Computational structural analysis of planar multibody systems with lower and higher kinematic pairs

• A computational algorithm for structural analysis of planar mechanisms is introduced.
• Kinematic structure of planar mechanisms is obtained from adjacency matrix.
• The algorithm automatically checks for possible structural transformations.
• Both lower and higher kinematic pairs are taken into consideration.
• Computational structural analysis allows the automatic modeling of multibody systems.

AbstracKinematic and dynamic modeling of multibody systems requires an initial stage of topological recognition or structural analysis, in which the analyst must identify the model coordinates and a sufficient number of constraint equations to relate them. This initial phase could be solved quickly, safely and automatically, determining the kinematic structure of the multibody system; that is, dividing it into a set of kinematic chains called structural groups. Furthermore, structural groups are widely used for structural synthesis and so, the analysis and design of multibody systems can be integrated into the same software package. On the basis of known graph-analytical methods for structural analysis, a computational method that determines the kinematic structure of a multibody system from its adjacency matrix is developed and evaluated. This method allows the choosing of any type of coordinates (relative, natural or reference point) and the kinematic and dynamic formulations most appropriate for solving the problem. The algorithm has been applied to a large number of mechanical systems of different complexity, offering the same kinematic structure as was obtained through the application of graph-analytical methods.