On the Analytical Lumped-Mass Model of an Elastic Four-Bar Mechanism

The lumped-parameter method for the elastodynamic analysis of mechanisms is applied to a particular case for which existing experimental evidence is available. The mechanism analyzed is a planar four-bar linkage, and the calculated results include steady-state deflection and stress and strain responses associated with the bending vibration of the three moving links. The analytical model is based on nonlinear differential equations derived by way of Euler-Bernoulli beam theory, and numerical solution is obtained through the use of a digital computer. Comparison of the analytical and experimental results shows very good agreement, supporting the use of the lumped-parameter approach in analyses of this type.