Snap-through instability is a familiar phenomenon in structural mechanics. Post-buckled and curved structures experience dramatic snap-through instabilities when external loads from mechanical, fluid, or thermal environments result in a loss of local stability and a violent jump to a remote stable equilibrium. Fatigue caused by snap-through is a concern in many engineered systems because of the large stress reversals involved. Snap-through is typically avoided by designing structures to be robust in response to complex and/or uncertain loading environments. However, these traditional ways of ensuring stability are often at odds with other important design objectives, such as minimizing weight.

This study theoretically and experimentally investigates the strategic actuation of lightweight and flexible piezoelectric material to change the loads required to initiate snap-through of clamped-clamped post-bucked beams. It then studies the possibility of using piezoelectric actuation to traverse stable transitions between remote equilibria, thus avoiding snap-through behavior altogether. It also finds the changes of mode shapes of post-buckled beams during the stable transitions. Finally, the study theoretically and experimentally identifies actuation strategies that stabilize equilibrium shapes of third- and fourth-order.

It is anticipated that the results of this study can be used to design new smart structures that have enhanced stability in the face of onerous loading environments. One possibility would be to embed piezoelectric actuators into advanced composite materials to enhance their stability without unduly sacrificing weight. Actuation can be used to enhance stability or alter structural shape. When not actuated, the piezoelectric elements could be used as health monitoring sensors or energy harvesters. The present theoretical model, which is cast in non-dimensional terms, enables a more general view of what is possible with the piezoelectric actuation and will allow researchers to more easily discern whether a candidate structure will be sufficiently amenable to piezoelectric actuation.