Research on stability of periodic elastic motion of a flexible four bar crank rocker mechanism

In this paper, the stability of periodical elastic motion of a flexible four bar crank rocker mechanism is analyzed using the first approximation of Liapunovʹs stability theorem and Floquet theory. A procedure for predicting the stability is presented. Experimental investigation on the stability is carried out. Strain responses of the coupler up-surface midpoint of the mechanism are measured for several angular velocities of the crank. The stability of periodical elastic motion of the coupler for these angular velocities is determined based on the strain responses. The experimentally obtained conclusions agree well with the analytical conclusions presented in Section 4. This shows that the stability analysis of periodical elastic motion of the mechanism is correct.