Limit position synthesis and analysis of compliant 4-bar mechanisms with specified energy levels using variable parametric pseudo-rigid-body model

This paper provides a synthesis and analysis procedure for the limit positions of compliant 4-bar mechanisms. The mechanism compliance is present at the output link which is considered to be fixed to the ground and can experience large non-linear elastic deflection at its pinned end. Under this condition, the mechanism mobility and its limit positions are dependent on the output link compliance. In addition, an elastic potential energy is stored at each limit position with a magnitude depending on the mechanism geometry and output link compliance properties. The developed procedure provides means of determining the complete mechanism geometry for (1) specified limit positions, or (2) specified energy level at each limit position. On the analysis side, the procedure provides the limit positions and energy levels for specified mechanism geometry. The compliant output link is modeled using the variable parametric pseudo-rigid-body model. In this model, the pseudo-rigid-body parameters vary for different loading conditions, thus, providing a more accurate model than that with fixed parameters. The procedure is presented in form of charts with minimum computational effort by the user. Illustrative examples are presented to prove the utility of the developed procedure.