Combined semi-recursive formulation and lumped fluid method for monolithic simulation of multibody and hydraulic dynamics

The use of multibody simulation tools allows complex machinery to be described in detail while still providing a solution for the system in real time. As mechanical components are often accompanied by other dynamical systems, such as hydraulics, description of each subsystem is required to fully describe the dynamics of complex machinery. A potential candidate for solving the multiphysics problem at hand is known as the unified or monolithic approach. This strongly coupled approach yields a single set of equations to be integrated and, compared to co-simulation and co-integration approaches, a relatively simple integration procedure. In this paper, a monolithic formulation for a combined simulation of multibody and hydraulic dynamics using an efficient semi-recursive formulation and the lumped fluid method is introduced. The results indicate that the proposed method shows potential for efficient simulation of combined multibody and hydraulic problems. The robustness of the multibody method is maintained when combined with the hydraulic dynamics description and higher efficiency is observed than with an equivalent global approach.