1.1. Benefits of the Finite Element Method for Modeling Multibody Systems

Multibody systems have conventionally been modeled as rigid body systems with superimposed elastic effects of one or more components. These methods have been well documented in multibody dynamics literature. A major limitation of these methods is that nonlinear large-deformation, finite-strain effects, or nonlinear material cannot be incorporated completely into model.

The finite element (FE) method used in Mechanical APDL offers an attractive approach to modeling a multibody system. While the Mechanical APDL multibody analysis method may require more computational resources and modeling time compared to standard analyses, it has the following advantages:

  • The finite element mesh automatically represents the geometry while the large deformation/rotation effects are built into the finite element formulation.

  • Inertial effects are greatly simplified by the consistent mass formulation or even point mass representations.

  • Interconnection of parts via joints is greatly simplified by considering the finite motions at the two nodes forming the joint element.

  • The parameterization of the finite rotation has been well documented in the literature and can be easily incorporated into the joint element formulations thereby enabling complete simulation of a multibody system.

Mechanical APDL has an extensive library of elements available for modeling the flexible, rigid, and joint components. You can model the material behavior of the flexible components using one of several material models. Mechanical APDL also provides modal and transient dynamics capabilities to analyze the spatial and temporal effects in a multibody simulation. Extensive postprocessing capabilities are also available to interpret the analysis results.

You can perform multibody simulation on a wide variety of mechanical systems. Typical applications include automobiles and automobile components, aircraft assemblages, spacecraft applications, and robotics.