicit numerical integration methods do not hav e the problem of excessive small step size. Implicit integration methods, h owever, generally require one to solve a large system equations simultaneou sly. The solution method proposed in this paper eliminates the problem of l arge system equations, while maintaining the advantage of the implicit meth od. Furthermore, the proposed method provides a well-conditioned iteration matrix for the implicit method, which is important to obtain accurate stabl e solutions.